pl_mpeg.hpp

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/*
PL_MPEG - MPEG1 Video decoder, MP2 Audio decoder, MPEG-PS demuxer
SPDX-License-Identifier: MIT
 
Dominic Szablewski - https://phoboslab.org
 
 
-- Synopsis
 
// Define `PL_MPEG_IMPLEMENTATION` in *one* C/C++ file before including this
// library to create the implementation.
 
#define PL_MPEG_IMPLEMENTATION
#include "fl/stl/cstddef.h"
#include "plmpeg.h"
 
// This function gets called for each decoded video frame
void my_video_callback(plm_t *plm, plm_frame_t *frame, void *user) {
    // Do something with frame->y.data, frame->cr.data, frame->cb.data
}
 
// This function gets called for each decoded audio frame
void my_audio_callback(plm_t *plm, plm_samples_t *frame, void *user) {
    // Do something with samples->interleaved
}
 
// Load a .mpg (MPEG Program Stream) file
plm_t *plm = plm_create_with_filename("some-file.mpg");
 
// Install the video & audio decode callbacks
plm_set_video_decode_callback(plm, my_video_callback, my_data);
plm_set_audio_decode_callback(plm, my_audio_callback, my_data);
 
 
// Decode
do {
    plm_decode(plm, time_since_last_call);
} while (!plm_has_ended(plm));
 
// All done
plm_destroy(plm);
 
 
 
-- Documentation
 
This library provides several interfaces to load, demux and decode MPEG video
and audio data. A high-level API combines the demuxer, video & audio decoders
in an easy to use wrapper.
 
Lower-level APIs for accessing the demuxer, video decoder and audio decoder, 
as well as providing different data sources are also available.
 
Interfaces are written in an object oriented style, meaning you create object 
instances via various different constructor functions (plm_*create()),
do some work on them and later dispose them via plm_*destroy().
 
plm_* ......... the high-level interface, combining demuxer and decoders
plm_buffer_* .. the data source used by all interfaces
plm_demux_* ... the MPEG-PS demuxer
plm_video_* ... the MPEG1 Video ("mpeg1") decoder
plm_audio_* ... the MPEG1 Audio Layer II ("mp2") decoder
 
 
With the high-level interface you have two options to decode video & audio:
 
 1. Use plm_decode() and just hand over the delta time since the last call.
    It will decode everything needed and call your callbacks (specified through
    plm_set_{video|audio}_decode_callback()) any number of times.
 
 2. Use plm_decode_video() and plm_decode_audio() to decode exactly one
    frame of video or audio data at a time. How you handle the synchronization 
    of both streams is up to you.
 
If you only want to decode video *or* audio through these functions, you should
disable the other stream (plm_set_{video|audio}_enabled(FALSE))
 
Video data is decoded into a struct with all 3 planes (Y, Cr, Cb) stored in
separate buffers. You can either convert this to RGB on the CPU (slow) via the
plm_frame_to_rgb() function or do it on the GPU with the following matrix:
 
mat4 bt601 = mat4(
    1.16438,  0.00000,  1.59603, -0.87079,
    1.16438, -0.39176, -0.81297,  0.52959,
    1.16438,  2.01723,  0.00000, -1.08139,
    0, 0, 0, 1
);
gl_FragColor = vec4(y, cb, cr, 1.0) * bt601;
 
Audio data is decoded into a struct with either one single float array with the
samples for the left and right channel interleaved, or if the 
PLM_AUDIO_SEPARATE_CHANNELS is defined *before* including this library, into
two separate float arrays - one for each channel.
 
 
Data can be supplied to the high level interface, the demuxer and the decoders
in three different ways:
 
 1. Using plm_create_from_filename() or with a file handle with 
    plm_create_from_file().
 
 2. Using plm_create_with_memory() and supplying a pointer to memory that
    contains the whole file.
 
 3. Using plm_create_with_buffer(), supplying your own plm_buffer_t instance and
    periodically writing to this buffer.
 
When using your own plm_buffer_t instance, you can fill this buffer using 
plm_buffer_write(). You can either monitor plm_buffer_get_remaining() and push 
data when appropriate, or install a callback on the buffer with 
plm_buffer_set_load_callback() that gets called whenever the buffer needs more 
data.
 
A buffer created with plm_buffer_create_with_capacity() is treated as a ring
buffer, meaning that data that has already been read, will be discarded. In
contrast, a buffer created with plm_buffer_create_for_appending() will keep all
data written to it in memory. This enables seeking in the already loaded data.
 
 
There should be no need to use the lower level plm_demux_*, plm_video_* and 
plm_audio_* functions, if all you want to do is read/decode an MPEG-PS file.
However, if you get raw mpeg1video data or raw mp2 audio data from a different
source, these functions can be used to decode the raw data directly. Similarly, 
if you only want to analyze an MPEG-PS file or extract raw video or audio
packets from it, you can use the plm_demux_* functions.
 
 
This library uses malloc(), realloc() and free() to manage memory. Typically 
all allocation happens up-front when creating the interface. However, the
default buffer size may be too small for certain inputs. In these cases plmpeg
will realloc() the buffer with a larger size whenever needed. You can configure
the default buffer size by defining PLM_BUFFER_DEFAULT_SIZE *before* 
including this library.
 
You can also define PLM_MALLOC, PLM_REALLOC and PLM_FREE to provide your own
memory management functions.
 
 
See below for detailed the API documentation.
 
*/
 
#pragma once
 
 
 
#define PLM_NO_STDIO
 
#include "pl_mpeg.h"
#include "fl/stl/malloc.h"
#include "fl/stl/noexcept.h"
 
 
// Include headers outside the namespace to avoid conflicts
 
#include "fl/stl/stddef.h"  // For NULL definition
 
#include "fl/stl/stdint.h"
#include "fl/math/math.h"
#include "fl/math/math.h"
#include "fl/stl/string.h"
#include "fl/stl/cstring.h"  // for fl::memset(), fl::memcpy(), fl::memmove()
 
 
// #ifdef __cplusplus
// namespace fl {
// namespace third_party {
// #endif
// #ifndef PLM_NO_STDIO
// #include <stdio.h>
// #endif
 
#ifndef TRUE
#define TRUE 1
#define FALSE 0
#endif
 
#ifndef PLM_MALLOC
    #define PLM_MALLOC(sz) fl::malloc(sz)
    #define PLM_FREE(p) fl::free(p)
    #define PLM_REALLOC(p, sz) fl::realloc(p, sz)
#endif
 
#define PLM_UNUSED(expr) (void)(expr)
#ifdef _MSC_VER
    #pragma warning(disable:4996)
#endif
 
namespace fl {
namespace third_party {
 
// -----------------------------------------------------------------------------
// plm (high-level interface) implementation
 
struct plm_t {
    plm_demux_t *demux;
    double time;
    int has_ended;
    int loop;
    int has_decoders;
 
    int video_enabled;
    int video_packet_type;
    plm_buffer_t *video_buffer;
    plm_video_t *video_decoder;
 
    int audio_enabled;
    int audio_stream_index;
    int audio_packet_type;
    double audio_lead_time;
    plm_buffer_t *audio_buffer;
    plm_audio_t *audio_decoder;
 
    plm_video_decode_callback video_decode_callback;
    void *video_decode_callback_user_data;
 
    plm_audio_decode_callback audio_decode_callback;
    void *audio_decode_callback_user_data;
};
 
int plm_init_decoders(plm_t *self) FL_NOEXCEPT;
void plm_handle_end(plm_t *self) FL_NOEXCEPT;
void plm_read_video_packet(plm_buffer_t *buffer, void *user) FL_NOEXCEPT;
void plm_read_audio_packet(plm_buffer_t *buffer, void *user) FL_NOEXCEPT;
void plm_read_packets(plm_t *self, int requested_type) FL_NOEXCEPT;
 
#ifndef PLM_NO_STDIO
 
plm_t *plm_create_with_filename(const char *filename) {
    plm_buffer_t *buffer = plm_buffer_create_with_filename(filename);
    if (!buffer) {
        return NULL;
    }
    return plm_create_with_buffer(buffer, TRUE);
}
 
plm_t *plm_create_with_file(FILE *fh, int close_when_done) {
    plm_buffer_t *buffer = plm_buffer_create_with_file(fh, close_when_done);
    return plm_create_with_buffer(buffer, TRUE);
}
 
#endif // PLM_NO_STDIO
 
plm_t *plm_create_with_memory(uint8_t *bytes, size_t length, int free_when_done) FL_NOEXCEPT {
    plm_buffer_t *buffer = plm_buffer_create_with_memory(bytes, length, free_when_done);
    return plm_create_with_buffer(buffer, TRUE);
}
 
plm_t *plm_create_with_buffer(plm_buffer_t *buffer, int destroy_when_done) FL_NOEXCEPT {
    plm_t *self = (plm_t *)PLM_MALLOC(sizeof(plm_t));
    fl::memset(self, 0, sizeof(plm_t));
 
    self->demux = plm_demux_create(buffer, destroy_when_done);
    self->video_enabled = TRUE;
    self->audio_enabled = TRUE;
    plm_init_decoders(self);
 
    return self;
}
 
int plm_init_decoders(plm_t *self) FL_NOEXCEPT {
    if (self->has_decoders) {
        return TRUE;
    }
 
    if (!plm_demux_has_headers(self->demux)) {
        return FALSE;
    }
 
    if (plm_demux_get_num_video_streams(self->demux) > 0) {
        if (self->video_enabled) {
            self->video_packet_type = PLM_DEMUX_PACKET_VIDEO_1;
        }
        if (!self->video_decoder) {
            self->video_buffer = plm_buffer_create_with_capacity(PLM_BUFFER_DEFAULT_SIZE);
            plm_buffer_set_load_callback(self->video_buffer, plm_read_video_packet, self);
            self->video_decoder = plm_video_create_with_buffer(self->video_buffer, TRUE);
        }
    }
 
    if (plm_demux_get_num_audio_streams(self->demux) > 0) {
        if (self->audio_enabled) {
            self->audio_packet_type = PLM_DEMUX_PACKET_AUDIO_1 + self->audio_stream_index;
        }
        if (!self->audio_decoder) {
            self->audio_buffer = plm_buffer_create_with_capacity(PLM_BUFFER_DEFAULT_SIZE);
            plm_buffer_set_load_callback(self->audio_buffer, plm_read_audio_packet, self);
            self->audio_decoder = plm_audio_create_with_buffer(self->audio_buffer, TRUE);
        }
    }
 
    self->has_decoders = TRUE;
    return TRUE;
}
 
void plm_destroy(plm_t *self) FL_NOEXCEPT {
    if (self->video_decoder) {
        plm_video_destroy(self->video_decoder);
    }
    if (self->audio_decoder) {
        plm_audio_destroy(self->audio_decoder);
    }
 
    plm_demux_destroy(self->demux);
    PLM_FREE(self);
}
 
int plm_get_audio_enabled(plm_t *self) FL_NOEXCEPT {
    return self->audio_enabled;
}
 
int plm_has_headers(plm_t *self) FL_NOEXCEPT {
    if (!plm_demux_has_headers(self->demux)) {
        return FALSE;
    }
    
    if (!plm_init_decoders(self)) {
        return FALSE;
    }
 
    if (
        (self->video_decoder && !plm_video_has_header(self->video_decoder)) ||
        (self->audio_decoder && !plm_audio_has_header(self->audio_decoder))
    ) {
        return FALSE;
    }
 
    return TRUE;
}
 
int plm_probe(plm_t *self, size_t probesize) FL_NOEXCEPT {
    int found_streams = plm_demux_probe(self->demux, probesize);
    if (!found_streams) {
        return FALSE;
    }
 
    // Re-init decoders
    self->has_decoders = FALSE;
    self->video_packet_type = 0;
    self->audio_packet_type = 0;
    return plm_init_decoders(self);
}
 
void plm_set_audio_enabled(plm_t *self, int enabled) FL_NOEXCEPT {
    self->audio_enabled = enabled;
 
    if (!enabled) {
        self->audio_packet_type = 0;
        return;
    }
 
    self->audio_packet_type = (plm_init_decoders(self) && self->audio_decoder)
        ? PLM_DEMUX_PACKET_AUDIO_1 + self->audio_stream_index
        : 0;
}
 
void plm_set_audio_stream(plm_t *self, int stream_index) FL_NOEXCEPT {
    if (stream_index < 0 || stream_index > 3) {
        return;
    }
    self->audio_stream_index = stream_index;
 
    // Set the correct audio_packet_type
    plm_set_audio_enabled(self, self->audio_enabled);
}
 
int plm_get_video_enabled(plm_t *self) FL_NOEXCEPT {
    return self->video_enabled;
}
 
void plm_set_video_enabled(plm_t *self, int enabled) FL_NOEXCEPT {
    self->video_enabled = enabled;
 
    if (!enabled) {
        self->video_packet_type = 0;
        return;
    }
 
    self->video_packet_type = (plm_init_decoders(self) && self->video_decoder)
        ? PLM_DEMUX_PACKET_VIDEO_1
        : 0;
}
 
int plm_get_num_video_streams(plm_t *self) FL_NOEXCEPT {
    return plm_demux_get_num_video_streams(self->demux);
}
 
int plm_get_width(plm_t *self) FL_NOEXCEPT {
    return (plm_init_decoders(self) && self->video_decoder)
        ? plm_video_get_width(self->video_decoder)
        : 0;
}
 
int plm_get_height(plm_t *self) FL_NOEXCEPT {
    return (plm_init_decoders(self) && self->video_decoder)
        ? plm_video_get_height(self->video_decoder)
        : 0;
}
 
double plm_get_framerate(plm_t *self) FL_NOEXCEPT {
    return (plm_init_decoders(self) && self->video_decoder)
        ? plm_video_get_framerate(self->video_decoder)
        : 0;
}
 
double plm_get_pixel_aspect_ratio(plm_t *self) FL_NOEXCEPT {
    return (plm_init_decoders(self) && self->video_decoder)
        ? plm_video_get_pixel_aspect_ratio(self->video_decoder)
        : 0;
}
 
int plm_get_num_audio_streams(plm_t *self) FL_NOEXCEPT {
    return plm_demux_get_num_audio_streams(self->demux);
}
 
int plm_get_samplerate(plm_t *self) FL_NOEXCEPT {
    return (plm_init_decoders(self) && self->audio_decoder)
        ? plm_audio_get_samplerate(self->audio_decoder)
        : 0;
}
 
double plm_get_audio_lead_time(plm_t *self) FL_NOEXCEPT {
    return self->audio_lead_time;
}
 
void plm_set_audio_lead_time(plm_t *self, double lead_time) FL_NOEXCEPT {
    self->audio_lead_time = lead_time;
}
 
double plm_get_time(plm_t *self) FL_NOEXCEPT {
    return self->time;
}
 
double plm_get_duration(plm_t *self) FL_NOEXCEPT {
    return plm_demux_get_duration(self->demux, PLM_DEMUX_PACKET_VIDEO_1);
}
 
void plm_rewind(plm_t *self) FL_NOEXCEPT {
    if (self->video_decoder) {
        plm_video_rewind(self->video_decoder);
    }
 
    if (self->audio_decoder) {
        plm_audio_rewind(self->audio_decoder);
    }
 
    plm_demux_rewind(self->demux);
    self->time = 0;
    self->has_ended = FALSE;
}
 
int plm_get_loop(plm_t *self) FL_NOEXCEPT {
    return self->loop;
}
 
void plm_set_loop(plm_t *self, int loop) FL_NOEXCEPT {
    self->loop = loop;
}
 
int plm_has_ended(plm_t *self) FL_NOEXCEPT {
    return self->has_ended;
}
 
void plm_set_video_decode_callback(plm_t *self, plm_video_decode_callback fp, void *user) FL_NOEXCEPT {
    self->video_decode_callback = fp;
    self->video_decode_callback_user_data = user;
}
 
void plm_set_audio_decode_callback(plm_t *self, plm_audio_decode_callback fp, void *user) FL_NOEXCEPT {
    self->audio_decode_callback = fp;
    self->audio_decode_callback_user_data = user;
}
 
void plm_decode(plm_t *self, double tick) FL_NOEXCEPT {
    if (!plm_init_decoders(self)) {
        return;
    }
 
    int decode_video = (self->video_decode_callback && self->video_packet_type);
    int decode_audio = (self->audio_decode_callback && self->audio_packet_type);
 
    if (!decode_video && !decode_audio) {
        // Nothing to do here
        return;
    }
 
    int did_decode = FALSE;
    int decode_video_failed = FALSE;
    int decode_audio_failed = FALSE;
 
    double video_target_time = self->time + tick;
    double audio_target_time = self->time + tick + self->audio_lead_time;
 
    do {
        did_decode = FALSE;
        
        if (decode_video && plm_video_get_time(self->video_decoder) < video_target_time) {
            plm_frame_t *frame = plm_video_decode(self->video_decoder);
            if (frame) {
                self->video_decode_callback(self, frame, self->video_decode_callback_user_data);
                did_decode = TRUE;
            }
            else {
                decode_video_failed = TRUE;
            }
        }
 
        if (decode_audio && plm_audio_get_time(self->audio_decoder) < audio_target_time) {
            plm_samples_t *samples = plm_audio_decode(self->audio_decoder);
            if (samples) {
                self->audio_decode_callback(self, samples, self->audio_decode_callback_user_data);
                did_decode = TRUE;
            }
            else {
                decode_audio_failed = TRUE;
            }
        }
    } while (did_decode);
    
    // Did all sources we wanted to decode fail and the demuxer is at the end?
    if (
        (!decode_video || decode_video_failed) && 
        (!decode_audio || decode_audio_failed) &&
        plm_demux_has_ended(self->demux)
    ) {
        plm_handle_end(self);
        return;
    }
 
    self->time += tick;
}
 
plm_frame_t *plm_decode_video(plm_t *self) FL_NOEXCEPT {
    if (!plm_init_decoders(self)) {
        return NULL;
    }
 
    if (!self->video_packet_type) {
        return NULL;
    }
 
    plm_frame_t *frame = plm_video_decode(self->video_decoder);
    if (frame) {
        self->time = frame->time;
    }
    else if (plm_demux_has_ended(self->demux)) {
        plm_handle_end(self);
    }
    return frame;
}
 
plm_samples_t *plm_decode_audio(plm_t *self) FL_NOEXCEPT {
    if (!plm_init_decoders(self)) {
        return NULL;
    }
 
    if (!self->audio_packet_type) {
        return NULL;
    }
 
    plm_samples_t *samples = plm_audio_decode(self->audio_decoder);
    if (samples) {
        self->time = samples->time;
    }
    else if (plm_demux_has_ended(self->demux)) {
        plm_handle_end(self);
    }
    return samples;
}
 
void plm_handle_end(plm_t *self) FL_NOEXCEPT {
    if (self->loop) {
        plm_rewind(self);
    }
    else {
        self->has_ended = TRUE;
    }
}
 
void plm_read_video_packet(plm_buffer_t *buffer, void *user) FL_NOEXCEPT {
    PLM_UNUSED(buffer);
    plm_t *self = (plm_t *)user;
    plm_read_packets(self, self->video_packet_type);
}
 
void plm_read_audio_packet(plm_buffer_t *buffer, void *user) FL_NOEXCEPT {
    PLM_UNUSED(buffer);
    plm_t *self = (plm_t *)user;
    plm_read_packets(self, self->audio_packet_type);
}
 
void plm_read_packets(plm_t *self, int requested_type) FL_NOEXCEPT {
    plm_packet_t *packet;
    while ((packet = plm_demux_decode(self->demux))) {
        if (packet->type == self->video_packet_type) {
            plm_buffer_write(self->video_buffer, packet->data, packet->length);
        }
        else if (packet->type == self->audio_packet_type) {
            plm_buffer_write(self->audio_buffer, packet->data, packet->length);
        }
 
        if (packet->type == requested_type) {
            return;
        }
    }
 
    if (plm_demux_has_ended(self->demux)) {
        if (self->video_buffer) {
            plm_buffer_signal_end(self->video_buffer);
        }
        if (self->audio_buffer) {
            plm_buffer_signal_end(self->audio_buffer);
        }
    }
}
 
plm_frame_t *plm_seek_frame(plm_t *self, double time, int seek_exact) FL_NOEXCEPT {
    if (!plm_init_decoders(self)) {
        return NULL;
    }
 
    if (!self->video_packet_type) {
        return NULL;
    }
 
    int type = self->video_packet_type;
 
    double start_time = plm_demux_get_start_time(self->demux, type);
    double duration = plm_demux_get_duration(self->demux, type);
 
    if (time < 0) {
        time = 0;
    }
    else if (time > duration) {
        time = duration;
    }
    
    plm_packet_t *packet = plm_demux_seek(self->demux, time, type, TRUE);
    if (!packet) {
        return NULL;
    }
 
    // Disable writing to the audio buffer while decoding video
    int previous_audio_packet_type = self->audio_packet_type;
    self->audio_packet_type = 0;
 
    // Clear video buffer and decode the found packet
    plm_video_rewind(self->video_decoder);
    plm_video_set_time(self->video_decoder, packet->pts - start_time);
    plm_buffer_write(self->video_buffer, packet->data, packet->length);
    plm_frame_t *frame = plm_video_decode(self->video_decoder);  
 
    // If we want to seek to an exact frame, we have to decode all frames
    // on top of the intra frame we just jumped to.
    if (seek_exact) {
        while (frame && frame->time < time) {
            frame = plm_video_decode(self->video_decoder);
        }
    }
 
    // Enable writing to the audio buffer again?
    self->audio_packet_type = previous_audio_packet_type;
 
    if (frame) {
        self->time = frame->time;
    }
 
    self->has_ended = FALSE;
    return frame;
}
 
int plm_seek(plm_t *self, double time, int seek_exact) FL_NOEXCEPT {
    plm_frame_t *frame = plm_seek_frame(self, time, seek_exact);
    
    if (!frame) {
        return FALSE;
    }
 
    if (self->video_decode_callback) {
        self->video_decode_callback(self, frame, self->video_decode_callback_user_data);    
    }
 
    // If audio is not enabled we are done here.
    if (!self->audio_packet_type) {
        return TRUE;
    }
 
    // Sync up Audio. This demuxes more packets until the first audio packet
    // with a PTS greater than the current time is found. plm_decode() is then
    // called to decode enough audio data to satisfy the audio_lead_time.
 
    double start_time = plm_demux_get_start_time(self->demux, self->video_packet_type);
    plm_audio_rewind(self->audio_decoder);
 
    plm_packet_t *packet = NULL;
    while ((packet = plm_demux_decode(self->demux))) {
        if (packet->type == self->video_packet_type) {
            plm_buffer_write(self->video_buffer, packet->data, packet->length);
        }
        else if (
            packet->type == self->audio_packet_type &&
            packet->pts - start_time > self->time
        ) {
            plm_audio_set_time(self->audio_decoder, packet->pts - start_time);
            plm_buffer_write(self->audio_buffer, packet->data, packet->length);
            plm_decode(self, 0);
            break;
        }
    }   
    
    return TRUE;
}
 
 
 
// -----------------------------------------------------------------------------
// plm_buffer implementation
 
enum plm_buffer_mode {
    PLM_BUFFER_MODE_FILE,
    PLM_BUFFER_MODE_FIXED_MEM,
    PLM_BUFFER_MODE_RING,
    PLM_BUFFER_MODE_APPEND
};
 
struct plm_buffer_t {
    size_t bit_index;
    size_t capacity;
    size_t length;
    size_t total_size;
    int discard_read_bytes;
    int has_ended;
    int free_when_done;
#ifndef PLM_NO_STDIO
    int close_when_done;
    FILE *fh;
#endif
    plm_buffer_load_callback load_callback;
    plm_buffer_seek_callback seek_callback;
    plm_buffer_tell_callback tell_callback;
    void *load_callback_user_data;
    uint8_t *bytes;
    enum plm_buffer_mode mode;
};
 
typedef struct {
    int16_t index;
    int16_t value;
} plm_vlc_t;
 
typedef struct {
    int16_t index;
    uint16_t value;
} plm_vlc_uint_t;
 
 
void plm_buffer_seek(plm_buffer_t *self, size_t pos) FL_NOEXCEPT;
size_t plm_buffer_tell(plm_buffer_t *self) FL_NOEXCEPT;
void plm_buffer_discard_read_bytes(plm_buffer_t *self) FL_NOEXCEPT;
 
#ifndef PLM_NO_STDIO
void plm_buffer_load_file_callback(plm_buffer_t *self, void *user);
void plm_buffer_seek_file_callback(plm_buffer_t *self, size_t offset, void *user);
size_t plm_buffer_tell_file_callback(plm_buffer_t *self, void *user);
#endif
 
int plm_buffer_has(plm_buffer_t *self, size_t count) FL_NOEXCEPT;
int plm_buffer_read(plm_buffer_t *self, int count) FL_NOEXCEPT;
void plm_buffer_align(plm_buffer_t *self) FL_NOEXCEPT;
void plm_buffer_skip(plm_buffer_t *self, size_t count) FL_NOEXCEPT;
int plm_buffer_skip_bytes(plm_buffer_t *self, uint8_t v) FL_NOEXCEPT;
int plm_buffer_next_start_code(plm_buffer_t *self) FL_NOEXCEPT;
int plm_buffer_find_start_code(plm_buffer_t *self, int code) FL_NOEXCEPT;
int plm_buffer_no_start_code(plm_buffer_t *self) FL_NOEXCEPT;
int16_t plm_buffer_read_vlc(plm_buffer_t *self, const plm_vlc_t *table) FL_NOEXCEPT;
uint16_t plm_buffer_read_vlc_uint(plm_buffer_t *self, const plm_vlc_uint_t *table) FL_NOEXCEPT;
 
#ifndef PLM_NO_STDIO
 
plm_buffer_t *plm_buffer_create_with_filename(const char *filename) {
    FILE *fh = fopen(filename, "rb");
    if (!fh) {
        return NULL;
    }
    return plm_buffer_create_with_file(fh, TRUE);
}
 
plm_buffer_t *plm_buffer_create_with_file(FILE *fh, int close_when_done) {
    plm_buffer_t *self = plm_buffer_create_with_capacity(PLM_BUFFER_DEFAULT_SIZE);
    self->fh = fh;
    self->close_when_done = close_when_done;
    self->mode = PLM_BUFFER_MODE_FILE;
    self->discard_read_bytes = TRUE;
    
    fseek(self->fh, 0, SEEK_END);
    self->total_size = ftell(self->fh);
    fseek(self->fh, 0, SEEK_SET);
 
    self->load_callback = plm_buffer_load_file_callback;
    self->seek_callback = plm_buffer_seek_file_callback;
    self->tell_callback = plm_buffer_tell_file_callback;
    return self;
}
 
#endif // PLM_NO_STDIO
 
plm_buffer_t *plm_buffer_create_with_callbacks(
    plm_buffer_load_callback load_callback,
    plm_buffer_seek_callback seek_callback,
    plm_buffer_tell_callback tell_callback,
    size_t length,
    void *user
) FL_NOEXCEPT {
    plm_buffer_t *self = plm_buffer_create_with_capacity(PLM_BUFFER_DEFAULT_SIZE);
    self->mode = PLM_BUFFER_MODE_FILE;
    self->total_size = length;
    self->load_callback = load_callback;
    self->seek_callback = seek_callback;
    self->tell_callback = tell_callback;
    self->load_callback_user_data = user;
    return self;
}
 
plm_buffer_t *plm_buffer_create_with_memory(uint8_t *bytes, size_t length, int free_when_done) FL_NOEXCEPT {
    plm_buffer_t *self = (plm_buffer_t *)PLM_MALLOC(sizeof(plm_buffer_t));
    fl::memset(self, 0, sizeof(plm_buffer_t));
    self->capacity = length;
    self->length = length;
    self->total_size = length;
    self->free_when_done = free_when_done;
    self->bytes = bytes;
    self->mode = PLM_BUFFER_MODE_FIXED_MEM;
    self->discard_read_bytes = FALSE;
    return self;
}
 
plm_buffer_t *plm_buffer_create_with_capacity(size_t capacity) FL_NOEXCEPT {
    plm_buffer_t *self = (plm_buffer_t *)PLM_MALLOC(sizeof(plm_buffer_t));
    fl::memset(self, 0, sizeof(plm_buffer_t));
    self->capacity = capacity;
    self->free_when_done = TRUE;
    self->bytes = (uint8_t *)PLM_MALLOC(capacity);
    self->mode = PLM_BUFFER_MODE_RING;
    self->discard_read_bytes = TRUE;
    return self;
}
 
plm_buffer_t *plm_buffer_create_for_appending(size_t initial_capacity) FL_NOEXCEPT {
    plm_buffer_t *self = plm_buffer_create_with_capacity(initial_capacity);
    self->mode = PLM_BUFFER_MODE_APPEND;
    self->discard_read_bytes = FALSE;
    return self;
}
 
void plm_buffer_destroy(plm_buffer_t *self) FL_NOEXCEPT {
#ifndef PLM_NO_STDIO
    if (self->fh && self->close_when_done) {
        fclose(self->fh);
    }
#endif
    if (self->free_when_done) {
        PLM_FREE(self->bytes);
    }
    PLM_FREE(self);
}
 
size_t plm_buffer_get_size(plm_buffer_t *self) FL_NOEXCEPT {
    return (self->mode == PLM_BUFFER_MODE_FILE)
        ? self->total_size
        : self->length;
}
 
size_t plm_buffer_get_remaining(plm_buffer_t *self) FL_NOEXCEPT {
    return self->length - (self->bit_index >> 3);
}
 
size_t plm_buffer_write(plm_buffer_t *self, uint8_t *bytes, size_t length) FL_NOEXCEPT {
    if (self->mode == PLM_BUFFER_MODE_FIXED_MEM) {
        return 0;
    }
 
    if (self->discard_read_bytes) {
        // This should be a ring buffer, but instead it just shifts all unread 
        // data to the beginning of the buffer and appends new data at the end. 
        // Seems to be good enough.
 
        plm_buffer_discard_read_bytes(self);
        if (self->mode == PLM_BUFFER_MODE_RING) {
            self->total_size = 0;
        }
    }
 
    // Do we have to resize to fit the new data?
    size_t bytes_available = self->capacity - self->length;
    if (bytes_available < length) {
        size_t new_size = self->capacity;
        do {
            new_size *= 2;
        } while (new_size - self->length < length);
        self->bytes = (uint8_t *)PLM_REALLOC(self->bytes, new_size);
        self->capacity = new_size;
    }
 
    fl::memcopy(self->bytes + self->length, bytes, length);
    self->length += length;
    self->has_ended = FALSE;
    return length;
}
 
void plm_buffer_signal_end(plm_buffer_t *self) FL_NOEXCEPT {
    self->total_size = self->length;
}
 
void plm_buffer_set_load_callback(plm_buffer_t *self, plm_buffer_load_callback fp, void *user) FL_NOEXCEPT {
    self->load_callback = fp;
    self->load_callback_user_data = user;
}
 
void plm_buffer_rewind(plm_buffer_t *self) FL_NOEXCEPT {
    plm_buffer_seek(self, 0);
}
 
void plm_buffer_seek(plm_buffer_t *self, size_t pos) FL_NOEXCEPT {
    self->has_ended = FALSE;
 
    if (self->seek_callback) {
        self->seek_callback(self, pos, self->load_callback_user_data);
        self->bit_index = 0;
        self->length = 0;
    }
    else if (self->mode == PLM_BUFFER_MODE_RING) {
        if (pos != 0) {
            // Seeking to non-0 is forbidden for dynamic-mem buffers
            return; 
        }
        self->bit_index = 0;
        self->length = 0;
        self->total_size = 0;
    }
    else if (pos < self->length) {
        self->bit_index = pos << 3;
    }
}
 
size_t plm_buffer_tell(plm_buffer_t *self) FL_NOEXCEPT {
    return self->tell_callback
        ? self->tell_callback(self, self->load_callback_user_data) + (self->bit_index >> 3) - self->length
        : self->bit_index >> 3;
}
 
void plm_buffer_discard_read_bytes(plm_buffer_t *self) FL_NOEXCEPT {
    size_t byte_pos = self->bit_index >> 3;
    if (byte_pos == self->length) {
        self->bit_index = 0;
        self->length = 0;
    }
    else if (byte_pos > 0) {
        memmove(self->bytes, self->bytes + byte_pos, self->length - byte_pos);
        self->bit_index -= byte_pos << 3;
        self->length -= byte_pos;
    }
}
 
#ifndef PLM_NO_STDIO
 
void plm_buffer_load_file_callback(plm_buffer_t *self, void *user) {
    PLM_UNUSED(user);
    
    if (self->discard_read_bytes) {
        plm_buffer_discard_read_bytes(self);
    }
 
    size_t bytes_available = self->capacity - self->length;
    size_t bytes_read = fread(self->bytes + self->length, 1, bytes_available, self->fh);
    self->length += bytes_read;
 
    if (bytes_read == 0) {
        self->has_ended = TRUE;
    }
}
 
void plm_buffer_seek_file_callback(plm_buffer_t *self, size_t offset, void *user) {
    PLM_UNUSED(user);
    fseek(self->fh, offset, SEEK_SET);
}
 
size_t plm_buffer_tell_file_callback(plm_buffer_t *self, void *user) {
    PLM_UNUSED(user);
    return ftell(self->fh);
}
 
#endif // PLM_NO_STDIO
 
int plm_buffer_has_ended(plm_buffer_t *self) FL_NOEXCEPT {
    return self->has_ended;
}
 
int plm_buffer_has(plm_buffer_t *self, size_t count) FL_NOEXCEPT {
    if (((self->length << 3) - self->bit_index) >= count) {
        return TRUE;
    }
 
    if (self->load_callback) {
        self->load_callback(self, self->load_callback_user_data);
        
        if (((self->length << 3) - self->bit_index) >= count) {
            return TRUE;
        }
    }   
    
    if (self->total_size != 0 && self->length == self->total_size) {
        self->has_ended = TRUE;
    }
    return FALSE;
}
 
int plm_buffer_read(plm_buffer_t *self, int count) FL_NOEXCEPT {
    if (!plm_buffer_has(self, count)) {
        return 0;
    }
 
    int value = 0;
    while (count) {
        int current_byte = self->bytes[self->bit_index >> 3];
 
        int remaining = 8 - (self->bit_index & 7); // Remaining bits in byte
        int read = remaining < count ? remaining : count; // Bits in self run
        int shift = remaining - read;
        int mask = (0xff >> (8 - read));
 
        value = (value << read) | ((current_byte & (mask << shift)) >> shift);
 
        self->bit_index += read;
        count -= read;
    }
 
    return value;
}
 
void plm_buffer_align(plm_buffer_t *self) FL_NOEXCEPT {
    self->bit_index = ((self->bit_index + 7) >> 3) << 3; // Align to next byte
}
 
void plm_buffer_skip(plm_buffer_t *self, size_t count) FL_NOEXCEPT {
    if (plm_buffer_has(self, count)) {
        self->bit_index += count;
    }
}
 
int plm_buffer_skip_bytes(plm_buffer_t *self, uint8_t v) FL_NOEXCEPT {
    plm_buffer_align(self);
    int skipped = 0;
    while (plm_buffer_has(self, 8) && self->bytes[self->bit_index >> 3] == v) {
        self->bit_index += 8;
        skipped++;
    }
    return skipped;
}
 
int plm_buffer_next_start_code(plm_buffer_t *self) FL_NOEXCEPT {
    plm_buffer_align(self);
 
    while (plm_buffer_has(self, (5 << 3))) {
        size_t byte_index = (self->bit_index) >> 3;
        if (
            self->bytes[byte_index] == 0x00 &&
            self->bytes[byte_index + 1] == 0x00 &&
            self->bytes[byte_index + 2] == 0x01
        ) {
            self->bit_index = (byte_index + 4) << 3;
            return self->bytes[byte_index + 3];
        }
        self->bit_index += 8;
    }
    return -1;
}
 
int plm_buffer_find_start_code(plm_buffer_t *self, int code) FL_NOEXCEPT {
    int current = 0;
    while (TRUE) {
        current = plm_buffer_next_start_code(self);
        if (current == code || current == -1) {
            return current;
        }
    }
    return -1;
}
 
int plm_buffer_has_start_code(plm_buffer_t *self, int code) FL_NOEXCEPT {
    size_t previous_bit_index = self->bit_index;
    int previous_discard_read_bytes = self->discard_read_bytes;
    
    self->discard_read_bytes = FALSE;
    int current = plm_buffer_find_start_code(self, code);
 
    self->bit_index = previous_bit_index;
    self->discard_read_bytes = previous_discard_read_bytes;
    return current;
}
 
int plm_buffer_peek_non_zero(plm_buffer_t *self, int bit_count) FL_NOEXCEPT {
    if (!plm_buffer_has(self, bit_count)) {
        return FALSE;
    }
 
    int val = plm_buffer_read(self, bit_count);
    self->bit_index -= bit_count;
    return val != 0;
}
 
int16_t plm_buffer_read_vlc(plm_buffer_t *self, const plm_vlc_t *table) FL_NOEXCEPT {
    plm_vlc_t state = {0, 0};
    do {
        state = table[state.index + plm_buffer_read(self, 1)];
    } while (state.index > 0);
    return state.value;
}
 
uint16_t plm_buffer_read_vlc_uint(plm_buffer_t *self, const plm_vlc_uint_t *table) FL_NOEXCEPT {
    return (uint16_t)plm_buffer_read_vlc(self, (const plm_vlc_t *)table);
}
 
 
 
// ----------------------------------------------------------------------------
// plm_demux implementation
 
static const int PLM_START_PACK = 0xBA;
static const int PLM_START_END = 0xB9;
static const int PLM_START_SYSTEM = 0xBB;
 
struct plm_demux_t {
    plm_buffer_t *buffer;
    int destroy_buffer_when_done;
    double system_clock_ref;
 
    size_t last_file_size;
    double last_decoded_pts;
    double start_time;
    double duration;
 
    int start_code;
    int has_pack_header;
    int has_system_header;
    int has_headers;
 
    int num_audio_streams;
    int num_video_streams;
    plm_packet_t current_packet;
    plm_packet_t next_packet;
};
 
 
void plm_demux_buffer_seek(plm_demux_t *self, size_t pos) FL_NOEXCEPT;
double plm_demux_decode_time(plm_demux_t *self) FL_NOEXCEPT;
plm_packet_t *plm_demux_decode_packet(plm_demux_t *self, int type) FL_NOEXCEPT;
plm_packet_t *plm_demux_get_packet(plm_demux_t *self) FL_NOEXCEPT;
 
plm_demux_t *plm_demux_create(plm_buffer_t *buffer, int destroy_when_done) FL_NOEXCEPT {
    plm_demux_t *self = (plm_demux_t *)PLM_MALLOC(sizeof(plm_demux_t));
    fl::memset(self, 0, sizeof(plm_demux_t));
 
    self->buffer = buffer;
    self->destroy_buffer_when_done = destroy_when_done;
 
    self->start_time = PLM_PACKET_INVALID_TS;
    self->duration = PLM_PACKET_INVALID_TS;
    self->start_code = -1;
 
    plm_demux_has_headers(self);
    return self;
}
 
void plm_demux_destroy(plm_demux_t *self) FL_NOEXCEPT {
    if (self->destroy_buffer_when_done) {
        plm_buffer_destroy(self->buffer);
    }
    PLM_FREE(self);
}
 
int plm_demux_has_headers(plm_demux_t *self) FL_NOEXCEPT {
    if (self->has_headers) {
        return TRUE;
    }
 
    // Decode pack header
    if (!self->has_pack_header) {
        if (
            self->start_code != PLM_START_PACK &&
            plm_buffer_find_start_code(self->buffer, PLM_START_PACK) == -1
        ) {
            return FALSE;
        }
 
        self->start_code = PLM_START_PACK;
        if (!plm_buffer_has(self->buffer, 64)) {
            return FALSE;
        }
        self->start_code = -1;
 
        if (plm_buffer_read(self->buffer, 4) != 0x02) {
            return FALSE;
        }
 
        self->system_clock_ref = plm_demux_decode_time(self);
        plm_buffer_skip(self->buffer, 1);
        plm_buffer_skip(self->buffer, 22); // mux_rate * 50
        plm_buffer_skip(self->buffer, 1);
 
        self->has_pack_header = TRUE;
    }
 
    // Decode system header
    if (!self->has_system_header) {
        if (
            self->start_code != PLM_START_SYSTEM &&
            plm_buffer_find_start_code(self->buffer, PLM_START_SYSTEM) == -1
        ) {
            return FALSE;
        }
 
        self->start_code = PLM_START_SYSTEM;
        if (!plm_buffer_has(self->buffer, 56)) {
            return FALSE;
        }
        self->start_code = -1;
 
        plm_buffer_skip(self->buffer, 16); // header_length
        plm_buffer_skip(self->buffer, 24); // rate bound
        self->num_audio_streams = plm_buffer_read(self->buffer, 6);
        plm_buffer_skip(self->buffer, 5); // misc flags
        self->num_video_streams = plm_buffer_read(self->buffer, 5);
 
        self->has_system_header = TRUE;
    }
 
    self->has_headers = TRUE;
    return TRUE;
}
 
int plm_demux_probe(plm_demux_t *self, size_t probesize) FL_NOEXCEPT {
    int previous_pos = plm_buffer_tell(self->buffer);
 
    int video_stream = FALSE;
    int audio_streams[4] = {FALSE, FALSE, FALSE, FALSE};
    do {
        self->start_code = plm_buffer_next_start_code(self->buffer);
        if (self->start_code == PLM_DEMUX_PACKET_VIDEO_1) {
            video_stream = TRUE;
        }
        else if (
            self->start_code >= PLM_DEMUX_PACKET_AUDIO_1 && 
            self->start_code <= PLM_DEMUX_PACKET_AUDIO_4
        ) {
            audio_streams[self->start_code - PLM_DEMUX_PACKET_AUDIO_1] = TRUE;
        }
    } while (
        self->start_code != -1 && 
        plm_buffer_tell(self->buffer) - previous_pos < probesize
    );
 
    self->num_video_streams = video_stream ? 1 : 0;
    self->num_audio_streams = 0;
    for (int i = 0; i < 4; i++) {
        if (audio_streams[i]) {
            self->num_audio_streams++;
        }
    }
 
    plm_demux_buffer_seek(self, previous_pos);
    return (self->num_video_streams || self->num_audio_streams);
}
 
int plm_demux_get_num_video_streams(plm_demux_t *self) FL_NOEXCEPT {
    return plm_demux_has_headers(self)
        ? self->num_video_streams
        : 0;
}
 
int plm_demux_get_num_audio_streams(plm_demux_t *self) FL_NOEXCEPT {
    return plm_demux_has_headers(self)
        ? self->num_audio_streams
        : 0;
}
 
void plm_demux_rewind(plm_demux_t *self) FL_NOEXCEPT {
    plm_buffer_rewind(self->buffer);
    self->current_packet.length = 0;
    self->next_packet.length = 0;
    self->start_code = -1;
}
 
int plm_demux_has_ended(plm_demux_t *self) FL_NOEXCEPT {
    return plm_buffer_has_ended(self->buffer);
}
 
void plm_demux_buffer_seek(plm_demux_t *self, size_t pos) FL_NOEXCEPT {
    plm_buffer_seek(self->buffer, pos);
    self->current_packet.length = 0;
    self->next_packet.length = 0;
    self->start_code = -1;
}
 
double plm_demux_get_start_time(plm_demux_t *self, int type) FL_NOEXCEPT {
    if (self->start_time != PLM_PACKET_INVALID_TS) {
        return self->start_time;
    }
 
    int previous_pos = plm_buffer_tell(self->buffer);
    int previous_start_code = self->start_code;
    
    // Find first video PTS
    plm_demux_rewind(self);
    do {
        plm_packet_t *packet = plm_demux_decode(self);
        if (!packet) {
            break;
        }
        if (packet->type == type) {
            self->start_time = packet->pts;
        }
    } while (self->start_time == PLM_PACKET_INVALID_TS);
 
    plm_demux_buffer_seek(self, previous_pos);
    self->start_code = previous_start_code;
    return self->start_time;
}
 
double plm_demux_get_duration(plm_demux_t *self, int type) FL_NOEXCEPT {
    size_t file_size = plm_buffer_get_size(self->buffer);
 
    if (
        self->duration != PLM_PACKET_INVALID_TS &&
        self->last_file_size == file_size
    ) {
        return self->duration;
    }
 
    size_t previous_pos = plm_buffer_tell(self->buffer);
    int previous_start_code = self->start_code;
    
    // Find last video PTS. Start searching 64kb from the end and go further
    // back if needed.
    long start_range = 64L * 1024L;
    long max_range = 4096L * 1024L;
    for (long range = start_range; range <= max_range; range *= 2) {
        long seek_pos = file_size - range;
        if (seek_pos < 0) {
            seek_pos = 0;
            range = max_range; // Make sure to bail after this round
        }
        plm_demux_buffer_seek(self, seek_pos);
        self->current_packet.length = 0;
 
        double last_pts = PLM_PACKET_INVALID_TS;
        plm_packet_t *packet = NULL;
        while ((packet = plm_demux_decode(self))) {
            if (packet->pts != PLM_PACKET_INVALID_TS && packet->type == type) {
                last_pts = packet->pts;
            }
        }
        if (last_pts != PLM_PACKET_INVALID_TS) {
            self->duration = last_pts - plm_demux_get_start_time(self, type);
            break;
        }
    }
 
    plm_demux_buffer_seek(self, previous_pos);
    self->start_code = previous_start_code;
    self->last_file_size = file_size;
    return self->duration;
}
 
plm_packet_t *plm_demux_seek(plm_demux_t *self, double seek_time, int type, int force_intra) FL_NOEXCEPT {
    if (!plm_demux_has_headers(self)) {
        return NULL;
    }
 
    // Using the current time, current byte position and the average bytes per
    // second for this file, try to jump to a byte position that hopefully has
    // packets containing timestamps within one second before to the desired 
    // seek_time.
 
    // If we hit close to the seek_time scan through all packets to find the
    // last one (just before the seek_time) containing an intra frame.
    // Otherwise we should at least be closer than before. Calculate the bytes
    // per second for the jumped range and jump again.
 
    // The number of retries here is hard-limited to a generous amount. Usually
    // the correct range is found after 1--5 jumps, even for files with very 
    // variable bitrates. If significantly more jumps are needed, there's
    // probably something wrong with the file and we just avoid getting into an
    // infinite loop. 32 retries should be enough for anybody.
 
    double duration = plm_demux_get_duration(self, type);
    long file_size = plm_buffer_get_size(self->buffer);
    long byterate = file_size / duration;
 
    double cur_time = self->last_decoded_pts;
    double scan_span = 1;
 
    if (seek_time > duration) {
        seek_time = duration;
    }
    else if (seek_time < 0) {
        seek_time = 0;
    }
    seek_time += self->start_time;
 
    for (int retry = 0; retry < 32; retry++) {
        int found_packet_with_pts = FALSE;
        int found_packet_in_range = FALSE;
        long last_valid_packet_start = -1;
        double first_packet_time = PLM_PACKET_INVALID_TS;
 
        long cur_pos = plm_buffer_tell(self->buffer);
 
        // Estimate byte offset and jump to it.
        long offset = (seek_time - cur_time - scan_span) * byterate;
        long seek_pos = cur_pos + offset;
        if (seek_pos < 0) {
            seek_pos = 0;
        }
        else if (seek_pos > file_size - 256) {
            seek_pos = file_size - 256;
        }
 
        plm_demux_buffer_seek(self, seek_pos);
 
        // Scan through all packets up to the seek_time to find the last packet
        // containing an intra frame.
        while (plm_buffer_find_start_code(self->buffer, type) != -1) {
            long packet_start = plm_buffer_tell(self->buffer);
            plm_packet_t *packet = plm_demux_decode_packet(self, type);
 
            // Skip packet if it has no PTS
            if (!packet || packet->pts == PLM_PACKET_INVALID_TS) {
                continue;
            }
 
            // Bail scanning through packets if we hit one that is outside
            // seek_time - scan_span.
            // We also adjust the cur_time and byterate values here so the next 
            // iteration can be a bit more precise.
            if (packet->pts > seek_time || packet->pts < seek_time - scan_span) {
                found_packet_with_pts = TRUE;
                byterate = (seek_pos - cur_pos) / (packet->pts - cur_time);
                cur_time = packet->pts;
                break;
            }
 
            // If we are still here, it means this packet is in close range to
            // the seek_time. If this is the first packet for this jump position
            // record the PTS. If we later have to back off, when there was no
            // intra frame in this range, we can lower the seek_time to not scan
            // this range again.
            if (!found_packet_in_range) {
                found_packet_in_range = TRUE;
                first_packet_time = packet->pts;
            }
 
            // Check if this is an intra frame packet. If so, record the buffer
            // position of the start of this packet. We want to jump back to it 
            // later, when we know it's the last intra frame before desired
            // seek time.
            if (force_intra) {
                for (size_t i = 0; i < packet->length - 6; i++) {
                    // Find the START_PICTURE code
                    if (
                        packet->data[i] == 0x00 &&
                        packet->data[i + 1] == 0x00 &&
                        packet->data[i + 2] == 0x01 &&
                        packet->data[i + 3] == 0x00
                    ) {
                        // Bits 11--13 in the picture header contain the frame 
                        // type, where 1=Intra
                        if ((packet->data[i + 5] & 0x38) == 8) {
                            last_valid_packet_start = packet_start;
                        }
                        break;
                    }
                }
            }
 
            // If we don't want intra frames, just use the last PTS found.
            else {
                last_valid_packet_start = packet_start;
            }
        }
 
        // If there was at least one intra frame in the range scanned above,
        // our search is over. Jump back to the packet and decode it again.
        if (last_valid_packet_start != -1) {
            plm_demux_buffer_seek(self, last_valid_packet_start);
            return plm_demux_decode_packet(self, type);
        }
 
        // If we hit the right range, but still found no intra frame, we have
        // to increases the scan_span. This is done exponentially to also handle
        // video files with very few intra frames.
        else if (found_packet_in_range) {
            scan_span *= 2;
            seek_time = first_packet_time;
        }
 
        // If we didn't find any packet with a PTS, it probably means we reached
        // the end of the file. Estimate byterate and cur_time accordingly.
        else if (!found_packet_with_pts) {
            byterate = (seek_pos - cur_pos) / (duration - cur_time);
            cur_time = duration;
        }
    }
 
    return NULL;
}
 
plm_packet_t *plm_demux_decode(plm_demux_t *self) FL_NOEXCEPT {
    if (!plm_demux_has_headers(self)) {
        return NULL;
    }
 
    if (self->current_packet.length) {
        size_t bits_till_next_packet = self->current_packet.length << 3;
        if (!plm_buffer_has(self->buffer, bits_till_next_packet)) {
            return NULL;
        }
        plm_buffer_skip(self->buffer, bits_till_next_packet);
        self->current_packet.length = 0;
    }
 
    // Pending packet waiting for data?
    if (self->next_packet.length) {
        return plm_demux_get_packet(self);
    }
 
    // Pending packet waiting for header?
    if (self->start_code != -1) {
        return plm_demux_decode_packet(self, self->start_code);
    }
 
    do {
        self->start_code = plm_buffer_next_start_code(self->buffer);
        if (
            self->start_code == PLM_DEMUX_PACKET_VIDEO_1 || 
            self->start_code == PLM_DEMUX_PACKET_PRIVATE || (
                self->start_code >= PLM_DEMUX_PACKET_AUDIO_1 && 
                self->start_code <= PLM_DEMUX_PACKET_AUDIO_4
            )
        ) {
            return plm_demux_decode_packet(self, self->start_code);
        }
    } while (self->start_code != -1);
 
    return NULL;
}
 
double plm_demux_decode_time(plm_demux_t *self) FL_NOEXCEPT {
    i64 clock = (i64)plm_buffer_read(self->buffer, 3) << 30;
    plm_buffer_skip(self->buffer, 1);
    clock |= (i64)plm_buffer_read(self->buffer, 15) << 15;
    plm_buffer_skip(self->buffer, 1);
    clock |= (i64)plm_buffer_read(self->buffer, 15);
    plm_buffer_skip(self->buffer, 1);
    return (double)clock / 90000.0;
}
 
plm_packet_t *plm_demux_decode_packet(plm_demux_t *self, int type) FL_NOEXCEPT {
    if (!plm_buffer_has(self->buffer, 16 << 3)) {
        return NULL;
    }
 
    self->start_code = -1;
 
    self->next_packet.type = type;
    self->next_packet.length = plm_buffer_read(self->buffer, 16);
    self->next_packet.length -= plm_buffer_skip_bytes(self->buffer, 0xff); // stuffing
 
    // skip P-STD
    if (plm_buffer_read(self->buffer, 2) == 0x01) {
        plm_buffer_skip(self->buffer, 16);
        self->next_packet.length -= 2;
    }
 
    int pts_dts_marker = plm_buffer_read(self->buffer, 2);
    if (pts_dts_marker == 0x03) {
        self->next_packet.pts = plm_demux_decode_time(self);
        self->last_decoded_pts = self->next_packet.pts;
        plm_buffer_skip(self->buffer, 40); // skip dts
        self->next_packet.length -= 10;
    }
    else if (pts_dts_marker == 0x02) {
        self->next_packet.pts = plm_demux_decode_time(self);
        self->last_decoded_pts = self->next_packet.pts;
        self->next_packet.length -= 5;
    }
    else if (pts_dts_marker == 0x00) {
        self->next_packet.pts = PLM_PACKET_INVALID_TS;
        plm_buffer_skip(self->buffer, 4);
        self->next_packet.length -= 1;
    }
    else {
        return NULL; // invalid
    }
    
    return plm_demux_get_packet(self);
}
 
plm_packet_t *plm_demux_get_packet(plm_demux_t *self) FL_NOEXCEPT {
    if (!plm_buffer_has(self->buffer, self->next_packet.length << 3)) {
        return NULL;
    }
 
    self->current_packet.data = self->buffer->bytes + (self->buffer->bit_index >> 3);
    self->current_packet.length = self->next_packet.length;
    self->current_packet.type = self->next_packet.type;
    self->current_packet.pts = self->next_packet.pts;
 
    self->next_packet.length = 0;
    return &self->current_packet;
}
 
 
 
// -----------------------------------------------------------------------------
// plm_video implementation
 
// Inspired by Java MPEG-1 Video Decoder and Player by Zoltan Korandi 
// https://sourceforge.net/projects/javampeg1video/
 
static const int PLM_VIDEO_PICTURE_TYPE_INTRA = 1;
static const int PLM_VIDEO_PICTURE_TYPE_PREDICTIVE = 2;
static const int PLM_VIDEO_PICTURE_TYPE_B = 3;
 
static const int PLM_START_SEQUENCE = 0xB3;
static const int PLM_START_SLICE_FIRST = 0x01;
static const int PLM_START_SLICE_LAST = 0xAF;
static const int PLM_START_PICTURE = 0x00;
static const int PLM_START_EXTENSION = 0xB5;
static const int PLM_START_USER_DATA = 0xB2;
 
#define PLM_START_IS_SLICE(c) \
    (c >= PLM_START_SLICE_FIRST && c <= PLM_START_SLICE_LAST)
 
static const float PLM_VIDEO_PIXEL_ASPECT_RATIO[] = {
    1.0000, /* square pixels */
    0.6735, /* 3:4? */
    0.7031, /* MPEG-1 / MPEG-2 video encoding divergence? */
    0.7615, 0.8055, 0.8437, 0.8935, 0.9157, 0.9815,
    1.0255, 1.0695, 1.0950, 1.1575, 1.2051,
};
 
static const double PLM_VIDEO_PICTURE_RATE[] = {
    0.000, 23.976, 24.000, 25.000, 29.970, 30.000, 50.000, 59.940,
    60.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000
};
 
static const uint8_t PLM_VIDEO_ZIG_ZAG[] = {
     0,  1,  8, 16,  9,  2,  3, 10,
    17, 24, 32, 25, 18, 11,  4,  5,
    12, 19, 26, 33, 40, 48, 41, 34,
    27, 20, 13,  6,  7, 14, 21, 28,
    35, 42, 49, 56, 57, 50, 43, 36,
    29, 22, 15, 23, 30, 37, 44, 51,
    58, 59, 52, 45, 38, 31, 39, 46,
    53, 60, 61, 54, 47, 55, 62, 63
};
 
static const uint8_t PLM_VIDEO_INTRA_QUANT_MATRIX[] = {
     8, 16, 19, 22, 26, 27, 29, 34,
    16, 16, 22, 24, 27, 29, 34, 37,
    19, 22, 26, 27, 29, 34, 34, 38,
    22, 22, 26, 27, 29, 34, 37, 40,
    22, 26, 27, 29, 32, 35, 40, 48,
    26, 27, 29, 32, 35, 40, 48, 58,
    26, 27, 29, 34, 38, 46, 56, 69,
    27, 29, 35, 38, 46, 56, 69, 83
};
 
static const uint8_t PLM_VIDEO_NON_INTRA_QUANT_MATRIX[] = {
    16, 16, 16, 16, 16, 16, 16, 16,
    16, 16, 16, 16, 16, 16, 16, 16,
    16, 16, 16, 16, 16, 16, 16, 16,
    16, 16, 16, 16, 16, 16, 16, 16,
    16, 16, 16, 16, 16, 16, 16, 16,
    16, 16, 16, 16, 16, 16, 16, 16,
    16, 16, 16, 16, 16, 16, 16, 16,
    16, 16, 16, 16, 16, 16, 16, 16
};
 
static const uint8_t PLM_VIDEO_PREMULTIPLIER_MATRIX[] = {
    32, 44, 42, 38, 32, 25, 17,  9,
    44, 62, 58, 52, 44, 35, 24, 12,
    42, 58, 55, 49, 42, 33, 23, 12,
    38, 52, 49, 44, 38, 30, 20, 10,
    32, 44, 42, 38, 32, 25, 17,  9,
    25, 35, 33, 30, 25, 20, 14,  7,
    17, 24, 23, 20, 17, 14,  9,  5,
     9, 12, 12, 10,  9,  7,  5,  2
};
 
static const plm_vlc_t PLM_VIDEO_MACROBLOCK_ADDRESS_INCREMENT[] = {
    {  1 << 1,    0}, {       0,    1},  //   0: x
    {  2 << 1,    0}, {  3 << 1,    0},  //   1: 0x
    {  4 << 1,    0}, {  5 << 1,    0},  //   2: 00x
    {       0,    3}, {       0,    2},  //   3: 01x
    {  6 << 1,    0}, {  7 << 1,    0},  //   4: 000x
    {       0,    5}, {       0,    4},  //   5: 001x
    {  8 << 1,    0}, {  9 << 1,    0},  //   6: 0000x
    {       0,    7}, {       0,    6},  //   7: 0001x
    { 10 << 1,    0}, { 11 << 1,    0},  //   8: 0000 0x
    { 12 << 1,    0}, { 13 << 1,    0},  //   9: 0000 1x
    { 14 << 1,    0}, { 15 << 1,    0},  //  10: 0000 00x
    { 16 << 1,    0}, { 17 << 1,    0},  //  11: 0000 01x
    { 18 << 1,    0}, { 19 << 1,    0},  //  12: 0000 10x
    {       0,    9}, {       0,    8},  //  13: 0000 11x
    {      -1,    0}, { 20 << 1,    0},  //  14: 0000 000x
    {      -1,    0}, { 21 << 1,    0},  //  15: 0000 001x
    { 22 << 1,    0}, { 23 << 1,    0},  //  16: 0000 010x
    {       0,   15}, {       0,   14},  //  17: 0000 011x
    {       0,   13}, {       0,   12},  //  18: 0000 100x
    {       0,   11}, {       0,   10},  //  19: 0000 101x
    { 24 << 1,    0}, { 25 << 1,    0},  //  20: 0000 0001x
    { 26 << 1,    0}, { 27 << 1,    0},  //  21: 0000 0011x
    { 28 << 1,    0}, { 29 << 1,    0},  //  22: 0000 0100x
    { 30 << 1,    0}, { 31 << 1,    0},  //  23: 0000 0101x
    { 32 << 1,    0}, {      -1,    0},  //  24: 0000 0001 0x
    {      -1,    0}, { 33 << 1,    0},  //  25: 0000 0001 1x
    { 34 << 1,    0}, { 35 << 1,    0},  //  26: 0000 0011 0x
    { 36 << 1,    0}, { 37 << 1,    0},  //  27: 0000 0011 1x
    { 38 << 1,    0}, { 39 << 1,    0},  //  28: 0000 0100 0x
    {       0,   21}, {       0,   20},  //  29: 0000 0100 1x
    {       0,   19}, {       0,   18},  //  30: 0000 0101 0x
    {       0,   17}, {       0,   16},  //  31: 0000 0101 1x
    {       0,   35}, {      -1,    0},  //  32: 0000 0001 00x
    {      -1,    0}, {       0,   34},  //  33: 0000 0001 11x
    {       0,   33}, {       0,   32},  //  34: 0000 0011 00x
    {       0,   31}, {       0,   30},  //  35: 0000 0011 01x
    {       0,   29}, {       0,   28},  //  36: 0000 0011 10x
    {       0,   27}, {       0,   26},  //  37: 0000 0011 11x
    {       0,   25}, {       0,   24},  //  38: 0000 0100 00x
    {       0,   23}, {       0,   22},  //  39: 0000 0100 01x
};
 
static const plm_vlc_t PLM_VIDEO_MACROBLOCK_TYPE_INTRA[] = {
    {  1 << 1,    0}, {       0,  0x01},  //   0: x
    {      -1,    0}, {       0,  0x11},  //   1: 0x
};
 
static const plm_vlc_t PLM_VIDEO_MACROBLOCK_TYPE_PREDICTIVE[] = {
    {  1 << 1,    0}, {       0, 0x0a},  //   0: x
    {  2 << 1,    0}, {       0, 0x02},  //   1: 0x
    {  3 << 1,    0}, {       0, 0x08},  //   2: 00x
    {  4 << 1,    0}, {  5 << 1,    0},  //   3: 000x
    {  6 << 1,    0}, {       0, 0x12},  //   4: 0000x
    {       0, 0x1a}, {       0, 0x01},  //   5: 0001x
    {      -1,    0}, {       0, 0x11},  //   6: 0000 0x
};
 
static const plm_vlc_t PLM_VIDEO_MACROBLOCK_TYPE_B[] = {
    {  1 << 1,    0}, {  2 << 1,    0},  //   0: x
    {  3 << 1,    0}, {  4 << 1,    0},  //   1: 0x
    {       0, 0x0c}, {       0, 0x0e},  //   2: 1x
    {  5 << 1,    0}, {  6 << 1,    0},  //   3: 00x
    {       0, 0x04}, {       0, 0x06},  //   4: 01x
    {  7 << 1,    0}, {  8 << 1,    0},  //   5: 000x
    {       0, 0x08}, {       0, 0x0a},  //   6: 001x
    {  9 << 1,    0}, { 10 << 1,    0},  //   7: 0000x
    {       0, 0x1e}, {       0, 0x01},  //   8: 0001x
    {      -1,    0}, {       0, 0x11},  //   9: 0000 0x
    {       0, 0x16}, {       0, 0x1a},  //  10: 0000 1x
};
 
static const plm_vlc_t *PLM_VIDEO_MACROBLOCK_TYPE[] = {
    NULL,
    PLM_VIDEO_MACROBLOCK_TYPE_INTRA,
    PLM_VIDEO_MACROBLOCK_TYPE_PREDICTIVE,
    PLM_VIDEO_MACROBLOCK_TYPE_B
};
 
static const plm_vlc_t PLM_VIDEO_CODE_BLOCK_PATTERN[] = {
    {  1 << 1,    0}, {  2 << 1,    0},  //   0: x
    {  3 << 1,    0}, {  4 << 1,    0},  //   1: 0x
    {  5 << 1,    0}, {  6 << 1,    0},  //   2: 1x
    {  7 << 1,    0}, {  8 << 1,    0},  //   3: 00x
    {  9 << 1,    0}, { 10 << 1,    0},  //   4: 01x
    { 11 << 1,    0}, { 12 << 1,    0},  //   5: 10x
    { 13 << 1,    0}, {       0,   60},  //   6: 11x
    { 14 << 1,    0}, { 15 << 1,    0},  //   7: 000x
    { 16 << 1,    0}, { 17 << 1,    0},  //   8: 001x
    { 18 << 1,    0}, { 19 << 1,    0},  //   9: 010x
    { 20 << 1,    0}, { 21 << 1,    0},  //  10: 011x
    { 22 << 1,    0}, { 23 << 1,    0},  //  11: 100x
    {       0,   32}, {       0,   16},  //  12: 101x
    {       0,    8}, {       0,    4},  //  13: 110x
    { 24 << 1,    0}, { 25 << 1,    0},  //  14: 0000x
    { 26 << 1,    0}, { 27 << 1,    0},  //  15: 0001x
    { 28 << 1,    0}, { 29 << 1,    0},  //  16: 0010x
    { 30 << 1,    0}, { 31 << 1,    0},  //  17: 0011x
    {       0,   62}, {       0,    2},  //  18: 0100x
    {       0,   61}, {       0,    1},  //  19: 0101x
    {       0,   56}, {       0,   52},  //  20: 0110x
    {       0,   44}, {       0,   28},  //  21: 0111x
    {       0,   40}, {       0,   20},  //  22: 1000x
    {       0,   48}, {       0,   12},  //  23: 1001x
    { 32 << 1,    0}, { 33 << 1,    0},  //  24: 0000 0x
    { 34 << 1,    0}, { 35 << 1,    0},  //  25: 0000 1x
    { 36 << 1,    0}, { 37 << 1,    0},  //  26: 0001 0x
    { 38 << 1,    0}, { 39 << 1,    0},  //  27: 0001 1x
    { 40 << 1,    0}, { 41 << 1,    0},  //  28: 0010 0x
    { 42 << 1,    0}, { 43 << 1,    0},  //  29: 0010 1x
    {       0,   63}, {       0,    3},  //  30: 0011 0x
    {       0,   36}, {       0,   24},  //  31: 0011 1x
    { 44 << 1,    0}, { 45 << 1,    0},  //  32: 0000 00x
    { 46 << 1,    0}, { 47 << 1,    0},  //  33: 0000 01x
    { 48 << 1,    0}, { 49 << 1,    0},  //  34: 0000 10x
    { 50 << 1,    0}, { 51 << 1,    0},  //  35: 0000 11x
    { 52 << 1,    0}, { 53 << 1,    0},  //  36: 0001 00x
    { 54 << 1,    0}, { 55 << 1,    0},  //  37: 0001 01x
    { 56 << 1,    0}, { 57 << 1,    0},  //  38: 0001 10x
    { 58 << 1,    0}, { 59 << 1,    0},  //  39: 0001 11x
    {       0,   34}, {       0,   18},  //  40: 0010 00x
    {       0,   10}, {       0,    6},  //  41: 0010 01x
    {       0,   33}, {       0,   17},  //  42: 0010 10x
    {       0,    9}, {       0,    5},  //  43: 0010 11x
    {      -1,    0}, { 60 << 1,    0},  //  44: 0000 000x
    { 61 << 1,    0}, { 62 << 1,    0},  //  45: 0000 001x
    {       0,   58}, {       0,   54},  //  46: 0000 010x
    {       0,   46}, {       0,   30},  //  47: 0000 011x
    {       0,   57}, {       0,   53},  //  48: 0000 100x
    {       0,   45}, {       0,   29},  //  49: 0000 101x
    {       0,   38}, {       0,   26},  //  50: 0000 110x
    {       0,   37}, {       0,   25},  //  51: 0000 111x
    {       0,   43}, {       0,   23},  //  52: 0001 000x
    {       0,   51}, {       0,   15},  //  53: 0001 001x
    {       0,   42}, {       0,   22},  //  54: 0001 010x
    {       0,   50}, {       0,   14},  //  55: 0001 011x
    {       0,   41}, {       0,   21},  //  56: 0001 100x
    {       0,   49}, {       0,   13},  //  57: 0001 101x
    {       0,   35}, {       0,   19},  //  58: 0001 110x
    {       0,   11}, {       0,    7},  //  59: 0001 111x
    {       0,   39}, {       0,   27},  //  60: 0000 0001x
    {       0,   59}, {       0,   55},  //  61: 0000 0010x
    {       0,   47}, {       0,   31},  //  62: 0000 0011x
};
 
static const plm_vlc_t PLM_VIDEO_MOTION[] = {
    {  1 << 1,    0}, {       0,    0},  //   0: x
    {  2 << 1,    0}, {  3 << 1,    0},  //   1: 0x
    {  4 << 1,    0}, {  5 << 1,    0},  //   2: 00x
    {       0,    1}, {       0,   -1},  //   3: 01x
    {  6 << 1,    0}, {  7 << 1,    0},  //   4: 000x
    {       0,    2}, {       0,   -2},  //   5: 001x
    {  8 << 1,    0}, {  9 << 1,    0},  //   6: 0000x
    {       0,    3}, {       0,   -3},  //   7: 0001x
    { 10 << 1,    0}, { 11 << 1,    0},  //   8: 0000 0x
    { 12 << 1,    0}, { 13 << 1,    0},  //   9: 0000 1x
    {      -1,    0}, { 14 << 1,    0},  //  10: 0000 00x
    { 15 << 1,    0}, { 16 << 1,    0},  //  11: 0000 01x
    { 17 << 1,    0}, { 18 << 1,    0},  //  12: 0000 10x
    {       0,    4}, {       0,   -4},  //  13: 0000 11x
    {      -1,    0}, { 19 << 1,    0},  //  14: 0000 001x
    { 20 << 1,    0}, { 21 << 1,    0},  //  15: 0000 010x
    {       0,    7}, {       0,   -7},  //  16: 0000 011x
    {       0,    6}, {       0,   -6},  //  17: 0000 100x
    {       0,    5}, {       0,   -5},  //  18: 0000 101x
    { 22 << 1,    0}, { 23 << 1,    0},  //  19: 0000 0011x
    { 24 << 1,    0}, { 25 << 1,    0},  //  20: 0000 0100x
    { 26 << 1,    0}, { 27 << 1,    0},  //  21: 0000 0101x
    { 28 << 1,    0}, { 29 << 1,    0},  //  22: 0000 0011 0x
    { 30 << 1,    0}, { 31 << 1,    0},  //  23: 0000 0011 1x
    { 32 << 1,    0}, { 33 << 1,    0},  //  24: 0000 0100 0x
    {       0,   10}, {       0,  -10},  //  25: 0000 0100 1x
    {       0,    9}, {       0,   -9},  //  26: 0000 0101 0x
    {       0,    8}, {       0,   -8},  //  27: 0000 0101 1x
    {       0,   16}, {       0,  -16},  //  28: 0000 0011 00x
    {       0,   15}, {       0,  -15},  //  29: 0000 0011 01x
    {       0,   14}, {       0,  -14},  //  30: 0000 0011 10x
    {       0,   13}, {       0,  -13},  //  31: 0000 0011 11x
    {       0,   12}, {       0,  -12},  //  32: 0000 0100 00x
    {       0,   11}, {       0,  -11},  //  33: 0000 0100 01x
};
 
static const plm_vlc_t PLM_VIDEO_DCT_SIZE_LUMINANCE[] = {
    {  1 << 1,    0}, {  2 << 1,    0},  //   0: x
    {       0,    1}, {       0,    2},  //   1: 0x
    {  3 << 1,    0}, {  4 << 1,    0},  //   2: 1x
    {       0,    0}, {       0,    3},  //   3: 10x
    {       0,    4}, {  5 << 1,    0},  //   4: 11x
    {       0,    5}, {  6 << 1,    0},  //   5: 111x
    {       0,    6}, {  7 << 1,    0},  //   6: 1111x
    {       0,    7}, {  8 << 1,    0},  //   7: 1111 1x
    {       0,    8}, {      -1,    0},  //   8: 1111 11x
};
 
static const plm_vlc_t PLM_VIDEO_DCT_SIZE_CHROMINANCE[] = {
    {  1 << 1,    0}, {  2 << 1,    0},  //   0: x
    {       0,    0}, {       0,    1},  //   1: 0x
    {       0,    2}, {  3 << 1,    0},  //   2: 1x
    {       0,    3}, {  4 << 1,    0},  //   3: 11x
    {       0,    4}, {  5 << 1,    0},  //   4: 111x
    {       0,    5}, {  6 << 1,    0},  //   5: 1111x
    {       0,    6}, {  7 << 1,    0},  //   6: 1111 1x
    {       0,    7}, {  8 << 1,    0},  //   7: 1111 11x
    {       0,    8}, {      -1,    0},  //   8: 1111 111x
};
 
static const plm_vlc_t *PLM_VIDEO_DCT_SIZE[] = {
    PLM_VIDEO_DCT_SIZE_LUMINANCE,
    PLM_VIDEO_DCT_SIZE_CHROMINANCE,
    PLM_VIDEO_DCT_SIZE_CHROMINANCE
};
 
 
//  dct_coeff bitmap:
//    0xff00  run
//    0x00ff  level
 
//  Decoded values are unsigned. Sign bit follows in the stream.
 
static const plm_vlc_uint_t PLM_VIDEO_DCT_COEFF[] = {
    {  1 << 1,        0}, {       0,   0x0001},  //   0: x
    {  2 << 1,        0}, {  3 << 1,        0},  //   1: 0x
    {  4 << 1,        0}, {  5 << 1,        0},  //   2: 00x
    {  6 << 1,        0}, {       0,   0x0101},  //   3: 01x
    {  7 << 1,        0}, {  8 << 1,        0},  //   4: 000x
    {  9 << 1,        0}, { 10 << 1,        0},  //   5: 001x
    {       0,   0x0002}, {       0,   0x0201},  //   6: 010x
    { 11 << 1,        0}, { 12 << 1,        0},  //   7: 0000x
    { 13 << 1,        0}, { 14 << 1,        0},  //   8: 0001x
    { 15 << 1,        0}, {       0,   0x0003},  //   9: 0010x
    {       0,   0x0401}, {       0,   0x0301},  //  10: 0011x
    { 16 << 1,        0}, {       0,   0xffff},  //  11: 0000 0x
    { 17 << 1,        0}, { 18 << 1,        0},  //  12: 0000 1x
    {       0,   0x0701}, {       0,   0x0601},  //  13: 0001 0x
    {       0,   0x0102}, {       0,   0x0501},  //  14: 0001 1x
    { 19 << 1,        0}, { 20 << 1,        0},  //  15: 0010 0x
    { 21 << 1,        0}, { 22 << 1,        0},  //  16: 0000 00x
    {       0,   0x0202}, {       0,   0x0901},  //  17: 0000 10x
    {       0,   0x0004}, {       0,   0x0801},  //  18: 0000 11x
    { 23 << 1,        0}, { 24 << 1,        0},  //  19: 0010 00x
    { 25 << 1,        0}, { 26 << 1,        0},  //  20: 0010 01x
    { 27 << 1,        0}, { 28 << 1,        0},  //  21: 0000 000x
    { 29 << 1,        0}, { 30 << 1,        0},  //  22: 0000 001x
    {       0,   0x0d01}, {       0,   0x0006},  //  23: 0010 000x
    {       0,   0x0c01}, {       0,   0x0b01},  //  24: 0010 001x
    {       0,   0x0302}, {       0,   0x0103},  //  25: 0010 010x
    {       0,   0x0005}, {       0,   0x0a01},  //  26: 0010 011x
    { 31 << 1,        0}, { 32 << 1,        0},  //  27: 0000 0000x
    { 33 << 1,        0}, { 34 << 1,        0},  //  28: 0000 0001x
    { 35 << 1,        0}, { 36 << 1,        0},  //  29: 0000 0010x
    { 37 << 1,        0}, { 38 << 1,        0},  //  30: 0000 0011x
    { 39 << 1,        0}, { 40 << 1,        0},  //  31: 0000 0000 0x
    { 41 << 1,        0}, { 42 << 1,        0},  //  32: 0000 0000 1x
    { 43 << 1,        0}, { 44 << 1,        0},  //  33: 0000 0001 0x
    { 45 << 1,        0}, { 46 << 1,        0},  //  34: 0000 0001 1x
    {       0,   0x1001}, {       0,   0x0502},  //  35: 0000 0010 0x
    {       0,   0x0007}, {       0,   0x0203},  //  36: 0000 0010 1x
    {       0,   0x0104}, {       0,   0x0f01},  //  37: 0000 0011 0x
    {       0,   0x0e01}, {       0,   0x0402},  //  38: 0000 0011 1x
    { 47 << 1,        0}, { 48 << 1,        0},  //  39: 0000 0000 00x
    { 49 << 1,        0}, { 50 << 1,        0},  //  40: 0000 0000 01x
    { 51 << 1,        0}, { 52 << 1,        0},  //  41: 0000 0000 10x
    { 53 << 1,        0}, { 54 << 1,        0},  //  42: 0000 0000 11x
    { 55 << 1,        0}, { 56 << 1,        0},  //  43: 0000 0001 00x
    { 57 << 1,        0}, { 58 << 1,        0},  //  44: 0000 0001 01x
    { 59 << 1,        0}, { 60 << 1,        0},  //  45: 0000 0001 10x
    { 61 << 1,        0}, { 62 << 1,        0},  //  46: 0000 0001 11x
    {      -1,        0}, { 63 << 1,        0},  //  47: 0000 0000 000x
    { 64 << 1,        0}, { 65 << 1,        0},  //  48: 0000 0000 001x
    { 66 << 1,        0}, { 67 << 1,        0},  //  49: 0000 0000 010x
    { 68 << 1,        0}, { 69 << 1,        0},  //  50: 0000 0000 011x
    { 70 << 1,        0}, { 71 << 1,        0},  //  51: 0000 0000 100x
    { 72 << 1,        0}, { 73 << 1,        0},  //  52: 0000 0000 101x
    { 74 << 1,        0}, { 75 << 1,        0},  //  53: 0000 0000 110x
    { 76 << 1,        0}, { 77 << 1,        0},  //  54: 0000 0000 111x
    {       0,   0x000b}, {       0,   0x0802},  //  55: 0000 0001 000x
    {       0,   0x0403}, {       0,   0x000a},  //  56: 0000 0001 001x
    {       0,   0x0204}, {       0,   0x0702},  //  57: 0000 0001 010x
    {       0,   0x1501}, {       0,   0x1401},  //  58: 0000 0001 011x
    {       0,   0x0009}, {       0,   0x1301},  //  59: 0000 0001 100x
    {       0,   0x1201}, {       0,   0x0105},  //  60: 0000 0001 101x
    {       0,   0x0303}, {       0,   0x0008},  //  61: 0000 0001 110x
    {       0,   0x0602}, {       0,   0x1101},  //  62: 0000 0001 111x
    { 78 << 1,        0}, { 79 << 1,        0},  //  63: 0000 0000 0001x
    { 80 << 1,        0}, { 81 << 1,        0},  //  64: 0000 0000 0010x
    { 82 << 1,        0}, { 83 << 1,        0},  //  65: 0000 0000 0011x
    { 84 << 1,        0}, { 85 << 1,        0},  //  66: 0000 0000 0100x
    { 86 << 1,        0}, { 87 << 1,        0},  //  67: 0000 0000 0101x
    { 88 << 1,        0}, { 89 << 1,        0},  //  68: 0000 0000 0110x
    { 90 << 1,        0}, { 91 << 1,        0},  //  69: 0000 0000 0111x
    {       0,   0x0a02}, {       0,   0x0902},  //  70: 0000 0000 1000x
    {       0,   0x0503}, {       0,   0x0304},  //  71: 0000 0000 1001x
    {       0,   0x0205}, {       0,   0x0107},  //  72: 0000 0000 1010x
    {       0,   0x0106}, {       0,   0x000f},  //  73: 0000 0000 1011x
    {       0,   0x000e}, {       0,   0x000d},  //  74: 0000 0000 1100x
    {       0,   0x000c}, {       0,   0x1a01},  //  75: 0000 0000 1101x
    {       0,   0x1901}, {       0,   0x1801},  //  76: 0000 0000 1110x
    {       0,   0x1701}, {       0,   0x1601},  //  77: 0000 0000 1111x
    { 92 << 1,        0}, { 93 << 1,        0},  //  78: 0000 0000 0001 0x
    { 94 << 1,        0}, { 95 << 1,        0},  //  79: 0000 0000 0001 1x
    { 96 << 1,        0}, { 97 << 1,        0},  //  80: 0000 0000 0010 0x
    { 98 << 1,        0}, { 99 << 1,        0},  //  81: 0000 0000 0010 1x
    {100 << 1,        0}, {101 << 1,        0},  //  82: 0000 0000 0011 0x
    {102 << 1,        0}, {103 << 1,        0},  //  83: 0000 0000 0011 1x
    {       0,   0x001f}, {       0,   0x001e},  //  84: 0000 0000 0100 0x
    {       0,   0x001d}, {       0,   0x001c},  //  85: 0000 0000 0100 1x
    {       0,   0x001b}, {       0,   0x001a},  //  86: 0000 0000 0101 0x
    {       0,   0x0019}, {       0,   0x0018},  //  87: 0000 0000 0101 1x
    {       0,   0x0017}, {       0,   0x0016},  //  88: 0000 0000 0110 0x
    {       0,   0x0015}, {       0,   0x0014},  //  89: 0000 0000 0110 1x
    {       0,   0x0013}, {       0,   0x0012},  //  90: 0000 0000 0111 0x
    {       0,   0x0011}, {       0,   0x0010},  //  91: 0000 0000 0111 1x
    {104 << 1,        0}, {105 << 1,        0},  //  92: 0000 0000 0001 00x
    {106 << 1,        0}, {107 << 1,        0},  //  93: 0000 0000 0001 01x
    {108 << 1,        0}, {109 << 1,        0},  //  94: 0000 0000 0001 10x
    {110 << 1,        0}, {111 << 1,        0},  //  95: 0000 0000 0001 11x
    {       0,   0x0028}, {       0,   0x0027},  //  96: 0000 0000 0010 00x
    {       0,   0x0026}, {       0,   0x0025},  //  97: 0000 0000 0010 01x
    {       0,   0x0024}, {       0,   0x0023},  //  98: 0000 0000 0010 10x
    {       0,   0x0022}, {       0,   0x0021},  //  99: 0000 0000 0010 11x
    {       0,   0x0020}, {       0,   0x010e},  // 100: 0000 0000 0011 00x
    {       0,   0x010d}, {       0,   0x010c},  // 101: 0000 0000 0011 01x
    {       0,   0x010b}, {       0,   0x010a},  // 102: 0000 0000 0011 10x
    {       0,   0x0109}, {       0,   0x0108},  // 103: 0000 0000 0011 11x
    {       0,   0x0112}, {       0,   0x0111},  // 104: 0000 0000 0001 000x
    {       0,   0x0110}, {       0,   0x010f},  // 105: 0000 0000 0001 001x
    {       0,   0x0603}, {       0,   0x1002},  // 106: 0000 0000 0001 010x
    {       0,   0x0f02}, {       0,   0x0e02},  // 107: 0000 0000 0001 011x
    {       0,   0x0d02}, {       0,   0x0c02},  // 108: 0000 0000 0001 100x
    {       0,   0x0b02}, {       0,   0x1f01},  // 109: 0000 0000 0001 101x
    {       0,   0x1e01}, {       0,   0x1d01},  // 110: 0000 0000 0001 110x
    {       0,   0x1c01}, {       0,   0x1b01},  // 111: 0000 0000 0001 111x
};
 
typedef struct {
    int full_px;
    int is_set;
    int r_size;
    int h;
    int v;
} plm_video_motion_t;
 
struct plm_video_t {
    double framerate;
    double pixel_aspect_ratio;
    double time;
    int frames_decoded;
    int width;
    int height;
    int mb_width;
    int mb_height;
    int mb_size;
 
    int luma_width;
    int luma_height;
 
    int chroma_width;
    int chroma_height;
 
    int start_code;
    int picture_type;
 
    plm_video_motion_t motion_forward;
    plm_video_motion_t motion_backward;
 
    int has_sequence_header;
 
    int quantizer_scale;
    int slice_begin;
    int macroblock_address;
 
    int mb_row;
    int mb_col;
 
    int macroblock_type;
    int macroblock_intra;
 
    int dc_predictor[3];
 
    plm_buffer_t *buffer;
    int destroy_buffer_when_done;
 
    plm_frame_t frame_current;
    plm_frame_t frame_forward;
    plm_frame_t frame_backward;
 
    uint8_t *frames_data;
 
    int block_data[64];
    uint8_t intra_quant_matrix[64];
    uint8_t non_intra_quant_matrix[64];
 
    int has_reference_frame;
    int assume_no_b_frames;
};
 
static inline uint8_t plm_clamp(int n) FL_NOEXCEPT {
    if (n > 255) {
        n = 255;
    }
    else if (n < 0) {
        n = 0;
    }
    return n;
}
 
int plm_video_decode_sequence_header(plm_video_t *self) FL_NOEXCEPT;
void plm_video_init_frame(plm_video_t *self, plm_frame_t *frame, uint8_t *base) FL_NOEXCEPT;
void plm_video_decode_picture(plm_video_t *self) FL_NOEXCEPT;
void plm_video_decode_slice(plm_video_t *self, int slice) FL_NOEXCEPT;
void plm_video_decode_macroblock(plm_video_t *self) FL_NOEXCEPT;
void plm_video_decode_motion_vectors(plm_video_t *self) FL_NOEXCEPT;
int plm_video_decode_motion_vector(plm_video_t *self, int r_size, int motion) FL_NOEXCEPT;
void plm_video_predict_macroblock(plm_video_t *self) FL_NOEXCEPT;
void plm_video_copy_macroblock(plm_video_t *self, plm_frame_t *s, int motion_h, int motion_v) FL_NOEXCEPT;
void plm_video_interpolate_macroblock(plm_video_t *self, plm_frame_t *s, int motion_h, int motion_v) FL_NOEXCEPT;
void plm_video_process_macroblock(plm_video_t *self, uint8_t *s, uint8_t *d, int mh, int mb, int bs, int interp) FL_NOEXCEPT;
void plm_video_decode_block(plm_video_t *self, int block) FL_NOEXCEPT;
void plm_video_idct(int *block) FL_NOEXCEPT;
 
plm_video_t * plm_video_create_with_buffer(plm_buffer_t *buffer, int destroy_when_done) FL_NOEXCEPT {
    plm_video_t *self = (plm_video_t *)PLM_MALLOC(sizeof(plm_video_t));
    fl::memset(self, 0, sizeof(plm_video_t));
    
    self->buffer = buffer;
    self->destroy_buffer_when_done = destroy_when_done;
 
    // Attempt to decode the sequence header
    self->start_code = plm_buffer_find_start_code(self->buffer, PLM_START_SEQUENCE);
    if (self->start_code != -1) {
        plm_video_decode_sequence_header(self);
    }
    return self;
}
 
void plm_video_destroy(plm_video_t *self) FL_NOEXCEPT {
    if (self->destroy_buffer_when_done) {
        plm_buffer_destroy(self->buffer);
    }
 
    if (self->has_sequence_header) {
        PLM_FREE(self->frames_data);
    }
 
    PLM_FREE(self);
}
 
double plm_video_get_framerate(plm_video_t *self) FL_NOEXCEPT {
    return plm_video_has_header(self)
        ? self->framerate
        : 0;
}
 
double plm_video_get_pixel_aspect_ratio(plm_video_t *self) FL_NOEXCEPT {
    return plm_video_has_header(self)
        ? self->pixel_aspect_ratio
        : 0;
}
 
int plm_video_get_width(plm_video_t *self) FL_NOEXCEPT {
    return plm_video_has_header(self)
        ? self->width
        : 0;
}
 
int plm_video_get_height(plm_video_t *self) FL_NOEXCEPT {
    return plm_video_has_header(self)
        ? self->height
        : 0;
}
 
void plm_video_set_no_delay(plm_video_t *self, int no_delay) FL_NOEXCEPT {
    self->assume_no_b_frames = no_delay;
}
 
double plm_video_get_time(plm_video_t *self) FL_NOEXCEPT {
    return self->time;
}
 
void plm_video_set_time(plm_video_t *self, double time) FL_NOEXCEPT {
    self->frames_decoded = self->framerate * time;
    self->time = time;
}
 
void plm_video_rewind(plm_video_t *self) FL_NOEXCEPT {
    plm_buffer_rewind(self->buffer);
    self->time = 0;
    self->frames_decoded = 0;
    self->has_reference_frame = FALSE;
    self->start_code = -1;
}
 
int plm_video_has_ended(plm_video_t *self) FL_NOEXCEPT {
    return plm_buffer_has_ended(self->buffer);
}
 
plm_frame_t *plm_video_decode(plm_video_t *self) FL_NOEXCEPT {
    if (!plm_video_has_header(self)) {
        return NULL;
    }
    
    plm_frame_t *frame = NULL;
    do {
        if (self->start_code != PLM_START_PICTURE) {
            self->start_code = plm_buffer_find_start_code(self->buffer, PLM_START_PICTURE);
            
            if (self->start_code == -1) {
                // If we reached the end of the file and the previously decoded
                // frame was a reference frame, we still have to return it.
                if (
                    self->has_reference_frame &&
                    !self->assume_no_b_frames &&
                    plm_buffer_has_ended(self->buffer) && (
                        self->picture_type == PLM_VIDEO_PICTURE_TYPE_INTRA ||
                        self->picture_type == PLM_VIDEO_PICTURE_TYPE_PREDICTIVE
                    )
                ) {
                    self->has_reference_frame = FALSE;
                    frame = &self->frame_backward;
                    break;
                }
 
                return NULL;
            }
        }
 
        // Make sure we have a full picture in the buffer before attempting to
        // decode it. Sadly, this can only be done by seeking for the start code
        // of the next picture. Also, if we didn't find the start code for the
        // next picture, but the source has ended, we assume that this last
        // picture is in the buffer.
        if (
            plm_buffer_has_start_code(self->buffer, PLM_START_PICTURE) == -1 &&
            !plm_buffer_has_ended(self->buffer)
        ) {
            return NULL;
        }
        plm_buffer_discard_read_bytes(self->buffer);
        
        plm_video_decode_picture(self);
 
        if (self->assume_no_b_frames) {
            frame = &self->frame_backward;
        }
        else if (self->picture_type == PLM_VIDEO_PICTURE_TYPE_B) {
            frame = &self->frame_current;
        }
        else if (self->has_reference_frame) {
            frame = &self->frame_forward;
        }
        else {
            self->has_reference_frame = TRUE;
        }
    } while (!frame);
    
    frame->time = self->time;
    self->frames_decoded++;
    self->time = (double)self->frames_decoded / self->framerate;
    
    return frame;
}
 
int plm_video_has_header(plm_video_t *self) FL_NOEXCEPT {
    if (self->has_sequence_header) {
        return TRUE;
    }
 
    if (self->start_code != PLM_START_SEQUENCE) {
        self->start_code = plm_buffer_find_start_code(self->buffer, PLM_START_SEQUENCE);
    }
    if (self->start_code == -1) {
        return FALSE;
    }
    
    if (!plm_video_decode_sequence_header(self)) {
        return FALSE;
    }
 
    return TRUE;
}
 
int plm_video_decode_sequence_header(plm_video_t *self) FL_NOEXCEPT {
    int max_header_size = 64 + 2 * 64 * 8; // 64 bit header + 2x 64 byte matrix
    if (!plm_buffer_has(self->buffer, max_header_size)) {
        return FALSE;
    }
 
    self->width = plm_buffer_read(self->buffer, 12);
    self->height = plm_buffer_read(self->buffer, 12);
 
    if (self->width <= 0 || self->height <= 0) {
        return FALSE;
    }
 
    // Get pixel aspect ratio
    int pixel_aspect_ratio_code;
    pixel_aspect_ratio_code = plm_buffer_read(self->buffer, 4);
    pixel_aspect_ratio_code -= 1;
    if (pixel_aspect_ratio_code < 0) {
        pixel_aspect_ratio_code = 0;
    }
    int par_last = (sizeof(PLM_VIDEO_PIXEL_ASPECT_RATIO) /
            sizeof(PLM_VIDEO_PIXEL_ASPECT_RATIO[0]) - 1);
    if (pixel_aspect_ratio_code > par_last) {
        pixel_aspect_ratio_code = par_last;
    }
    self->pixel_aspect_ratio =
        PLM_VIDEO_PIXEL_ASPECT_RATIO[pixel_aspect_ratio_code];
 
    // Get frame rate
    self->framerate = PLM_VIDEO_PICTURE_RATE[plm_buffer_read(self->buffer, 4)];
 
    // Skip bit_rate, marker, buffer_size and constrained bit
    plm_buffer_skip(self->buffer, 18 + 1 + 10 + 1);
 
    // Load custom intra quant matrix?
    if (plm_buffer_read(self->buffer, 1)) { 
        for (int i = 0; i < 64; i++) {
            int idx = PLM_VIDEO_ZIG_ZAG[i];
            self->intra_quant_matrix[idx] = plm_buffer_read(self->buffer, 8);
        }
    }
    else {
        fl::memcopy(self->intra_quant_matrix, PLM_VIDEO_INTRA_QUANT_MATRIX, 64);
    }
 
    // Load custom non intra quant matrix?
    if (plm_buffer_read(self->buffer, 1)) { 
        for (int i = 0; i < 64; i++) {
            int idx = PLM_VIDEO_ZIG_ZAG[i];
            self->non_intra_quant_matrix[idx] = plm_buffer_read(self->buffer, 8);
        }
    }
    else {
        fl::memcopy(self->non_intra_quant_matrix, PLM_VIDEO_NON_INTRA_QUANT_MATRIX, 64);
    }
 
    self->mb_width = (self->width + 15) >> 4;
    self->mb_height = (self->height + 15) >> 4;
    self->mb_size = self->mb_width * self->mb_height;
 
    self->luma_width = self->mb_width << 4;
    self->luma_height = self->mb_height << 4;
 
    self->chroma_width = self->mb_width << 3;
    self->chroma_height = self->mb_height << 3;
 
 
    // Allocate one big chunk of data for all 3 frames = 9 planes
    size_t luma_plane_size = self->luma_width * self->luma_height;
    size_t chroma_plane_size = self->chroma_width * self->chroma_height;
    size_t frame_data_size = (luma_plane_size + 2 * chroma_plane_size);
 
    self->frames_data = (uint8_t*)PLM_MALLOC(frame_data_size * 3);
    plm_video_init_frame(self, &self->frame_current, self->frames_data + frame_data_size * 0);
    plm_video_init_frame(self, &self->frame_forward, self->frames_data + frame_data_size * 1);
    plm_video_init_frame(self, &self->frame_backward, self->frames_data + frame_data_size * 2);
 
    self->has_sequence_header = TRUE;
    return TRUE;
}
 
void plm_video_init_frame(plm_video_t *self, plm_frame_t *frame, uint8_t *base) FL_NOEXCEPT {
    size_t luma_plane_size = self->luma_width * self->luma_height;
    size_t chroma_plane_size = self->chroma_width * self->chroma_height;
 
    frame->width = self->width;
    frame->height = self->height;
    frame->y.width = self->luma_width;
    frame->y.height = self->luma_height;
    frame->y.data = base;
 
    frame->cr.width = self->chroma_width;
    frame->cr.height = self->chroma_height;
    frame->cr.data = base + luma_plane_size;
 
    frame->cb.width = self->chroma_width;
    frame->cb.height = self->chroma_height;
    frame->cb.data = base + luma_plane_size + chroma_plane_size;
}
 
void plm_video_decode_picture(plm_video_t *self) FL_NOEXCEPT {
    plm_buffer_skip(self->buffer, 10); // skip temporalReference
    self->picture_type = plm_buffer_read(self->buffer, 3);
    plm_buffer_skip(self->buffer, 16); // skip vbv_delay
 
    // D frames or unknown coding type
    if (self->picture_type <= 0 || self->picture_type > PLM_VIDEO_PICTURE_TYPE_B) {
        return;
    }
 
    // Forward full_px, f_code
    if (
        self->picture_type == PLM_VIDEO_PICTURE_TYPE_PREDICTIVE ||
        self->picture_type == PLM_VIDEO_PICTURE_TYPE_B
    ) {
        self->motion_forward.full_px = plm_buffer_read(self->buffer, 1);
        int f_code = plm_buffer_read(self->buffer, 3);
        if (f_code == 0) {
            // Ignore picture with zero f_code
            return;
        }
        self->motion_forward.r_size = f_code - 1;
    }
 
    // Backward full_px, f_code
    if (self->picture_type == PLM_VIDEO_PICTURE_TYPE_B) {
        self->motion_backward.full_px = plm_buffer_read(self->buffer, 1);
        int f_code = plm_buffer_read(self->buffer, 3);
        if (f_code == 0) {
            // Ignore picture with zero f_code
            return;
        }
        self->motion_backward.r_size = f_code - 1;
    }
 
    plm_frame_t frame_temp = self->frame_forward;
    if (
        self->picture_type == PLM_VIDEO_PICTURE_TYPE_INTRA ||
        self->picture_type == PLM_VIDEO_PICTURE_TYPE_PREDICTIVE
    ) {
        self->frame_forward = self->frame_backward;
    }
 
 
    // Find first slice start code; skip extension and user data
    do {
        self->start_code = plm_buffer_next_start_code(self->buffer);
    } while (
        self->start_code == PLM_START_EXTENSION || 
        self->start_code == PLM_START_USER_DATA
    );
 
    // Decode all slices
    while (PLM_START_IS_SLICE(self->start_code)) {
        plm_video_decode_slice(self, self->start_code & 0x000000FF);
        if (self->macroblock_address >= self->mb_size - 2) {
            break;
        }
        self->start_code = plm_buffer_next_start_code(self->buffer);
    }
 
    // If this is a reference picture rotate the prediction pointers
    if (
        self->picture_type == PLM_VIDEO_PICTURE_TYPE_INTRA ||
        self->picture_type == PLM_VIDEO_PICTURE_TYPE_PREDICTIVE
    ) {
        self->frame_backward = self->frame_current;
        self->frame_current = frame_temp;
    }
}
 
void plm_video_decode_slice(plm_video_t *self, int slice) FL_NOEXCEPT {
    self->slice_begin = TRUE;
    self->macroblock_address = (slice - 1) * self->mb_width - 1;
 
    // Reset motion vectors and DC predictors
    self->motion_backward.h = self->motion_forward.h = 0;
    self->motion_backward.v = self->motion_forward.v = 0;
    self->dc_predictor[0] = 128;
    self->dc_predictor[1] = 128;
    self->dc_predictor[2] = 128;
 
    self->quantizer_scale = plm_buffer_read(self->buffer, 5);
 
    // Skip extra
    while (plm_buffer_read(self->buffer, 1)) {
        plm_buffer_skip(self->buffer, 8);
    }
 
    do {
        plm_video_decode_macroblock(self);
    } while (
        self->macroblock_address < self->mb_size - 1 &&
        plm_buffer_peek_non_zero(self->buffer, 23)
    );
}
 
void plm_video_decode_macroblock(plm_video_t *self) FL_NOEXCEPT {
    // Decode increment
    int increment = 0;
    int t = plm_buffer_read_vlc(self->buffer, PLM_VIDEO_MACROBLOCK_ADDRESS_INCREMENT);
 
    while (t == 34) {
        // macroblock_stuffing
        t = plm_buffer_read_vlc(self->buffer, PLM_VIDEO_MACROBLOCK_ADDRESS_INCREMENT);
    }
    while (t == 35) {
        // macroblock_escape
        increment += 33;
        t = plm_buffer_read_vlc(self->buffer, PLM_VIDEO_MACROBLOCK_ADDRESS_INCREMENT);
    }
    increment += t;
 
    // Process any skipped macroblocks
    if (self->slice_begin) {
        // The first increment of each slice is relative to beginning of the
        // previous row, not the previous macroblock
        self->slice_begin = FALSE;
        self->macroblock_address += increment;
    }
    else {
        if (self->macroblock_address + increment >= self->mb_size) {
            return; // invalid
        }
        if (increment > 1) {
            // Skipped macroblocks reset DC predictors
            self->dc_predictor[0] = 128;
            self->dc_predictor[1] = 128;
            self->dc_predictor[2] = 128;
 
            // Skipped macroblocks in P-pictures reset motion vectors
            if (self->picture_type == PLM_VIDEO_PICTURE_TYPE_PREDICTIVE) {
                self->motion_forward.h = 0;
                self->motion_forward.v = 0;
            }
        }
 
        // Predict skipped macroblocks
        while (increment > 1) {
            self->macroblock_address++;
            self->mb_row = self->macroblock_address / self->mb_width;
            self->mb_col = self->macroblock_address % self->mb_width;
 
            plm_video_predict_macroblock(self);
            increment--;
        }
        self->macroblock_address++;
    }
 
    self->mb_row = self->macroblock_address / self->mb_width;
    self->mb_col = self->macroblock_address % self->mb_width;
 
    if (self->mb_col >= self->mb_width || self->mb_row >= self->mb_height) {
        return; // corrupt stream;
    }
 
    // Process the current macroblock
    const plm_vlc_t *table = PLM_VIDEO_MACROBLOCK_TYPE[self->picture_type];
    self->macroblock_type = plm_buffer_read_vlc(self->buffer, table);
 
    self->macroblock_intra = (self->macroblock_type & 0x01);
    self->motion_forward.is_set = (self->macroblock_type & 0x08);
    self->motion_backward.is_set = (self->macroblock_type & 0x04);
 
    // Quantizer scale
    if ((self->macroblock_type & 0x10) != 0) {
        self->quantizer_scale = plm_buffer_read(self->buffer, 5);
    }
 
    if (self->macroblock_intra) {
        // Intra-coded macroblocks reset motion vectors
        self->motion_backward.h = self->motion_forward.h = 0;
        self->motion_backward.v = self->motion_forward.v = 0;
    }
    else {
        // Non-intra macroblocks reset DC predictors
        self->dc_predictor[0] = 128;
        self->dc_predictor[1] = 128;
        self->dc_predictor[2] = 128;
 
        plm_video_decode_motion_vectors(self);
        plm_video_predict_macroblock(self);
    }
 
    // Decode blocks
    int cbp = ((self->macroblock_type & 0x02) != 0)
        ? plm_buffer_read_vlc(self->buffer, PLM_VIDEO_CODE_BLOCK_PATTERN)
        : (self->macroblock_intra ? 0x3f : 0);
 
    for (int block = 0, mask = 0x20; block < 6; block++) {
        if ((cbp & mask) != 0) {
            plm_video_decode_block(self, block);
        }
        mask >>= 1;
    }
}
 
void plm_video_decode_motion_vectors(plm_video_t *self) FL_NOEXCEPT {
 
    // Forward
    if (self->motion_forward.is_set) {
        int r_size = self->motion_forward.r_size;
        self->motion_forward.h = plm_video_decode_motion_vector(self, r_size, self->motion_forward.h);
        self->motion_forward.v = plm_video_decode_motion_vector(self, r_size, self->motion_forward.v);
    }
    else if (self->picture_type == PLM_VIDEO_PICTURE_TYPE_PREDICTIVE) {
        // No motion information in P-picture, reset vectors
        self->motion_forward.h = 0;
        self->motion_forward.v = 0;
    }
 
    if (self->motion_backward.is_set) {
        int r_size = self->motion_backward.r_size;
        self->motion_backward.h = plm_video_decode_motion_vector(self, r_size, self->motion_backward.h);
        self->motion_backward.v = plm_video_decode_motion_vector(self, r_size, self->motion_backward.v);
    }
}
 
int plm_video_decode_motion_vector(plm_video_t *self, int r_size, int motion) FL_NOEXCEPT {
    int fscale = 1 << r_size;
    int m_code = plm_buffer_read_vlc(self->buffer, PLM_VIDEO_MOTION);
    int r = 0;
    int d;
 
    if ((m_code != 0) && (fscale != 1)) {
        r = plm_buffer_read(self->buffer, r_size);
        d = ((fl::abs(m_code) - 1) << r_size) + r + 1;
        if (m_code < 0) {
            d = -d;
        }
    }
    else {
        d = m_code;
    }
 
    motion += d;
    if (motion > (fscale << 4) - 1) {
        motion -= fscale << 5;
    }
    else if (motion < (int)((unsigned)(-fscale) << 4)) {
        motion += fscale << 5;
    }
 
    return motion;
}
 
void plm_video_predict_macroblock(plm_video_t *self) FL_NOEXCEPT {
    int fw_h = self->motion_forward.h;
    int fw_v = self->motion_forward.v;
 
    if (self->motion_forward.full_px) {
        fw_h <<= 1;
        fw_v <<= 1;
    }
 
    if (self->picture_type == PLM_VIDEO_PICTURE_TYPE_B) {
        int bw_h = self->motion_backward.h;
        int bw_v = self->motion_backward.v;
 
        if (self->motion_backward.full_px) {
            bw_h <<= 1;
            bw_v <<= 1;
        }
 
        if (self->motion_forward.is_set) {
            plm_video_copy_macroblock(self, &self->frame_forward, fw_h, fw_v);
            if (self->motion_backward.is_set) {
                plm_video_interpolate_macroblock(self, &self->frame_backward, bw_h, bw_v);
            }
        }
        else {
            plm_video_copy_macroblock(self, &self->frame_backward, bw_h, bw_v);
        }
    }
    else {
        plm_video_copy_macroblock(self, &self->frame_forward, fw_h, fw_v);
    }
}
 
void plm_video_copy_macroblock(plm_video_t *self, plm_frame_t *s, int motion_h, int motion_v) FL_NOEXCEPT {
    plm_frame_t *d = &self->frame_current;
    plm_video_process_macroblock(self, s->y.data, d->y.data, motion_h, motion_v, 16, FALSE);
    plm_video_process_macroblock(self, s->cr.data, d->cr.data, motion_h / 2, motion_v / 2, 8, FALSE);
    plm_video_process_macroblock(self, s->cb.data, d->cb.data, motion_h / 2, motion_v / 2, 8, FALSE);
}
 
void plm_video_interpolate_macroblock(plm_video_t *self, plm_frame_t *s, int motion_h, int motion_v) FL_NOEXCEPT {
    plm_frame_t *d = &self->frame_current;
    plm_video_process_macroblock(self, s->y.data, d->y.data, motion_h, motion_v, 16, TRUE);
    plm_video_process_macroblock(self, s->cr.data, d->cr.data, motion_h / 2, motion_v / 2, 8, TRUE);
    plm_video_process_macroblock(self, s->cb.data, d->cb.data, motion_h / 2, motion_v / 2, 8, TRUE);
}
 
#define PLM_BLOCK_SET(DEST, DEST_INDEX, DEST_WIDTH, SOURCE_INDEX, SOURCE_WIDTH, BLOCK_SIZE, OP) do { \
    int dest_scan = DEST_WIDTH - BLOCK_SIZE; \
    int source_scan = SOURCE_WIDTH - BLOCK_SIZE; \
    for (int y = 0; y < BLOCK_SIZE; y++) { \
        for (int x = 0; x < BLOCK_SIZE; x++) { \
            DEST[DEST_INDEX] = OP; \
            SOURCE_INDEX++; DEST_INDEX++; \
        } \
        SOURCE_INDEX += source_scan; \
        DEST_INDEX += dest_scan; \
    }} while(FALSE)
 
void plm_video_process_macroblock(
    plm_video_t *self, uint8_t *s, uint8_t *d,
    int motion_h, int motion_v, int block_size, int interpolate
) FL_NOEXCEPT {
    int dw = self->mb_width * block_size;
 
    int hp = motion_h >> 1;
    int vp = motion_v >> 1;
    int odd_h = (motion_h & 1) == 1;
    int odd_v = (motion_v & 1) == 1;
 
    unsigned int si = ((self->mb_row * block_size) + vp) * dw + (self->mb_col * block_size) + hp;
    unsigned int di = (self->mb_row * dw + self->mb_col) * block_size;
    
    unsigned int max_address = (dw * (self->mb_height * block_size - block_size + 1) - block_size);
    if (si > max_address || di > max_address) {
        return; // corrupt video
    }
 
    #define PLM_MB_CASE(INTERPOLATE, ODD_H, ODD_V, OP) \
        case ((INTERPOLATE << 2) | (ODD_H << 1) | (ODD_V)): \
            PLM_BLOCK_SET(d, di, dw, si, dw, block_size, OP); \
            break
 
    switch ((interpolate << 2) | (odd_h << 1) | (odd_v)) {
        PLM_MB_CASE(0, 0, 0, (s[si]));
        PLM_MB_CASE(0, 0, 1, (s[si] + s[si + dw] + 1) >> 1);
        PLM_MB_CASE(0, 1, 0, (s[si] + s[si + 1] + 1) >> 1);
        PLM_MB_CASE(0, 1, 1, (s[si] + s[si + 1] + s[si + dw] + s[si + dw + 1] + 2) >> 2);
 
        PLM_MB_CASE(1, 0, 0, (d[di] + (s[si]) + 1) >> 1);
        PLM_MB_CASE(1, 0, 1, (d[di] + ((s[si] + s[si + dw] + 1) >> 1) + 1) >> 1);
        PLM_MB_CASE(1, 1, 0, (d[di] + ((s[si] + s[si + 1] + 1) >> 1) + 1) >> 1);
        PLM_MB_CASE(1, 1, 1, (d[di] + ((s[si] + s[si + 1] + s[si + dw] + s[si + dw + 1] + 2) >> 2) + 1) >> 1);
    }
 
    #undef PLM_MB_CASE
}
 
void plm_video_decode_block(plm_video_t *self, int block) FL_NOEXCEPT {
 
    int n = 0;
    uint8_t *quant_matrix;
 
    // Decode DC coefficient of intra-coded blocks
    if (self->macroblock_intra) {
        int predictor;
        int dct_size;
 
        // DC prediction
        int plane_index = block > 3 ? block - 3 : 0;
        predictor = self->dc_predictor[plane_index];
        dct_size = plm_buffer_read_vlc(self->buffer, PLM_VIDEO_DCT_SIZE[plane_index]);
 
        // Read DC coeff
        if (dct_size > 0) {
            int differential = plm_buffer_read(self->buffer, dct_size);
            if ((differential & (1 << (dct_size - 1))) != 0) {
                self->block_data[0] = predictor + differential;
            }
            else {
                self->block_data[0] = predictor + (-(1 << dct_size) | (differential + 1));
            }
        }
        else {
            self->block_data[0] = predictor;
        }
 
        // Save predictor value
        self->dc_predictor[plane_index] = self->block_data[0];
 
        // Dequantize + premultiply
        self->block_data[0] <<= (3 + 5);
 
        quant_matrix = self->intra_quant_matrix;
        n = 1;
    }
    else {
        quant_matrix = self->non_intra_quant_matrix;
    }
 
    // Decode AC coefficients (+DC for non-intra)
    int level = 0;
    while (TRUE) {
        int run = 0;
        uint16_t coeff = plm_buffer_read_vlc_uint(self->buffer, PLM_VIDEO_DCT_COEFF);
 
        if ((coeff == 0x0001) && (n > 0) && (plm_buffer_read(self->buffer, 1) == 0)) {
            // end_of_block
            break;
        }
        if (coeff == 0xffff) {
            // escape
            run = plm_buffer_read(self->buffer, 6);
            level = plm_buffer_read(self->buffer, 8);
            if (level == 0) {
                level = plm_buffer_read(self->buffer, 8);
            }
            else if (level == 128) {
                level = plm_buffer_read(self->buffer, 8) - 256;
            }
            else if (level > 128) {
                level = level - 256;
            }
        }
        else {
            run = coeff >> 8;
            level = coeff & 0xff;
            if (plm_buffer_read(self->buffer, 1)) {
                level = -level;
            }
        }
 
        n += run;
        if (n < 0 || n >= 64) {
            return; // invalid
        }
 
        int de_zig_zagged = PLM_VIDEO_ZIG_ZAG[n];
        n++;
 
        // Dequantize, oddify, clip
        level = (unsigned)level << 1;
        if (!self->macroblock_intra) {
            level += (level < 0 ? -1 : 1);
        }
        level = (level * self->quantizer_scale * quant_matrix[de_zig_zagged]) >> 4;
        if ((level & 1) == 0) {
            level -= level > 0 ? 1 : -1;
        }
        if (level > 2047) {
            level = 2047;
        }
        else if (level < -2048) {
            level = -2048;
        }
 
        // Save premultiplied coefficient
        self->block_data[de_zig_zagged] = level * PLM_VIDEO_PREMULTIPLIER_MATRIX[de_zig_zagged];
    }
 
    // Move block to its place
    uint8_t *d;
    int dw;
    int di;
 
    if (block < 4) {
        d = self->frame_current.y.data;
        dw = self->luma_width;
        di = (self->mb_row * self->luma_width + self->mb_col) << 4;
        if ((block & 1) != 0) {
            di += 8;
        }
        if ((block & 2) != 0) {
            di += self->luma_width << 3;
        }
    }
    else {
        d = (block == 4) ? self->frame_current.cb.data : self->frame_current.cr.data;
        dw = self->chroma_width;
        di = ((self->mb_row * self->luma_width) << 2) + (self->mb_col << 3);
    }
 
    int *s = self->block_data;
    int si = 0;
    if (self->macroblock_intra) {
        // Overwrite (no prediction)
        if (n == 1) {
            int clamped = plm_clamp((s[0] + 128) >> 8);
            PLM_BLOCK_SET(d, di, dw, si, 8, 8, clamped);
            s[0] = 0;
        }
        else {
            plm_video_idct(s);
            PLM_BLOCK_SET(d, di, dw, si, 8, 8, plm_clamp(s[si]));
            fl::memset(self->block_data, 0, sizeof(self->block_data));
        }
    }
    else {
        // Add data to the predicted macroblock
        if (n == 1) {
            int value = (s[0] + 128) >> 8;
            PLM_BLOCK_SET(d, di, dw, si, 8, 8, plm_clamp(d[di] + value));
            s[0] = 0;
        }
        else {
            plm_video_idct(s);
            PLM_BLOCK_SET(d, di, dw, si, 8, 8, plm_clamp(d[di] + s[si]));
            fl::memset(self->block_data, 0, sizeof(self->block_data));
        }
    }
}
 
void plm_video_idct(int *block) FL_NOEXCEPT {
    int
        b1, b3, b4, b6, b7, tmp1, tmp2, m0,
        x0, x1, x2, x3, x4, y3, y4, y5, y6, y7;
 
    // Transform columns
    for (int i = 0; i < 8; ++i) {
        b1 = block[4 * 8 + i];
        b3 = block[2 * 8 + i] + block[6 * 8 + i];
        b4 = block[5 * 8 + i] - block[3 * 8 + i];
        tmp1 = block[1 * 8 + i] + block[7 * 8 + i];
        tmp2 = block[3 * 8 + i] + block[5 * 8 + i];
        b6 = block[1 * 8 + i] - block[7 * 8 + i];
        b7 = tmp1 + tmp2;
        m0 = block[0 * 8 + i];
        x4 = ((b6 * 473 - b4 * 196 + 128) >> 8) - b7;
        x0 = x4 - (((tmp1 - tmp2) * 362 + 128) >> 8);
        x1 = m0 - b1;
        x2 = (((block[2 * 8 + i] - block[6 * 8 + i]) * 362 + 128) >> 8) - b3;
        x3 = m0 + b1;
        y3 = x1 + x2;
        y4 = x3 + b3;
        y5 = x1 - x2;
        y6 = x3 - b3;
        y7 = -x0 - ((b4 * 473 + b6 * 196 + 128) >> 8);
        block[0 * 8 + i] = b7 + y4;
        block[1 * 8 + i] = x4 + y3;
        block[2 * 8 + i] = y5 - x0;
        block[3 * 8 + i] = y6 - y7;
        block[4 * 8 + i] = y6 + y7;
        block[5 * 8 + i] = x0 + y5;
        block[6 * 8 + i] = y3 - x4;
        block[7 * 8 + i] = y4 - b7;
    }
 
    // Transform rows
    for (int i = 0; i < 64; i += 8) {
        b1 = block[4 + i];
        b3 = block[2 + i] + block[6 + i];
        b4 = block[5 + i] - block[3 + i];
        tmp1 = block[1 + i] + block[7 + i];
        tmp2 = block[3 + i] + block[5 + i];
        b6 = block[1 + i] - block[7 + i];
        b7 = tmp1 + tmp2;
        m0 = block[0 + i];
        x4 = ((b6 * 473 - b4 * 196 + 128) >> 8) - b7;
        x0 = x4 - (((tmp1 - tmp2) * 362 + 128) >> 8);
        x1 = m0 - b1;
        x2 = (((block[2 + i] - block[6 + i]) * 362 + 128) >> 8) - b3;
        x3 = m0 + b1;
        y3 = x1 + x2;
        y4 = x3 + b3;
        y5 = x1 - x2;
        y6 = x3 - b3;
        y7 = -x0 - ((b4 * 473 + b6 * 196 + 128) >> 8);
        block[0 + i] = (b7 + y4 + 128) >> 8;
        block[1 + i] = (x4 + y3 + 128) >> 8;
        block[2 + i] = (y5 - x0 + 128) >> 8;
        block[3 + i] = (y6 - y7 + 128) >> 8;
        block[4 + i] = (y6 + y7 + 128) >> 8;
        block[5 + i] = (x0 + y5 + 128) >> 8;
        block[6 + i] = (y3 - x4 + 128) >> 8;
        block[7 + i] = (y4 - b7 + 128) >> 8;
    }
}
 
// YCbCr conversion following the BT.601 standard:
// https://infogalactic.com/info/YCbCr#ITU-R_BT.601_conversion
 
#define PLM_PUT_PIXEL(RI, GI, BI, Y_OFFSET, DEST_OFFSET) \
    y = ((frame->y.data[y_index + Y_OFFSET]-16) * 76309) >> 16; \
    dest[d_index + DEST_OFFSET + RI] = plm_clamp(y + r); \
    dest[d_index + DEST_OFFSET + GI] = plm_clamp(y - g); \
    dest[d_index + DEST_OFFSET + BI] = plm_clamp(y + b);
 
#define PLM_DEFINE_FRAME_CONVERT_FUNCTION(NAME, BYTES_PER_PIXEL, RI, GI, BI) \
    void NAME(plm_frame_t *frame, uint8_t *dest, int stride) { \
        int cols = frame->width >> 1; \
        int rows = frame->height >> 1; \
        int yw = frame->y.width; \
        int cw = frame->cb.width; \
        for (int row = 0; row < rows; row++) { \
            int c_index = row * cw; \
            int y_index = row * 2 * yw; \
            int d_index = row * 2 * stride; \
            for (int col = 0; col < cols; col++) { \
                int y; \
                int cr = frame->cr.data[c_index] - 128; \
                int cb = frame->cb.data[c_index] - 128; \
                int r = (cr * 104597) >> 16; \
                int g = (cb * 25674 + cr * 53278) >> 16; \
                int b = (cb * 132201) >> 16; \
                PLM_PUT_PIXEL(RI, GI, BI, 0,      0); \
                PLM_PUT_PIXEL(RI, GI, BI, 1,      BYTES_PER_PIXEL); \
                PLM_PUT_PIXEL(RI, GI, BI, yw,     stride); \
                PLM_PUT_PIXEL(RI, GI, BI, yw + 1, stride + BYTES_PER_PIXEL); \
                c_index += 1; \
                y_index += 2; \
                d_index += 2 * BYTES_PER_PIXEL; \
            } \
        } \
    }
 
PLM_DEFINE_FRAME_CONVERT_FUNCTION(plm_frame_to_rgb,  3, 0, 1, 2)
PLM_DEFINE_FRAME_CONVERT_FUNCTION(plm_frame_to_bgr,  3, 2, 1, 0)
PLM_DEFINE_FRAME_CONVERT_FUNCTION(plm_frame_to_rgba, 4, 0, 1, 2)
PLM_DEFINE_FRAME_CONVERT_FUNCTION(plm_frame_to_bgra, 4, 2, 1, 0)
PLM_DEFINE_FRAME_CONVERT_FUNCTION(plm_frame_to_argb, 4, 1, 2, 3)
PLM_DEFINE_FRAME_CONVERT_FUNCTION(plm_frame_to_abgr, 4, 3, 2, 1)
 
 
#undef PLM_PUT_PIXEL
#undef PLM_DEFINE_FRAME_CONVERT_FUNCTION
 
 
 
// -----------------------------------------------------------------------------
// plm_audio implementation
 
// Based on kjmp2 by Martin J. Fiedler
// http://keyj.emphy.de/kjmp2/
 
static const int PLM_AUDIO_FRAME_SYNC = 0x7ff;
 
static const int PLM_AUDIO_MPEG_2_5 = 0x0;
static const int PLM_AUDIO_MPEG_2 = 0x2;
static const int PLM_AUDIO_MPEG_1 = 0x3;
 
static const int PLM_AUDIO_LAYER_III = 0x1;
static const int PLM_AUDIO_LAYER_II = 0x2;
static const int PLM_AUDIO_LAYER_I = 0x3;
 
static const int PLM_AUDIO_MODE_STEREO = 0x0;
static const int PLM_AUDIO_MODE_JOINT_STEREO = 0x1;
static const int PLM_AUDIO_MODE_DUAL_CHANNEL = 0x2;
static const int PLM_AUDIO_MODE_MONO = 0x3;
 
static const unsigned short PLM_AUDIO_SAMPLE_RATE[] = {
    44100, 48000, 32000, 0, // MPEG-1
    22050, 24000, 16000, 0  // MPEG-2
};
 
static const short PLM_AUDIO_BIT_RATE[] = {
    32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384, // MPEG-1
     8, 16, 24, 32, 40, 48,  56,  64,  80,  96, 112, 128, 144, 160  // MPEG-2
};
 
static const int32_t PLM_AUDIO_SCALEFACTOR_BASE[] = {
    0x02000000, 0x01965FEA, 0x01428A30
};
 
static const float PLM_AUDIO_SYNTHESIS_WINDOW[] = {
         0.0,     -0.5,     -0.5,     -0.5,     -0.5,     -0.5,
        -0.5,     -1.0,     -1.0,     -1.0,     -1.0,     -1.5,
        -1.5,     -2.0,     -2.0,     -2.5,     -2.5,     -3.0,
        -3.5,     -3.5,     -4.0,     -4.5,     -5.0,     -5.5,
        -6.5,     -7.0,     -8.0,     -8.5,     -9.5,    -10.5,
       -12.0,    -13.0,    -14.5,    -15.5,    -17.5,    -19.0,
       -20.5,    -22.5,    -24.5,    -26.5,    -29.0,    -31.5,
       -34.0,    -36.5,    -39.5,    -42.5,    -45.5,    -48.5,
       -52.0,    -55.5,    -58.5,    -62.5,    -66.0,    -69.5,
       -73.5,    -77.0,    -80.5,    -84.5,    -88.0,    -91.5,
       -95.0,    -98.0,   -101.0,   -104.0,    106.5,    109.0,
       111.0,    112.5,    113.5,    114.0,    114.0,    113.5,
       112.0,    110.5,    107.5,    104.0,    100.0,     94.5,
        88.5,     81.5,     73.0,     63.5,     53.0,     41.5,
        28.5,     14.5,     -1.0,    -18.0,    -36.0,    -55.5,
       -76.5,    -98.5,   -122.0,   -147.0,   -173.5,   -200.5,
      -229.5,   -259.5,   -290.5,   -322.5,   -355.5,   -389.5,
      -424.0,   -459.5,   -495.5,   -532.0,   -568.5,   -605.0,
      -641.5,   -678.0,   -714.0,   -749.0,   -783.5,   -817.0,
      -849.0,   -879.5,   -908.5,   -935.0,   -959.5,   -981.0,
     -1000.5,  -1016.0,  -1028.5,  -1037.5,  -1042.5,  -1043.5,
     -1040.0,  -1031.5,   1018.5,   1000.0,    976.0,    946.5,
       911.0,    869.5,    822.0,    767.5,    707.0,    640.0,
       565.5,    485.0,    397.0,    302.5,    201.0,     92.5,
       -22.5,   -144.0,   -272.5,   -407.0,   -547.5,   -694.0,
      -846.0,  -1003.0,  -1165.0,  -1331.5,  -1502.0,  -1675.5,
     -1852.5,  -2031.5,  -2212.5,  -2394.0,  -2576.5,  -2758.5,
     -2939.5,  -3118.5,  -3294.5,  -3467.5,  -3635.5,  -3798.5,
     -3955.0,  -4104.5,  -4245.5,  -4377.5,  -4499.0,  -4609.5,
     -4708.0,  -4792.5,  -4863.5,  -4919.0,  -4958.0,  -4979.5,
     -4983.0,  -4967.5,  -4931.5,  -4875.0,  -4796.0,  -4694.5,
     -4569.5,  -4420.0,  -4246.0,  -4046.0,  -3820.0,  -3567.0,
      3287.0,   2979.5,   2644.0,   2280.5,   1888.0,   1467.5,
      1018.5,    541.0,     35.0,   -499.0,  -1061.0,  -1650.0,
     -2266.5,  -2909.0,  -3577.0,  -4270.0,  -4987.5,  -5727.5,
     -6490.0,  -7274.0,  -8077.5,  -8899.5,  -9739.0, -10594.5,
    -11464.5, -12347.0, -13241.0, -14144.5, -15056.0, -15973.5,
    -16895.5, -17820.0, -18744.5, -19668.0, -20588.0, -21503.0,
    -22410.5, -23308.5, -24195.0, -25068.5, -25926.5, -26767.0,
    -27589.0, -28389.0, -29166.5, -29919.0, -30644.5, -31342.0,
    -32009.5, -32645.0, -33247.0, -33814.5, -34346.0, -34839.5,
    -35295.0, -35710.0, -36084.5, -36417.5, -36707.5, -36954.0,
    -37156.5, -37315.0, -37428.0, -37496.0,  37519.0,  37496.0,
     37428.0,  37315.0,  37156.5,  36954.0,  36707.5,  36417.5,
     36084.5,  35710.0,  35295.0,  34839.5,  34346.0,  33814.5,
     33247.0,  32645.0,  32009.5,  31342.0,  30644.5,  29919.0,
     29166.5,  28389.0,  27589.0,  26767.0,  25926.5,  25068.5,
     24195.0,  23308.5,  22410.5,  21503.0,  20588.0,  19668.0,
     18744.5,  17820.0,  16895.5,  15973.5,  15056.0,  14144.5,
     13241.0,  12347.0,  11464.5,  10594.5,   9739.0,   8899.5,
      8077.5,   7274.0,   6490.0,   5727.5,   4987.5,   4270.0,
      3577.0,   2909.0,   2266.5,   1650.0,   1061.0,    499.0,
       -35.0,   -541.0,  -1018.5,  -1467.5,  -1888.0,  -2280.5,
     -2644.0,  -2979.5,   3287.0,   3567.0,   3820.0,   4046.0,
      4246.0,   4420.0,   4569.5,   4694.5,   4796.0,   4875.0,
      4931.5,   4967.5,   4983.0,   4979.5,   4958.0,   4919.0,
      4863.5,   4792.5,   4708.0,   4609.5,   4499.0,   4377.5,
      4245.5,   4104.5,   3955.0,   3798.5,   3635.5,   3467.5,
      3294.5,   3118.5,   2939.5,   2758.5,   2576.5,   2394.0,
      2212.5,   2031.5,   1852.5,   1675.5,   1502.0,   1331.5,
      1165.0,   1003.0,    846.0,    694.0,    547.5,    407.0,
       272.5,    144.0,     22.5,    -92.5,   -201.0,   -302.5,
      -397.0,   -485.0,   -565.5,   -640.0,   -707.0,   -767.5,
      -822.0,   -869.5,   -911.0,   -946.5,   -976.0,  -1000.0,
      1018.5,   1031.5,   1040.0,   1043.5,   1042.5,   1037.5,
      1028.5,   1016.0,   1000.5,    981.0,    959.5,    935.0,
       908.5,    879.5,    849.0,    817.0,    783.5,    749.0,
       714.0,    678.0,    641.5,    605.0,    568.5,    532.0,
       495.5,    459.5,    424.0,    389.5,    355.5,    322.5,
       290.5,    259.5,    229.5,    200.5,    173.5,    147.0,
       122.0,     98.5,     76.5,     55.5,     36.0,     18.0,
         1.0,    -14.5,    -28.5,    -41.5,    -53.0,    -63.5,
       -73.0,    -81.5,    -88.5,    -94.5,   -100.0,   -104.0,
      -107.5,   -110.5,   -112.0,   -113.5,   -114.0,   -114.0,
      -113.5,   -112.5,   -111.0,   -109.0,    106.5,    104.0,
       101.0,     98.0,     95.0,     91.5,     88.0,     84.5,
        80.5,     77.0,     73.5,     69.5,     66.0,     62.5,
        58.5,     55.5,     52.0,     48.5,     45.5,     42.5,
        39.5,     36.5,     34.0,     31.5,     29.0,     26.5,
        24.5,     22.5,     20.5,     19.0,     17.5,     15.5,
        14.5,     13.0,     12.0,     10.5,      9.5,      8.5,
         8.0,      7.0,      6.5,      5.5,      5.0,      4.5,
         4.0,      3.5,      3.5,      3.0,      2.5,      2.5,
         2.0,      2.0,      1.5,      1.5,      1.0,      1.0,
         1.0,      1.0,      0.5,      0.5,      0.5,      0.5,
         0.5,      0.5
};
 
// Quantizer lookup, step 1: bitrate classes
static const uint8_t PLM_AUDIO_QUANT_LUT_STEP_1[2][16] = {
    // 32, 48, 56, 64, 80, 96,112,128,160,192,224,256,320,384 <- bitrate
    { 0,  0,  1,  1,  1,  2,  2,  2,  2,  2,  2,  2,  2,  2 }, // mono
    // 16, 24, 28, 32, 40, 48, 56, 64, 80, 96,112,128,160,192 <- bitrate / chan
    { 0,  0,  0,  0,  0,  0,  1,  1,  1,  2,  2,  2,  2,  2 } // stereo
};
 
// Quantizer lookup, step 2: bitrate class, sample rate -> B2 table idx, sblimit
#define PLM_AUDIO_QUANT_TAB_A (27 | 64)   // Table 3-B.2a: high-rate, sblimit = 27
#define PLM_AUDIO_QUANT_TAB_B (30 | 64)   // Table 3-B.2b: high-rate, sblimit = 30
#define PLM_AUDIO_QUANT_TAB_C 8           // Table 3-B.2c:  low-rate, sblimit =  8
#define PLM_AUDIO_QUANT_TAB_D 12          // Table 3-B.2d:  low-rate, sblimit = 12
 
static const uint8_t QUANT_LUT_STEP_2[3][3] = {
    //44.1 kHz,              48 kHz,                32 kHz
    { PLM_AUDIO_QUANT_TAB_C, PLM_AUDIO_QUANT_TAB_C, PLM_AUDIO_QUANT_TAB_D }, // 32 - 48 kbit/sec/ch
    { PLM_AUDIO_QUANT_TAB_A, PLM_AUDIO_QUANT_TAB_A, PLM_AUDIO_QUANT_TAB_A }, // 56 - 80 kbit/sec/ch
    { PLM_AUDIO_QUANT_TAB_B, PLM_AUDIO_QUANT_TAB_A, PLM_AUDIO_QUANT_TAB_B }  // 96+   kbit/sec/ch
};
 
// Quantizer lookup, step 3: B2 table, subband -> nbal, row index
// (upper 4 bits: nbal, lower 4 bits: row index)
static const uint8_t PLM_AUDIO_QUANT_LUT_STEP_3[3][32] = {
    // Low-rate table (3-B.2c and 3-B.2d)
    {
        0x44,0x44,
        0x34,0x34,0x34,0x34,0x34,0x34,0x34,0x34,0x34,0x34
    },
    // High-rate table (3-B.2a and 3-B.2b)
    {
        0x43,0x43,0x43,
        0x42,0x42,0x42,0x42,0x42,0x42,0x42,0x42,
        0x31,0x31,0x31,0x31,0x31,0x31,0x31,0x31,0x31,0x31,0x31,0x31,
        0x20,0x20,0x20,0x20,0x20,0x20,0x20
    },
    // MPEG-2 LSR table (B.2 in ISO 13818-3)
    {
        0x45,0x45,0x45,0x45,
        0x34,0x34,0x34,0x34,0x34,0x34,0x34,
        0x24,0x24,0x24,0x24,0x24,0x24,0x24,0x24,0x24,0x24,
        0x24,0x24,0x24,0x24,0x24,0x24,0x24,0x24,0x24
    }
};
 
// Quantizer lookup, step 4: table row, allocation[] value -> quant table index
static const uint8_t PLM_AUDIO_QUANT_LUT_STEP_4[6][16] = {
    { 0, 1, 2, 17 },
    { 0, 1, 2,  3, 4, 5, 6, 17 },
    { 0, 1, 2,  3, 4, 5, 6,  7,  8,  9, 10, 11, 12, 13, 14, 17 },
    { 0, 1, 3,  5, 6, 7, 8,  9, 10, 11, 12, 13, 14, 15, 16, 17 },
    { 0, 1, 2,  4, 5, 6, 7,  8,  9, 10, 11, 12, 13, 14, 15, 17 },
    { 0, 1, 2,  3, 4, 5, 6,  7,  8,  9, 10, 11, 12, 13, 14, 15 }
};
 
typedef struct plm_quantizer_spec_t {
    unsigned short levels;
    unsigned char group;
    unsigned char bits;
} plm_quantizer_spec_t;
 
static const plm_quantizer_spec_t PLM_AUDIO_QUANT_TAB[] = {
    {     3, 1,  5 },  //  1
    {     5, 1,  7 },  //  2
    {     7, 0,  3 },  //  3
    {     9, 1, 10 },  //  4
    {    15, 0,  4 },  //  5
    {    31, 0,  5 },  //  6
    {    63, 0,  6 },  //  7
    {   127, 0,  7 },  //  8
    {   255, 0,  8 },  //  9
    {   511, 0,  9 },  // 10
    {  1023, 0, 10 },  // 11
    {  2047, 0, 11 },  // 12
    {  4095, 0, 12 },  // 13
    {  8191, 0, 13 },  // 14
    { 16383, 0, 14 },  // 15
    { 32767, 0, 15 },  // 16
    { 65535, 0, 16 }   // 17
};
 
struct plm_audio_t {
    double time;
    int samples_decoded;
    int samplerate_index;
    int bitrate_index;
    int version;
    int layer;
    int mode;
    int bound;
    int v_pos;
    int next_frame_data_size;
    int has_header;
    
    plm_buffer_t *buffer;
    int destroy_buffer_when_done;
 
    const plm_quantizer_spec_t *allocation[2][32];
    uint8_t scale_factor_info[2][32];
    int scale_factor[2][32][3];
    int sample[2][32][3];
 
    plm_samples_t samples;
    float D[1024];
    float V[2][1024];
    float U[32];
};
 
int plm_audio_find_frame_sync(plm_audio_t *self) FL_NOEXCEPT;
int plm_audio_decode_header(plm_audio_t *self) FL_NOEXCEPT;
void plm_audio_decode_frame(plm_audio_t *self) FL_NOEXCEPT;
const plm_quantizer_spec_t *plm_audio_read_allocation(plm_audio_t *self, int sb, int tab3) FL_NOEXCEPT;
void plm_audio_read_samples(plm_audio_t *self, int ch, int sb, int part) FL_NOEXCEPT;
void plm_audio_idct36(int s[32][3], int ss, float *d, int dp) FL_NOEXCEPT;
 
plm_audio_t *plm_audio_create_with_buffer(plm_buffer_t *buffer, int destroy_when_done) FL_NOEXCEPT {
    plm_audio_t *self = (plm_audio_t *)PLM_MALLOC(sizeof(plm_audio_t));
    fl::memset(self, 0, sizeof(plm_audio_t));
 
    self->samples.count = PLM_AUDIO_SAMPLES_PER_FRAME;
    self->buffer = buffer;
    self->destroy_buffer_when_done = destroy_when_done;
    self->samplerate_index = 3; // Indicates 0
 
    fl::memcopy(self->D, PLM_AUDIO_SYNTHESIS_WINDOW, 512 * sizeof(float));
    fl::memcopy(self->D + 512, PLM_AUDIO_SYNTHESIS_WINDOW, 512 * sizeof(float));
 
    // Attempt to decode first header
    self->next_frame_data_size = plm_audio_decode_header(self);
 
    return self;
}
 
void plm_audio_destroy(plm_audio_t *self) FL_NOEXCEPT {
    if (self->destroy_buffer_when_done) {
        plm_buffer_destroy(self->buffer);
    }
    PLM_FREE(self);
}
 
int plm_audio_has_header(plm_audio_t *self) FL_NOEXCEPT {
    if (self->has_header) {
        return TRUE;
    }
    
    self->next_frame_data_size = plm_audio_decode_header(self);
    return self->has_header;
}
 
int plm_audio_get_samplerate(plm_audio_t *self) FL_NOEXCEPT {
    return plm_audio_has_header(self)
        ? PLM_AUDIO_SAMPLE_RATE[self->samplerate_index]
        : 0;
}
 
double plm_audio_get_time(plm_audio_t *self) FL_NOEXCEPT {
    return self->time;
}
 
void plm_audio_set_time(plm_audio_t *self, double time) FL_NOEXCEPT {
    self->samples_decoded = time * 
        (double)PLM_AUDIO_SAMPLE_RATE[self->samplerate_index];
    self->time = time;
}
 
void plm_audio_rewind(plm_audio_t *self) FL_NOEXCEPT {
    plm_buffer_rewind(self->buffer);
    self->time = 0;
    self->samples_decoded = 0;
    self->next_frame_data_size = 0;
}
 
int plm_audio_has_ended(plm_audio_t *self) FL_NOEXCEPT {
    return plm_buffer_has_ended(self->buffer);
}
 
plm_samples_t *plm_audio_decode(plm_audio_t *self) FL_NOEXCEPT {
    // Do we have at least enough information to decode the frame header?
    if (!self->next_frame_data_size) {
        if (!plm_buffer_has(self->buffer, 48)) {
            return NULL;
        }
        self->next_frame_data_size = plm_audio_decode_header(self);
    }
 
    if (
        self->next_frame_data_size == 0 ||
        !plm_buffer_has(self->buffer, self->next_frame_data_size << 3)
    ) {
        return NULL;
    }
 
    plm_audio_decode_frame(self);
    self->next_frame_data_size = 0;
    
    self->samples.time = self->time;
 
    self->samples_decoded += PLM_AUDIO_SAMPLES_PER_FRAME;
    self->time = (double)self->samples_decoded / 
        (double)PLM_AUDIO_SAMPLE_RATE[self->samplerate_index];
    
    return &self->samples;
}
 
int plm_audio_find_frame_sync(plm_audio_t *self) FL_NOEXCEPT {
    size_t i;
    for (i = self->buffer->bit_index >> 3; i < self->buffer->length-1; i++) {
        if (
            self->buffer->bytes[i] == 0xFF &&
            (self->buffer->bytes[i+1] & 0xFE) == 0xFC
        ) {
            self->buffer->bit_index = ((i+1) << 3) + 3;
            return TRUE;
        }
    }
    self->buffer->bit_index = (i + 1) << 3;
    return FALSE;
}
 
int plm_audio_decode_header(plm_audio_t *self) FL_NOEXCEPT {
    if (!plm_buffer_has(self->buffer, 48)) {
        return 0;
    }
 
    plm_buffer_skip_bytes(self->buffer, 0x00);
    int sync = plm_buffer_read(self->buffer, 11);
 
 
    // Attempt to resync if no syncword was found. This sucks balls. The MP2 
    // stream contains a syncword just before every frame (11 bits set to 1).
    // However, this syncword is not guaranteed to not occur elsewhere in the
    // stream. So, if we have to resync, we also have to check if the header 
    // (samplerate, bitrate) differs from the one we had before. This all
    // may still lead to garbage data being decoded :/
 
    if (sync != PLM_AUDIO_FRAME_SYNC && !plm_audio_find_frame_sync(self)) {
        return 0;
    }
 
    self->version = plm_buffer_read(self->buffer, 2);
    self->layer = plm_buffer_read(self->buffer, 2);
    int hasCRC = !plm_buffer_read(self->buffer, 1);
 
    if (
        self->version != PLM_AUDIO_MPEG_1 ||
        self->layer != PLM_AUDIO_LAYER_II
    ) {
        return 0;
    }
 
    int bitrate_index = plm_buffer_read(self->buffer, 4) - 1;
    if (bitrate_index > 13) {
        return 0;
    }
 
    int samplerate_index = plm_buffer_read(self->buffer, 2);
    if (samplerate_index == 3) {
        return 0;
    }
 
    int padding = plm_buffer_read(self->buffer, 1);
    plm_buffer_skip(self->buffer, 1); // f_private
    int mode = plm_buffer_read(self->buffer, 2);
 
    // If we already have a header, make sure the samplerate, bitrate and mode
    // are still the same, otherwise we might have missed sync.
    if (
        self->has_header && (
            self->bitrate_index != bitrate_index ||
            self->samplerate_index != samplerate_index ||
            self->mode != mode
        )
    ) {
        return 0;
    }
 
    self->bitrate_index = bitrate_index;
    self->samplerate_index = samplerate_index;
    self->mode = mode;
    self->has_header = TRUE;
 
    // Parse the mode_extension, set up the stereo bound
    if (mode == PLM_AUDIO_MODE_JOINT_STEREO) {
        self->bound = (plm_buffer_read(self->buffer, 2) + 1) << 2;
    }
    else {
        plm_buffer_skip(self->buffer, 2);
        self->bound = (mode == PLM_AUDIO_MODE_MONO) ? 0 : 32;
    }
 
    // Discard the last 4 bits of the header and the CRC value, if present
    plm_buffer_skip(self->buffer, 4); // copyright(1), original(1), emphasis(2)
    if (hasCRC) {
        plm_buffer_skip(self->buffer, 16);
    }
 
    // Compute frame size, check if we have enough data to decode the whole
    // frame.
    int bitrate = PLM_AUDIO_BIT_RATE[self->bitrate_index];
    int samplerate = PLM_AUDIO_SAMPLE_RATE[self->samplerate_index];
    int frame_size = (144000 * bitrate / samplerate) + padding;
    return frame_size - (hasCRC ? 6 : 4);
}
 
void plm_audio_decode_frame(plm_audio_t *self) FL_NOEXCEPT {
    // Prepare the quantizer table lookups
    int tab3 = 0;
    int sblimit = 0;
    
    int tab1 = (self->mode == PLM_AUDIO_MODE_MONO) ? 0 : 1;
    int tab2 = PLM_AUDIO_QUANT_LUT_STEP_1[tab1][self->bitrate_index];
    tab3 = QUANT_LUT_STEP_2[tab2][self->samplerate_index];
    sblimit = tab3 & 63;
    tab3 >>= 6;
 
    if (self->bound > sblimit) {
        self->bound = sblimit;
    }
 
    // Read the allocation information
    for (int sb = 0; sb < self->bound; sb++) {
        self->allocation[0][sb] = plm_audio_read_allocation(self, sb, tab3);
        self->allocation[1][sb] = plm_audio_read_allocation(self, sb, tab3);
    }
 
    for (int sb = self->bound; sb < sblimit; sb++) {
        self->allocation[0][sb] =
            self->allocation[1][sb] =
            plm_audio_read_allocation(self, sb, tab3);
    }
 
    // Read scale factor selector information
    int channels = (self->mode == PLM_AUDIO_MODE_MONO) ? 1 : 2;
    for (int sb = 0; sb < sblimit; sb++) {
        for (int ch = 0; ch < channels; ch++) {
            if (self->allocation[ch][sb]) {
                self->scale_factor_info[ch][sb] = plm_buffer_read(self->buffer, 2);
            }
        }
        if (self->mode == PLM_AUDIO_MODE_MONO) {
            self->scale_factor_info[1][sb] = self->scale_factor_info[0][sb];
        }
    }
 
    // Read scale factors
    for (int sb = 0; sb < sblimit; sb++) {
        for (int ch = 0; ch < channels; ch++) {
            if (self->allocation[ch][sb]) {
                int *sf = self->scale_factor[ch][sb];
                switch (self->scale_factor_info[ch][sb]) {
                    case 0:
                        sf[0] = plm_buffer_read(self->buffer, 6);
                        sf[1] = plm_buffer_read(self->buffer, 6);
                        sf[2] = plm_buffer_read(self->buffer, 6);
                        break;
                    case 1:
                        sf[0] = 
                        sf[1] = plm_buffer_read(self->buffer, 6);
                        sf[2] = plm_buffer_read(self->buffer, 6);
                        break;
                    case 2:
                        sf[0] = 
                        sf[1] = 
                        sf[2] = plm_buffer_read(self->buffer, 6);
                        break;
                    case 3:
                        sf[0] = plm_buffer_read(self->buffer, 6);
                        sf[1] = 
                        sf[2] = plm_buffer_read(self->buffer, 6);
                        break;
                }
            }
        }
        if (self->mode == PLM_AUDIO_MODE_MONO) {
            self->scale_factor[1][sb][0] = self->scale_factor[0][sb][0];
            self->scale_factor[1][sb][1] = self->scale_factor[0][sb][1];
            self->scale_factor[1][sb][2] = self->scale_factor[0][sb][2];
        }
    }
 
    // Coefficient input and reconstruction
    int out_pos = 0;
    for (int part = 0; part < 3; part++) {
        for (int granule = 0; granule < 4; granule++) {
 
            // Read the samples
            for (int sb = 0; sb < self->bound; sb++) {
                plm_audio_read_samples(self, 0, sb, part);
                plm_audio_read_samples(self, 1, sb, part);
            }
            for (int sb = self->bound; sb < sblimit; sb++) {
                plm_audio_read_samples(self, 0, sb, part);
                self->sample[1][sb][0] = self->sample[0][sb][0];
                self->sample[1][sb][1] = self->sample[0][sb][1];
                self->sample[1][sb][2] = self->sample[0][sb][2];
            }
            for (int sb = sblimit; sb < 32; sb++) {
                self->sample[0][sb][0] = 0;
                self->sample[0][sb][1] = 0;
                self->sample[0][sb][2] = 0;
                self->sample[1][sb][0] = 0;
                self->sample[1][sb][1] = 0;
                self->sample[1][sb][2] = 0;
            }
 
            // Synthesis loop
            for (int p = 0; p < 3; p++) {
                // Shifting step
                self->v_pos = (self->v_pos - 64) & 1023;
 
                for (int ch = 0; ch < 2; ch++) {
                    plm_audio_idct36(self->sample[ch], p, self->V[ch], self->v_pos);
 
                    // Build U, windowing, calculate output
                    fl::memset(self->U, 0, sizeof(self->U));
 
                    int d_index = 512 - (self->v_pos >> 1);
                    int v_index = (self->v_pos % 128) >> 1;
                    while (v_index < 1024) {
                        for (int i = 0; i < 32; ++i) {
                            self->U[i] += self->D[d_index++] * self->V[ch][v_index++];
                        }
 
                        v_index += 128 - 32;
                        d_index += 64 - 32;
                    }
 
                    d_index -= (512 - 32);
                    v_index = (128 - 32 + 1024) - v_index;
                    while (v_index < 1024) {
                        for (int i = 0; i < 32; ++i) {
                            self->U[i] += self->D[d_index++] * self->V[ch][v_index++];
                        }
 
                        v_index += 128 - 32;
                        d_index += 64 - 32;
                    }
 
                    // Output samples
                    #ifdef PLM_AUDIO_SEPARATE_CHANNELS
                        float *out_channel = ch == 0
                            ? self->samples.left
                            : self->samples.right;
                        for (int j = 0; j < 32; j++) {
                            out_channel[out_pos + j] = self->U[j] / -1090519040.0f;
                        }
                    #else
                        for (int j = 0; j < 32; j++) {
                            self->samples.interleaved[((out_pos + j) << 1) + ch] = 
                                self->U[j] / -1090519040.0f;
                        }
                    #endif
                } // End of synthesis channel loop
                out_pos += 32;
            } // End of synthesis sub-block loop
 
        } // Decoding of the granule finished
    }
 
    plm_buffer_align(self->buffer);
}
 
const plm_quantizer_spec_t *plm_audio_read_allocation(plm_audio_t *self, int sb, int tab3) FL_NOEXCEPT {
    int tab4 = PLM_AUDIO_QUANT_LUT_STEP_3[tab3][sb];
    int qtab = PLM_AUDIO_QUANT_LUT_STEP_4[tab4 & 15][plm_buffer_read(self->buffer, tab4 >> 4)];
    return qtab ? (&PLM_AUDIO_QUANT_TAB[qtab - 1]) : 0;
}
 
void plm_audio_read_samples(plm_audio_t *self, int ch, int sb, int part) FL_NOEXCEPT {
    const plm_quantizer_spec_t *q = self->allocation[ch][sb];
    int sf = self->scale_factor[ch][sb][part];
    int *sample = self->sample[ch][sb];
    int val = 0;
 
    if (!q) {
        // No bits allocated for this subband
        sample[0] = sample[1] = sample[2] = 0;
        return;
    }
 
    // Resolve scalefactor
    if (sf == 63) {
        sf = 0;
    }
    else {
        int shift = (sf / 3) | 0;
        sf = (PLM_AUDIO_SCALEFACTOR_BASE[sf % 3] + ((1 << shift) >> 1)) >> shift;
    }
 
    // Decode samples
    int adj = q->levels;
    if (q->group) {
        // Decode grouped samples
        val = plm_buffer_read(self->buffer, q->bits);
        sample[0] = val % adj;
        val /= adj;
        sample[1] = val % adj;
        sample[2] = val / adj;
    }
    else {
        // Decode direct samples
        sample[0] = plm_buffer_read(self->buffer, q->bits);
        sample[1] = plm_buffer_read(self->buffer, q->bits);
        sample[2] = plm_buffer_read(self->buffer, q->bits);
    }
 
    // Postmultiply samples
    int scale = 65536 / (adj + 1);
    adj = ((adj + 1) >> 1) - 1;
 
    val = (adj - sample[0]) * scale;
    sample[0] = (val * (sf >> 12) + ((val * (sf & 4095) + 2048) >> 12)) >> 12;
 
    val = (adj - sample[1]) * scale;
    sample[1] = (val * (sf >> 12) + ((val * (sf & 4095) + 2048) >> 12)) >> 12;
 
    val = (adj - sample[2]) * scale;
    sample[2] = (val * (sf >> 12) + ((val * (sf & 4095) + 2048) >> 12)) >> 12;
}
 
void plm_audio_idct36(int s[32][3], int ss, float *d, int dp) FL_NOEXCEPT {
    float t01, t02, t03, t04, t05, t06, t07, t08, t09, t10, t11, t12,
        t13, t14, t15, t16, t17, t18, t19, t20, t21, t22, t23, t24,
        t25, t26, t27, t28, t29, t30, t31, t32, t33;
 
    t01 = (float)(s[0][ss] + s[31][ss]); t02 = (float)(s[0][ss] - s[31][ss]) * 0.500602998235f;
    t03 = (float)(s[1][ss] + s[30][ss]); t04 = (float)(s[1][ss] - s[30][ss]) * 0.505470959898f;
    t05 = (float)(s[2][ss] + s[29][ss]); t06 = (float)(s[2][ss] - s[29][ss]) * 0.515447309923f;
    t07 = (float)(s[3][ss] + s[28][ss]); t08 = (float)(s[3][ss] - s[28][ss]) * 0.53104259109f;
    t09 = (float)(s[4][ss] + s[27][ss]); t10 = (float)(s[4][ss] - s[27][ss]) * 0.553103896034f;
    t11 = (float)(s[5][ss] + s[26][ss]); t12 = (float)(s[5][ss] - s[26][ss]) * 0.582934968206f;
    t13 = (float)(s[6][ss] + s[25][ss]); t14 = (float)(s[6][ss] - s[25][ss]) * 0.622504123036f;
    t15 = (float)(s[7][ss] + s[24][ss]); t16 = (float)(s[7][ss] - s[24][ss]) * 0.674808341455f;
    t17 = (float)(s[8][ss] + s[23][ss]); t18 = (float)(s[8][ss] - s[23][ss]) * 0.744536271002f;
    t19 = (float)(s[9][ss] + s[22][ss]); t20 = (float)(s[9][ss] - s[22][ss]) * 0.839349645416f;
    t21 = (float)(s[10][ss] + s[21][ss]); t22 = (float)(s[10][ss] - s[21][ss]) * 0.972568237862f;
    t23 = (float)(s[11][ss] + s[20][ss]); t24 = (float)(s[11][ss] - s[20][ss]) * 1.16943993343f;
    t25 = (float)(s[12][ss] + s[19][ss]); t26 = (float)(s[12][ss] - s[19][ss]) * 1.48416461631f;
    t27 = (float)(s[13][ss] + s[18][ss]); t28 = (float)(s[13][ss] - s[18][ss]) * 2.05778100995f;
    t29 = (float)(s[14][ss] + s[17][ss]); t30 = (float)(s[14][ss] - s[17][ss]) * 3.40760841847f;
    t31 = (float)(s[15][ss] + s[16][ss]); t32 = (float)(s[15][ss] - s[16][ss]) * 10.1900081235f;
 
    t33 = t01 + t31; t31 = (t01 - t31) * 0.502419286188f;
    t01 = t03 + t29; t29 = (t03 - t29) * 0.52249861494f;
    t03 = t05 + t27; t27 = (t05 - t27) * 0.566944034816f;
    t05 = t07 + t25; t25 = (t07 - t25) * 0.64682178336f;
    t07 = t09 + t23; t23 = (t09 - t23) * 0.788154623451f;
    t09 = t11 + t21; t21 = (t11 - t21) * 1.06067768599f;
    t11 = t13 + t19; t19 = (t13 - t19) * 1.72244709824f;
    t13 = t15 + t17; t17 = (t15 - t17) * 5.10114861869f;
    t15 = t33 + t13; t13 = (t33 - t13) * 0.509795579104f;
    t33 = t01 + t11; t01 = (t01 - t11) * 0.601344886935f;
    t11 = t03 + t09; t09 = (t03 - t09) * 0.899976223136f;
    t03 = t05 + t07; t07 = (t05 - t07) * 2.56291544774f;
    t05 = t15 + t03; t15 = (t15 - t03) * 0.541196100146f;
    t03 = t33 + t11; t11 = (t33 - t11) * 1.30656296488f;
    t33 = t05 + t03; t05 = (t05 - t03) * 0.707106781187f;
    t03 = t15 + t11; t15 = (t15 - t11) * 0.707106781187f;
    t03 += t15;
    t11 = t13 + t07; t13 = (t13 - t07) * 0.541196100146f;
    t07 = t01 + t09; t09 = (t01 - t09) * 1.30656296488f;
    t01 = t11 + t07; t07 = (t11 - t07) * 0.707106781187f;
    t11 = t13 + t09; t13 = (t13 - t09) * 0.707106781187f;
    t11 += t13; t01 += t11;
    t11 += t07; t07 += t13;
    t09 = t31 + t17; t31 = (t31 - t17) * 0.509795579104f;
    t17 = t29 + t19; t29 = (t29 - t19) * 0.601344886935f;
    t19 = t27 + t21; t21 = (t27 - t21) * 0.899976223136f;
    t27 = t25 + t23; t23 = (t25 - t23) * 2.56291544774f;
    t25 = t09 + t27; t09 = (t09 - t27) * 0.541196100146f;
    t27 = t17 + t19; t19 = (t17 - t19) * 1.30656296488f;
    t17 = t25 + t27; t27 = (t25 - t27) * 0.707106781187f;
    t25 = t09 + t19; t19 = (t09 - t19) * 0.707106781187f;
    t25 += t19;
    t09 = t31 + t23; t31 = (t31 - t23) * 0.541196100146f;
    t23 = t29 + t21; t21 = (t29 - t21) * 1.30656296488f;
    t29 = t09 + t23; t23 = (t09 - t23) * 0.707106781187f;
    t09 = t31 + t21; t31 = (t31 - t21) * 0.707106781187f;
    t09 += t31; t29 += t09; t09 += t23; t23 += t31;
    t17 += t29; t29 += t25; t25 += t09; t09 += t27;
    t27 += t23; t23 += t19; t19 += t31;
    t21 = t02 + t32; t02 = (t02 - t32) * 0.502419286188f;
    t32 = t04 + t30; t04 = (t04 - t30) * 0.52249861494f;
    t30 = t06 + t28; t28 = (t06 - t28) * 0.566944034816f;
    t06 = t08 + t26; t08 = (t08 - t26) * 0.64682178336f;
    t26 = t10 + t24; t10 = (t10 - t24) * 0.788154623451f;
    t24 = t12 + t22; t22 = (t12 - t22) * 1.06067768599f;
    t12 = t14 + t20; t20 = (t14 - t20) * 1.72244709824f;
    t14 = t16 + t18; t16 = (t16 - t18) * 5.10114861869f;
    t18 = t21 + t14; t14 = (t21 - t14) * 0.509795579104f;
    t21 = t32 + t12; t32 = (t32 - t12) * 0.601344886935f;
    t12 = t30 + t24; t24 = (t30 - t24) * 0.899976223136f;
    t30 = t06 + t26; t26 = (t06 - t26) * 2.56291544774f;
    t06 = t18 + t30; t18 = (t18 - t30) * 0.541196100146f;
    t30 = t21 + t12; t12 = (t21 - t12) * 1.30656296488f;
    t21 = t06 + t30; t30 = (t06 - t30) * 0.707106781187f;
    t06 = t18 + t12; t12 = (t18 - t12) * 0.707106781187f;
    t06 += t12;
    t18 = t14 + t26; t26 = (t14 - t26) * 0.541196100146f;
    t14 = t32 + t24; t24 = (t32 - t24) * 1.30656296488f;
    t32 = t18 + t14; t14 = (t18 - t14) * 0.707106781187f;
    t18 = t26 + t24; t24 = (t26 - t24) * 0.707106781187f;
    t18 += t24; t32 += t18;
    t18 += t14; t26 = t14 + t24;
    t14 = t02 + t16; t02 = (t02 - t16) * 0.509795579104f;
    t16 = t04 + t20; t04 = (t04 - t20) * 0.601344886935f;
    t20 = t28 + t22; t22 = (t28 - t22) * 0.899976223136f;
    t28 = t08 + t10; t10 = (t08 - t10) * 2.56291544774f;
    t08 = t14 + t28; t14 = (t14 - t28) * 0.541196100146f;
    t28 = t16 + t20; t20 = (t16 - t20) * 1.30656296488f;
    t16 = t08 + t28; t28 = (t08 - t28) * 0.707106781187f;
    t08 = t14 + t20; t20 = (t14 - t20) * 0.707106781187f;
    t08 += t20;
    t14 = t02 + t10; t02 = (t02 - t10) * 0.541196100146f;
    t10 = t04 + t22; t22 = (t04 - t22) * 1.30656296488f;
    t04 = t14 + t10; t10 = (t14 - t10) * 0.707106781187f;
    t14 = t02 + t22; t02 = (t02 - t22) * 0.707106781187f;
    t14 += t02; t04 += t14; t14 += t10; t10 += t02;
    t16 += t04; t04 += t08; t08 += t14; t14 += t28;
    t28 += t10; t10 += t20; t20 += t02; t21 += t16;
    t16 += t32; t32 += t04; t04 += t06; t06 += t08;
    t08 += t18; t18 += t14; t14 += t30; t30 += t28;
    t28 += t26; t26 += t10; t10 += t12; t12 += t20;
    t20 += t24; t24 += t02;
 
    d[dp + 48] = -t33;
    d[dp + 49] = d[dp + 47] = -t21;
    d[dp + 50] = d[dp + 46] = -t17;
    d[dp + 51] = d[dp + 45] = -t16;
    d[dp + 52] = d[dp + 44] = -t01;
    d[dp + 53] = d[dp + 43] = -t32;
    d[dp + 54] = d[dp + 42] = -t29;
    d[dp + 55] = d[dp + 41] = -t04;
    d[dp + 56] = d[dp + 40] = -t03;
    d[dp + 57] = d[dp + 39] = -t06;
    d[dp + 58] = d[dp + 38] = -t25;
    d[dp + 59] = d[dp + 37] = -t08;
    d[dp + 60] = d[dp + 36] = -t11;
    d[dp + 61] = d[dp + 35] = -t18;
    d[dp + 62] = d[dp + 34] = -t09;
    d[dp + 63] = d[dp + 33] = -t14;
    d[dp + 32] = -t05;
    d[dp + 0] = t05; d[dp + 31] = -t30;
    d[dp + 1] = t30; d[dp + 30] = -t27;
    d[dp + 2] = t27; d[dp + 29] = -t28;
    d[dp + 3] = t28; d[dp + 28] = -t07;
    d[dp + 4] = t07; d[dp + 27] = -t26;
    d[dp + 5] = t26; d[dp + 26] = -t23;
    d[dp + 6] = t23; d[dp + 25] = -t10;
    d[dp + 7] = t10; d[dp + 24] = -t15;
    d[dp + 8] = t15; d[dp + 23] = -t12;
    d[dp + 9] = t12; d[dp + 22] = -t19;
    d[dp + 10] = t19; d[dp + 21] = -t20;
    d[dp + 11] = t20; d[dp + 20] = -t13;
    d[dp + 12] = t13; d[dp + 19] = -t24;
    d[dp + 13] = t24; d[dp + 18] = -t31;
    d[dp + 14] = t31; d[dp + 17] = -t02;
    d[dp + 15] = t02; d[dp + 16] = 0.0;
}
 
 
} // namespace third_party
} // namespace fl