AutoResearchMp3.h File Reference

Detailed Description

On-device verification of the fixed-point MP3 decoder.

FastLED ships minimp3 in fixed-point mode by default – the choice is made in the header, not by a build flag – so every embedded target runs the integer pipeline. That pipeline is where 32-bit-specific defects live, and host testing on x86-64 is structurally blind to a whole class of them: an int64 add costs one instruction there and two plus carry on a 32-bit machine, signed overflow that the optimiser is entitled to assume away behaves differently under different register pressure, and alignment padding in the scratch arena differs outright.

So this checks the decode is bit-exact against the host, not merely plausible: an FNV-1a over the emitted PCM, compared to the value the same mp3dec_decode_frame_r produced on the host. A checksum rather than a PSNR because there is no tolerance to allow – the fixed-point decoder is deterministic, and any difference at all is a defect worth seeing.

Definition in file AutoResearchMp3.h.

#include <FastLED.h>
#include "fl/stl/int.h"
#include "fl/stl/cstring.h"
#include "fl/stl/unique_ptr.h"
#include "AutoResearchMp3Fixture.h"
#include "fl/codec/mp3.h"
#include "third_party/minimp3/minimp3.h"

Include dependency graph for AutoResearchMp3.h:

Go to the source code of this file.

Classes
struct	autoresearch::mp3_check::Decoded
struct	autoresearch::mp3_check::Result

Namespaces
namespace	autoresearch
namespace	autoresearch::mp3_check

Functions
Decoded	autoresearch::mp3_check::decodeStream (fl::third_party::mp3dec_t *dec, fl::third_party::mp3dec_scratch_t *scratch, fl::i16 *pcm, const mp3_fixture::Stream &stream)
	Decode one stream.
fl::u32	autoresearch::mp3_check::fnv1a (fl::u32 hash, const fl::i16 *samples, fl::u32 count)
fl::u32	autoresearch::mp3_check::fnv1a_mix (fl::u32 hash, fl::u32 value)
	Fold one stream's checksum into the run-wide one, so a single reported value covers every stream in order.
void	autoresearch::mp3_check::recordFailure (Result &r, const char *name, fl::u32 expected_hash, fl::u32 actual_hash, fl::u32 expected_samples, fl::u32 actual_samples)
Result	autoresearch::mp3_check::run ()

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Class Documentation

autoresearch::mp3_check::Decoded

struct autoresearch::mp3_check::Decoded

Class Members
u32	channels
u32	fnv1a
u32	frames
u32	hz
u32	layer
u32	samples

autoresearch::mp3_check::Result

struct autoresearch::mp3_check::Result

Class Members
u32	actual_fnv1a
u32	actual_samples
u32	audio_micros
u32	combined_fnv1a
u32	decode_micros
u32	expected_fnv1a
u32	expected_samples
const char *	first_failure
u32	frames_decoded
u32	samples_decoded
u32	scratch_bytes
bool	shared_decoder_matched
u32	streams_failed
u32	streams_run
bool	success
u32	verify_micros