hd108BrightnessHeader()

void fl::hd108BrightnessHeader ( u8 brightness_8bit, u8 * f0_out, u8 * f1_out )

inline

Generate HD108 per-channel gain header bytes.

Parameters

brightness_8bit	8-bit brightness (0-255) - UNUSED, kept for API compatibility. Callers advertising a working brightness parameter on top of this are advertising something that does not happen; see encodeHD108() (FastLED#4042).
f0_out	Output: first header byte
f1_out	Output: second header byte

Note

HD108 uses per-channel gain encoding: 5 bits each for R/G/B

All gains set to maximum (31) for maximum precision

Brightness control via 16-bit PWM values (applied before encoding)

Future: Per channel gain control for higher color range

Definition at line 83 of file encoder_utils.h.

                                                                                           {
    (void)brightness_8bit;  // Unused - brightness applied to 16-bit values instead
 
    // Use maximum gain for all channels for maximum precision
    // Brightness control happens via 16-bit PWM values
    constexpr u8 r_gain = 31;
    constexpr u8 g_gain = 31;
    constexpr u8 b_gain = 31;
 
    // Correct HD108 per-channel encoding:
    // f0: [1][RRRRR][GG] - marker bit, 5-bit R gain, 2 MSBs of G gain
    // f1: [GGG][BBBBB]   - 3 LSBs of G gain, 5-bit B gain
    *f0_out = 0x80 | ((r_gain & 0x1F) << 2) | ((g_gain >> 3) & 0x03);
    *f1_out = ((g_gain & 0x07) << 5) | (b_gain & 0x1F);
}

References FL_NO_EXCEPT.

Referenced by encodeHD108(), encodeHD108_HD(), and fl::PixelIterator::writeHD108().

Here is the caller graph for this function: