Apparently you can push the chroma extremely far

This commit is contained in:
minjaesong
2025-09-30 01:05:14 +09:00
parent 836e69a40b
commit 41a8b578b5
5 changed files with 387 additions and 50 deletions

View File

@@ -89,6 +89,12 @@ static const channel_layout_config_t channel_layouts[] = {
{CHANNEL_LAYOUT_COCG_A, 3, {NULL, "Co", "Cg", "A"}, 0, 1, 1, 1} // 5: Co-Cg-A
};
// Helper function to check if alpha channel is needed for given channel layout
static int needs_alpha_channel(int channel_layout) {
if (channel_layout < 0 || channel_layout >= 6) return 0;
return channel_layouts[channel_layout].has_alpha;
}
// Default settings
#define DEFAULT_WIDTH 560
#define DEFAULT_HEIGHT 448
@@ -173,13 +179,14 @@ static int validate_mp2_bitrate(int bitrate) {
return 0; // Invalid bitrate
}
static const int QLUT[] = {1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,66,68,70,72,74,76,78,80,82,84,86,88,90,92,94,96,98,100,102,104,106,108,110,112,114,116,118,120,122,124,126,128,132,136,140,144,148,152,156,160,164,168,172,176,180,184,188,192,196,200,204,208,212,216,220,224,228,232,236,240,244,248,252,256,264,272,280,288,296,304,312,320,328,336,344,352,360,368,376,384,392,400,408,416,424,432,440,448,456,464,472,480,488,496,504,512,528,544,560,576,592,608,624,640,656,672,688,704,720,736,752,768,784,800,816,832,848,864,880,896,912,928,944,960,976,992,1008,1024,1056,1088,1120,1152,1184,1216,1248,1280,1312,1344,1376,1408,1440,1472,1504,1536,1568,1600,1632,1664,1696,1728,1760,1792,1824,1856,1888,1920,1952,1984,2016,2048,2112,2176,2240,2304,2368,2432,2496,2560,2624,2688,2752,2816,2880,2944,3008,3072,3136,3200,3264,3328,3392,3456,3520,3584,3648,3712,3776,3840,3904,3968,4032,4096};
// Quality level to quantisation mapping for different channels
static const int QUALITY_Y[] = {60, 42, 25, 12, 6, 2};
static const int QUALITY_CO[] = {120, 90, 60, 30, 15, 3};
static const int QUALITY_CG[] = {240, 180, 120, 60, 30, 5};
//static const int QUALITY_Y[] = { 25, 12, 6, 3, 2, 1};
//static const int QUALITY_CO[] = {60, 30, 15, 7, 5, 2};
//static const int QUALITY_CG[] = {120, 60, 30, 15, 10, 4};
// the values are indices to the QLUT
static const int QUALITY_Y[] = {59, 41, 24, 11, 5, 1}; // 60, 42, 25, 12, 6, 2
static const int QUALITY_CO[] = {123, 108, 91, 76, 59, 29}; // 240, 180, 120, 90, 60, 30
static const int QUALITY_CG[] = {132, 119, 100, 87, 68, 37}; // 296, 224, 148, 112, 74, 38
static const int QUALITY_ALPHA[] = {59, 41, 24, 11, 5, 1};
// psychovisual tuning parameters
static const float ANISOTROPY_MULT[] = {2.0f, 1.8f, 1.6f, 1.4f, 1.2f, 1.0f};
@@ -256,7 +263,7 @@ typedef struct {
// Frame buffers - ping-pong implementation
uint8_t *frame_rgb[2]; // [0] and [1] alternate between current and previous
int frame_buffer_index; // 0 or 1, indicates which set is "current"
float *current_frame_y, *current_frame_co, *current_frame_cg;
float *current_frame_y, *current_frame_co, *current_frame_cg, *current_frame_alpha;
// Convenience pointers (updated each frame to point to current ping-pong buffers)
uint8_t *current_frame_rgb;
@@ -290,11 +297,13 @@ typedef struct {
int16_t *reusable_quantised_y;
int16_t *reusable_quantised_co;
int16_t *reusable_quantised_cg;
int16_t *reusable_quantised_alpha;
// Coefficient delta storage for P-frames (previous frame's coefficients)
float *previous_coeffs_y; // Previous frame Y coefficients for all tiles
float *previous_coeffs_co; // Previous frame Co coefficients for all tiles
float *previous_coeffs_cg; // Previous frame Cg coefficients for all tiles
float *previous_coeffs_y; // Previous frame Y coefficients for all tiles
float *previous_coeffs_co; // Previous frame Co coefficients for all tiles
float *previous_coeffs_cg; // Previous frame Cg coefficients for all tiles
float *previous_coeffs_alpha; // Previous frame Alpha coefficients for all tiles
int previous_coeffs_allocated; // Flag to track allocation
// Statistics
@@ -489,6 +498,7 @@ static int initialise_encoder(tav_encoder_t *enc) {
enc->current_frame_y = malloc(frame_size * sizeof(float));
enc->current_frame_co = malloc(frame_size * sizeof(float));
enc->current_frame_cg = malloc(frame_size * sizeof(float));
enc->current_frame_alpha = malloc(frame_size * sizeof(float));
// Allocate tile structures
enc->tiles = malloc(num_tiles * sizeof(dwt_tile_t));
@@ -517,19 +527,21 @@ static int initialise_encoder(tav_encoder_t *enc) {
enc->reusable_quantised_y = malloc(coeff_count_per_tile * sizeof(int16_t));
enc->reusable_quantised_co = malloc(coeff_count_per_tile * sizeof(int16_t));
enc->reusable_quantised_cg = malloc(coeff_count_per_tile * sizeof(int16_t));
enc->reusable_quantised_alpha = malloc(coeff_count_per_tile * sizeof(int16_t));
// Allocate coefficient delta storage for P-frames (per-tile coefficient storage)
size_t total_coeff_size = num_tiles * coeff_count_per_tile * sizeof(float);
enc->previous_coeffs_y = malloc(total_coeff_size);
enc->previous_coeffs_co = malloc(total_coeff_size);
enc->previous_coeffs_cg = malloc(total_coeff_size);
enc->previous_coeffs_alpha = malloc(total_coeff_size);
enc->previous_coeffs_allocated = 0; // Will be set to 1 after first I-frame
if (!enc->frame_rgb[0] || !enc->frame_rgb[1] ||
!enc->current_frame_y || !enc->current_frame_co || !enc->current_frame_cg ||
!enc->current_frame_y || !enc->current_frame_co || !enc->current_frame_cg || !enc->current_frame_alpha ||
!enc->tiles || !enc->zstd_ctx || !enc->compressed_buffer ||
!enc->reusable_quantised_y || !enc->reusable_quantised_co || !enc->reusable_quantised_cg ||
!enc->previous_coeffs_y || !enc->previous_coeffs_co || !enc->previous_coeffs_cg) {
!enc->reusable_quantised_y || !enc->reusable_quantised_co || !enc->reusable_quantised_cg || !enc->reusable_quantised_alpha ||
!enc->previous_coeffs_y || !enc->previous_coeffs_co || !enc->previous_coeffs_cg || !enc->previous_coeffs_alpha) {
return -1;
}
@@ -1360,9 +1372,9 @@ static size_t serialise_tile_data(tav_encoder_t *enc, int tile_x, int tile_y,
buffer[offset++] = 0; // qCo override
buffer[offset++] = 0; // qCg override
// technically, putting this in here would create three redundant copies of the same value, but it's much easier to code this way :v
int this_frame_qY = enc->quantiser_y;
int this_frame_qCo = enc->quantiser_co;
int this_frame_qCg = enc->quantiser_cg;
int this_frame_qY = QLUT[enc->quantiser_y];
int this_frame_qCo = QLUT[enc->quantiser_co];
int this_frame_qCg = QLUT[enc->quantiser_cg];
if (mode == TAV_MODE_SKIP) {
// No coefficient data for SKIP/MOTION modes
@@ -1377,6 +1389,7 @@ static size_t serialise_tile_data(tav_encoder_t *enc, int tile_x, int tile_y,
int16_t *quantised_y = enc->reusable_quantised_y;
int16_t *quantised_co = enc->reusable_quantised_co;
int16_t *quantised_cg = enc->reusable_quantised_cg;
int16_t *quantised_alpha = enc->reusable_quantised_alpha;
// Debug: check DWT coefficients before quantisation
/*if (tile_x == 0 && tile_y == 0) {
@@ -1881,6 +1894,36 @@ static void rgb_to_colour_space_frame(tav_encoder_t *enc, const uint8_t *rgb,
}
}
// RGBA to colour space conversion for full frames with alpha channel
static void rgba_to_colour_space_frame(tav_encoder_t *enc, const uint8_t *rgba,
float *c1, float *c2, float *c3, float *alpha,
int width, int height) {
const int total_pixels = width * height;
if (enc->ictcp_mode) {
// ICtCp mode with alpha
for (int i = 0; i < total_pixels; i++) {
double I, Ct, Cp;
srgb8_to_ictcp_hlg(rgba[i*4], rgba[i*4+1], rgba[i*4+2], &I, &Ct, &Cp);
c1[i] = (float)I;
c2[i] = (float)Ct;
c3[i] = (float)Cp;
alpha[i] = (float)rgba[i*4+3] / 255.0f; // Normalize alpha to [0,1]
}
} else {
// YCoCg mode with alpha - extract RGB first, then convert
uint8_t *temp_rgb = malloc(total_pixels * 3);
for (int i = 0; i < total_pixels; i++) {
temp_rgb[i*3] = rgba[i*4]; // R
temp_rgb[i*3+1] = rgba[i*4+1]; // G
temp_rgb[i*3+2] = rgba[i*4+2]; // B
alpha[i] = (float)rgba[i*4+3] / 255.0f; // Normalize alpha to [0,1]
}
rgb_to_ycocg(temp_rgb, c1, c2, c3, width, height);
free(temp_rgb);
}
}
// Write TAV file header
static int write_tav_header(tav_encoder_t *enc) {
if (!enc->output_fp) return -1;
@@ -2917,9 +2960,9 @@ int main(int argc, char *argv[]) {
cleanup_encoder(enc);
return 1;
}
enc->quantiser_y = CLAMP(enc->quantiser_y, 1, 255);
enc->quantiser_co = CLAMP(enc->quantiser_co, 1, 255);
enc->quantiser_cg = CLAMP(enc->quantiser_cg, 1, 255);
enc->quantiser_y = CLAMP(enc->quantiser_y, 0, 255);
enc->quantiser_co = CLAMP(enc->quantiser_co, 0, 255);
enc->quantiser_cg = CLAMP(enc->quantiser_cg, 0, 255);
break;
case 'w':
enc->wavelet_filter = CLAMP(atoi(optarg), 0, 255);
@@ -3051,9 +3094,9 @@ int main(int argc, char *argv[]) {
printf("Colour space: %s\n", enc->ictcp_mode ? "ICtCp" : "YCoCg-R");
printf("Quantisation: %s\n", enc->perceptual_tuning ? "Perceptual (HVS-optimised)" : "Uniform (legacy)");
if (enc->ictcp_mode) {
printf("Base quantiser: I=%d, Ct=%d, Cp=%d\n", enc->quantiser_y, enc->quantiser_co, enc->quantiser_cg);
printf("Base quantiser: I=%d, Ct=%d, Cp=%d\n", QLUT[enc->quantiser_y], QLUT[enc->quantiser_co], QLUT[enc->quantiser_cg]);
} else {
printf("Base quantiser: Y=%d, Co=%d, Cg=%d\n", enc->quantiser_y, enc->quantiser_co, enc->quantiser_cg);
printf("Base quantiser: Y=%d, Co=%d, Cg=%d\n", QLUT[enc->quantiser_y], QLUT[enc->quantiser_co], QLUT[enc->quantiser_cg]);
}
if (enc->perceptual_tuning) {
printf("Perceptual tuning enabled\n");
@@ -3357,6 +3400,10 @@ static void cleanup_encoder(tav_encoder_t *enc) {
free(enc->subtitle_file);
free(enc->frame_rgb[0]);
free(enc->frame_rgb[1]);
free(enc->current_frame_y);
free(enc->current_frame_co);
free(enc->current_frame_cg);
free(enc->current_frame_alpha);
free(enc->tiles);
free(enc->compressed_buffer);
free(enc->mp2_buffer);
@@ -3365,11 +3412,13 @@ static void cleanup_encoder(tav_encoder_t *enc) {
free(enc->reusable_quantised_y);
free(enc->reusable_quantised_co);
free(enc->reusable_quantised_cg);
free(enc->reusable_quantised_alpha);
// Free coefficient delta storage
free(enc->previous_coeffs_y);
free(enc->previous_coeffs_co);
free(enc->previous_coeffs_cg);
free(enc->previous_coeffs_alpha);
// Free subtitle list
if (enc->subtitles) {