TAV-DT multithreaded decoding

This commit is contained in:
minjaesong
2025-12-12 16:26:30 +09:00
parent b9d9d221dd
commit 42341b4e10

View File

@@ -73,23 +73,24 @@ static const int QUALITY_CG[] = {148, 133, 113, 99, 76, 39};
#define DECODE_SLOT_EMPTY 0
#define DECODE_SLOT_PENDING 1
#define DECODE_SLOT_DONE 2
#define DECODE_SLOT_PROCESSING 2
#define DECODE_SLOT_DONE 3
// GOP decode job structure
typedef struct {
// Input
uint8_t *compressed_data; // Raw GOP data to decode
uint8_t *compressed_data; // Raw GOP data to decode (owned by job)
size_t compressed_size;
int gop_size; // Number of frames in this GOP
int job_id; // Sequential job ID for ordering output
// Output
uint8_t **rgb_frames; // Decoded RGB24 frames [gop_size]
int frames_allocated; // How many frames are allocated
size_t frame_size; // Size of each frame in bytes
int decode_result; // 0 = success, -1 = error
// Status
volatile int status;
volatile int status; // DECODE_SLOT_EMPTY, PENDING, or DONE
} gop_decode_job_t;
/**
@@ -375,6 +376,217 @@ static int read_and_decode_header(dt_decoder_t *dec, dt_packet_header_t *header)
return 0;
}
// =============================================================================
// Multithreading Support
// =============================================================================
/**
* Worker thread function for parallel GOP decoding
*/
static void *decoder_worker_thread(void *arg) {
dt_decoder_t *dec = (dt_decoder_t *)arg;
int thread_id = -1;
// Find our thread ID
for (int i = 0; i < dec->num_threads; i++) {
if (pthread_equal(dec->worker_threads[i], pthread_self())) {
thread_id = i;
break;
}
}
if (thread_id < 0) {
fprintf(stderr, "Error: Worker thread couldn't find its ID\n");
return NULL;
}
tav_video_context_t *video_ctx = dec->worker_video_ctx[thread_id];
while (1) {
pthread_mutex_lock(&dec->mutex);
// Look for a pending job and claim it
int job_idx = -1;
for (int i = 0; i < dec->num_slots; i++) {
if (dec->slots[i].status == DECODE_SLOT_PENDING) {
job_idx = i;
dec->slots[i].status = DECODE_SLOT_PROCESSING; // Claim it - prevents other threads from picking it
break;
}
}
if (job_idx < 0) {
// No jobs available, check if we should exit
if (dec->threads_should_exit) {
pthread_mutex_unlock(&dec->mutex);
break;
}
// Wait for a job
pthread_cond_wait(&dec->cond_job_available, &dec->mutex);
pthread_mutex_unlock(&dec->mutex);
continue;
}
pthread_mutex_unlock(&dec->mutex);
// Decode this GOP
gop_decode_job_t *job = &dec->slots[job_idx];
// The compressed data format: [type(1)][gop_size(1)][size(4)][zstd_data]
const uint8_t *zstd_data = job->compressed_data + 6;
size_t zstd_size = job->compressed_size > 6 ? job->compressed_size - 6 : 0;
job->decode_result = tav_video_decode_gop(video_ctx, zstd_data, zstd_size,
job->gop_size, job->rgb_frames);
// Mark as done
pthread_mutex_lock(&dec->mutex);
job->status = DECODE_SLOT_DONE;
dec->jobs_completed++;
pthread_cond_broadcast(&dec->cond_slot_free);
pthread_mutex_unlock(&dec->mutex);
}
return NULL;
}
/**
* Initialize decoder threads
*/
static int init_decoder_threads(dt_decoder_t *dec) {
if (dec->num_threads <= 1) {
return 0; // Single-threaded, nothing to initialize
}
dec->num_slots = dec->num_threads + 2; // Pipeline with lookahead
dec->slots = calloc(dec->num_slots, sizeof(gop_decode_job_t));
if (!dec->slots) {
fprintf(stderr, "Error: Cannot allocate decode slots\n");
return -1;
}
// Initialize slots
for (int i = 0; i < dec->num_slots; i++) {
dec->slots[i].status = DECODE_SLOT_EMPTY;
dec->slots[i].job_id = -1;
dec->slots[i].rgb_frames = NULL;
dec->slots[i].compressed_data = NULL;
}
// Create per-thread video decoder contexts
dec->worker_video_ctx = calloc(dec->num_threads, sizeof(tav_video_context_t*));
if (!dec->worker_video_ctx) {
free(dec->slots);
return -1;
}
tav_video_params_t vparams;
vparams.width = dec->width;
vparams.height = dec->is_interlaced ? dec->height / 2 : dec->height;
vparams.decomp_levels = DT_SPATIAL_LEVELS;
vparams.temporal_levels = DT_TEMPORAL_LEVELS;
vparams.wavelet_filter = 1; // CDF 9/7
vparams.temporal_wavelet = 255; // Haar
vparams.entropy_coder = 1; // EZBC
vparams.channel_layout = 0; // YCoCg-R
vparams.perceptual_tuning = 1;
vparams.quantiser_y = QUALITY_Y[dec->quality_index];
vparams.quantiser_co = QUALITY_CO[dec->quality_index];
vparams.quantiser_cg = QUALITY_CG[dec->quality_index];
vparams.encoder_preset = 0x01; // Sports
vparams.monoblock = 1;
for (int i = 0; i < dec->num_threads; i++) {
dec->worker_video_ctx[i] = tav_video_create(&vparams);
if (!dec->worker_video_ctx[i]) {
fprintf(stderr, "Error: Cannot create video decoder for thread %d\n", i);
return -1;
}
}
// Initialize threading primitives
pthread_mutex_init(&dec->mutex, NULL);
pthread_cond_init(&dec->cond_job_available, NULL);
pthread_cond_init(&dec->cond_slot_free, NULL);
dec->threads_should_exit = 0;
dec->next_write_slot = 0;
dec->jobs_submitted = 0;
dec->jobs_completed = 0;
// Create worker threads
dec->worker_threads = calloc(dec->num_threads, sizeof(pthread_t));
if (!dec->worker_threads) {
return -1;
}
for (int i = 0; i < dec->num_threads; i++) {
if (pthread_create(&dec->worker_threads[i], NULL, decoder_worker_thread, dec) != 0) {
fprintf(stderr, "Error: Cannot create worker thread %d\n", i);
return -1;
}
}
if (dec->verbose) {
printf("Initialized %d decoder threads\n", dec->num_threads);
}
return 0;
}
/**
* Cleanup decoder threads
*/
static void cleanup_decoder_threads(dt_decoder_t *dec) {
if (dec->num_threads <= 1) {
return;
}
// Signal threads to exit
pthread_mutex_lock(&dec->mutex);
dec->threads_should_exit = 1;
pthread_cond_broadcast(&dec->cond_job_available);
pthread_mutex_unlock(&dec->mutex);
// Wait for threads
if (dec->worker_threads) {
for (int i = 0; i < dec->num_threads; i++) {
pthread_join(dec->worker_threads[i], NULL);
}
free(dec->worker_threads);
}
// Free video contexts
if (dec->worker_video_ctx) {
for (int i = 0; i < dec->num_threads; i++) {
if (dec->worker_video_ctx[i]) {
tav_video_free(dec->worker_video_ctx[i]);
}
}
free(dec->worker_video_ctx);
}
// Free slots
if (dec->slots) {
for (int i = 0; i < dec->num_slots; i++) {
if (dec->slots[i].rgb_frames) {
for (int f = 0; f < dec->slots[i].gop_size; f++) {
free(dec->slots[i].rgb_frames[f]);
}
free(dec->slots[i].rgb_frames);
}
if (dec->slots[i].compressed_data) {
free(dec->slots[i].compressed_data);
}
}
free(dec->slots);
}
pthread_mutex_destroy(&dec->mutex);
pthread_cond_destroy(&dec->cond_job_available);
pthread_cond_destroy(&dec->cond_slot_free);
}
// =============================================================================
// Subpacket Decoding
// =============================================================================
@@ -490,6 +702,161 @@ static int decode_audio_subpacket(dt_decoder_t *dec, const uint8_t *data, size_t
return 0;
}
/**
* Multithreaded video decoding - submit GOP to worker pool
*/
static int decode_video_subpacket_mt(dt_decoder_t *dec, const uint8_t *data, size_t data_len,
size_t *consumed) {
// Minimum: 16 byte LDPC header
if (data_len < DT_TAV_HEADER_SIZE * 2) return -1;
size_t offset = 0;
// LDPC decode TAV header (16 bytes -> 8 bytes)
uint8_t decoded_tav_header[DT_TAV_HEADER_SIZE];
int ldpc_result = ldpc_decode(data + offset, DT_TAV_HEADER_SIZE * 2, decoded_tav_header);
if (ldpc_result < 0) {
if (dec->verbose) {
fprintf(stderr, "Warning: LDPC decode failed for TAV header\n");
}
memcpy(decoded_tav_header, data + offset, DT_TAV_HEADER_SIZE);
} else if (ldpc_result > 0) {
dec->fec_corrections++;
}
offset += DT_TAV_HEADER_SIZE * 2;
// Parse TAV header
uint8_t gop_size = decoded_tav_header[0];
uint32_t compressed_size;
uint32_t rs_block_count;
memcpy(&compressed_size, decoded_tav_header + 1, 4);
rs_block_count = decoded_tav_header[5] |
((uint32_t)decoded_tav_header[6] << 8) |
((uint32_t)decoded_tav_header[7] << 16);
// Calculate RS payload size
size_t rs_total = rs_block_count * RS_BLOCK_SIZE;
if (offset + rs_total > data_len) {
*consumed = data_len;
return -1;
}
// RS decode payload
uint8_t *rs_data = malloc(rs_total);
if (!rs_data) return -1;
memcpy(rs_data, data + offset, rs_total);
uint8_t *decoded_payload = malloc(compressed_size);
if (!decoded_payload) {
free(rs_data);
return -1;
}
int rs_result = rs_decode_blocks(rs_data, rs_total, decoded_payload, compressed_size);
if (rs_result > 0) {
dec->fec_corrections += rs_result;
}
free(rs_data);
// Lazy initialization of multithreading (after first packet header is known)
if (!dec->worker_threads && dec->num_threads > 1) {
if (init_decoder_threads(dec) != 0) {
fprintf(stderr, "Error: Cannot initialize decoder threads, falling back to single-threaded\n");
dec->num_threads = 1;
// Fall back to single-threaded decoding for this packet
free(decoded_payload);
*consumed = offset + rs_total;
return -1;
}
if (dec->verbose) {
printf("Initialized multithreaded decoding: %d threads\n", dec->num_threads);
}
}
// Find an empty slot
int slot_idx = -1;
pthread_mutex_lock(&dec->mutex);
while (slot_idx < 0) {
// Try to write completed GOPs first
for (int i = 0; i < dec->num_slots; i++) {
if (dec->slots[i].status == DECODE_SLOT_DONE &&
dec->slots[i].job_id == dec->next_write_slot) {
gop_decode_job_t *job = &dec->slots[i];
pthread_mutex_unlock(&dec->mutex);
// Write frames to temp file
if (job->decode_result == 0 && dec->video_temp_fp) {
for (int f = 0; f < job->gop_size; f++) {
fwrite(job->rgb_frames[f], 1, job->frame_size, dec->video_temp_fp);
dec->frames_decoded++;
}
}
pthread_mutex_lock(&dec->mutex);
// Free job resources while holding mutex
for (int f = 0; f < job->gop_size; f++) {
free(job->rgb_frames[f]);
}
free(job->rgb_frames);
free(job->compressed_data);
job->status = DECODE_SLOT_EMPTY;
job->rgb_frames = NULL;
job->compressed_data = NULL;
dec->next_write_slot++;
break;
}
}
// Look for empty slot
for (int i = 0; i < dec->num_slots; i++) {
if (dec->slots[i].status == DECODE_SLOT_EMPTY) {
slot_idx = i;
break;
}
}
if (slot_idx < 0) {
// Wait for a slot to become available
pthread_cond_wait(&dec->cond_slot_free, &dec->mutex);
}
}
// Fill the slot
gop_decode_job_t *job = &dec->slots[slot_idx];
int internal_height = dec->is_interlaced ? dec->height / 2 : dec->height;
size_t frame_size = dec->width * internal_height * 3;
job->compressed_data = decoded_payload; // Transfer ownership
job->compressed_size = compressed_size;
job->gop_size = gop_size;
job->job_id = dec->jobs_submitted++;
job->frame_size = frame_size;
job->decode_result = -1;
// Allocate frame buffers
job->rgb_frames = malloc(gop_size * sizeof(uint8_t*));
for (int i = 0; i < gop_size; i++) {
job->rgb_frames[i] = malloc(frame_size);
}
// Submit job
job->status = DECODE_SLOT_PENDING;
pthread_cond_broadcast(&dec->cond_job_available);
pthread_mutex_unlock(&dec->mutex);
offset += rs_total;
*consumed = offset;
return 0;
}
static int decode_video_subpacket(dt_decoder_t *dec, const uint8_t *data, size_t data_len,
size_t *consumed) {
// Minimum: 16 byte LDPC header
@@ -797,229 +1164,6 @@ static int spawn_ffmpeg(dt_decoder_t *dec) {
// =============================================================================
// Multithreading Support
// =============================================================================
// Worker thread function - decodes GOPs in parallel
static void *decoder_worker_thread(void *arg) {
dt_decoder_t *dec = (dt_decoder_t *)arg;
// Get thread index by finding our thread ID in the array
int thread_idx = -1;
pthread_t self = pthread_self();
for (int i = 0; i < dec->num_threads; i++) {
if (pthread_equal(dec->worker_threads[i], self)) {
thread_idx = i;
break;
}
}
if (thread_idx < 0) thread_idx = 0; // Fallback
tav_video_context_t *my_video_ctx = dec->worker_video_ctx[thread_idx];
while (1) {
pthread_mutex_lock(&dec->mutex);
// Find a pending slot to work on
int slot_idx = -1;
while (slot_idx < 0 && !dec->threads_should_exit) {
for (int i = 0; i < dec->num_slots; i++) {
if (dec->slots[i].status == DECODE_SLOT_PENDING &&
dec->slots[i].compressed_data != NULL) {
dec->slots[i].status = DECODE_SLOT_DONE; // Claim it temporarily
slot_idx = i;
break;
}
}
if (slot_idx < 0 && !dec->threads_should_exit) {
pthread_cond_wait(&dec->cond_job_available, &dec->mutex);
}
}
if (dec->threads_should_exit && slot_idx < 0) {
pthread_mutex_unlock(&dec->mutex);
break;
}
pthread_mutex_unlock(&dec->mutex);
if (slot_idx < 0) continue;
gop_decode_job_t *job = &dec->slots[slot_idx];
// Decode GOP using our thread's decoder context
job->decode_result = tav_video_decode_gop(
my_video_ctx,
job->compressed_data,
job->compressed_size,
job->gop_size,
job->rgb_frames
);
// Free compressed data
free(job->compressed_data);
job->compressed_data = NULL;
// Mark as done
pthread_mutex_lock(&dec->mutex);
job->status = DECODE_SLOT_DONE;
dec->jobs_completed++;
pthread_cond_broadcast(&dec->cond_slot_free);
pthread_mutex_unlock(&dec->mutex);
}
return NULL;
}
static int init_decoder_threads(dt_decoder_t *dec) {
if (dec->num_threads <= 0) {
return 0; // Single-threaded mode
}
// Limit threads
if (dec->num_threads > MAX_DECODE_THREADS) {
dec->num_threads = MAX_DECODE_THREADS;
}
// Number of slots = threads + 2 for pipelining
dec->num_slots = dec->num_threads + 2;
// Allocate slots
dec->slots = calloc(dec->num_slots, sizeof(gop_decode_job_t));
if (!dec->slots) {
fprintf(stderr, "Error: Failed to allocate decode slots\n");
return -1;
}
// Allocate frame buffers for each slot
int internal_height = dec->is_interlaced ? dec->height / 2 : dec->height;
size_t frame_size = dec->width * internal_height * 3;
int max_gop_size = 16; // TAV-DT uses fixed 16-frame GOPs
for (int i = 0; i < dec->num_slots; i++) {
dec->slots[i].rgb_frames = malloc(max_gop_size * sizeof(uint8_t*));
if (!dec->slots[i].rgb_frames) {
fprintf(stderr, "Error: Failed to allocate frame pointers for slot %d\n", i);
return -1;
}
for (int f = 0; f < max_gop_size; f++) {
dec->slots[i].rgb_frames[f] = malloc(frame_size);
if (!dec->slots[i].rgb_frames[f]) {
fprintf(stderr, "Error: Failed to allocate frame buffer for slot %d\n", i);
return -1;
}
}
dec->slots[i].frames_allocated = max_gop_size;
dec->slots[i].status = DECODE_SLOT_EMPTY;
dec->slots[i].job_id = -1;
}
// Create per-thread video decoder contexts
dec->worker_video_ctx = malloc(dec->num_threads * sizeof(tav_video_context_t*));
if (!dec->worker_video_ctx) {
fprintf(stderr, "Error: Failed to allocate worker video contexts\n");
return -1;
}
tav_video_params_t video_params = {
.width = dec->width,
.height = internal_height,
.decomp_levels = DT_SPATIAL_LEVELS,
.temporal_levels = DT_TEMPORAL_LEVELS,
.wavelet_filter = 1, // CDF 9/7
.temporal_wavelet = 255, // Haar
.entropy_coder = 1, // EZBC
.channel_layout = 0, // YCoCg-R
.perceptual_tuning = 1,
.quantiser_y = QUALITY_Y[dec->quality_index],
.quantiser_co = QUALITY_CO[dec->quality_index],
.quantiser_cg = QUALITY_CG[dec->quality_index],
.encoder_preset = 0x01, // Sports
.monoblock = 1
};
for (int i = 0; i < dec->num_threads; i++) {
dec->worker_video_ctx[i] = tav_video_create(&video_params);
if (!dec->worker_video_ctx[i]) {
fprintf(stderr, "Error: Failed to create video context for thread %d\n", i);
return -1;
}
}
// Initialize synchronization primitives
pthread_mutex_init(&dec->mutex, NULL);
pthread_cond_init(&dec->cond_job_available, NULL);
pthread_cond_init(&dec->cond_slot_free, NULL);
dec->threads_should_exit = 0;
dec->next_write_slot = 0;
dec->jobs_submitted = 0;
dec->jobs_completed = 0;
// Create worker threads
dec->worker_threads = malloc(dec->num_threads * sizeof(pthread_t));
if (!dec->worker_threads) {
fprintf(stderr, "Error: Failed to allocate worker threads\n");
return -1;
}
for (int i = 0; i < dec->num_threads; i++) {
if (pthread_create(&dec->worker_threads[i], NULL, decoder_worker_thread, dec) != 0) {
fprintf(stderr, "Error: Failed to create worker thread %d\n", i);
return -1;
}
}
if (dec->verbose) {
printf("Initialized %d decoder worker threads with %d slots\n",
dec->num_threads, dec->num_slots);
}
return 0;
}
static void cleanup_decoder_threads(dt_decoder_t *dec) {
if (dec->num_threads <= 0) return;
// Signal threads to exit
pthread_mutex_lock(&dec->mutex);
dec->threads_should_exit = 1;
pthread_cond_broadcast(&dec->cond_job_available);
pthread_mutex_unlock(&dec->mutex);
// Wait for threads to finish
for (int i = 0; i < dec->num_threads; i++) {
pthread_join(dec->worker_threads[i], NULL);
}
free(dec->worker_threads);
dec->worker_threads = NULL;
// Free per-thread video contexts
for (int i = 0; i < dec->num_threads; i++) {
tav_video_free(dec->worker_video_ctx[i]);
}
free(dec->worker_video_ctx);
dec->worker_video_ctx = NULL;
// Free slots
for (int i = 0; i < dec->num_slots; i++) {
if (dec->slots[i].rgb_frames) {
for (int f = 0; f < dec->slots[i].frames_allocated; f++) {
free(dec->slots[i].rgb_frames[f]);
}
free(dec->slots[i].rgb_frames);
}
if (dec->slots[i].compressed_data) {
free(dec->slots[i].compressed_data);
}
}
free(dec->slots);
dec->slots = NULL;
// Destroy sync primitives
pthread_mutex_destroy(&dec->mutex);
pthread_cond_destroy(&dec->cond_job_available);
pthread_cond_destroy(&dec->cond_slot_free);
}
// =============================================================================
// Main Decoding Loop
// =============================================================================
@@ -1067,9 +1211,14 @@ static int process_packet(dt_decoder_t *dec) {
// Process TAV subpacket (video comes after audio)
if (header.offset_to_video < header.packet_size) {
size_t tav_consumed = 0;
if (dec->num_threads > 1) {
decode_video_subpacket_mt(dec, packet_data + header.offset_to_video,
header.packet_size - header.offset_to_video, &tav_consumed);
} else {
decode_video_subpacket(dec, packet_data + header.offset_to_video,
header.packet_size - header.offset_to_video, &tav_consumed);
}
}
dec->packets_processed++;
@@ -1104,6 +1253,9 @@ static int run_decoder(dt_decoder_t *dec) {
fprintf(stderr, "Warning: Cannot create temp video file, video will be skipped\n");
}
// Note: Multithreading will be initialized lazily after reading first packet header
// (need to know dimensions and quality settings first)
// Decode all packets
if (dec->verbose) {
printf("Decoding TAV-DT stream...\n");
@@ -1114,6 +1266,58 @@ static int run_decoder(dt_decoder_t *dec) {
// Progress is shown in process_packet
}
// Flush remaining GOPs in multithreaded mode
if (dec->num_threads > 1) {
pthread_mutex_lock(&dec->mutex);
// Write all remaining completed GOPs in order
while (dec->next_write_slot < dec->jobs_submitted) {
int found = -1;
for (int i = 0; i < dec->num_slots; i++) {
if (dec->slots[i].status == DECODE_SLOT_DONE &&
dec->slots[i].job_id == dec->next_write_slot) {
found = i;
break;
}
}
if (found >= 0) {
gop_decode_job_t *job = &dec->slots[found];
pthread_mutex_unlock(&dec->mutex);
// Write frames
if (job->decode_result == 0 && dec->video_temp_fp) {
for (int f = 0; f < job->gop_size; f++) {
fwrite(job->rgb_frames[f], 1, job->frame_size, dec->video_temp_fp);
dec->frames_decoded++;
}
}
pthread_mutex_lock(&dec->mutex);
// Free resources while holding mutex
for (int f = 0; f < job->gop_size; f++) {
free(job->rgb_frames[f]);
}
free(job->rgb_frames);
free(job->compressed_data);
job->status = DECODE_SLOT_EMPTY;
job->rgb_frames = NULL;
job->compressed_data = NULL;
dec->next_write_slot++;
} else {
// Wait for the GOP to complete
pthread_cond_wait(&dec->cond_slot_free, &dec->mutex);
}
}
pthread_mutex_unlock(&dec->mutex);
// Cleanup threads
cleanup_decoder_threads(dec);
}
// Close temp files for reading by FFmpeg
if (dec->audio_temp_fp) {
fclose(dec->audio_temp_fp);