2 * Copyright (c) 2004 Roman Shaposhnik
3 * Copyright (c) 2008 Alexander Strange (astrange@ithinksw.com)
5 * Many thanks to Steven M. Schultz for providing clever ideas and
6 * to Michael Niedermayer <michaelni@gmx.at> for writing initial
9 * This file is part of FFmpeg.
11 * FFmpeg is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU Lesser General Public
13 * License as published by the Free Software Foundation; either
14 * version 2.1 of the License, or (at your option) any later version.
16 * FFmpeg is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 * Lesser General Public License for more details.
21 * You should have received a copy of the GNU Lesser General Public
22 * License along with FFmpeg; if not, write to the Free Software
23 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
28 * Multithreading support functions
29 * @see doc/multithreading.txt
37 typedef int (action_func)(AVCodecContext *c, void *arg);
38 typedef int (action_func2)(AVCodecContext *c, void *arg, int jobnr, int threadnr);
40 typedef struct ThreadContext {
50 pthread_cond_t last_job_cond;
51 pthread_cond_t current_job_cond;
52 pthread_mutex_t current_job_lock;
57 /// Max number of frame buffers that can be allocated when using frame threads.
58 #define MAX_BUFFERS 32
61 * Context used by codec threads and stored in their AVCodecContext thread_opaque.
63 typedef struct PerThreadContext {
64 struct FrameThreadContext *parent;
67 pthread_cond_t input_cond; ///< Used to wait for a new packet from the main thread.
68 pthread_cond_t progress_cond; ///< Used by child threads to wait for progress to change.
69 pthread_cond_t output_cond; ///< Used by the main thread to wait for frames to finish.
71 pthread_mutex_t mutex; ///< Mutex used to protect the contents of the PerThreadContext.
72 pthread_mutex_t progress_mutex; ///< Mutex used to protect frame progress values and progress_cond.
74 AVCodecContext *avctx; ///< Context used to decode packets passed to this thread.
76 AVPacket avpkt; ///< Input packet (for decoding) or output (for encoding).
77 int allocated_buf_size; ///< Size allocated for avpkt.data
79 AVFrame frame; ///< Output frame (for decoding) or input (for encoding).
80 int got_frame; ///< The output of got_picture_ptr from the last avcodec_decode_video() call.
81 int result; ///< The result of the last codec decode/encode() call.
84 STATE_INPUT_READY, ///< Set when the thread is awaiting a packet.
85 STATE_SETTING_UP, ///< Set before the codec has called ff_thread_finish_setup().
86 STATE_GET_BUFFER, /**<
87 * Set when the codec calls get_buffer().
88 * State is returned to STATE_SETTING_UP afterwards.
90 STATE_SETUP_FINISHED ///< Set after the codec has called ff_thread_finish_setup().
94 * Array of frames passed to ff_thread_release_buffer().
95 * Frames are released after all threads referencing them are finished.
97 AVFrame released_buffers[MAX_BUFFERS];
98 int num_released_buffers;
101 * Array of progress values used by ff_thread_get_buffer().
103 int progress[MAX_BUFFERS][2];
104 uint8_t progress_used[MAX_BUFFERS];
106 AVFrame *requested_frame; ///< AVFrame the codec passed to get_buffer()
110 * Context stored in the client AVCodecContext thread_opaque.
112 typedef struct FrameThreadContext {
113 PerThreadContext *threads; ///< The contexts for each thread.
114 PerThreadContext *prev_thread; ///< The last thread submit_packet() was called on.
116 pthread_mutex_t buffer_mutex; ///< Mutex used to protect get/release_buffer().
118 int next_decoding; ///< The next context to submit a packet to.
119 int next_finished; ///< The next context to return output from.
122 * Set for the first N packets, where N is the number of threads.
123 * While it is set, ff_thread_en/decode_frame won't return any results.
126 int die; ///< Set when threads should exit.
127 } FrameThreadContext;
129 static void* attribute_align_arg worker(void *v)
131 AVCodecContext *avctx = v;
132 ThreadContext *c = avctx->thread_opaque;
133 int our_job = c->job_count;
134 int thread_count = avctx->thread_count;
137 pthread_mutex_lock(&c->current_job_lock);
138 self_id = c->current_job++;
140 while (our_job >= c->job_count) {
141 if (c->current_job == thread_count + c->job_count)
142 pthread_cond_signal(&c->last_job_cond);
144 pthread_cond_wait(&c->current_job_cond, &c->current_job_lock);
148 pthread_mutex_unlock(&c->current_job_lock);
152 pthread_mutex_unlock(&c->current_job_lock);
154 c->rets[our_job%c->rets_count] = c->func ? c->func(avctx, (char*)c->args + our_job*c->job_size):
155 c->func2(avctx, c->args, our_job, self_id);
157 pthread_mutex_lock(&c->current_job_lock);
158 our_job = c->current_job++;
162 static av_always_inline void avcodec_thread_park_workers(ThreadContext *c, int thread_count)
164 pthread_cond_wait(&c->last_job_cond, &c->current_job_lock);
165 pthread_mutex_unlock(&c->current_job_lock);
168 static void thread_free(AVCodecContext *avctx)
170 ThreadContext *c = avctx->thread_opaque;
173 pthread_mutex_lock(&c->current_job_lock);
175 pthread_cond_broadcast(&c->current_job_cond);
176 pthread_mutex_unlock(&c->current_job_lock);
178 for (i=0; i<avctx->thread_count; i++)
179 pthread_join(c->workers[i], NULL);
181 pthread_mutex_destroy(&c->current_job_lock);
182 pthread_cond_destroy(&c->current_job_cond);
183 pthread_cond_destroy(&c->last_job_cond);
185 av_freep(&avctx->thread_opaque);
188 static int avcodec_thread_execute(AVCodecContext *avctx, action_func* func, void *arg, int *ret, int job_count, int job_size)
190 ThreadContext *c= avctx->thread_opaque;
193 if (!(avctx->active_thread_type&FF_THREAD_SLICE) || avctx->thread_count <= 1)
194 return avcodec_default_execute(avctx, func, arg, ret, job_count, job_size);
199 pthread_mutex_lock(&c->current_job_lock);
201 c->current_job = avctx->thread_count;
202 c->job_count = job_count;
203 c->job_size = job_size;
208 c->rets_count = job_count;
210 c->rets = &dummy_ret;
213 pthread_cond_broadcast(&c->current_job_cond);
215 avcodec_thread_park_workers(c, avctx->thread_count);
220 static int avcodec_thread_execute2(AVCodecContext *avctx, action_func2* func2, void *arg, int *ret, int job_count)
222 ThreadContext *c= avctx->thread_opaque;
224 return avcodec_thread_execute(avctx, NULL, arg, ret, job_count, 0);
227 static int thread_init(AVCodecContext *avctx)
231 int thread_count = avctx->thread_count;
233 if (thread_count <= 1)
236 c = av_mallocz(sizeof(ThreadContext));
240 c->workers = av_mallocz(sizeof(pthread_t)*thread_count);
246 avctx->thread_opaque = c;
251 pthread_cond_init(&c->current_job_cond, NULL);
252 pthread_cond_init(&c->last_job_cond, NULL);
253 pthread_mutex_init(&c->current_job_lock, NULL);
254 pthread_mutex_lock(&c->current_job_lock);
255 for (i=0; i<thread_count; i++) {
256 if(pthread_create(&c->workers[i], NULL, worker, avctx)) {
257 avctx->thread_count = i;
258 pthread_mutex_unlock(&c->current_job_lock);
259 ff_thread_free(avctx);
264 avcodec_thread_park_workers(c, thread_count);
266 avctx->execute = avcodec_thread_execute;
267 avctx->execute2 = avcodec_thread_execute2;
272 * Codec worker thread.
274 * Automatically calls ff_thread_finish_setup() if the codec does
275 * not provide an update_thread_context method, or if the codec returns
278 static attribute_align_arg void *frame_worker_thread(void *arg)
280 PerThreadContext *p = arg;
281 FrameThreadContext *fctx = p->parent;
282 AVCodecContext *avctx = p->avctx;
283 AVCodec *codec = avctx->codec;
286 if (p->state == STATE_INPUT_READY && !fctx->die) {
287 pthread_mutex_lock(&p->mutex);
288 while (p->state == STATE_INPUT_READY && !fctx->die)
289 pthread_cond_wait(&p->input_cond, &p->mutex);
290 pthread_mutex_unlock(&p->mutex);
293 if (fctx->die) break;
295 if (!codec->update_thread_context) ff_thread_finish_setup(avctx);
297 pthread_mutex_lock(&p->mutex);
298 avcodec_get_frame_defaults(&p->frame);
300 p->result = codec->decode(avctx, &p->frame, &p->got_frame, &p->avpkt);
302 if (p->state == STATE_SETTING_UP) ff_thread_finish_setup(avctx);
304 p->state = STATE_INPUT_READY;
306 pthread_mutex_lock(&p->progress_mutex);
307 pthread_cond_signal(&p->output_cond);
308 pthread_mutex_unlock(&p->progress_mutex);
310 pthread_mutex_unlock(&p->mutex);
317 * Updates the next thread's AVCodecContext with values from the reference thread's context.
319 * @param dst The destination context.
320 * @param src The source context.
321 * @param for_user 0 if the destination is a codec thread, 1 if the destination is the user's thread
323 static int update_context_from_thread(AVCodecContext *dst, AVCodecContext *src, int for_user)
328 dst->sub_id = src->sub_id;
329 dst->time_base = src->time_base;
330 dst->width = src->width;
331 dst->height = src->height;
332 dst->pix_fmt = src->pix_fmt;
334 dst->has_b_frames = src->has_b_frames;
335 dst->idct_algo = src->idct_algo;
336 dst->slice_count = src->slice_count;
338 dst->bits_per_coded_sample = src->bits_per_coded_sample;
339 dst->sample_aspect_ratio = src->sample_aspect_ratio;
340 dst->dtg_active_format = src->dtg_active_format;
342 dst->profile = src->profile;
343 dst->level = src->level;
345 dst->bits_per_raw_sample = src->bits_per_raw_sample;
346 dst->ticks_per_frame = src->ticks_per_frame;
347 dst->color_primaries = src->color_primaries;
349 dst->color_trc = src->color_trc;
350 dst->colorspace = src->colorspace;
351 dst->color_range = src->color_range;
352 dst->chroma_sample_location = src->chroma_sample_location;
356 dst->coded_frame = src->coded_frame;
357 dst->has_b_frames += src->thread_count - 1;
359 if (dst->codec->update_thread_context)
360 err = dst->codec->update_thread_context(dst, src);
367 * Update the next thread's AVCodecContext with values set by the user.
369 * @param dst The destination context.
370 * @param src The source context.
372 static void update_context_from_user(AVCodecContext *dst, AVCodecContext *src)
374 #define copy_fields(s, e) memcpy(&dst->s, &src->s, (char*)&dst->e - (char*)&dst->s);
375 dst->flags = src->flags;
377 dst->draw_horiz_band= src->draw_horiz_band;
378 dst->get_buffer = src->get_buffer;
379 dst->release_buffer = src->release_buffer;
381 dst->opaque = src->opaque;
382 dst->hurry_up = src->hurry_up;
383 dst->dsp_mask = src->dsp_mask;
384 dst->debug = src->debug;
385 dst->debug_mv = src->debug_mv;
387 dst->slice_flags = src->slice_flags;
388 dst->flags2 = src->flags2;
390 copy_fields(skip_loop_filter, bidir_refine);
392 dst->frame_number = src->frame_number;
393 dst->reordered_opaque = src->reordered_opaque;
397 static void free_progress(AVFrame *f)
399 PerThreadContext *p = f->owner->thread_opaque;
400 int *progress = f->thread_opaque;
402 p->progress_used[(progress - p->progress[0]) / 2] = 0;
405 /// Releases the buffers that this decoding thread was the last user of.
406 static void release_delayed_buffers(PerThreadContext *p)
408 FrameThreadContext *fctx = p->parent;
410 while (p->num_released_buffers > 0) {
411 AVFrame *f = &p->released_buffers[--p->num_released_buffers];
413 pthread_mutex_lock(&fctx->buffer_mutex);
415 f->thread_opaque = NULL;
417 f->owner->release_buffer(f->owner, f);
418 pthread_mutex_unlock(&fctx->buffer_mutex);
422 static int submit_packet(PerThreadContext *p, AVPacket *avpkt)
424 FrameThreadContext *fctx = p->parent;
425 PerThreadContext *prev_thread = fctx->prev_thread;
426 AVCodec *codec = p->avctx->codec;
427 uint8_t *buf = p->avpkt.data;
429 if (!avpkt->size && !(codec->capabilities & CODEC_CAP_DELAY)) return 0;
431 pthread_mutex_lock(&p->mutex);
433 release_delayed_buffers(p);
437 if (prev_thread->state == STATE_SETTING_UP) {
438 pthread_mutex_lock(&prev_thread->progress_mutex);
439 while (prev_thread->state == STATE_SETTING_UP)
440 pthread_cond_wait(&prev_thread->progress_cond, &prev_thread->progress_mutex);
441 pthread_mutex_unlock(&prev_thread->progress_mutex);
444 err = update_context_from_thread(p->avctx, prev_thread->avctx, 0);
446 pthread_mutex_unlock(&p->mutex);
451 av_fast_malloc(&buf, &p->allocated_buf_size, avpkt->size + FF_INPUT_BUFFER_PADDING_SIZE);
454 memcpy(buf, avpkt->data, avpkt->size);
455 memset(buf + avpkt->size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
457 p->state = STATE_SETTING_UP;
458 pthread_cond_signal(&p->input_cond);
459 pthread_mutex_unlock(&p->mutex);
462 * If the client doesn't have a thread-safe get_buffer(),
463 * then decoding threads call back to the main thread,
464 * and it calls back to the client here.
467 if (!p->avctx->thread_safe_callbacks &&
468 p->avctx->get_buffer != avcodec_default_get_buffer) {
469 while (p->state != STATE_SETUP_FINISHED && p->state != STATE_INPUT_READY) {
470 pthread_mutex_lock(&p->progress_mutex);
471 while (p->state == STATE_SETTING_UP)
472 pthread_cond_wait(&p->progress_cond, &p->progress_mutex);
474 if (p->state == STATE_GET_BUFFER) {
475 p->result = p->avctx->get_buffer(p->avctx, p->requested_frame);
476 p->state = STATE_SETTING_UP;
477 pthread_cond_signal(&p->progress_cond);
479 pthread_mutex_unlock(&p->progress_mutex);
483 fctx->prev_thread = p;
488 int ff_thread_decode_frame(AVCodecContext *avctx,
489 AVFrame *picture, int *got_picture_ptr,
492 FrameThreadContext *fctx = avctx->thread_opaque;
493 int finished = fctx->next_finished;
498 * Submit a packet to the next decoding thread.
501 p = &fctx->threads[fctx->next_decoding];
502 update_context_from_user(p->avctx, avctx);
503 err = submit_packet(p, avpkt);
506 fctx->next_decoding++;
509 * If we're still receiving the initial packets, don't return a frame.
512 if (fctx->delaying && avpkt->size) {
513 if (fctx->next_decoding >= (avctx->thread_count-1)) fctx->delaying = 0;
520 * Return the next available frame from the oldest thread.
521 * If we're at the end of the stream, then we have to skip threads that
522 * didn't output a frame, because we don't want to accidentally signal
523 * EOF (avpkt->size == 0 && *got_picture_ptr == 0).
527 p = &fctx->threads[finished++];
529 if (p->state != STATE_INPUT_READY) {
530 pthread_mutex_lock(&p->progress_mutex);
531 while (p->state != STATE_INPUT_READY)
532 pthread_cond_wait(&p->output_cond, &p->progress_mutex);
533 pthread_mutex_unlock(&p->progress_mutex);
537 *got_picture_ptr = p->got_frame;
538 picture->pkt_dts = p->avpkt.dts;
541 * A later call with avkpt->size == 0 may loop over all threads,
542 * including this one, searching for a frame to return before being
543 * stopped by the "finished != fctx->next_finished" condition.
544 * Make sure we don't mistakenly return the same frame again.
548 if (finished >= avctx->thread_count) finished = 0;
549 } while (!avpkt->size && !*got_picture_ptr && finished != fctx->next_finished);
551 update_context_from_thread(avctx, p->avctx, 1);
553 if (fctx->next_decoding >= avctx->thread_count) fctx->next_decoding = 0;
555 fctx->next_finished = finished;
560 void ff_thread_report_progress(AVFrame *f, int n, int field)
563 int *progress = f->thread_opaque;
565 if (!progress || progress[field] >= n) return;
567 p = f->owner->thread_opaque;
569 if (f->owner->debug&FF_DEBUG_THREADS)
570 av_log(f->owner, AV_LOG_DEBUG, "%p finished %d field %d\n", progress, n, field);
572 pthread_mutex_lock(&p->progress_mutex);
574 pthread_cond_broadcast(&p->progress_cond);
575 pthread_mutex_unlock(&p->progress_mutex);
578 void ff_thread_await_progress(AVFrame *f, int n, int field)
581 int *progress = f->thread_opaque;
583 if (!progress || progress[field] >= n) return;
585 p = f->owner->thread_opaque;
587 if (f->owner->debug&FF_DEBUG_THREADS)
588 av_log(f->owner, AV_LOG_DEBUG, "thread awaiting %d field %d from %p\n", n, field, progress);
590 pthread_mutex_lock(&p->progress_mutex);
591 while (progress[field] < n)
592 pthread_cond_wait(&p->progress_cond, &p->progress_mutex);
593 pthread_mutex_unlock(&p->progress_mutex);
596 void ff_thread_finish_setup(AVCodecContext *avctx) {
597 PerThreadContext *p = avctx->thread_opaque;
599 if (!(avctx->active_thread_type&FF_THREAD_FRAME)) return;
601 pthread_mutex_lock(&p->progress_mutex);
602 p->state = STATE_SETUP_FINISHED;
603 pthread_cond_broadcast(&p->progress_cond);
604 pthread_mutex_unlock(&p->progress_mutex);
607 /// Waits for all threads to finish.
608 static void park_frame_worker_threads(FrameThreadContext *fctx, int thread_count)
612 for (i = 0; i < thread_count; i++) {
613 PerThreadContext *p = &fctx->threads[i];
615 if (p->state != STATE_INPUT_READY) {
616 pthread_mutex_lock(&p->progress_mutex);
617 while (p->state != STATE_INPUT_READY)
618 pthread_cond_wait(&p->output_cond, &p->progress_mutex);
619 pthread_mutex_unlock(&p->progress_mutex);
624 static void frame_thread_free(AVCodecContext *avctx, int thread_count)
626 FrameThreadContext *fctx = avctx->thread_opaque;
627 AVCodec *codec = avctx->codec;
630 park_frame_worker_threads(fctx, thread_count);
632 if (fctx->prev_thread)
633 update_context_from_thread(fctx->threads->avctx, fctx->prev_thread->avctx, 0);
637 for (i = 0; i < thread_count; i++) {
638 PerThreadContext *p = &fctx->threads[i];
640 pthread_mutex_lock(&p->mutex);
641 pthread_cond_signal(&p->input_cond);
642 pthread_mutex_unlock(&p->mutex);
644 pthread_join(p->thread, NULL);
647 codec->close(p->avctx);
651 release_delayed_buffers(p);
654 for (i = 0; i < thread_count; i++) {
655 PerThreadContext *p = &fctx->threads[i];
657 avcodec_default_free_buffers(p->avctx);
659 pthread_mutex_destroy(&p->mutex);
660 pthread_mutex_destroy(&p->progress_mutex);
661 pthread_cond_destroy(&p->input_cond);
662 pthread_cond_destroy(&p->progress_cond);
663 pthread_cond_destroy(&p->output_cond);
664 av_freep(&p->avpkt.data);
667 av_freep(&p->avctx->priv_data);
672 av_freep(&fctx->threads);
673 pthread_mutex_destroy(&fctx->buffer_mutex);
674 av_freep(&avctx->thread_opaque);
677 static int frame_thread_init(AVCodecContext *avctx)
679 int thread_count = avctx->thread_count;
680 AVCodec *codec = avctx->codec;
681 AVCodecContext *src = avctx;
682 FrameThreadContext *fctx;
685 avctx->thread_opaque = fctx = av_mallocz(sizeof(FrameThreadContext));
687 fctx->threads = av_mallocz(sizeof(PerThreadContext) * thread_count);
688 pthread_mutex_init(&fctx->buffer_mutex, NULL);
691 for (i = 0; i < thread_count; i++) {
692 AVCodecContext *copy = av_malloc(sizeof(AVCodecContext));
693 PerThreadContext *p = &fctx->threads[i];
695 pthread_mutex_init(&p->mutex, NULL);
696 pthread_mutex_init(&p->progress_mutex, NULL);
697 pthread_cond_init(&p->input_cond, NULL);
698 pthread_cond_init(&p->progress_cond, NULL);
699 pthread_cond_init(&p->output_cond, NULL);
705 copy->thread_opaque = p;
706 copy->pkt = &p->avpkt;
712 err = codec->init(copy);
714 update_context_from_thread(avctx, copy, 1);
717 copy->priv_data = av_malloc(codec->priv_data_size);
718 memcpy(copy->priv_data, src->priv_data, codec->priv_data_size);
720 if (codec->init_thread_copy)
721 err = codec->init_thread_copy(copy);
726 pthread_create(&p->thread, NULL, frame_worker_thread, p);
732 frame_thread_free(avctx, i+1);
737 void ff_thread_flush(AVCodecContext *avctx)
739 FrameThreadContext *fctx = avctx->thread_opaque;
741 if (!avctx->thread_opaque) return;
743 park_frame_worker_threads(fctx, avctx->thread_count);
745 if (fctx->prev_thread)
746 update_context_from_thread(fctx->threads->avctx, fctx->prev_thread->avctx, 0);
748 fctx->next_decoding = fctx->next_finished = 0;
750 fctx->prev_thread = NULL;
753 static int *allocate_progress(PerThreadContext *p)
757 for (i = 0; i < MAX_BUFFERS; i++)
758 if (!p->progress_used[i]) break;
760 if (i == MAX_BUFFERS) {
761 av_log(p->avctx, AV_LOG_ERROR, "allocate_progress() overflow\n");
765 p->progress_used[i] = 1;
767 return p->progress[i];
770 int ff_thread_get_buffer(AVCodecContext *avctx, AVFrame *f)
772 PerThreadContext *p = avctx->thread_opaque;
777 if (!(avctx->active_thread_type&FF_THREAD_FRAME)) {
778 f->thread_opaque = NULL;
779 return avctx->get_buffer(avctx, f);
782 if (p->state != STATE_SETTING_UP) {
783 av_log(avctx, AV_LOG_ERROR, "get_buffer() cannot be called after ff_thread_finish_setup()\n");
787 pthread_mutex_lock(&p->parent->buffer_mutex);
788 f->thread_opaque = progress = allocate_progress(p);
791 pthread_mutex_unlock(&p->parent->buffer_mutex);
798 if (avctx->thread_safe_callbacks ||
799 avctx->get_buffer == avcodec_default_get_buffer) {
800 err = avctx->get_buffer(avctx, f);
802 p->requested_frame = f;
803 p->state = STATE_GET_BUFFER;
804 pthread_mutex_lock(&p->progress_mutex);
805 pthread_cond_signal(&p->progress_cond);
807 while (p->state != STATE_SETTING_UP)
808 pthread_cond_wait(&p->progress_cond, &p->progress_mutex);
812 pthread_mutex_unlock(&p->progress_mutex);
815 pthread_mutex_unlock(&p->parent->buffer_mutex);
818 * Buffer age is difficult to keep track of between
819 * multiple threads, and the optimizations it allows
820 * are not worth the effort. It is disabled for now.
827 void ff_thread_release_buffer(AVCodecContext *avctx, AVFrame *f)
829 PerThreadContext *p = avctx->thread_opaque;
831 if (!(avctx->active_thread_type&FF_THREAD_FRAME)) {
832 avctx->release_buffer(avctx, f);
836 if (p->num_released_buffers >= MAX_BUFFERS) {
837 av_log(p->avctx, AV_LOG_ERROR, "too many thread_release_buffer calls!\n");
841 if(avctx->debug & FF_DEBUG_BUFFERS)
842 av_log(avctx, AV_LOG_DEBUG, "thread_release_buffer called on pic %p, %d buffers used\n",
843 f, f->owner->internal_buffer_count);
845 p->released_buffers[p->num_released_buffers++] = *f;
846 memset(f->data, 0, sizeof(f->data));
850 * Set the threading algorithms used.
852 * Threading requires more than one thread.
853 * Frame threading requires entire frames to be passed to the codec,
854 * and introduces extra decoding delay, so is incompatible with low_delay.
856 * @param avctx The context.
858 static void validate_thread_parameters(AVCodecContext *avctx)
860 int frame_threading_supported = (avctx->codec->capabilities & CODEC_CAP_FRAME_THREADS)
861 && !(avctx->flags & CODEC_FLAG_TRUNCATED)
862 && !(avctx->flags & CODEC_FLAG_LOW_DELAY)
863 && !(avctx->flags2 & CODEC_FLAG2_CHUNKS);
864 if (avctx->thread_count == 1) {
865 avctx->active_thread_type = 0;
866 } else if (frame_threading_supported && (avctx->thread_type & FF_THREAD_FRAME)) {
867 avctx->active_thread_type = FF_THREAD_FRAME;
869 avctx->active_thread_type = FF_THREAD_SLICE;
873 int ff_thread_init(AVCodecContext *avctx, int thread_count)
875 if (avctx->thread_opaque) {
876 av_log(avctx, AV_LOG_ERROR, "avcodec_thread_init is ignored after avcodec_open\n");
880 avctx->thread_count = FFMAX(1, thread_count);
883 validate_thread_parameters(avctx);
885 if (avctx->active_thread_type&FF_THREAD_SLICE)
886 return thread_init(avctx);
887 else if (avctx->active_thread_type&FF_THREAD_FRAME)
888 return frame_thread_init(avctx);
894 void ff_thread_free(AVCodecContext *avctx)
896 if (avctx->active_thread_type&FF_THREAD_FRAME)
897 frame_thread_free(avctx, avctx->thread_count);