/*

  * This file is part of FFmpeg.

  *

  * FFmpeg is free software; you can redistribute it and/or

  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *

  * FFmpeg is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public

  * License along with FFmpeg; if not, write to the Free Software

  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 /**
  * @file
  * Frame multithreading support functions
  * @see doc/multithreading.txt
  */
 
 #include "config.h"
 

 #include <stdatomic.h>

 #include <stdint.h>
 
 #include "avcodec.h"

 #include "hwaccel.h"

 #include "internal.h"
 #include "pthread_internal.h"
 #include "thread.h"

 #include "version.h"

 
 #include "libavutil/avassert.h"
 #include "libavutil/buffer.h"
 #include "libavutil/common.h"
 #include "libavutil/cpu.h"
 #include "libavutil/frame.h"

 #include "libavutil/internal.h"

 #include "libavutil/log.h"
 #include "libavutil/mem.h"

 #include "libavutil/opt.h"

 #include "libavutil/thread.h"

 enum {
     ///< Set when the thread is awaiting a packet.
     STATE_INPUT_READY,
     ///< Set before the codec has called ff_thread_finish_setup().
     STATE_SETTING_UP,
     /**
      * Set when the codec calls get_buffer().
      * State is returned to STATE_SETTING_UP afterwards.
      */
     STATE_GET_BUFFER,
      /**
       * Set when the codec calls get_format().
       * State is returned to STATE_SETTING_UP afterwards.
       */
     STATE_GET_FORMAT,
     ///< Set after the codec has called ff_thread_finish_setup().
     STATE_SETUP_FINISHED,
 };
 

 /**

  * Context used by codec threads and stored in their AVCodecInternal thread_ctx.

  */
 typedef struct PerThreadContext {
     struct FrameThreadContext *parent;
 
     pthread_t      thread;
     int            thread_init;
     pthread_cond_t input_cond;      ///< Used to wait for a new packet from the main thread.
     pthread_cond_t progress_cond;   ///< Used by child threads to wait for progress to change.
     pthread_cond_t output_cond;     ///< Used by the main thread to wait for frames to finish.
 
     pthread_mutex_t mutex;          ///< Mutex used to protect the contents of the PerThreadContext.
     pthread_mutex_t progress_mutex; ///< Mutex used to protect frame progress values and progress_cond.
 
     AVCodecContext *avctx;          ///< Context used to decode packets passed to this thread.
 
     AVPacket       avpkt;           ///< Input packet (for decoding) or output (for encoding).
 

     AVFrame *frame;                 ///< Output frame (for decoding) or input (for encoding).

     int     got_frame;              ///< The output of got_picture_ptr from the last avcodec_decode_video() call.
     int     result;                 ///< The result of the last codec decode/encode() call.
 

     atomic_int state;

 
     /**
      * Array of frames passed to ff_thread_release_buffer().
      * Frames are released after all threads referencing them are finished.
      */
     AVFrame *released_buffers;
     int  num_released_buffers;
     int      released_buffers_allocated;
 
     AVFrame *requested_frame;       ///< AVFrame the codec passed to get_buffer()
     int      requested_flags;       ///< flags passed to get_buffer() for requested_frame

 
     const enum AVPixelFormat *available_formats; ///< Format array for get_format()
     enum AVPixelFormat result_format;            ///< get_format() result

 
     int die;                        ///< Set when the thread should exit.

 
     int hwaccel_serializing;

     int async_serializing;

 
     atomic_int debug_threads;       ///< Set if the FF_DEBUG_THREADS option is set.

 } PerThreadContext;
 
 /**

  * Context stored in the client AVCodecInternal thread_ctx.

  */
 typedef struct FrameThreadContext {
     PerThreadContext *threads;     ///< The contexts for each thread.
     PerThreadContext *prev_thread; ///< The last thread submit_packet() was called on.
 
     pthread_mutex_t buffer_mutex;  ///< Mutex used to protect get/release_buffer().

     /**
      * This lock is used for ensuring threads run in serial when hwaccel
      * is used.
      */
     pthread_mutex_t hwaccel_mutex;

     pthread_mutex_t async_mutex;

     pthread_cond_t async_cond;
     int async_lock;

 
     int next_decoding;             ///< The next context to submit a packet to.
     int next_finished;             ///< The next context to return output from.
 
     int delaying;                  /**<
                                     * Set for the first N packets, where N is the number of threads.
                                     * While it is set, ff_thread_en/decode_frame won't return any results.
                                     */
 } FrameThreadContext;
 

 #define THREAD_SAFE_CALLBACKS(avctx) \
 ((avctx)->thread_safe_callbacks || (avctx)->get_buffer2 == avcodec_default_get_buffer2)

 static void async_lock(FrameThreadContext *fctx)
 {
     pthread_mutex_lock(&fctx->async_mutex);
     while (fctx->async_lock)
         pthread_cond_wait(&fctx->async_cond, &fctx->async_mutex);
     fctx->async_lock = 1;
     pthread_mutex_unlock(&fctx->async_mutex);
 }
 
 static void async_unlock(FrameThreadContext *fctx)
 {
     pthread_mutex_lock(&fctx->async_mutex);
     av_assert0(fctx->async_lock);
     fctx->async_lock = 0;
     pthread_cond_broadcast(&fctx->async_cond);
     pthread_mutex_unlock(&fctx->async_mutex);
 }
 

 /**
  * Codec worker thread.
  *
  * Automatically calls ff_thread_finish_setup() if the codec does
  * not provide an update_thread_context method, or if the codec returns
  * before calling it.
  */
 static attribute_align_arg void *frame_worker_thread(void *arg)
 {
     PerThreadContext *p = arg;
     AVCodecContext *avctx = p->avctx;
     const AVCodec *codec = avctx->codec;
 

     pthread_mutex_lock(&p->mutex);

     while (1) {

         while (atomic_load(&p->state) == STATE_INPUT_READY && !p->die)
             pthread_cond_wait(&p->input_cond, &p->mutex);

         if (p->die) break;

         if (!codec->update_thread_context && THREAD_SAFE_CALLBACKS(avctx))

             ff_thread_finish_setup(avctx);
 

         /* If a decoder supports hwaccel, then it must call ff_get_format().
          * Since that call must happen before ff_thread_finish_setup(), the
          * decoder is required to implement update_thread_context() and call
          * ff_thread_finish_setup() manually. Therefore the above
          * ff_thread_finish_setup() call did not happen and hwaccel_serializing
          * cannot be true here. */
         av_assert0(!p->hwaccel_serializing);
 
         /* if the previous thread uses hwaccel then we take the lock to ensure
          * the threads don't run concurrently */
         if (avctx->hwaccel) {
             pthread_mutex_lock(&p->parent->hwaccel_mutex);
             p->hwaccel_serializing = 1;
         }
 

         av_frame_unref(p->frame);

         p->got_frame = 0;

         p->result = codec->decode(avctx, p->frame, &p->got_frame, &p->avpkt);

         if ((p->result < 0 || !p->got_frame) && p->frame->buf[0]) {
             if (avctx->internal->allocate_progress)
                 av_log(avctx, AV_LOG_ERROR, "A frame threaded decoder did not "
                        "free the frame on failure. This is a bug, please report it.\n");
             av_frame_unref(p->frame);
         }
 

         if (atomic_load(&p->state) == STATE_SETTING_UP)
             ff_thread_finish_setup(avctx);

         if (p->hwaccel_serializing) {
             p->hwaccel_serializing = 0;
             pthread_mutex_unlock(&p->parent->hwaccel_mutex);
         }
 

         if (p->async_serializing) {
             p->async_serializing = 0;

 
             async_unlock(p->parent);

         }
 

         pthread_mutex_lock(&p->progress_mutex);

         atomic_store(&p->state, STATE_INPUT_READY);

         pthread_cond_broadcast(&p->progress_cond);

         pthread_cond_signal(&p->output_cond);
         pthread_mutex_unlock(&p->progress_mutex);
     }

     pthread_mutex_unlock(&p->mutex);

 
     return NULL;
 }
 
 /**
  * Update the next thread's AVCodecContext with values from the reference thread's context.
  *
  * @param dst The destination context.
  * @param src The source context.
  * @param for_user 0 if the destination is a codec thread, 1 if the destination is the user's thread

  * @return 0 on success, negative error code on failure

  */
 static int update_context_from_thread(AVCodecContext *dst, AVCodecContext *src, int for_user)
 {
     int err = 0;
 

     if (dst != src && (for_user || !(src->codec_descriptor->props & AV_CODEC_PROP_INTRA_ONLY))) {

         dst->time_base = src->time_base;

         dst->framerate = src->framerate;

         dst->width     = src->width;
         dst->height    = src->height;
         dst->pix_fmt   = src->pix_fmt;

         dst->sw_pix_fmt = src->sw_pix_fmt;

 
         dst->coded_width  = src->coded_width;
         dst->coded_height = src->coded_height;
 
         dst->has_b_frames = src->has_b_frames;
         dst->idct_algo    = src->idct_algo;
 
         dst->bits_per_coded_sample = src->bits_per_coded_sample;
         dst->sample_aspect_ratio   = src->sample_aspect_ratio;
 
         dst->profile = src->profile;
         dst->level   = src->level;
 
         dst->bits_per_raw_sample = src->bits_per_raw_sample;
         dst->ticks_per_frame     = src->ticks_per_frame;
         dst->color_primaries     = src->color_primaries;
 
         dst->color_trc   = src->color_trc;
         dst->colorspace  = src->colorspace;
         dst->color_range = src->color_range;
         dst->chroma_sample_location = src->chroma_sample_location;
 
         dst->hwaccel = src->hwaccel;
         dst->hwaccel_context = src->hwaccel_context;

 
         dst->channels       = src->channels;
         dst->sample_rate    = src->sample_rate;
         dst->sample_fmt     = src->sample_fmt;
         dst->channel_layout = src->channel_layout;

         dst->internal->hwaccel_priv_data = src->internal->hwaccel_priv_data;

 
         if (!!dst->hw_frames_ctx != !!src->hw_frames_ctx ||
             (dst->hw_frames_ctx && dst->hw_frames_ctx->data != src->hw_frames_ctx->data)) {
             av_buffer_unref(&dst->hw_frames_ctx);
 
             if (src->hw_frames_ctx) {
                 dst->hw_frames_ctx = av_buffer_ref(src->hw_frames_ctx);
                 if (!dst->hw_frames_ctx)
                     return AVERROR(ENOMEM);
             }
         }

 
         dst->hwaccel_flags = src->hwaccel_flags;

     }
 
     if (for_user) {

         dst->delay       = src->thread_count - 1;

 #if FF_API_CODED_FRAME
 FF_DISABLE_DEPRECATION_WARNINGS

         dst->coded_frame = src->coded_frame;

 FF_ENABLE_DEPRECATION_WARNINGS
 #endif

     } else {
         if (dst->codec->update_thread_context)
             err = dst->codec->update_thread_context(dst, src);
     }
 
     return err;
 }
 
 /**
  * Update the next thread's AVCodecContext with values set by the user.
  *
  * @param dst The destination context.
  * @param src The source context.
  * @return 0 on success, negative error code on failure
  */
 static int update_context_from_user(AVCodecContext *dst, AVCodecContext *src)
 {
 #define copy_fields(s, e) memcpy(&dst->s, &src->s, (char*)&dst->e - (char*)&dst->s);
     dst->flags          = src->flags;
 
     dst->draw_horiz_band= src->draw_horiz_band;
     dst->get_buffer2    = src->get_buffer2;
 
     dst->opaque   = src->opaque;
     dst->debug    = src->debug;

     dst->debug_mv = src->debug_mv;

 
     dst->slice_flags = src->slice_flags;
     dst->flags2      = src->flags2;
 
     copy_fields(skip_loop_filter, subtitle_header);
 
     dst->frame_number     = src->frame_number;
     dst->reordered_opaque = src->reordered_opaque;

     dst->thread_safe_callbacks = src->thread_safe_callbacks;

 
     if (src->slice_count && src->slice_offset) {
         if (dst->slice_count < src->slice_count) {

             int err = av_reallocp_array(&dst->slice_offset, src->slice_count,
                                         sizeof(*dst->slice_offset));
             if (err < 0)
                 return err;

         }
         memcpy(dst->slice_offset, src->slice_offset,
                src->slice_count * sizeof(*dst->slice_offset));
     }
     dst->slice_count = src->slice_count;
     return 0;
 #undef copy_fields
 }
 
 /// Releases the buffers that this decoding thread was the last user of.
 static void release_delayed_buffers(PerThreadContext *p)
 {
     FrameThreadContext *fctx = p->parent;
 
     while (p->num_released_buffers > 0) {
         AVFrame *f;
 
         pthread_mutex_lock(&fctx->buffer_mutex);
 
         // fix extended data in case the caller screwed it up

         av_assert0(p->avctx->codec_type == AVMEDIA_TYPE_VIDEO ||
                    p->avctx->codec_type == AVMEDIA_TYPE_AUDIO);

         f = &p->released_buffers[--p->num_released_buffers];
         f->extended_data = f->data;
         av_frame_unref(f);
 
         pthread_mutex_unlock(&fctx->buffer_mutex);
     }
 }
 

 static int submit_packet(PerThreadContext *p, AVCodecContext *user_avctx,
                          AVPacket *avpkt)

 {
     FrameThreadContext *fctx = p->parent;
     PerThreadContext *prev_thread = fctx->prev_thread;
     const AVCodec *codec = p->avctx->codec;

     int ret;

     if (!avpkt->size && !(codec->capabilities & AV_CODEC_CAP_DELAY))
         return 0;

 
     pthread_mutex_lock(&p->mutex);
 

     ret = update_context_from_user(p->avctx, user_avctx);
     if (ret) {
         pthread_mutex_unlock(&p->mutex);
         return ret;
     }

     atomic_store_explicit(&p->debug_threads,
                           (p->avctx->debug & FF_DEBUG_THREADS) != 0,
                           memory_order_relaxed);

     release_delayed_buffers(p);
 
     if (prev_thread) {
         int err;

         if (atomic_load(&prev_thread->state) == STATE_SETTING_UP) {

             pthread_mutex_lock(&prev_thread->progress_mutex);

             while (atomic_load(&prev_thread->state) == STATE_SETTING_UP)

                 pthread_cond_wait(&prev_thread->progress_cond, &prev_thread->progress_mutex);
             pthread_mutex_unlock(&prev_thread->progress_mutex);
         }
 
         err = update_context_from_thread(p->avctx, prev_thread->avctx, 0);
         if (err) {
             pthread_mutex_unlock(&p->mutex);
             return err;
         }
     }
 

     av_packet_unref(&p->avpkt);

     ret = av_packet_ref(&p->avpkt, avpkt);
     if (ret < 0) {
         pthread_mutex_unlock(&p->mutex);
         av_log(p->avctx, AV_LOG_ERROR, "av_packet_ref() failed in submit_packet()\n");
         return ret;
     }

     atomic_store(&p->state, STATE_SETTING_UP);

     pthread_cond_signal(&p->input_cond);
     pthread_mutex_unlock(&p->mutex);
 
     /*
      * If the client doesn't have a thread-safe get_buffer(),
      * then decoding threads call back to the main thread,
      * and it calls back to the client here.
      */
 
     if (!p->avctx->thread_safe_callbacks && (

          p->avctx->get_format != avcodec_default_get_format ||

          p->avctx->get_buffer2 != avcodec_default_get_buffer2)) {

         while (atomic_load(&p->state) != STATE_SETUP_FINISHED && atomic_load(&p->state) != STATE_INPUT_READY) {

             int call_done = 1;

             pthread_mutex_lock(&p->progress_mutex);

             while (atomic_load(&p->state) == STATE_SETTING_UP)

                 pthread_cond_wait(&p->progress_cond, &p->progress_mutex);
 

             switch (atomic_load_explicit(&p->state, memory_order_acquire)) {

             case STATE_GET_BUFFER:

                 p->result = ff_get_buffer(p->avctx, p->requested_frame, p->requested_flags);

                 break;
             case STATE_GET_FORMAT:

                 p->result_format = ff_get_format(p->avctx, p->available_formats);

                 break;
             default:
                 call_done = 0;
                 break;
             }
             if (call_done) {

                 atomic_store(&p->state, STATE_SETTING_UP);

                 pthread_cond_signal(&p->progress_cond);
             }
             pthread_mutex_unlock(&p->progress_mutex);
         }
     }
 
     fctx->prev_thread = p;
     fctx->next_decoding++;
 
     return 0;
 }
 
 int ff_thread_decode_frame(AVCodecContext *avctx,
                            AVFrame *picture, int *got_picture_ptr,
                            AVPacket *avpkt)
 {

     FrameThreadContext *fctx = avctx->internal->thread_ctx;

     int finished = fctx->next_finished;
     PerThreadContext *p;

     int err;

 
     /* release the async lock, permitting blocked hwaccel threads to
      * go forward while we are in this function */

     async_unlock(fctx);

 
     /*
      * Submit a packet to the next decoding thread.
      */
 
     p = &fctx->threads[fctx->next_decoding];

     err = submit_packet(p, avctx, avpkt);

     if (err)
         goto finish;

 
     /*
      * If we're still receiving the initial packets, don't return a frame.
      */
 

     if (fctx->next_decoding > (avctx->thread_count-1-(avctx->codec_id == AV_CODEC_ID_FFV1)))
         fctx->delaying = 0;

     if (fctx->delaying) {

         *got_picture_ptr=0;

         if (avpkt->size) {

             err = avpkt->size;

             goto finish;
         }

     }
 
     /*
      * Return the next available frame from the oldest thread.
      * If we're at the end of the stream, then we have to skip threads that

      * didn't output a frame/error, because we don't want to accidentally signal
      * EOF (avpkt->size == 0 && *got_picture_ptr == 0 && err >= 0).

      */
 
     do {
         p = &fctx->threads[finished++];
 

         if (atomic_load(&p->state) != STATE_INPUT_READY) {

             pthread_mutex_lock(&p->progress_mutex);

             while (atomic_load_explicit(&p->state, memory_order_relaxed) != STATE_INPUT_READY)

                 pthread_cond_wait(&p->output_cond, &p->progress_mutex);
             pthread_mutex_unlock(&p->progress_mutex);
         }
 

         av_frame_move_ref(picture, p->frame);

         *got_picture_ptr = p->got_frame;
         picture->pkt_dts = p->avpkt.dts;

         err = p->result;

         /*
          * A later call with avkpt->size == 0 may loop over all threads,

          * including this one, searching for a frame/error to return before being

          * stopped by the "finished != fctx->next_finished" condition.

          * Make sure we don't mistakenly return the same frame/error again.

          */
         p->got_frame = 0;

         p->result = 0;

 
         if (finished >= avctx->thread_count) finished = 0;

     } while (!avpkt->size && !*got_picture_ptr && err >= 0 && finished != fctx->next_finished);

 
     update_context_from_thread(avctx, p->avctx, 1);
 
     if (fctx->next_decoding >= avctx->thread_count) fctx->next_decoding = 0;
 
     fctx->next_finished = finished;
 
     /* return the size of the consumed packet if no error occurred */

     if (err >= 0)
         err = avpkt->size;

 finish:

     async_lock(fctx);

     return err;

 }
 
 void ff_thread_report_progress(ThreadFrame *f, int n, int field)
 {
     PerThreadContext *p;

     atomic_int *progress = f->progress ? (atomic_int*)f->progress->data : NULL;

     if (!progress ||

         atomic_load_explicit(&progress[field], memory_order_relaxed) >= n)

         return;

     p = f->owner[field]->internal->thread_ctx;

     if (atomic_load_explicit(&p->debug_threads, memory_order_relaxed))

         av_log(f->owner[field], AV_LOG_DEBUG,
                "%p finished %d field %d\n", progress, n, field);

     pthread_mutex_lock(&p->progress_mutex);
 

     atomic_store_explicit(&progress[field], n, memory_order_release);

     pthread_cond_broadcast(&p->progress_cond);
     pthread_mutex_unlock(&p->progress_mutex);
 }
 
 void ff_thread_await_progress(ThreadFrame *f, int n, int field)
 {
     PerThreadContext *p;

     atomic_int *progress = f->progress ? (atomic_int*)f->progress->data : NULL;

     if (!progress ||
         atomic_load_explicit(&progress[field], memory_order_acquire) >= n)
         return;

     p = f->owner[field]->internal->thread_ctx;

     if (atomic_load_explicit(&p->debug_threads, memory_order_relaxed))

         av_log(f->owner[field], AV_LOG_DEBUG,
                "thread awaiting %d field %d from %p\n", n, field, progress);

 
     pthread_mutex_lock(&p->progress_mutex);

     while (atomic_load_explicit(&progress[field], memory_order_relaxed) < n)

         pthread_cond_wait(&p->progress_cond, &p->progress_mutex);
     pthread_mutex_unlock(&p->progress_mutex);
 }
 
 void ff_thread_finish_setup(AVCodecContext *avctx) {

     PerThreadContext *p = avctx->internal->thread_ctx;

 
     if (!(avctx->active_thread_type&FF_THREAD_FRAME)) return;
 

     if (avctx->hwaccel && !p->hwaccel_serializing) {
         pthread_mutex_lock(&p->parent->hwaccel_mutex);
         p->hwaccel_serializing = 1;
     }
 

     /* this assumes that no hwaccel calls happen before ff_thread_finish_setup() */
     if (avctx->hwaccel &&
         !(avctx->hwaccel->caps_internal & HWACCEL_CAP_ASYNC_SAFE)) {
         p->async_serializing = 1;

 
         async_lock(p->parent);

     }
 

     pthread_mutex_lock(&p->progress_mutex);

     if(atomic_load(&p->state) == STATE_SETUP_FINISHED){

         av_log(avctx, AV_LOG_WARNING, "Multiple ff_thread_finish_setup() calls\n");
     }
 

     atomic_store(&p->state, STATE_SETUP_FINISHED);
 

     pthread_cond_broadcast(&p->progress_cond);
     pthread_mutex_unlock(&p->progress_mutex);
 }
 
 /// Waits for all threads to finish.
 static void park_frame_worker_threads(FrameThreadContext *fctx, int thread_count)
 {
     int i;
 

     async_unlock(fctx);

     for (i = 0; i < thread_count; i++) {
         PerThreadContext *p = &fctx->threads[i];
 

         if (atomic_load(&p->state) != STATE_INPUT_READY) {

             pthread_mutex_lock(&p->progress_mutex);

             while (atomic_load(&p->state) != STATE_INPUT_READY)

                 pthread_cond_wait(&p->output_cond, &p->progress_mutex);
             pthread_mutex_unlock(&p->progress_mutex);
         }

         p->got_frame = 0;

     }

     async_lock(fctx);

 }
 
 void ff_frame_thread_free(AVCodecContext *avctx, int thread_count)
 {

     FrameThreadContext *fctx = avctx->internal->thread_ctx;

     const AVCodec *codec = avctx->codec;
     int i;
 
     park_frame_worker_threads(fctx, thread_count);
 
     if (fctx->prev_thread && fctx->prev_thread != fctx->threads)

         if (update_context_from_thread(fctx->threads->avctx, fctx->prev_thread->avctx, 0) < 0) {
             av_log(avctx, AV_LOG_ERROR, "Final thread update failed\n");
             fctx->prev_thread->avctx->internal->is_copy = fctx->threads->avctx->internal->is_copy;
             fctx->threads->avctx->internal->is_copy = 1;
         }

 
     for (i = 0; i < thread_count; i++) {
         PerThreadContext *p = &fctx->threads[i];
 
         pthread_mutex_lock(&p->mutex);

         p->die = 1;

         pthread_cond_signal(&p->input_cond);
         pthread_mutex_unlock(&p->mutex);
 
         if (p->thread_init)
             pthread_join(p->thread, NULL);

         p->thread_init=0;

         if (codec->close && p->avctx)

             codec->close(p->avctx);
 
         release_delayed_buffers(p);

         av_frame_free(&p->frame);

     }
 
     for (i = 0; i < thread_count; i++) {
         PerThreadContext *p = &fctx->threads[i];
 
         pthread_mutex_destroy(&p->mutex);
         pthread_mutex_destroy(&p->progress_mutex);
         pthread_cond_destroy(&p->input_cond);
         pthread_cond_destroy(&p->progress_cond);
         pthread_cond_destroy(&p->output_cond);

         av_packet_unref(&p->avpkt);

         av_freep(&p->released_buffers);
 

         if (i && p->avctx) {

             av_freep(&p->avctx->priv_data);
             av_freep(&p->avctx->slice_offset);
         }
 

         if (p->avctx) {

             av_freep(&p->avctx->internal);

             av_buffer_unref(&p->avctx->hw_frames_ctx);
         }
 

         av_freep(&p->avctx);
     }
 
     av_freep(&fctx->threads);
     pthread_mutex_destroy(&fctx->buffer_mutex);

     pthread_mutex_destroy(&fctx->hwaccel_mutex);

     pthread_mutex_destroy(&fctx->async_mutex);

     pthread_cond_destroy(&fctx->async_cond);

     av_freep(&avctx->internal->thread_ctx);

 
     if (avctx->priv_data && avctx->codec && avctx->codec->priv_class)
         av_opt_free(avctx->priv_data);
     avctx->codec = NULL;

 }
 
 int ff_frame_thread_init(AVCodecContext *avctx)
 {
     int thread_count = avctx->thread_count;
     const AVCodec *codec = avctx->codec;
     AVCodecContext *src = avctx;
     FrameThreadContext *fctx;
     int i, err = 0;
 
     if (!thread_count) {
         int nb_cpus = av_cpu_count();

 #if FF_API_DEBUG_MV

         if ((avctx->debug & (FF_DEBUG_VIS_QP | FF_DEBUG_VIS_MB_TYPE)) || avctx->debug_mv)
             nb_cpus = 1;

 #endif

         // use number of cores + 1 as thread count if there is more than one
         if (nb_cpus > 1)
             thread_count = avctx->thread_count = FFMIN(nb_cpus + 1, MAX_AUTO_THREADS);
         else
             thread_count = avctx->thread_count = 1;
     }
 
     if (thread_count <= 1) {
         avctx->active_thread_type = 0;
         return 0;
     }
 

     avctx->internal->thread_ctx = fctx = av_mallocz(sizeof(FrameThreadContext));

     if (!fctx)
         return AVERROR(ENOMEM);

     fctx->threads = av_mallocz_array(thread_count, sizeof(PerThreadContext));

     if (!fctx->threads) {
         av_freep(&avctx->internal->thread_ctx);
         return AVERROR(ENOMEM);
     }
 

     pthread_mutex_init(&fctx->buffer_mutex, NULL);

     pthread_mutex_init(&fctx->hwaccel_mutex, NULL);

     pthread_mutex_init(&fctx->async_mutex, NULL);

     pthread_cond_init(&fctx->async_cond, NULL);

     fctx->async_lock = 1;

     fctx->delaying = 1;
 
     for (i = 0; i < thread_count; i++) {
         AVCodecContext *copy = av_malloc(sizeof(AVCodecContext));
         PerThreadContext *p  = &fctx->threads[i];
 
         pthread_mutex_init(&p->mutex, NULL);
         pthread_mutex_init(&p->progress_mutex, NULL);
         pthread_cond_init(&p->input_cond, NULL);
         pthread_cond_init(&p->progress_cond, NULL);
         pthread_cond_init(&p->output_cond, NULL);
 

         p->frame = av_frame_alloc();
         if (!p->frame) {

             av_freep(&copy);

             err = AVERROR(ENOMEM);
             goto error;
         }
 

         p->parent = fctx;
         p->avctx  = copy;
 
         if (!copy) {
             err = AVERROR(ENOMEM);
             goto error;
         }
 
         *copy = *src;
 

         copy->internal = av_malloc(sizeof(AVCodecInternal));
         if (!copy->internal) {

             copy->priv_data = NULL;

             err = AVERROR(ENOMEM);
             goto error;
         }
         *copy->internal = *src->internal;
         copy->internal->thread_ctx = p;

         copy->internal->last_pkt_props = &p->avpkt;

         if (!i) {
             src = copy;
 
             if (codec->init)
                 err = codec->init(copy);
 
             update_context_from_thread(avctx, copy, 1);
         } else {
             copy->priv_data = av_malloc(codec->priv_data_size);
             if (!copy->priv_data) {
                 err = AVERROR(ENOMEM);
                 goto error;
             }
             memcpy(copy->priv_data, src->priv_data, codec->priv_data_size);
             copy->internal->is_copy = 1;
 
             if (codec->init_thread_copy)
                 err = codec->init_thread_copy(copy);
         }
 
         if (err) goto error;
 

         atomic_init(&p->debug_threads, (copy->debug & FF_DEBUG_THREADS) != 0);
 

         err = AVERROR(pthread_create(&p->thread, NULL, frame_worker_thread, p));
         p->thread_init= !err;
         if(!p->thread_init)
             goto error;

     }
 
     return 0;
 
 error:
     ff_frame_thread_free(avctx, i+1);
 
     return err;
 }
 
 void ff_thread_flush(AVCodecContext *avctx)
 {
     int i;

     FrameThreadContext *fctx = avctx->internal->thread_ctx;

     if (!fctx) return;

 
     park_frame_worker_threads(fctx, avctx->thread_count);
     if (fctx->prev_thread) {
         if (fctx->prev_thread != &fctx->threads[0])
             update_context_from_thread(fctx->threads[0].avctx, fctx->prev_thread->avctx, 0);
     }
 
     fctx->next_decoding = fctx->next_finished = 0;
     fctx->delaying = 1;
     fctx->prev_thread = NULL;
     for (i = 0; i < avctx->thread_count; i++) {
         PerThreadContext *p = &fctx->threads[i];
         // Make sure decode flush calls with size=0 won't return old frames
         p->got_frame = 0;

         av_frame_unref(p->frame);

         p->result = 0;

 
         release_delayed_buffers(p);

 
         if (avctx->codec->flush)
             avctx->codec->flush(p->avctx);

     }
 }
 

 int ff_thread_can_start_frame(AVCodecContext *avctx)
 {

     PerThreadContext *p = avctx->internal->thread_ctx;

     if ((avctx->active_thread_type&FF_THREAD_FRAME) && atomic_load(&p->state) != STATE_SETTING_UP &&

         (avctx->codec->update_thread_context || !THREAD_SAFE_CALLBACKS(avctx))) {
         return 0;
     }
     return 1;
 }
 
 static int thread_get_buffer_internal(AVCodecContext *avctx, ThreadFrame *f, int flags)

 {

     PerThreadContext *p = avctx->internal->thread_ctx;

     int err;
 

     f->owner[0] = f->owner[1] = avctx;

 
     if (!(avctx->active_thread_type & FF_THREAD_FRAME))
         return ff_get_buffer(avctx, f->f, flags);
 

     if (atomic_load(&p->state) != STATE_SETTING_UP &&

         (avctx->codec->update_thread_context || !THREAD_SAFE_CALLBACKS(avctx))) {

         av_log(avctx, AV_LOG_ERROR, "get_buffer() cannot be called after ff_thread_finish_setup()\n");
         return -1;
     }
 
     if (avctx->internal->allocate_progress) {

         atomic_int *progress;
         f->progress = av_buffer_alloc(2 * sizeof(*progress));

         if (!f->progress) {
             return AVERROR(ENOMEM);
         }

         progress = (atomic_int*)f->progress->data;

         atomic_init(&progress[0], -1);
         atomic_init(&progress[1], -1);

     }
 
     pthread_mutex_lock(&p->parent->buffer_mutex);

     if (avctx->thread_safe_callbacks ||
         avctx->get_buffer2 == avcodec_default_get_buffer2) {

         err = ff_get_buffer(avctx, f->f, flags);
     } else {

         pthread_mutex_lock(&p->progress_mutex);

         p->requested_frame = f->f;
         p->requested_flags = flags;

         atomic_store_explicit(&p->state, STATE_GET_BUFFER, memory_order_release);

         pthread_cond_broadcast(&p->progress_cond);

         while (atomic_load(&p->state) != STATE_SETTING_UP)

             pthread_cond_wait(&p->progress_cond, &p->progress_mutex);
 
         err = p->result;
 
         pthread_mutex_unlock(&p->progress_mutex);
 
     }

     if (!THREAD_SAFE_CALLBACKS(avctx) && !avctx->codec->update_thread_context)

         ff_thread_finish_setup(avctx);
     if (err)
         av_buffer_unref(&f->progress);
 
     pthread_mutex_unlock(&p->parent->buffer_mutex);
 
     return err;
 }
 

 enum AVPixelFormat ff_thread_get_format(AVCodecContext *avctx, const enum AVPixelFormat *fmt)
 {
     enum AVPixelFormat res;

     PerThreadContext *p = avctx->internal->thread_ctx;

     if (!(avctx->active_thread_type & FF_THREAD_FRAME) || avctx->thread_safe_callbacks ||
         avctx->get_format == avcodec_default_get_format)

         return ff_get_format(avctx, fmt);

     if (atomic_load(&p->state) != STATE_SETTING_UP) {

         av_log(avctx, AV_LOG_ERROR, "get_format() cannot be called after ff_thread_finish_setup()\n");
         return -1;
     }
     pthread_mutex_lock(&p->progress_mutex);
     p->available_formats = fmt;

     atomic_store(&p->state, STATE_GET_FORMAT);

     pthread_cond_broadcast(&p->progress_cond);
 

     while (atomic_load(&p->state) != STATE_SETTING_UP)

         pthread_cond_wait(&p->progress_cond, &p->progress_mutex);
 
     res = p->result_format;
 
     pthread_mutex_unlock(&p->progress_mutex);
 
     return res;
 }
 
 int ff_thread_get_buffer(AVCodecContext *avctx, ThreadFrame *f, int flags)
 {
     int ret = thread_get_buffer_internal(avctx, f, flags);
     if (ret < 0)
         av_log(avctx, AV_LOG_ERROR, "thread_get_buffer() failed\n");
     return ret;
 }
 

 void ff_thread_release_buffer(AVCodecContext *avctx, ThreadFrame *f)
 {

     PerThreadContext *p = avctx->internal->thread_ctx;

     FrameThreadContext *fctx;
     AVFrame *dst, *tmp;
     int can_direct_free = !(avctx->active_thread_type & FF_THREAD_FRAME) ||
                           avctx->thread_safe_callbacks                   ||

                           avctx->get_buffer2 == avcodec_default_get_buffer2;

     if (!f->f || !f->f->buf[0])

         return;
 
     if (avctx->debug & FF_DEBUG_BUFFERS)
         av_log(avctx, AV_LOG_DEBUG, "thread_release_buffer called on pic %p\n", f);
 
     av_buffer_unref(&f->progress);

     f->owner[0] = f->owner[1] = NULL;

 
     if (can_direct_free) {
         av_frame_unref(f->f);
         return;
     }
 
     fctx = p->parent;
     pthread_mutex_lock(&fctx->buffer_mutex);
 
     if (p->num_released_buffers + 1 >= INT_MAX / sizeof(*p->released_buffers))
         goto fail;
     tmp = av_fast_realloc(p->released_buffers, &p->released_buffers_allocated,
                           (p->num_released_buffers + 1) *
                           sizeof(*p->released_buffers));
     if (!tmp)
         goto fail;
     p->released_buffers = tmp;
 
     dst = &p->released_buffers[p->num_released_buffers];
     av_frame_move_ref(dst, f->f);
 
     p->num_released_buffers++;
 
 fail:
     pthread_mutex_unlock(&fctx->buffer_mutex);
 }