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/*

 * Copyright (c) 2004 Roman Shaposhnik

 * Copyright (c) 2008 Alexander Strange (astrange@ithinksw.com)

 *

 * Many thanks to Steven M. Schultz for providing clever ideas and

 * to Michael Niedermayer  for writing initial

 * implementation.

 *

 * 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

 * Multithreading support functions

 * @see doc/multithreading.txt

 */

#include "config.h"

#include "avcodec.h"

#include "internal.h"

#include "thread.h"

#include "libavutil/avassert.h"

#include "libavutil/common.h"

#include "libavutil/cpu.h"

#include "libavutil/internal.h"

#if HAVE_PTHREADS

#include 

#elif HAVE_W32THREADS

#include "compat/w32pthreads.h"

#elif HAVE_OS2THREADS

#include "compat/os2threads.h"

#endif

typedef int (action_func)(AVCodecContext *c, void *arg);

typedef int (action_func2)(AVCodecContext *c, void *arg, int jobnr, int threadnr);

typedef struct ThreadContext {

    pthread_t *workers;

    action_func *func;

    action_func2 *func2;

    void *args;

    int *rets;

    int rets_count;

    int job_count;

    int job_size;

    pthread_cond_t last_job_cond;

    pthread_cond_t current_job_cond;

    pthread_mutex_t current_job_lock;

    unsigned current_execute;

    int current_job;

    int done;

    int *entries;

    int entries_count;

    int thread_count;

    pthread_cond_t *progress_cond;

    pthread_mutex_t *progress_mutex;

} ThreadContext;

/**

 * Context used by codec threads and stored in their AVCodecContext thread_opaque.

 */

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).

    uint8_t       *buf;             ///< backup storage for packet data when the input packet is not refcounted

    int            allocated_buf_size; ///< Size allocated for buf

    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.

    enum {

        STATE_INPUT_READY,          ///< Set when the thread is awaiting a packet.

        STATE_SETTING_UP,           ///< Set before the codec has called ff_thread_finish_setup().

        STATE_GET_BUFFER,           /**<

                                     * Set when the codec calls get_buffer().

                                     * State is returned to STATE_SETTING_UP afterwards.

                                     */

        STATE_GET_FORMAT,           /**<

                                     * Set when the codec calls get_format().

                                     * State is returned to STATE_SETTING_UP afterwards.

                                     */

        STATE_SETUP_FINISHED        ///< Set after the codec has called ff_thread_finish_setup().

    } 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

} PerThreadContext;

/**

 * Context stored in the client AVCodecContext thread_opaque.

 */

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().

    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.

                                    */

    int die;                       ///< Set when threads should exit.

} FrameThreadContext;

/* H264 slice threading seems to be buggy with more than 16 threads,

 * limit the number of threads to 16 for automatic detection */

#define MAX_AUTO_THREADS 16

static void* attribute_align_arg worker(void *v)

{

    AVCodecContext *avctx = v;

    ThreadContext *c = avctx->thread_opaque;

    unsigned last_execute = 0;

    int our_job = c->job_count;

    int thread_count = avctx->thread_count;

    int self_id;

    pthread_mutex_lock(&c->current_job_lock);

    self_id = c->current_job++;

    for (;;){

        while (our_job >= c->job_count) {

            if (c->current_job == thread_count + c->job_count)

                pthread_cond_signal(&c->last_job_cond);

            while (last_execute == c->current_execute && !c->done)

                pthread_cond_wait(&c->current_job_cond, &c->current_job_lock);

            last_execute = c->current_execute;

            our_job = self_id;

            if (c->done) {

                pthread_mutex_unlock(&c->current_job_lock);

                return NULL;

            }

        }

        pthread_mutex_unlock(&c->current_job_lock);

        c->rets[our_job%c->rets_count] = c->func ? c->func(avctx, (char*)c->args + our_job*c->job_size):

                                                   c->func2(avctx, c->args, our_job, self_id);

        pthread_mutex_lock(&c->current_job_lock);

        our_job = c->current_job++;

    }

}

static av_always_inline void avcodec_thread_park_workers(ThreadContext *c, int thread_count)

{

    while (c->current_job != thread_count + c->job_count)

        pthread_cond_wait(&c->last_job_cond, &c->current_job_lock);

    pthread_mutex_unlock(&c->current_job_lock);

}

static void thread_free(AVCodecContext *avctx)

{

    ThreadContext *c = avctx->thread_opaque;

    int i;

    pthread_mutex_lock(&c->current_job_lock);

    c->done = 1;

    pthread_cond_broadcast(&c->current_job_cond);

    pthread_mutex_unlock(&c->current_job_lock);

    for (i=0; ithread_count; i++)

         pthread_join(c->workers[i], NULL);

    pthread_mutex_destroy(&c->current_job_lock);

    pthread_cond_destroy(&c->current_job_cond);

    pthread_cond_destroy(&c->last_job_cond);

    av_free(c->workers);

    av_freep(&avctx->thread_opaque);

}

static int avcodec_thread_execute(AVCodecContext *avctx, action_func* func, void *arg, int *ret, int job_count, int job_size)

{

    ThreadContext *c= avctx->thread_opaque;

    int dummy_ret;

    if (!(avctx->active_thread_type&FF_THREAD_SLICE) || avctx->thread_count <= 1)

        return avcodec_default_execute(avctx, func, arg, ret, job_count, job_size);

    if (job_count <= 0)

        return 0;

    pthread_mutex_lock(&c->current_job_lock);

    c->current_job = avctx->thread_count;

    c->job_count = job_count;

    c->job_size = job_size;

    c->args = arg;

    c->func = func;

    if (ret) {

        c->rets = ret;

        c->rets_count = job_count;

    } else {

        c->rets = &dummy_ret;

        c->rets_count = 1;

    }

    c->current_execute++;

    pthread_cond_broadcast(&c->current_job_cond);

    avcodec_thread_park_workers(c, avctx->thread_count);

    return 0;

}

static int avcodec_thread_execute2(AVCodecContext *avctx, action_func2* func2, void *arg, int *ret, int job_count)

{

    ThreadContext *c= avctx->thread_opaque;

    c->func2 = func2;

    return avcodec_thread_execute(avctx, NULL, arg, ret, job_count, 0);

}

static int thread_init_internal(AVCodecContext *avctx)

{

    int i;

    ThreadContext *c;

    int thread_count = avctx->thread_count;

    if (!thread_count) {

        int nb_cpus = av_cpu_count();

        if  (avctx->height)

            nb_cpus = FFMIN(nb_cpus, (avctx->height+15)/16);

        // 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;

    }

    c = av_mallocz(sizeof(ThreadContext));

    if (!c)

        return -1;

    c->workers = av_mallocz(sizeof(pthread_t)*thread_count);

    if (!c->workers) {

        av_free(c);

        return -1;

    }

    avctx->thread_opaque = c;

    c->current_job = 0;

    c->job_count = 0;

    c->job_size = 0;

    c->done = 0;

    pthread_cond_init(&c->current_job_cond, NULL);

    pthread_cond_init(&c->last_job_cond, NULL);

    pthread_mutex_init(&c->current_job_lock, NULL);

    pthread_mutex_lock(&c->current_job_lock);

    for (i=0; i

        if(pthread_create(&c->workers[i], NULL, worker, avctx)) {

           avctx->thread_count = i;

           pthread_mutex_unlock(&c->current_job_lock);

           ff_thread_free(avctx);

           return -1;

        }

    }

    avcodec_thread_park_workers(c, thread_count);

    avctx->execute = avcodec_thread_execute;

    avctx->execute2 = avcodec_thread_execute2;

    return 0;

}

#define THREAD_SAFE_CALLBACKS(avctx) \

((avctx)->thread_safe_callbacks || (!(avctx)->get_buffer && (avctx)->get_buffer2 == avcodec_default_get_buffer2))

/**

 * 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;

    FrameThreadContext *fctx = p->parent;

    AVCodecContext *avctx = p->avctx;

    const AVCodec *codec = avctx->codec;

    pthread_mutex_lock(&p->mutex);

    while (1) {

            while (p->state == STATE_INPUT_READY && !fctx->die)

                pthread_cond_wait(&p->input_cond, &p->mutex);

        if (fctx->die) break;

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

            ff_thread_finish_setup(avctx);

        avcodec_get_frame_defaults(&p->frame);

        p->got_frame = 0;

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

        /* many decoders assign whole AVFrames, thus overwriting extended_data;

         * make sure it's set correctly */

        p->frame.extended_data = p->frame.data;

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

        pthread_mutex_lock(&p->progress_mutex);

#if 0 //BUFREF-FIXME

        for (i = 0; i < MAX_BUFFERS; i++)

            if (p->progress_used[i] && (p->got_frame || p->result<0 || avctx->codec_id != AV_CODEC_ID_H264)) {

                p->progress[i][0] = INT_MAX;

                p->progress[i][1] = INT_MAX;

            }

#endif

        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

 */

static int update_context_from_thread(AVCodecContext *dst, AVCodecContext *src, int for_user)

{

    int err = 0;

    if (dst != src) {

        dst->time_base = src->time_base;

        dst->width     = src->width;

        dst->height    = src->height;

        dst->pix_fmt   = src->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->dtg_active_format     = src->dtg_active_format;

        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;

    }

    if (for_user) {

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

        dst->coded_frame = src->coded_frame;

    } 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;

#if FF_API_GET_BUFFER

FF_DISABLE_DEPRECATION_WARNINGS

    dst->get_buffer     = src->get_buffer;

    dst->release_buffer = src->release_buffer;

FF_ENABLE_DEPRECATION_WARNINGS

#endif

    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 *tmp = av_realloc(dst->slice_offset, src->slice_count *

                                  sizeof(*dst->slice_offset));

            if (!tmp) {

                av_free(dst->slice_offset);

                return AVERROR(ENOMEM);

            }

            dst->slice_offset = tmp;

        }

        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, AVPacket *avpkt)

{

    FrameThreadContext *fctx = p->parent;

    PerThreadContext *prev_thread = fctx->prev_thread;

    const AVCodec *codec = p->avctx->codec;

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

    pthread_mutex_lock(&p->mutex);

    release_delayed_buffers(p);

    if (prev_thread) {

        int err;

        if (prev_thread->state == STATE_SETTING_UP) {

            pthread_mutex_lock(&prev_thread->progress_mutex);

            while (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_buffer_unref(&p->avpkt.buf);

    p->avpkt = *avpkt;

    if (avpkt->buf)

        p->avpkt.buf = av_buffer_ref(avpkt->buf);

    else {

        av_fast_malloc(&p->buf, &p->allocated_buf_size, avpkt->size + FF_INPUT_BUFFER_PADDING_SIZE);

        p->avpkt.data = p->buf;

        memcpy(p->buf, avpkt->data, avpkt->size);

        memset(p->buf + avpkt->size, 0, FF_INPUT_BUFFER_PADDING_SIZE);

    }

    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.

     */

FF_DISABLE_DEPRECATION_WARNINGS

    if (!p->avctx->thread_safe_callbacks && (

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

#if FF_API_GET_BUFFER

         p->avctx->get_buffer ||

#endif

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

FF_ENABLE_DEPRECATION_WARNINGS

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

            int call_done = 1;

            pthread_mutex_lock(&p->progress_mutex);

            while (p->state == STATE_SETTING_UP)

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

            switch (p->state) {

            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 = p->avctx->get_format(p->avctx, p->available_formats);

                break;

            default:

                call_done = 0;

                break;

            }

            if (call_done) {

                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->thread_opaque;

    int finished = fctx->next_finished;

    PerThreadContext *p;

    int err;

    /*

     * Submit a packet to the next decoding thread.

     */

    p = &fctx->threads[fctx->next_decoding];

    err = update_context_from_user(p->avctx, avctx);

    if (err) return err;

    err = submit_packet(p, avpkt);

    if (err) return err;

    /*

     * 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)

            return avpkt->size;

    }

    /*

     * 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, because we don't want to accidentally signal

     * EOF (avpkt->size == 0 && *got_picture_ptr == 0).

     */

    do {

        p = &fctx->threads[finished++];

        if (p->state != STATE_INPUT_READY) {

            pthread_mutex_lock(&p->progress_mutex);

            while (p->state != 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;

        /*

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

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

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

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

         */

        p->got_frame = 0;

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

    } while (!avpkt->size && !*got_picture_ptr && 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 */

    return (p->result >= 0) ? avpkt->size : p->result;

}

void ff_thread_report_progress(ThreadFrame *f, int n, int field)

{

    PerThreadContext *p;

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

    if (!progress || progress[field] >= n) return;

    p = f->owner->thread_opaque;

    if (f->owner->debug&FF_DEBUG_THREADS)

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

    pthread_mutex_lock(&p->progress_mutex);

    progress[field] = n;

    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;

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

    if (!progress || progress[field] >= n) return;

    p = f->owner->thread_opaque;

    if (f->owner->debug&FF_DEBUG_THREADS)

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

    pthread_mutex_lock(&p->progress_mutex);

    while (progress[field] < 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->thread_opaque;

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

    if(p->state == STATE_SETUP_FINISHED){

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

    }

    pthread_mutex_lock(&p->progress_mutex);

    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;

    for (i = 0; i < thread_count; i++) {

        PerThreadContext *p = &fctx->threads[i];

        if (p->state != STATE_INPUT_READY) {

            pthread_mutex_lock(&p->progress_mutex);

            while (p->state != STATE_INPUT_READY)

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

            pthread_mutex_unlock(&p->progress_mutex);

        }

        p->got_frame = 0;

    }

}

static void frame_thread_free(AVCodecContext *avctx, int thread_count)

{

    FrameThreadContext *fctx = avctx->thread_opaque;

    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;

        }

    fctx->die = 1;

    for (i = 0; i < thread_count; i++) {

        PerThreadContext *p = &fctx->threads[i];

        pthread_mutex_lock(&p->mutex);

        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)

            codec->close(p->avctx);

        avctx->codec = NULL;

        release_delayed_buffers(p);

        av_frame_unref(&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_buffer_unref(&p->avpkt.buf);

        av_freep(&p->buf);

        av_freep(&p->released_buffers);

        if (i) {

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

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

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

        }

        av_freep(&p->avctx);

    }

    av_freep(&fctx->threads);

    pthread_mutex_destroy(&fctx->buffer_mutex);

    av_freep(&avctx->thread_opaque);

}

static int 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 ((avctx->debug & (FF_DEBUG_VIS_QP | FF_DEBUG_VIS_MB_TYPE)) || avctx->debug_mv)

            nb_cpus = 1;

        // 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->thread_opaque = fctx = av_mallocz(sizeof(FrameThreadContext));

    fctx->threads = av_mallocz(sizeof(PerThreadContext) * thread_count);

    pthread_mutex_init(&fctx->buffer_mutex, NULL);

    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->parent = fctx;

        p->avctx  = copy;

        if (!copy) {

            err = AVERROR(ENOMEM);

            goto error;

        }

        *copy = *src;

        copy->thread_opaque = p;

        copy->pkt = &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 = av_malloc(sizeof(AVCodecInternal));

            if (!copy->internal) {

                err = AVERROR(ENOMEM);

                goto error;

            }

            *copy->internal = *src->internal;

            copy->internal->is_copy = 1;

            if (codec->init_thread_copy)

                err = codec->init_thread_copy(copy);

        }

        if (err) goto error;

        err = AVERROR(pthread_create(&p->thread, NULL, frame_worker_thread, p));

        p->thread_init= !err;

        if(!p->thread_init)

            goto error;

    }

    return 0;

error:

    frame_thread_free(avctx, i+1);

    return err;

}

void ff_thread_flush(AVCodecContext *avctx)

{

    int i;

    FrameThreadContext *fctx = avctx->thread_opaque;

    if (!avctx->thread_opaque) 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);

        if (avctx->codec->flush)

            avctx->codec->flush(fctx->threads[0].avctx);

    }

    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);

        release_delayed_buffers(p);

    }

}

int ff_thread_can_start_frame(AVCodecContext *avctx)

{

    PerThreadContext *p = avctx->thread_opaque;

    if ((avctx->active_thread_type&FF_THREAD_FRAME) && 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->thread_opaque;

    int err;

    f->owner = avctx;

    ff_init_buffer_info(avctx, f->f);

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

        return ff_get_buffer(avctx, f->f, flags);

    if (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) {

        int *progress;

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

        if (!f->progress) {

            return AVERROR(ENOMEM);

        }

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

        progress[0] = progress[1] = -1;

    }

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

FF_DISABLE_DEPRECATION_WARNINGS

    if (avctx->thread_safe_callbacks || (

#if FF_API_GET_BUFFER

        !avctx->get_buffer &&

#endif

        avctx->get_buffer2 == avcodec_default_get_buffer2)) {

FF_ENABLE_DEPRECATION_WARNINGS

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

    } else {

        pthread_mutex_lock(&p->progress_mutex);

        p->requested_frame = f->f;

        p->requested_flags = flags;

        p->state = STATE_GET_BUFFER;

        pthread_cond_broadcast(&p->progress_cond);

        while (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->thread_opaque;

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

        avctx->get_format == avcodec_default_get_format)

        return avctx->get_format(avctx, fmt);

    if (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;

    p->state = STATE_GET_FORMAT;

    pthread_cond_broadcast(&p->progress_cond);

    while (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->thread_opaque;

    FrameThreadContext *fctx;

    AVFrame *dst, *tmp;

FF_DISABLE_DEPRECATION_WARNINGS

    int can_direct_free = !(avctx->active_thread_type & FF_THREAD_FRAME) ||

                          avctx->thread_safe_callbacks                   ||

                          (

#if FF_API_GET_BUFFER

                           !avctx->get_buffer &&

#endif

                           avctx->get_buffer2 == avcodec_default_get_buffer2);

FF_ENABLE_DEPRECATION_WARNINGS

    if (!f->f->data[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    = 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);

}

/**

 * Set the threading algorithms used.

 *

 * Threading requires more than one thread.

 * Frame threading requires entire frames to be passed to the codec,

 * and introduces extra decoding delay, so is incompatible with low_delay.

 *

 * @param avctx The context.

 */

static void validate_thread_parameters(AVCodecContext *avctx)

{

    int frame_threading_supported = (avctx->codec->capabilities & CODEC_CAP_FRAME_THREADS)

                                && !(avctx->flags & CODEC_FLAG_TRUNCATED)

                                && !(avctx->flags & CODEC_FLAG_LOW_DELAY)

                                && !(avctx->flags2 & CODEC_FLAG2_CHUNKS);

    if (avctx->thread_count == 1) {

        avctx->active_thread_type = 0;

    } else if (frame_threading_supported && (avctx->thread_type & FF_THREAD_FRAME)) {

        avctx->active_thread_type = FF_THREAD_FRAME;

    } else if (avctx->codec->capabilities & CODEC_CAP_SLICE_THREADS &&

               avctx->thread_type & FF_THREAD_SLICE) {

        avctx->active_thread_type = FF_THREAD_SLICE;

    } else if (!(avctx->codec->capabilities & CODEC_CAP_AUTO_THREADS)) {

        avctx->thread_count       = 1;

        avctx->active_thread_type = 0;

    }

    if (avctx->thread_count > MAX_AUTO_THREADS)

        av_log(avctx, AV_LOG_WARNING,

               "Application has requested %d threads. Using a thread count greater than %d is not recommended.\n",

               avctx->thread_count, MAX_AUTO_THREADS);

}

int ff_thread_init(AVCodecContext *avctx)

{

#if HAVE_W32THREADS

    w32thread_init();

#endif

    validate_thread_parameters(avctx);

    if (avctx->active_thread_type&FF_THREAD_SLICE)

        return thread_init_internal(avctx);

    else if (avctx->active_thread_type&FF_THREAD_FRAME)

        return frame_thread_init(avctx);

    return 0;

}

void ff_thread_free(AVCodecContext *avctx)

{