lavc: split slice and frame threading functions into separate files

5 files changed, 1057 insertions, 949 deletions

diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index b3ecf7999d..205359e877 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -677,8 +677,8 @@ OBJS-$(CONFIG_REMOVE_EXTRADATA_BSF)       += remove_extradata_bsf.o
 OBJS-$(CONFIG_TEXT2MOVSUB_BSF)            += movsub_bsf.o
 
 # thread libraries
-OBJS-$(HAVE_PTHREADS)                  += pthread.o
-OBJS-$(HAVE_W32THREADS)                += pthread.o
+OBJS-$(HAVE_PTHREADS)                  += pthread.o pthread_slice.o pthread_frame.o
+OBJS-$(HAVE_W32THREADS)                += pthread.o pthread_slice.o pthread_frame.o
 
 SKIPHEADERS                            += %_tablegen.h                  \
                                           %_tables.h                    \
diff --git a/libavcodec/pthread.c b/libavcodec/pthread.c
index ce969af166..682fd051cc 100644
--- a/libavcodec/pthread.c
+++ b/libavcodec/pthread.c
@@ -29,948 +29,10 @@
  * @see doc/multithreading.txt
  */
 
-#include "config.h"
-
 #include "avcodec.h"
 #include "internal.h"
+#include "pthread_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 <pthread.h>
-#elif HAVE_W32THREADS
-#include "compat/w32pthreads.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;
-} 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_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
-} 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 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; i<avctx->thread_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 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);
-
-    thread_park_workers(c, avctx->thread_count);
-
-    return 0;
-}
-
-static int thread_execute2(AVCodecContext *avctx, action_func2* func2, void *arg, int *ret, int job_count)
-{
-    ThreadContext *c= avctx->thread_opaque;
-    c->func2 = func2;
-    return 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();
-        av_log(avctx, AV_LOG_DEBUG, "detected %d logical cores\n", nb_cpus);
-        // 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<thread_count; 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;
-        }
-    }
-
-    thread_park_workers(c, thread_count);
-
-    avctx->execute = thread_execute;
-    avctx->execute2 = thread_execute2;
-    return 0;
-}
-
-/**
- * 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;
-
-    while (1) {
-        if (p->state == STATE_INPUT_READY && !fctx->die) {
-            pthread_mutex_lock(&p->mutex);
-            while (p->state == STATE_INPUT_READY && !fctx->die)
-                pthread_cond_wait(&p->input_cond, &p->mutex);
-            pthread_mutex_unlock(&p->mutex);
-        }
-
-        if (fctx->die) break;
-
-        if (!codec->update_thread_context && avctx->thread_safe_callbacks)
-            ff_thread_finish_setup(avctx);
-
-        pthread_mutex_lock(&p->mutex);
-        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);
-
-        p->state = STATE_INPUT_READY;
-
-        pthread_mutex_lock(&p->progress_mutex);
-        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;
-    }
-
-    if (for_user) {
-        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->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;
-
-    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);
-        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 && (
-#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) {
-            pthread_mutex_lock(&p->progress_mutex);
-            while (p->state == STATE_SETTING_UP)
-                pthread_cond_wait(&p->progress_cond, &p->progress_mutex);
-
-            if (p->state == STATE_GET_BUFFER) {
-                p->result = ff_get_buffer(p->avctx, p->requested_frame, p->requested_flags);
-                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->delaying) {
-        if (fctx->next_decoding >= (avctx->thread_count-1)) fctx->delaying = 0;
-
-        *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;
-    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;
-    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;
-
-    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);
-        }
-    }
-}
-
-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)
-        update_context_from_thread(fctx->threads->avctx, fctx->prev_thread->avctx, 0);
-
-    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);
-
-        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();
-        av_log(avctx, AV_LOG_DEBUG, "detected %d logical cores\n", nb_cpus);
-        // 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;
-
-        if (!pthread_create(&p->thread, NULL, frame_worker_thread, p))
-            p->thread_init = 1;
-    }
-
-    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_get_buffer(AVCodecContext *avctx, ThreadFrame *f, int flags)
-{
-    PerThreadContext *p = avctx->thread_opaque;
-    int err;
-
-    f->owner = avctx;
-
-    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 || !avctx->thread_safe_callbacks)) {
-        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 {
-        p->requested_frame = f->f;
-        p->requested_flags = flags;
-        p->state = STATE_GET_BUFFER;
-        pthread_mutex_lock(&p->progress_mutex);
-        pthread_cond_signal(&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 (!avctx->thread_safe_callbacks && !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;
-}
-
-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.
@@ -1007,16 +69,12 @@ static void validate_thread_parameters(AVCodecContext *avctx)
 
 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);
+        return ff_slice_thread_init(avctx);
     else if (avctx->active_thread_type&FF_THREAD_FRAME)
-        return frame_thread_init(avctx);
+        return ff_frame_thread_init(avctx);
 
     return 0;
 }
@@ -1024,7 +82,7 @@ int ff_thread_init(AVCodecContext *avctx)
 void ff_thread_free(AVCodecContext *avctx)
 {
     if (avctx->active_thread_type&FF_THREAD_FRAME)
-        frame_thread_free(avctx, avctx->thread_count);
+        ff_frame_thread_free(avctx, avctx->thread_count);
     else
-        thread_free(avctx);
+        ff_slice_thread_free(avctx);
 }
diff --git a/libavcodec/pthread_frame.c b/libavcodec/pthread_frame.c
new file mode 100644
index 0000000000..d16078f454
--- /dev/null
+++ b/libavcodec/pthread_frame.c
@@ -0,0 +1,792 @@
+/*
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; 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 <stdint.h>
+
+#if HAVE_PTHREADS
+#include <pthread.h>
+#elif HAVE_W32THREADS
+#include "compat/w32pthreads.h"
+#endif
+
+#include "avcodec.h"
+#include "internal.h"
+#include "pthread_internal.h"
+#include "thread.h"
+
+#include "libavutil/avassert.h"
+#include "libavutil/buffer.h"
+#include "libavutil/common.h"
+#include "libavutil/cpu.h"
+#include "libavutil/frame.h"
+#include "libavutil/log.h"
+#include "libavutil/mem.h"
+
+/**
+ * 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_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
+} 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;
+
+/**
+ * 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;
+
+    while (1) {
+        if (p->state == STATE_INPUT_READY && !fctx->die) {
+            pthread_mutex_lock(&p->mutex);
+            while (p->state == STATE_INPUT_READY && !fctx->die)
+                pthread_cond_wait(&p->input_cond, &p->mutex);
+            pthread_mutex_unlock(&p->mutex);
+        }
+
+        if (fctx->die) break;
+
+        if (!codec->update_thread_context && avctx->thread_safe_callbacks)
+            ff_thread_finish_setup(avctx);
+
+        pthread_mutex_lock(&p->mutex);
+        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);
+
+        p->state = STATE_INPUT_READY;
+
+        pthread_mutex_lock(&p->progress_mutex);
+        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;
+    }
+
+    if (for_user) {
+        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->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;
+
+    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);
+        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 && (
+#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) {
+            pthread_mutex_lock(&p->progress_mutex);
+            while (p->state == STATE_SETTING_UP)
+                pthread_cond_wait(&p->progress_cond, &p->progress_mutex);
+
+            if (p->state == STATE_GET_BUFFER) {
+                p->result = ff_get_buffer(p->avctx, p->requested_frame, p->requested_flags);
+                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->delaying) {
+        if (fctx->next_decoding >= (avctx->thread_count-1)) fctx->delaying = 0;
+
+        *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;
+    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;
+    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;
+
+    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);
+        }
+    }
+}
+
+void ff_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)
+        update_context_from_thread(fctx->threads->avctx, fctx->prev_thread->avctx, 0);
+
+    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);
+
+        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);
+}
+
+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 HAVE_W32THREADS
+    w32thread_init();
+#endif
+
+    if (!thread_count) {
+        int nb_cpus = av_cpu_count();
+        av_log(avctx, AV_LOG_DEBUG, "detected %d logical cores\n", nb_cpus);
+        // 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;
+
+        if (!pthread_create(&p->thread, NULL, frame_worker_thread, p))
+            p->thread_init = 1;
+    }
+
+    return 0;
+
+error:
+    ff_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_get_buffer(AVCodecContext *avctx, ThreadFrame *f, int flags)
+{
+    PerThreadContext *p = avctx->thread_opaque;
+    int err;
+
+    f->owner = avctx;
+
+    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 || !avctx->thread_safe_callbacks)) {
+        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 {
+        p->requested_frame = f->f;
+        p->requested_flags = flags;
+        p->state = STATE_GET_BUFFER;
+        pthread_mutex_lock(&p->progress_mutex);
+        pthread_cond_signal(&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 (!avctx->thread_safe_callbacks && !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;
+}
+
+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);
+}
diff --git a/libavcodec/pthread_internal.h b/libavcodec/pthread_internal.h
new file mode 100644
index 0000000000..5dfd0b2a26
--- /dev/null
+++ b/libavcodec/pthread_internal.h
@@ -0,0 +1,34 @@
+/*
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVCODEC_PTHREAD_INTERNAL_H
+#define AVCODEC_PTHREAD_INTERNAL_H
+
+#include "avcodec.h"
+
+/* 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
+
+int ff_slice_thread_init(AVCodecContext *avctx);
+void ff_slice_thread_free(AVCodecContext *avctx);
+
+int ff_frame_thread_init(AVCodecContext *avctx);
+void ff_frame_thread_free(AVCodecContext *avctx, int thread_count);
+
+#endif // AVCODEC_PTHREAD_INTERNAL_H
diff --git a/libavcodec/pthread_slice.c b/libavcodec/pthread_slice.c
new file mode 100644
index 0000000000..67ba3dd381
--- /dev/null
+++ b/libavcodec/pthread_slice.c
@@ -0,0 +1,224 @@
+/*
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * Slice multithreading support functions
+ * @see doc/multithreading.txt
+ */
+
+#include "config.h"
+
+#if HAVE_PTHREADS
+#include <pthread.h>
+#elif HAVE_W32THREADS
+#include "compat/w32pthreads.h"
+#endif
+
+#include "avcodec.h"
+#include "internal.h"
+#include "pthread_internal.h"
+#include "thread.h"
+
+#include "libavutil/common.h"
+#include "libavutil/cpu.h"
+#include "libavutil/mem.h"
+
+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;
+} ThreadContext;
+
+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++;
+    }
+}
+
+void ff_slice_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; i<avctx->thread_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 av_always_inline void 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 int 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);
+
+    thread_park_workers(c, avctx->thread_count);
+
+    return 0;
+}
+
+static int thread_execute2(AVCodecContext *avctx, action_func2* func2, void *arg, int *ret, int job_count)
+{
+    ThreadContext *c= avctx->thread_opaque;
+    c->func2 = func2;
+    return thread_execute(avctx, NULL, arg, ret, job_count, 0);
+}
+
+int ff_slice_thread_init(AVCodecContext *avctx)
+{
+    int i;
+    ThreadContext *c;
+    int thread_count = avctx->thread_count;
+
+#if HAVE_W32THREADS
+    w32thread_init();
+#endif
+
+    if (!thread_count) {
+        int nb_cpus = av_cpu_count();
+        av_log(avctx, AV_LOG_DEBUG, "detected %d logical cores\n", nb_cpus);
+        // 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<thread_count; 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;
+        }
+    }
+
+    thread_park_workers(c, thread_count);
+
+    avctx->execute = thread_execute;
+    avctx->execute2 = thread_execute2;
+    return 0;
+}