Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 977 insertions, 0 deletions

diff --git a/media/ffvpx/libavcodec/pthread_frame.c b/media/ffvpx/libavcodec/pthread_frame.c
new file mode 100644
index 0000000000..d9d5afaa82
--- /dev/null
+++ b/media/ffvpx/libavcodec/pthread_frame.c
@@ -0,0 +1,977 @@
+/*
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * Frame multithreading support functions
+ * @see doc/multithreading.txt
+ */
+
+#include "config.h"
+
+#include <stdatomic.h>
+#include <stdint.h>
+
+#include "avcodec.h"
+#include "codec_internal.h"
+#include "decode.h"
+#include "hwconfig.h"
+#include "internal.h"
+#include "pthread_internal.h"
+#include "thread.h"
+#include "threadframe.h"
+#include "version_major.h"
+
+#include "libavutil/avassert.h"
+#include "libavutil/buffer.h"
+#include "libavutil/common.h"
+#include "libavutil/cpu.h"
+#include "libavutil/frame.h"
+#include "libavutil/internal.h"
+#include "libavutil/log.h"
+#include "libavutil/mem.h"
+#include "libavutil/opt.h"
+#include "libavutil/thread.h"
+
+enum {
+    ///< Set when the thread is awaiting a packet.
+    STATE_INPUT_READY,
+    ///< Set before the codec has called ff_thread_finish_setup().
+    STATE_SETTING_UP,
+    /**
+     * Set when the codec calls get_buffer().
+     * State is returned to STATE_SETTING_UP afterwards.
+     */
+    STATE_GET_BUFFER,
+     /**
+      * Set when the codec calls get_format().
+      * State is returned to STATE_SETTING_UP afterwards.
+      */
+    STATE_GET_FORMAT,
+    ///< Set after the codec has called ff_thread_finish_setup().
+    STATE_SETUP_FINISHED,
+};
+
+enum {
+    UNINITIALIZED,  ///< Thread has not been created, AVCodec->close mustn't be called
+    NEEDS_CLOSE,    ///< FFCodec->close needs to be called
+    INITIALIZED,    ///< Thread has been properly set up
+};
+
+/**
+ * Context used by codec threads and stored in their AVCodecInternal thread_ctx.
+ */
+typedef struct PerThreadContext {
+    struct FrameThreadContext *parent;
+
+    pthread_t      thread;
+    int            thread_init;
+    unsigned       pthread_init_cnt;///< Number of successfully initialized mutexes/conditions
+    pthread_cond_t input_cond;      ///< Used to wait for a new packet from the main thread.
+    pthread_cond_t progress_cond;   ///< Used by child threads to wait for progress to change.
+    pthread_cond_t output_cond;     ///< Used by the main thread to wait for frames to finish.
+
+    pthread_mutex_t mutex;          ///< Mutex used to protect the contents of the PerThreadContext.
+    pthread_mutex_t progress_mutex; ///< Mutex used to protect frame progress values and progress_cond.
+
+    AVCodecContext *avctx;          ///< Context used to decode packets passed to this thread.
+
+    AVPacket       *avpkt;          ///< Input packet (for decoding) or output (for encoding).
+
+    AVFrame *frame;                 ///< Output frame (for decoding) or input (for encoding).
+    int     got_frame;              ///< The output of got_picture_ptr from the last avcodec_decode_video() call.
+    int     result;                 ///< The result of the last codec decode/encode() call.
+
+    atomic_int state;
+
+    int die;                        ///< Set when the thread should exit.
+
+    int hwaccel_serializing;
+    int async_serializing;
+
+    atomic_int debug_threads;       ///< Set if the FF_DEBUG_THREADS option is set.
+} PerThreadContext;
+
+/**
+ * Context stored in the client AVCodecInternal thread_ctx.
+ */
+typedef struct FrameThreadContext {
+    PerThreadContext *threads;     ///< The contexts for each thread.
+    PerThreadContext *prev_thread; ///< The last thread submit_packet() was called on.
+
+    unsigned    pthread_init_cnt;  ///< Number of successfully initialized mutexes/conditions
+    pthread_mutex_t buffer_mutex;  ///< Mutex used to protect get/release_buffer().
+    /**
+     * This lock is used for ensuring threads run in serial when hwaccel
+     * is used.
+     */
+    pthread_mutex_t hwaccel_mutex;
+    pthread_mutex_t async_mutex;
+    pthread_cond_t async_cond;
+    int async_lock;
+
+    int next_decoding;             ///< The next context to submit a packet to.
+    int next_finished;             ///< The next context to return output from.
+
+    int delaying;                  /**<
+                                    * Set for the first N packets, where N is the number of threads.
+                                    * While it is set, ff_thread_en/decode_frame won't return any results.
+                                    */
+
+    /* hwaccel state is temporarily stored here in order to transfer its ownership
+     * to the next decoding thread without the need for extra synchronization */
+    const AVHWAccel *stash_hwaccel;
+    void            *stash_hwaccel_context;
+    void            *stash_hwaccel_priv;
+} FrameThreadContext;
+
+static void async_lock(FrameThreadContext *fctx)
+{
+    pthread_mutex_lock(&fctx->async_mutex);
+    while (fctx->async_lock)
+        pthread_cond_wait(&fctx->async_cond, &fctx->async_mutex);
+    fctx->async_lock = 1;
+    pthread_mutex_unlock(&fctx->async_mutex);
+}
+
+static void async_unlock(FrameThreadContext *fctx)
+{
+    pthread_mutex_lock(&fctx->async_mutex);
+    av_assert0(fctx->async_lock);
+    fctx->async_lock = 0;
+    pthread_cond_broadcast(&fctx->async_cond);
+    pthread_mutex_unlock(&fctx->async_mutex);
+}
+
+static void thread_set_name(PerThreadContext *p)
+{
+    AVCodecContext *avctx = p->avctx;
+    int idx = p - p->parent->threads;
+    char name[16];
+
+    snprintf(name, sizeof(name), "av:%.7s:df%d", avctx->codec->name, idx);
+
+    ff_thread_setname(name);
+}
+
+/**
+ * Codec worker thread.
+ *
+ * Automatically calls ff_thread_finish_setup() if the codec does
+ * not provide an update_thread_context method, or if the codec returns
+ * before calling it.
+ */
+static attribute_align_arg void *frame_worker_thread(void *arg)
+{
+    PerThreadContext *p = arg;
+    AVCodecContext *avctx = p->avctx;
+    const FFCodec *codec = ffcodec(avctx->codec);
+
+    thread_set_name(p);
+
+    pthread_mutex_lock(&p->mutex);
+    while (1) {
+        while (atomic_load(&p->state) == STATE_INPUT_READY && !p->die)
+            pthread_cond_wait(&p->input_cond, &p->mutex);
+
+        if (p->die) break;
+
+        if (!codec->update_thread_context)
+            ff_thread_finish_setup(avctx);
+
+        /* If a decoder supports hwaccel, then it must call ff_get_format().
+         * Since that call must happen before ff_thread_finish_setup(), the
+         * decoder is required to implement update_thread_context() and call
+         * ff_thread_finish_setup() manually. Therefore the above
+         * ff_thread_finish_setup() call did not happen and hwaccel_serializing
+         * cannot be true here. */
+        av_assert0(!p->hwaccel_serializing);
+
+        /* if the previous thread uses hwaccel then we take the lock to ensure
+         * the threads don't run concurrently */
+        if (avctx->hwaccel) {
+            pthread_mutex_lock(&p->parent->hwaccel_mutex);
+            p->hwaccel_serializing = 1;
+        }
+
+        av_frame_unref(p->frame);
+        p->got_frame = 0;
+        p->result = codec->cb.decode(avctx, p->frame, &p->got_frame, p->avpkt);
+
+        if ((p->result < 0 || !p->got_frame) && p->frame->buf[0])
+            ff_thread_release_buffer(avctx, p->frame);
+
+        if (atomic_load(&p->state) == STATE_SETTING_UP)
+            ff_thread_finish_setup(avctx);
+
+        if (p->hwaccel_serializing) {
+            /* wipe hwaccel state to avoid stale pointers lying around;
+             * the state was transferred to FrameThreadContext in
+             * ff_thread_finish_setup(), so nothing is leaked */
+            avctx->hwaccel                     = NULL;
+            avctx->hwaccel_context             = NULL;
+            avctx->internal->hwaccel_priv_data = NULL;
+
+            p->hwaccel_serializing = 0;
+            pthread_mutex_unlock(&p->parent->hwaccel_mutex);
+        }
+        av_assert0(!avctx->hwaccel);
+
+        if (p->async_serializing) {
+            p->async_serializing = 0;
+
+            async_unlock(p->parent);
+        }
+
+        pthread_mutex_lock(&p->progress_mutex);
+
+        atomic_store(&p->state, STATE_INPUT_READY);
+
+        pthread_cond_broadcast(&p->progress_cond);
+        pthread_cond_signal(&p->output_cond);
+        pthread_mutex_unlock(&p->progress_mutex);
+    }
+    pthread_mutex_unlock(&p->mutex);
+
+    return NULL;
+}
+
+/**
+ * Update the next thread's AVCodecContext with values from the reference thread's context.
+ *
+ * @param dst The destination context.
+ * @param src The source context.
+ * @param for_user 0 if the destination is a codec thread, 1 if the destination is the user's thread
+ * @return 0 on success, negative error code on failure
+ */
+static int update_context_from_thread(AVCodecContext *dst, AVCodecContext *src, int for_user)
+{
+    const FFCodec *const codec = ffcodec(dst->codec);
+    int err = 0;
+
+    if (dst != src && (for_user || codec->update_thread_context)) {
+        dst->time_base = src->time_base;
+        dst->framerate = src->framerate;
+        dst->width     = src->width;
+        dst->height    = src->height;
+        dst->pix_fmt   = src->pix_fmt;
+        dst->sw_pix_fmt = src->sw_pix_fmt;
+
+        dst->coded_width  = src->coded_width;
+        dst->coded_height = src->coded_height;
+
+        dst->has_b_frames = src->has_b_frames;
+        dst->idct_algo    = src->idct_algo;
+        dst->properties   = src->properties;
+
+        dst->bits_per_coded_sample = src->bits_per_coded_sample;
+        dst->sample_aspect_ratio   = src->sample_aspect_ratio;
+
+        dst->profile = src->profile;
+        dst->level   = src->level;
+
+        dst->bits_per_raw_sample = src->bits_per_raw_sample;
+        dst->ticks_per_frame     = src->ticks_per_frame;
+        dst->color_primaries     = src->color_primaries;
+
+        dst->color_trc   = src->color_trc;
+        dst->colorspace  = src->colorspace;
+        dst->color_range = src->color_range;
+        dst->chroma_sample_location = src->chroma_sample_location;
+
+        dst->sample_rate    = src->sample_rate;
+        dst->sample_fmt     = src->sample_fmt;
+#if FF_API_OLD_CHANNEL_LAYOUT
+FF_DISABLE_DEPRECATION_WARNINGS
+        dst->channels       = src->channels;
+        dst->channel_layout = src->channel_layout;
+FF_ENABLE_DEPRECATION_WARNINGS
+#endif
+        err = av_channel_layout_copy(&dst->ch_layout, &src->ch_layout);
+        if (err < 0)
+            return err;
+
+        if (!!dst->hw_frames_ctx != !!src->hw_frames_ctx ||
+            (dst->hw_frames_ctx && dst->hw_frames_ctx->data != src->hw_frames_ctx->data)) {
+            av_buffer_unref(&dst->hw_frames_ctx);
+
+            if (src->hw_frames_ctx) {
+                dst->hw_frames_ctx = av_buffer_ref(src->hw_frames_ctx);
+                if (!dst->hw_frames_ctx)
+                    return AVERROR(ENOMEM);
+            }
+        }
+
+        dst->hwaccel_flags = src->hwaccel_flags;
+
+        err = av_buffer_replace(&dst->internal->pool, src->internal->pool);
+        if (err < 0)
+            return err;
+    }
+
+    if (for_user) {
+        if (codec->update_thread_context_for_user)
+            err = codec->update_thread_context_for_user(dst, src);
+    } else {
+        if (codec->update_thread_context)
+            err = 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)
+{
+    int err;
+
+    dst->flags          = src->flags;
+
+    dst->draw_horiz_band= src->draw_horiz_band;
+    dst->get_buffer2    = src->get_buffer2;
+
+    dst->opaque   = src->opaque;
+    dst->debug    = src->debug;
+
+    dst->slice_flags = src->slice_flags;
+    dst->flags2      = src->flags2;
+    dst->export_side_data = src->export_side_data;
+
+    dst->skip_loop_filter = src->skip_loop_filter;
+    dst->skip_idct        = src->skip_idct;
+    dst->skip_frame       = src->skip_frame;
+
+    dst->frame_num        = src->frame_num;
+#if FF_API_AVCTX_FRAME_NUMBER
+FF_DISABLE_DEPRECATION_WARNINGS
+    dst->frame_number     = src->frame_number;
+FF_ENABLE_DEPRECATION_WARNINGS
+#endif
+#if FF_API_REORDERED_OPAQUE
+FF_DISABLE_DEPRECATION_WARNINGS
+    dst->reordered_opaque = src->reordered_opaque;
+FF_ENABLE_DEPRECATION_WARNINGS
+#endif
+
+    if (src->slice_count && src->slice_offset) {
+        if (dst->slice_count < src->slice_count) {
+            int err = av_reallocp_array(&dst->slice_offset, src->slice_count,
+                                        sizeof(*dst->slice_offset));
+            if (err < 0)
+                return err;
+        }
+        memcpy(dst->slice_offset, src->slice_offset,
+               src->slice_count * sizeof(*dst->slice_offset));
+    }
+    dst->slice_count = src->slice_count;
+
+    av_packet_unref(dst->internal->last_pkt_props);
+    err = av_packet_copy_props(dst->internal->last_pkt_props, src->internal->last_pkt_props);
+    if (err < 0)
+        return err;
+
+    return 0;
+}
+
+static int submit_packet(PerThreadContext *p, AVCodecContext *user_avctx,
+                         AVPacket *avpkt)
+{
+    FrameThreadContext *fctx = p->parent;
+    PerThreadContext *prev_thread = fctx->prev_thread;
+    const AVCodec *codec = p->avctx->codec;
+    int ret;
+
+    if (!avpkt->size && !(codec->capabilities & AV_CODEC_CAP_DELAY))
+        return 0;
+
+    pthread_mutex_lock(&p->mutex);
+
+    ret = update_context_from_user(p->avctx, user_avctx);
+    if (ret) {
+        pthread_mutex_unlock(&p->mutex);
+        return ret;
+    }
+    atomic_store_explicit(&p->debug_threads,
+                          (p->avctx->debug & FF_DEBUG_THREADS) != 0,
+                          memory_order_relaxed);
+
+    if (prev_thread) {
+        int err;
+        if (atomic_load(&prev_thread->state) == STATE_SETTING_UP) {
+            pthread_mutex_lock(&prev_thread->progress_mutex);
+            while (atomic_load(&prev_thread->state) == STATE_SETTING_UP)
+                pthread_cond_wait(&prev_thread->progress_cond, &prev_thread->progress_mutex);
+            pthread_mutex_unlock(&prev_thread->progress_mutex);
+        }
+
+        err = update_context_from_thread(p->avctx, prev_thread->avctx, 0);
+        if (err) {
+            pthread_mutex_unlock(&p->mutex);
+            return err;
+        }
+    }
+
+    /* transfer the stashed hwaccel state, if any */
+    av_assert0(!p->avctx->hwaccel);
+    FFSWAP(const AVHWAccel*, p->avctx->hwaccel,                     fctx->stash_hwaccel);
+    FFSWAP(void*,            p->avctx->hwaccel_context,             fctx->stash_hwaccel_context);
+    FFSWAP(void*,            p->avctx->internal->hwaccel_priv_data, fctx->stash_hwaccel_priv);
+
+    av_packet_unref(p->avpkt);
+    ret = av_packet_ref(p->avpkt, avpkt);
+    if (ret < 0) {
+        pthread_mutex_unlock(&p->mutex);
+        av_log(p->avctx, AV_LOG_ERROR, "av_packet_ref() failed in submit_packet()\n");
+        return ret;
+    }
+
+    atomic_store(&p->state, STATE_SETTING_UP);
+    pthread_cond_signal(&p->input_cond);
+    pthread_mutex_unlock(&p->mutex);
+
+    fctx->prev_thread = p;
+    fctx->next_decoding++;
+
+    return 0;
+}
+
+int ff_thread_decode_frame(AVCodecContext *avctx,
+                           AVFrame *picture, int *got_picture_ptr,
+                           AVPacket *avpkt)
+{
+    FrameThreadContext *fctx = avctx->internal->thread_ctx;
+    int finished = fctx->next_finished;
+    PerThreadContext *p;
+    int err;
+
+    /* release the async lock, permitting blocked hwaccel threads to
+     * go forward while we are in this function */
+    async_unlock(fctx);
+
+    /*
+     * Submit a packet to the next decoding thread.
+     */
+
+    p = &fctx->threads[fctx->next_decoding];
+    err = submit_packet(p, avctx, avpkt);
+    if (err)
+        goto finish;
+
+    /*
+     * If we're still receiving the initial packets, don't return a frame.
+     */
+
+    if (fctx->next_decoding > (avctx->thread_count-1-(avctx->codec_id == AV_CODEC_ID_FFV1)))
+        fctx->delaying = 0;
+
+    if (fctx->delaying) {
+        *got_picture_ptr=0;
+        if (avpkt->size) {
+            err = avpkt->size;
+            goto finish;
+        }
+    }
+
+    /*
+     * Return the next available frame from the oldest thread.
+     * If we're at the end of the stream, then we have to skip threads that
+     * didn't output a frame/error, because we don't want to accidentally signal
+     * EOF (avpkt->size == 0 && *got_picture_ptr == 0 && err >= 0).
+     */
+
+    do {
+        p = &fctx->threads[finished++];
+
+        if (atomic_load(&p->state) != STATE_INPUT_READY) {
+            pthread_mutex_lock(&p->progress_mutex);
+            while (atomic_load_explicit(&p->state, memory_order_relaxed) != STATE_INPUT_READY)
+                pthread_cond_wait(&p->output_cond, &p->progress_mutex);
+            pthread_mutex_unlock(&p->progress_mutex);
+        }
+
+        av_frame_move_ref(picture, p->frame);
+        *got_picture_ptr = p->got_frame;
+        picture->pkt_dts = p->avpkt->dts;
+        err = p->result;
+
+        /*
+         * A later call with avkpt->size == 0 may loop over all threads,
+         * including this one, searching for a frame/error to return before being
+         * stopped by the "finished != fctx->next_finished" condition.
+         * Make sure we don't mistakenly return the same frame/error again.
+         */
+        p->got_frame = 0;
+        p->result = 0;
+
+        if (finished >= avctx->thread_count) finished = 0;
+    } while (!avpkt->size && !*got_picture_ptr && err >= 0 && finished != fctx->next_finished);
+
+    update_context_from_thread(avctx, p->avctx, 1);
+
+    if (fctx->next_decoding >= avctx->thread_count) fctx->next_decoding = 0;
+
+    fctx->next_finished = finished;
+
+    /* return the size of the consumed packet if no error occurred */
+    if (err >= 0)
+        err = avpkt->size;
+finish:
+    async_lock(fctx);
+    return err;
+}
+
+void ff_thread_report_progress(ThreadFrame *f, int n, int field)
+{
+    PerThreadContext *p;
+    atomic_int *progress = f->progress ? (atomic_int*)f->progress->data : NULL;
+
+    if (!progress ||
+        atomic_load_explicit(&progress[field], memory_order_relaxed) >= n)
+        return;
+
+    p = f->owner[field]->internal->thread_ctx;
+
+    if (atomic_load_explicit(&p->debug_threads, memory_order_relaxed))
+        av_log(f->owner[field], AV_LOG_DEBUG,
+               "%p finished %d field %d\n", progress, n, field);
+
+    pthread_mutex_lock(&p->progress_mutex);
+
+    atomic_store_explicit(&progress[field], n, memory_order_release);
+
+    pthread_cond_broadcast(&p->progress_cond);
+    pthread_mutex_unlock(&p->progress_mutex);
+}
+
+void ff_thread_await_progress(const ThreadFrame *f, int n, int field)
+{
+    PerThreadContext *p;
+    atomic_int *progress = f->progress ? (atomic_int*)f->progress->data : NULL;
+
+    if (!progress ||
+        atomic_load_explicit(&progress[field], memory_order_acquire) >= n)
+        return;
+
+    p = f->owner[field]->internal->thread_ctx;
+
+    if (atomic_load_explicit(&p->debug_threads, memory_order_relaxed))
+        av_log(f->owner[field], AV_LOG_DEBUG,
+               "thread awaiting %d field %d from %p\n", n, field, progress);
+
+    pthread_mutex_lock(&p->progress_mutex);
+    while (atomic_load_explicit(&progress[field], memory_order_relaxed) < n)
+        pthread_cond_wait(&p->progress_cond, &p->progress_mutex);
+    pthread_mutex_unlock(&p->progress_mutex);
+}
+
+void ff_thread_finish_setup(AVCodecContext *avctx) {
+    PerThreadContext *p = avctx->internal->thread_ctx;
+
+    if (!(avctx->active_thread_type&FF_THREAD_FRAME)) return;
+
+    if (avctx->hwaccel && !p->hwaccel_serializing) {
+        pthread_mutex_lock(&p->parent->hwaccel_mutex);
+        p->hwaccel_serializing = 1;
+    }
+
+    /* this assumes that no hwaccel calls happen before ff_thread_finish_setup() */
+    if (avctx->hwaccel &&
+        !(avctx->hwaccel->caps_internal & HWACCEL_CAP_ASYNC_SAFE)) {
+        p->async_serializing = 1;
+
+        async_lock(p->parent);
+    }
+
+    /* save hwaccel state for passing to the next thread;
+     * this is done here so that this worker thread can wipe its own hwaccel
+     * state after decoding, without requiring synchronization */
+    av_assert0(!p->parent->stash_hwaccel);
+    p->parent->stash_hwaccel         = avctx->hwaccel;
+    p->parent->stash_hwaccel_context = avctx->hwaccel_context;
+    p->parent->stash_hwaccel_priv    = avctx->internal->hwaccel_priv_data;
+
+    pthread_mutex_lock(&p->progress_mutex);
+    if(atomic_load(&p->state) == STATE_SETUP_FINISHED){
+        av_log(avctx, AV_LOG_WARNING, "Multiple ff_thread_finish_setup() calls\n");
+    }
+
+    atomic_store(&p->state, STATE_SETUP_FINISHED);
+
+    pthread_cond_broadcast(&p->progress_cond);
+    pthread_mutex_unlock(&p->progress_mutex);
+}
+
+/// Waits for all threads to finish.
+static void park_frame_worker_threads(FrameThreadContext *fctx, int thread_count)
+{
+    int i;
+
+    async_unlock(fctx);
+
+    for (i = 0; i < thread_count; i++) {
+        PerThreadContext *p = &fctx->threads[i];
+
+        if (atomic_load(&p->state) != STATE_INPUT_READY) {
+            pthread_mutex_lock(&p->progress_mutex);
+            while (atomic_load(&p->state) != STATE_INPUT_READY)
+                pthread_cond_wait(&p->output_cond, &p->progress_mutex);
+            pthread_mutex_unlock(&p->progress_mutex);
+        }
+        p->got_frame = 0;
+    }
+
+    async_lock(fctx);
+}
+
+#define OFF(member) offsetof(FrameThreadContext, member)
+DEFINE_OFFSET_ARRAY(FrameThreadContext, thread_ctx, pthread_init_cnt,
+                    (OFF(buffer_mutex), OFF(hwaccel_mutex), OFF(async_mutex)),
+                    (OFF(async_cond)));
+#undef OFF
+
+#define OFF(member) offsetof(PerThreadContext, member)
+DEFINE_OFFSET_ARRAY(PerThreadContext, per_thread, pthread_init_cnt,
+                    (OFF(progress_mutex), OFF(mutex)),
+                    (OFF(input_cond), OFF(progress_cond), OFF(output_cond)));
+#undef OFF
+
+void ff_frame_thread_free(AVCodecContext *avctx, int thread_count)
+{
+    FrameThreadContext *fctx = avctx->internal->thread_ctx;
+    const FFCodec *codec = ffcodec(avctx->codec);
+    int i;
+
+    park_frame_worker_threads(fctx, thread_count);
+
+    for (i = 0; i < thread_count; i++) {
+        PerThreadContext *p = &fctx->threads[i];
+        AVCodecContext *ctx = p->avctx;
+
+        if (ctx->internal) {
+            if (p->thread_init == INITIALIZED) {
+                pthread_mutex_lock(&p->mutex);
+                p->die = 1;
+                pthread_cond_signal(&p->input_cond);
+                pthread_mutex_unlock(&p->mutex);
+
+                pthread_join(p->thread, NULL);
+            }
+            if (codec->close && p->thread_init != UNINITIALIZED)
+                codec->close(ctx);
+
+            if (ctx->priv_data) {
+                if (codec->p.priv_class)
+                    av_opt_free(ctx->priv_data);
+                av_freep(&ctx->priv_data);
+            }
+
+            av_freep(&ctx->slice_offset);
+
+            av_buffer_unref(&ctx->internal->pool);
+            av_packet_free(&ctx->internal->last_pkt_props);
+            av_freep(&ctx->internal);
+            av_buffer_unref(&ctx->hw_frames_ctx);
+        }
+
+        av_frame_free(&p->frame);
+
+        ff_pthread_free(p, per_thread_offsets);
+        av_packet_free(&p->avpkt);
+
+        av_freep(&p->avctx);
+    }
+
+    av_freep(&fctx->threads);
+    ff_pthread_free(fctx, thread_ctx_offsets);
+
+    /* if we have stashed hwaccel state, move it to the user-facing context,
+     * so it will be freed in avcodec_close() */
+    av_assert0(!avctx->hwaccel);
+    FFSWAP(const AVHWAccel*, avctx->hwaccel,                     fctx->stash_hwaccel);
+    FFSWAP(void*,            avctx->hwaccel_context,             fctx->stash_hwaccel_context);
+    FFSWAP(void*,            avctx->internal->hwaccel_priv_data, fctx->stash_hwaccel_priv);
+
+    av_freep(&avctx->internal->thread_ctx);
+}
+
+static av_cold int init_thread(PerThreadContext *p, int *threads_to_free,
+                               FrameThreadContext *fctx, AVCodecContext *avctx,
+                               const FFCodec *codec, int first)
+{
+    AVCodecContext *copy;
+    int err;
+
+    atomic_init(&p->state, STATE_INPUT_READY);
+
+    copy = av_memdup(avctx, sizeof(*avctx));
+    if (!copy)
+        return AVERROR(ENOMEM);
+    copy->priv_data = NULL;
+
+    /* From now on, this PerThreadContext will be cleaned up by
+     * ff_frame_thread_free in case of errors. */
+    (*threads_to_free)++;
+
+    p->parent = fctx;
+    p->avctx  = copy;
+
+    copy->internal = av_mallocz(sizeof(*copy->internal));
+    if (!copy->internal)
+        return AVERROR(ENOMEM);
+    copy->internal->thread_ctx = p;
+
+    copy->delay = avctx->delay;
+
+    if (codec->priv_data_size) {
+        copy->priv_data = av_mallocz(codec->priv_data_size);
+        if (!copy->priv_data)
+            return AVERROR(ENOMEM);
+
+        if (codec->p.priv_class) {
+            *(const AVClass **)copy->priv_data = codec->p.priv_class;
+            err = av_opt_copy(copy->priv_data, avctx->priv_data);
+            if (err < 0)
+                return err;
+        }
+    }
+
+    err = ff_pthread_init(p, per_thread_offsets);
+    if (err < 0)
+        return err;
+
+    if (!(p->frame = av_frame_alloc()) ||
+        !(p->avpkt = av_packet_alloc()))
+        return AVERROR(ENOMEM);
+
+    if (!first)
+        copy->internal->is_copy = 1;
+
+    copy->internal->last_pkt_props = av_packet_alloc();
+    if (!copy->internal->last_pkt_props)
+        return AVERROR(ENOMEM);
+
+    if (codec->init) {
+        err = codec->init(copy);
+        if (err < 0) {
+            if (codec->caps_internal & FF_CODEC_CAP_INIT_CLEANUP)
+                p->thread_init = NEEDS_CLOSE;
+            return err;
+        }
+    }
+    p->thread_init = NEEDS_CLOSE;
+
+    if (first)
+        update_context_from_thread(avctx, copy, 1);
+
+    atomic_init(&p->debug_threads, (copy->debug & FF_DEBUG_THREADS) != 0);
+
+    err = AVERROR(pthread_create(&p->thread, NULL, frame_worker_thread, p));
+    if (err < 0)
+        return err;
+    p->thread_init = INITIALIZED;
+
+    return 0;
+}
+
+int ff_frame_thread_init(AVCodecContext *avctx)
+{
+    int thread_count = avctx->thread_count;
+    const FFCodec *codec = ffcodec(avctx->codec);
+    FrameThreadContext *fctx;
+    int err, i = 0;
+
+    if (!thread_count) {
+        int nb_cpus = av_cpu_count();
+        // use number of cores + 1 as thread count if there is more than one
+        if (nb_cpus > 1)
+            thread_count = avctx->thread_count = FFMIN(nb_cpus + 1, MAX_AUTO_THREADS);
+        else
+            thread_count = avctx->thread_count = 1;
+    }
+
+    if (thread_count <= 1) {
+        avctx->active_thread_type = 0;
+        return 0;
+    }
+
+    avctx->internal->thread_ctx = fctx = av_mallocz(sizeof(FrameThreadContext));
+    if (!fctx)
+        return AVERROR(ENOMEM);
+
+    err = ff_pthread_init(fctx, thread_ctx_offsets);
+    if (err < 0) {
+        ff_pthread_free(fctx, thread_ctx_offsets);
+        av_freep(&avctx->internal->thread_ctx);
+        return err;
+    }
+
+    fctx->async_lock = 1;
+    fctx->delaying = 1;
+
+    if (codec->p.type == AVMEDIA_TYPE_VIDEO)
+        avctx->delay = avctx->thread_count - 1;
+
+    fctx->threads = av_calloc(thread_count, sizeof(*fctx->threads));
+    if (!fctx->threads) {
+        err = AVERROR(ENOMEM);
+        goto error;
+    }
+
+    for (; i < thread_count; ) {
+        PerThreadContext *p  = &fctx->threads[i];
+        int first = !i;
+
+        err = init_thread(p, &i, fctx, avctx, codec, first);
+        if (err < 0)
+            goto error;
+    }
+
+    return 0;
+
+error:
+    ff_frame_thread_free(avctx, i);
+    return err;
+}
+
+void ff_thread_flush(AVCodecContext *avctx)
+{
+    int i;
+    FrameThreadContext *fctx = avctx->internal->thread_ctx;
+
+    if (!fctx) return;
+
+    park_frame_worker_threads(fctx, avctx->thread_count);
+    if (fctx->prev_thread) {
+        if (fctx->prev_thread != &fctx->threads[0])
+            update_context_from_thread(fctx->threads[0].avctx, fctx->prev_thread->avctx, 0);
+    }
+
+    fctx->next_decoding = fctx->next_finished = 0;
+    fctx->delaying = 1;
+    fctx->prev_thread = NULL;
+    for (i = 0; i < avctx->thread_count; i++) {
+        PerThreadContext *p = &fctx->threads[i];
+        // Make sure decode flush calls with size=0 won't return old frames
+        p->got_frame = 0;
+        av_frame_unref(p->frame);
+        p->result = 0;
+
+        if (ffcodec(avctx->codec)->flush)
+            ffcodec(avctx->codec)->flush(p->avctx);
+    }
+}
+
+int ff_thread_can_start_frame(AVCodecContext *avctx)
+{
+    PerThreadContext *p = avctx->internal->thread_ctx;
+
+    if ((avctx->active_thread_type&FF_THREAD_FRAME) && atomic_load(&p->state) != STATE_SETTING_UP &&
+        ffcodec(avctx->codec)->update_thread_context) {
+        return 0;
+    }
+
+    return 1;
+}
+
+static int thread_get_buffer_internal(AVCodecContext *avctx, AVFrame *f, int flags)
+{
+    PerThreadContext *p;
+    int err;
+
+    if (!(avctx->active_thread_type & FF_THREAD_FRAME))
+        return ff_get_buffer(avctx, f, flags);
+
+    p = avctx->internal->thread_ctx;
+FF_DISABLE_DEPRECATION_WARNINGS
+    if (atomic_load(&p->state) != STATE_SETTING_UP &&
+        ffcodec(avctx->codec)->update_thread_context) {
+FF_ENABLE_DEPRECATION_WARNINGS
+        av_log(avctx, AV_LOG_ERROR, "get_buffer() cannot be called after ff_thread_finish_setup()\n");
+        return -1;
+    }
+
+    pthread_mutex_lock(&p->parent->buffer_mutex);
+    err = ff_get_buffer(avctx, f, flags);
+
+    pthread_mutex_unlock(&p->parent->buffer_mutex);
+
+    return err;
+}
+
+int ff_thread_get_buffer(AVCodecContext *avctx, AVFrame *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;
+}
+
+int ff_thread_get_ext_buffer(AVCodecContext *avctx, ThreadFrame *f, int flags)
+{
+    int ret;
+
+    f->owner[0] = f->owner[1] = avctx;
+    /* Hint: It is possible for this function to be called with codecs
+     * that don't support frame threading at all, namely in case
+     * a frame-threaded decoder shares code with codecs that are not.
+     * This currently affects non-MPEG-4 mpegvideo codecs and and VP7.
+     * The following check will always be true for them. */
+    if (!(avctx->active_thread_type & FF_THREAD_FRAME))
+        return ff_get_buffer(avctx, f->f, flags);
+
+    if (ffcodec(avctx->codec)->caps_internal & FF_CODEC_CAP_ALLOCATE_PROGRESS) {
+        atomic_int *progress;
+        f->progress = av_buffer_alloc(2 * sizeof(*progress));
+        if (!f->progress) {
+            return AVERROR(ENOMEM);
+        }
+        progress = (atomic_int*)f->progress->data;
+
+        atomic_init(&progress[0], -1);
+        atomic_init(&progress[1], -1);
+    }
+
+    ret = ff_thread_get_buffer(avctx, f->f, flags);
+    if (ret)
+        av_buffer_unref(&f->progress);
+    return ret;
+}
+
+void ff_thread_release_buffer(AVCodecContext *avctx, AVFrame *f)
+{
+    if (!f)
+        return;
+
+    if (avctx->debug & FF_DEBUG_BUFFERS)
+        av_log(avctx, AV_LOG_DEBUG, "thread_release_buffer called on pic %p\n", f);
+
+    av_frame_unref(f);
+}
+
+void ff_thread_release_ext_buffer(AVCodecContext *avctx, ThreadFrame *f)
+{
+    av_buffer_unref(&f->progress);
+    f->owner[0] = f->owner[1] = NULL;
+    ff_thread_release_buffer(avctx, f->f);
+}