virtualenv/FFmpeg
1
0
Fork 0
mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-12-23 12:43:46 +02:00
Code Issues Releases Activity

Frame-based multithreading framework using pthreads

Browse Source 
See doc/multithreading.txt for details on use in codecs.

Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>
This commit is contained in:
Alexander Strange 2011-02-07 21:15:44 -05:00 committed by Ronald S. Bultje
parent c2bd7578af
commit 37b00b47cb
11 changed files with 1068 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
doc/APIchanges
View File

@ -13,6 +13,11 @@ libavutil: 2009-03-08
API changes, most recent first:
2011-02-09 - XXXXXXX - lavc 52.111.0 - threading API
Add CODEC_CAP_FRAME_THREADS with new restrictions on get_buffer()/
release_buffer()/draw_horiz_band() callbacks for appropriate codecs.
Add thread_type and active_thread_type fields to AVCodecContext.
2011-02-08 - 3940caa - lavf 52.98.0 - av_probe_input_buffer
Add av_probe_input_buffer() to avformat.h for probing format from a
ByteIOContext.

65
doc/multithreading.txt Normal file
View File

@ -0,0 +1,65 @@
FFmpeg multithreading methods
==============================================
FFmpeg provides two methods for multithreading codecs.
Slice threading decodes multiple parts of a frame at the same time, using
AVCodecContext execute() and execute2().
Frame threading decodes multiple frames at the same time.
It accepts N future frames and delays decoded pictures by N-1 frames.
The later frames are decoded in separate threads while the user is
displaying the current one.
Restrictions on clients
==============================================
Slice threading -
* The client's draw_horiz_band() must be thread-safe according to the comment
in avcodec.h.
Frame threading -
* Restrictions with slice threading also apply.
* For best performance, the client should set thread_safe_callbacks if it
provides a thread-safe get_buffer() callback.
* There is one frame of delay added for every thread beyond the first one.
Clients must be able to handle this; the pkt_dts and pkt_pts fields in
AVFrame will work as usual.
Restrictions on codec implementations
==============================================
Slice threading -
None except that there must be something worth executing in parallel.
Frame threading -
* Codecs can only accept entire pictures per packet.
* Codecs similar to ffv1, whose streams don't reset across frames,
will not work because their bitstreams cannot be decoded in parallel.
* The contents of buffers must not be read before ff_thread_await_progress()
has been called on them. reget_buffer() and buffer age optimizations no longer work.
* The contents of buffers must not be written to after ff_thread_report_progress()
has been called on them. This includes draw_edges().
Porting codecs to frame threading
==============================================
Find all context variables that are needed by the next frame. Move all
code changing them, as well as code calling get_buffer(), up to before
the decode process starts. Call ff_thread_finish_setup() afterwards. If
some code can't be moved, have update_thread_context() run it in the next
thread.
If the codec allocates writable tables in its init(), add an init_thread_copy()
which re-allocates them for other threads.
Add CODEC_CAP_FRAME_THREADS to the codec capabilities. There will be very little
speed gain at this point but it should work.
Call ff_thread_report_progress() after some part of the current picture has decoded.
A good place to put this is where draw_horiz_band() is called - add this if it isn't
called anywhere, as it's useful too and the implementation is trivial when you're
doing this. Note that draw_edges() needs to be called before reporting progress.
Before accessing a reference frame or its MVs, call ff_thread_await_progress().

1
ffplay.c
View File

@ -1694,6 +1694,7 @@ static int input_init(AVFilterContext *ctx, const char *args, void *opaque)
codec->get_buffer = input_get_buffer;
codec->release_buffer = input_release_buffer;
codec->reget_buffer = input_reget_buffer;
codec->thread_safe_callbacks = 1;
}
priv->frame = avcodec_alloc_frame();

89
libavcodec/avcodec.h
View File

@ -32,7 +32,7 @@
#include "libavutil/cpu.h"
#define LIBAVCODEC_VERSION_MAJOR 52
#define LIBAVCODEC_VERSION_MINOR 110
#define LIBAVCODEC_VERSION_MINOR 111
#define LIBAVCODEC_VERSION_MICRO 0
#define LIBAVCODEC_VERSION_INT AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
@ -728,6 +728,10 @@ typedef struct RcOverride{
* Codec is able to deal with negative linesizes
*/
#define CODEC_CAP_NEG_LINESIZES 0x0800
/**
* Codec supports frame-level multithreading.
*/
#define CODEC_CAP_FRAME_THREADS 0x1000
//The following defines may change, don't expect compatibility if you use them.
#define MB_TYPE_INTRA4x4 0x0001
@ -1027,7 +1031,20 @@ typedef struct AVPanScan{
* - decoding: Read by user.\
*/\
int64_t pkt_dts;\
\
/**\
* the AVCodecContext which ff_thread_get_buffer() was last called on\
* - encoding: Set by libavcodec.\
* - decoding: Set by libavcodec.\
*/\
struct AVCodecContext *owner;\
\
/**\
* used by multithreading to store frame-specific info\
* - encoding: Set by libavcodec.\
* - decoding: Set by libavcodec.\
*/\
void *thread_opaque;
#define FF_QSCALE_TYPE_MPEG1 0
#define FF_QSCALE_TYPE_MPEG2 1
@ -1239,6 +1256,10 @@ typedef struct AVCodecContext {
* decoder to draw a horizontal band. It improves cache usage. Not
* all codecs can do that. You must check the codec capabilities
* beforehand.
* When multithreading is used, it may be called from multiple threads
* at the same time; threads might draw different parts of the same AVFrame,
* or multiple AVFrames, and there is no guarantee that slices will be drawn
* in order.
* The function is also used by hardware acceleration APIs.
* It is called at least once during frame decoding to pass
* the data needed for hardware render.
@ -1492,6 +1513,9 @@ typedef struct AVCodecContext {
* if CODEC_CAP_DR1 is not set then get_buffer() must call
* avcodec_default_get_buffer() instead of providing buffers allocated by
* some other means.
* If frame multithreading is used and thread_safe_callbacks is set,
* it may be called from a different thread, but not from more than one at once.
* Does not need to be reentrant.
* - encoding: unused
* - decoding: Set by libavcodec, user can override.
*/
@ -1501,6 +1525,8 @@ typedef struct AVCodecContext {
* Called to release buffers which were allocated with get_buffer.
* A released buffer can be reused in get_buffer().
* pic.data[*] must be set to NULL.
* May be called from a different thread if frame multithreading is used,
* but not by more than one thread at once, so does not need to be reentrant.
* - encoding: unused
* - decoding: Set by libavcodec, user can override.
*/
@ -1804,6 +1830,7 @@ typedef struct AVCodecContext {
#define FF_DEBUG_VIS_QP 0x00002000
#define FF_DEBUG_VIS_MB_TYPE 0x00004000
#define FF_DEBUG_BUFFERS 0x00008000
#define FF_DEBUG_THREADS 0x00010000
/**
* debug
@ -2827,6 +2854,44 @@ typedef struct AVCodecContext {
* - encoding: unused
*/
AVPacket *pkt;
/**
* Whether this is a copy of the context which had init() called on it.
* This is used by multithreading - shared tables and picture pointers
* should be freed from the original context only.
* - encoding: Set by libavcodec.
* - decoding: Set by libavcodec.
*/
int is_copy;
/**
* Which multithreading methods to use.
* Use of FF_THREAD_FRAME will increase decoding delay by one frame per thread,
* so clients which cannot provide future frames should not use it.
*
* - encoding: Set by user, otherwise the default is used.
* - decoding: Set by user, otherwise the default is used.
*/
int thread_type;
#define FF_THREAD_FRAME 1 //< Decode more than one frame at once
#define FF_THREAD_SLICE 2 //< Decode more than one part of a single frame at once
/**
* Which multithreading methods are in use by the codec.
* - encoding: Set by libavcodec.
* - decoding: Set by libavcodec.
*/
int active_thread_type;
/**
* Set by the client if its custom get_buffer() callback can be called
* from another thread, which allows faster multithreaded decoding.
* draw_horiz_band() will be called from other threads regardless of this setting.
* Ignored if the default get_buffer() is used.
* - encoding: Set by user.
* - decoding: Set by user.
*/
int thread_safe_callbacks;
} AVCodecContext;
/**
@ -2879,6 +2944,26 @@ typedef struct AVCodec {
uint8_t max_lowres; ///< maximum value for lowres supported by the decoder
AVClass *priv_class; ///< AVClass for the private context
const AVProfile *profiles; ///< array of recognized profiles, or NULL if unknown, array is terminated by {FF_PROFILE_UNKNOWN}
/**
* @defgroup framethreading Frame-level threading support functions.
* @{
*/
/**
* If defined, called on thread contexts when they are created.
* If the codec allocates writable tables in init(), re-allocate them here.
* priv_data will be set to a copy of the original.
*/
int (*init_thread_copy)(AVCodecContext *);
/**
* Copy necessary context variables from a previous thread context to the current one.
* If not defined, the next thread will start automatically; otherwise, the codec
* must call ff_thread_finish_setup().
*
* dst and src will (rarely) point to the same context, in which case memcpy should be skipped.
*/
int (*update_thread_context)(AVCodecContext *dst, const AVCodecContext *src);
/** @} */
} AVCodec;
/**

4
libavcodec/options.c
View File

@ -250,6 +250,7 @@ static const AVOption options[]={
{"vis_qp", "visualize quantization parameter (QP), lower QP are tinted greener", 0, FF_OPT_TYPE_CONST, FF_DEBUG_VIS_QP, INT_MIN, INT_MAX, V|D, "debug"},
{"vis_mb_type", "visualize block types", 0, FF_OPT_TYPE_CONST, FF_DEBUG_VIS_MB_TYPE, INT_MIN, INT_MAX, V|D, "debug"},
{"buffers", "picture buffer allocations", 0, FF_OPT_TYPE_CONST, FF_DEBUG_BUFFERS, INT_MIN, INT_MAX, V|D, "debug"},
{"thread_ops", "threading operations", 0, FF_OPT_TYPE_CONST, FF_DEBUG_THREADS, INT_MIN, INT_MAX, V|D, "debug"},
{"vismv", "visualize motion vectors (MVs)", OFFSET(debug_mv), FF_OPT_TYPE_INT, DEFAULT, 0, INT_MAX, V|D, "debug_mv"},
{"pf", "forward predicted MVs of P-frames", 0, FF_OPT_TYPE_CONST, FF_DEBUG_VIS_MV_P_FOR, INT_MIN, INT_MAX, V|D, "debug_mv"},
{"bf", "forward predicted MVs of B-frames", 0, FF_OPT_TYPE_CONST, FF_DEBUG_VIS_MV_B_FOR, INT_MIN, INT_MAX, V|D, "debug_mv"},
@ -431,6 +432,9 @@ static const AVOption options[]={
{"cholesky", NULL, 0, FF_OPT_TYPE_CONST, AV_LPC_TYPE_CHOLESKY, INT_MIN, INT_MAX, A|E, "lpc_type"},
{"lpc_passes", "number of passes to use for Cholesky factorization during LPC analysis", OFFSET(lpc_passes), FF_OPT_TYPE_INT, -1, INT_MIN, INT_MAX, A|E},
{"slices", "number of slices, used in parallelized decoding", OFFSET(slices), FF_OPT_TYPE_INT, 0, 0, INT_MAX, V|E},
{"thread_type", "select multithreading type", OFFSET(thread_type), FF_OPT_TYPE_INT, FF_THREAD_SLICE|FF_THREAD_FRAME, 0, INT_MAX, V|E|D, "thread_type"},
{"slice", NULL, 0, FF_OPT_TYPE_CONST, FF_THREAD_SLICE, INT_MIN, INT_MAX, V|E|D, "thread_type"},
{"frame", NULL, 0, FF_OPT_TYPE_CONST, FF_THREAD_FRAME, INT_MIN, INT_MAX, V|E|D, "thread_type"},
{NULL},
};

722
libavcodec/pthread.c
View File

@ -1,5 +1,6 @@
/*
* Copyright (c) 2004 Roman Shaposhnik
* Copyright (c) 2008 Alexander Strange (astrange@ithinksw.com)
*
* Many thanks to Steven M. Schultz for providing clever ideas and
* to Michael Niedermayer <michaelni@gmx.at> for writing initial
@ -21,9 +22,17 @@
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* Multithreading support functions
* @see doc/multithreading.txt
*/
#include <pthread.h>
#include "avcodec.h"
#include "thread.h"
typedef int (action_func)(AVCodecContext *c, void *arg);
typedef int (action_func2)(AVCodecContext *c, void *arg, int jobnr, int threadnr);
@ -45,6 +54,78 @@ typedef struct ThreadContext {
int done;
} ThreadContext;
/// Max number of frame buffers that can be allocated when using frame threads.
#define MAX_BUFFERS 32
/**
* Context used by codec threads and stored in their AVCodecContext thread_opaque.
*/
typedef struct PerThreadContext {
struct FrameThreadContext *parent;
pthread_t thread;
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).
int allocated_buf_size; ///< Size allocated for avpkt.data
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[MAX_BUFFERS];
int num_released_buffers;
/**
* Array of progress values used by ff_thread_get_buffer().
*/
int progress[MAX_BUFFERS][2];
uint8_t progress_used[MAX_BUFFERS];
AVFrame *requested_frame; ///< AVFrame the codec passed to get_buffer()
} 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;
static void* attribute_align_arg worker(void *v)
{
AVCodecContext *avctx = v;
@ -84,7 +165,7 @@ static av_always_inline void avcodec_thread_park_workers(ThreadContext *c, int t
pthread_mutex_unlock(&c->current_job_lock);
}
void avcodec_thread_free(AVCodecContext *avctx)
static void thread_free(AVCodecContext *avctx)
{
ThreadContext *c = avctx->thread_opaque;
int i;
@ -109,6 +190,9 @@ static int avcodec_thread_execute(AVCodecContext *avctx, action_func* func, void
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;
@ -140,12 +224,11 @@ static int avcodec_thread_execute2(AVCodecContext *avctx, action_func2* func2, v
return avcodec_thread_execute(avctx, NULL, arg, ret, job_count, 0);
}
int avcodec_thread_init(AVCodecContext *avctx, int thread_count)
static int thread_init(AVCodecContext *avctx)
{
int i;
ThreadContext *c;
avctx->thread_count = thread_count;
int thread_count = avctx->thread_count;
if (thread_count <= 1)
return 0;
@ -184,3 +267,634 @@ int avcodec_thread_init(AVCodecContext *avctx, int thread_count)
avctx->execute2 = avcodec_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;
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) 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);
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;
}
/**
* Updates 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->sub_id = src->sub_id;
dst->time_base = src->time_base;
dst->width = src->width;
dst->height = src->height;
dst->pix_fmt = src->pix_fmt;
dst->has_b_frames = src->has_b_frames;
dst->idct_algo = src->idct_algo;
dst->slice_count = src->slice_count;
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;
}
if (for_user) {
dst->coded_frame = src->coded_frame;
dst->has_b_frames += src->thread_count - 1;
} 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.
*/
static void 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_buffer = src->get_buffer;
dst->release_buffer = src->release_buffer;
dst->opaque = src->opaque;
dst->hurry_up = src->hurry_up;
dst->dsp_mask = src->dsp_mask;
dst->debug = src->debug;
dst->debug_mv = src->debug_mv;
dst->slice_flags = src->slice_flags;
dst->flags2 = src->flags2;
copy_fields(skip_loop_filter, bidir_refine);
dst->frame_number = src->frame_number;
dst->reordered_opaque = src->reordered_opaque;
#undef copy_fields
}
static void free_progress(AVFrame *f)
{
PerThreadContext *p = f->owner->thread_opaque;
int *progress = f->thread_opaque;
p->progress_used[(progress - p->progress[0]) / 2] = 0;
}
/// 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 = &p->released_buffers[--p->num_released_buffers];
pthread_mutex_lock(&fctx->buffer_mutex);
free_progress(f);
f->thread_opaque = NULL;
f->owner->release_buffer(f->owner, 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;
AVCodec *codec = p->avctx->codec;
uint8_t *buf = p->avpkt.data;
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_fast_malloc(&buf, &p->allocated_buf_size, avpkt->size + FF_INPUT_BUFFER_PADDING_SIZE);
p->avpkt = *avpkt;
p->avpkt.data = buf;
memcpy(buf, avpkt->data, avpkt->size);
memset(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.
*/
if (!p->avctx->thread_safe_callbacks &&
p->avctx->get_buffer != avcodec_default_get_buffer) {
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 = p->avctx->get_buffer(p->avctx, p->requested_frame);
p->state = STATE_SETTING_UP;
pthread_cond_signal(&p->progress_cond);
}
pthread_mutex_unlock(&p->progress_mutex);
}
}
fctx->prev_thread = p;
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];
update_context_from_user(p->avctx, avctx);
err = submit_packet(p, avpkt);
if (err) return err;
fctx->next_decoding++;
/*
* If we're still receiving the initial packets, don't return a frame.
*/
if (fctx->delaying && avpkt->size) {
if (fctx->next_decoding >= (avctx->thread_count-1)) fctx->delaying = 0;
*got_picture_ptr=0;
return 0;
}
/*
* 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);
}
*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 p->result;
}
void ff_thread_report_progress(AVFrame *f, int n, int field)
{
PerThreadContext *p;
int *progress = f->thread_opaque;
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(AVFrame *f, int n, int field)
{
PerThreadContext *p;
int *progress = f->thread_opaque;
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;
AVCodec *codec = avctx->codec;
int i;
park_frame_worker_threads(fctx, thread_count);
if (fctx->prev_thread)
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);
pthread_join(p->thread, NULL);
if (codec->close)
codec->close(p->avctx);
avctx->codec = NULL;
release_delayed_buffers(p);
}
for (i = 0; i < thread_count; i++) {
PerThreadContext *p = &fctx->threads[i];
avcodec_default_free_buffers(p->avctx);
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_freep(&p->avpkt.data);
if (i)
av_freep(&p->avctx->priv_data);
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;
AVCodec *codec = avctx->codec;
AVCodecContext *src = avctx;
FrameThreadContext *fctx;
int i, err = 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;
*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->is_copy = 1;
copy->priv_data = av_malloc(codec->priv_data_size);
memcpy(copy->priv_data, src->priv_data, codec->priv_data_size);
if (codec->init_thread_copy)
err = codec->init_thread_copy(copy);
}
if (err) goto error;
pthread_create(&p->thread, NULL, frame_worker_thread, p);
}
return 0;
error:
frame_thread_free(avctx, i+1);
return err;
}
void ff_thread_flush(AVCodecContext *avctx)
{
FrameThreadContext *fctx = avctx->thread_opaque;
if (!avctx->thread_opaque) return;
park_frame_worker_threads(fctx, avctx->thread_count);
if (fctx->prev_thread)
update_context_from_thread(fctx->threads->avctx, fctx->prev_thread->avctx, 0);
fctx->next_decoding = fctx->next_finished = 0;
fctx->delaying = 1;
fctx->prev_thread = NULL;
}
static int *allocate_progress(PerThreadContext *p)
{
int i;
for (i = 0; i < MAX_BUFFERS; i++)
if (!p->progress_used[i]) break;
if (i == MAX_BUFFERS) {
av_log(p->avctx, AV_LOG_ERROR, "allocate_progress() overflow\n");
return NULL;
}
p->progress_used[i] = 1;
return p->progress[i];
}
int ff_thread_get_buffer(AVCodecContext *avctx, AVFrame *f)
{
PerThreadContext *p = avctx->thread_opaque;
int *progress, err;
f->owner = avctx;
if (!(avctx->active_thread_type&FF_THREAD_FRAME)) {
f->thread_opaque = NULL;
return avctx->get_buffer(avctx, f);
}
if (p->state != STATE_SETTING_UP) {
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);
f->thread_opaque = progress = allocate_progress(p);
if (!progress) {
pthread_mutex_unlock(&p->parent->buffer_mutex);
return -1;
}
progress[0] =
progress[1] = -1;
if (avctx->thread_safe_callbacks ||
avctx->get_buffer == avcodec_default_get_buffer) {
err = avctx->get_buffer(avctx, f);
} else {
p->requested_frame = f;
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);
}
pthread_mutex_unlock(&p->parent->buffer_mutex);
/*
* Buffer age is difficult to keep track of between
* multiple threads, and the optimizations it allows
* are not worth the effort. It is disabled for now.
*/
f->age = INT_MAX;
return err;
}
void ff_thread_release_buffer(AVCodecContext *avctx, AVFrame *f)
{
PerThreadContext *p = avctx->thread_opaque;
if (!(avctx->active_thread_type&FF_THREAD_FRAME)) {
avctx->release_buffer(avctx, f);
return;
}
if (p->num_released_buffers >= MAX_BUFFERS) {
av_log(p->avctx, AV_LOG_ERROR, "too many thread_release_buffer calls!\n");
return;
}
if(avctx->debug & FF_DEBUG_BUFFERS)
av_log(avctx, AV_LOG_DEBUG, "thread_release_buffer called on pic %p, %d buffers used\n",
f, f->owner->internal_buffer_count);
p->released_buffers[p->num_released_buffers++] = *f;
memset(f->data, 0, sizeof(f->data));
}
/**
* Set the threading algorithms used.
*
* Threading requires more than one thread.
* Frame threading requires entire frames to be passed to the codec,
* and introduces extra decoding delay, so is incompatible with low_delay.
*
* @param avctx The context.
*/
static void validate_thread_parameters(AVCodecContext *avctx)
{
int frame_threading_supported = (avctx->codec->capabilities & CODEC_CAP_FRAME_THREADS)
&& !(avctx->flags & CODEC_FLAG_TRUNCATED)
&& !(avctx->flags & CODEC_FLAG_LOW_DELAY)
&& !(avctx->flags2 & CODEC_FLAG2_CHUNKS);
if (avctx->thread_count == 1) {
avctx->active_thread_type = 0;
} else if (frame_threading_supported && (avctx->thread_type & FF_THREAD_FRAME)) {
avctx->active_thread_type = FF_THREAD_FRAME;
} else {
avctx->active_thread_type = FF_THREAD_SLICE;
}
}
int avcodec_thread_init(AVCodecContext *avctx, int thread_count)
{
if (avctx->thread_opaque) {
av_log(avctx, AV_LOG_ERROR, "avcodec_thread_init is ignored after avcodec_open\n");
return -1;
}
avctx->thread_count = FFMAX(1, thread_count);
if (avctx->codec) {
validate_thread_parameters(avctx);
if (avctx->active_thread_type&FF_THREAD_SLICE)
return thread_init(avctx);
else if (avctx->active_thread_type&FF_THREAD_FRAME)
return frame_thread_init(avctx);
}
return 0;
}
void avcodec_thread_free(AVCodecContext *avctx)
{
if (avctx->active_thread_type&FF_THREAD_FRAME)
frame_thread_free(avctx, avctx->thread_count);
else
thread_free(avctx);
}

111
libavcodec/thread.h Normal file
View File

@ -0,0 +1,111 @@
/*
* Copyright (c) 2008 Alexander Strange <astrange@ithinksw.com>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* Multithreading support functions
* @author Alexander Strange <astrange@ithinksw.com>
*/
#ifndef AVCODEC_THREAD_H
#define AVCODEC_THREAD_H
#include "config.h"
#include "avcodec.h"
/**
* Waits for decoding threads to finish and resets internal
* state. Called by avcodec_flush_buffers().
*
* @param avctx The context.
*/
void ff_thread_flush(AVCodecContext *avctx);
/**
* Submits a new frame to a decoding thread.
* Returns the next available frame in picture. *got_picture_ptr
* will be 0 if none is available.
*
* Parameters are the same as avcodec_decode_video2().
*/
int ff_thread_decode_frame(AVCodecContext *avctx, AVFrame *picture,
int *got_picture_ptr, AVPacket *avpkt);
/**
* If the codec defines update_thread_context(), call this
* when they are ready for the next thread to start decoding
* the next frame. After calling it, do not change any variables
* read by the update_thread_context() method, or call ff_thread_get_buffer().
*
* @param avctx The context.
*/
void ff_thread_finish_setup(AVCodecContext *avctx);
/**
* Notifies later decoding threads when part of their reference picture
* is ready.
* Call this when some part of the picture is finished decoding.
* Later calls with lower values of progress have no effect.
*
* @param f The picture being decoded.
* @param progress Value, in arbitrary units, of how much of the picture has decoded.
* @param field The field being decoded, for field-picture codecs.
* 0 for top field or frame pictures, 1 for bottom field.
*/
void ff_thread_report_progress(AVFrame *f, int progress, int field);
/**
* Waits for earlier decoding threads to finish reference pictures
* Call this before accessing some part of a picture, with a given
* value for progress, and it will return after the responsible decoding
* thread calls ff_thread_report_progress() with the same or
* higher value for progress.
*
* @param f The picture being referenced.
* @param progress Value, in arbitrary units, to wait for.
* @param field The field being referenced, for field-picture codecs.
* 0 for top field or frame pictures, 1 for bottom field.
*/
void ff_thread_await_progress(AVFrame *f, int progress, int field);
/**
* Wrapper around get_buffer() for frame-multithreaded codecs.
* Call this function instead of avctx->get_buffer(f).
* Cannot be called after the codec has called ff_thread_finish_setup().
*
* @param avctx The current context.
* @param f The frame to write into.
*/
int ff_thread_get_buffer(AVCodecContext *avctx, AVFrame *f);
/**
* Wrapper around release_buffer() frame-for multithreaded codecs.
* Call this function instead of avctx->release_buffer(f).
* The AVFrame will be copied and the actual release_buffer() call
* will be performed later. The contents of data pointed to by the
* AVFrame should not be changed until ff_thread_get_buffer() is called
* on it.
*
* @param avctx The current context.
* @param f The picture being released.
*/
void ff_thread_release_buffer(AVCodecContext *avctx, AVFrame *f);
#endif /* AVCODEC_THREAD_H */

60
libavcodec/utils.c
View File

@ -37,6 +37,7 @@
#include "dsputil.h"
#include "libavutil/opt.h"
#include "imgconvert.h"
#include "thread.h"
#include "audioconvert.h"
#include "internal.h"
#include <stdlib.h>
@ -261,6 +262,11 @@ int avcodec_default_get_buffer(AVCodecContext *s, AVFrame *pic){
(*picture_number)++;
if(buf->base[0] && (buf->width != w || buf->height != h || buf->pix_fmt != s->pix_fmt)){
if(s->active_thread_type&FF_THREAD_FRAME) {
av_log_missing_feature(s, "Width/height changing with frame threads is", 0);
return -1;
}
for(i=0; i<4; i++){
av_freep(&buf->base[i]);
buf->data[i]= NULL;
@ -532,13 +538,21 @@ int attribute_align_arg avcodec_open(AVCodecContext *avctx, AVCodec *codec)
goto free_and_end;
}
avctx->frame_number = 0;
if (HAVE_THREADS && !avctx->thread_opaque) {
ret = avcodec_thread_init(avctx, avctx->thread_count);
if (ret < 0) {
goto free_and_end;
}
}
if (avctx->codec->max_lowres < avctx->lowres) {
av_log(avctx, AV_LOG_ERROR, "The maximum value for lowres supported by the decoder is %d\n",
avctx->codec->max_lowres);
goto free_and_end;
}
if(avctx->codec->init){
if(avctx->codec->init && !(avctx->active_thread_type&FF_THREAD_FRAME)){
ret = avctx->codec->init(avctx);
if (ret < 0) {
goto free_and_end;
@ -636,14 +650,18 @@ int attribute_align_arg avcodec_decode_video2(AVCodecContext *avctx, AVFrame *pi
avctx->pkt = avpkt;
if((avctx->codec->capabilities & CODEC_CAP_DELAY) || avpkt->size){
ret = avctx->codec->decode(avctx, picture, got_picture_ptr,
avpkt);
if((avctx->codec->capabilities & CODEC_CAP_DELAY) || avpkt->size || (avctx->active_thread_type&FF_THREAD_FRAME)){
if (HAVE_PTHREADS && avctx->active_thread_type&FF_THREAD_FRAME)
ret = ff_thread_decode_frame(avctx, picture, got_picture_ptr,
avpkt);
else {
ret = avctx->codec->decode(avctx, picture, got_picture_ptr,
avpkt);
picture->pkt_dts= avpkt->dts;
}
emms_c(); //needed to avoid an emms_c() call before every return;
picture->pkt_dts= avpkt->dts;
if (*got_picture_ptr)
avctx->frame_number++;
}else
@ -768,6 +786,7 @@ av_cold int avcodec_close(AVCodecContext *avctx)
if(avctx->codec && avctx->codec->encode)
av_freep(&avctx->extradata);
avctx->codec = NULL;
avctx->active_thread_type = 0;
entangled_thread_counter--;
/* Release any user-supplied mutex. */
@ -1029,6 +1048,8 @@ void avcodec_init(void)
void avcodec_flush_buffers(AVCodecContext *avctx)
{
if(HAVE_PTHREADS && avctx->active_thread_type&FF_THREAD_FRAME)
ff_thread_flush(avctx);
if(avctx->codec->flush)
avctx->codec->flush(avctx);
}
@ -1229,3 +1250,30 @@ unsigned int ff_toupper4(unsigned int x)
+ (toupper((x>>16)&0xFF)<<16)
+ (toupper((x>>24)&0xFF)<<24);
}
#if !HAVE_PTHREADS
int ff_thread_get_buffer(AVCodecContext *avctx, AVFrame *f)
{
f->owner = avctx;
return avctx->get_buffer(avctx, f);
}
void ff_thread_release_buffer(AVCodecContext *avctx, AVFrame *f)
{
f->owner->release_buffer(f->owner, f);
}
void ff_thread_finish_setup(AVCodecContext *avctx)
{
}
void ff_thread_report_progress(AVFrame *f, int progress, int field)
{
}
void ff_thread_await_progress(AVFrame *f, int progress, int field)
{
}
#endif

6
libavcodec/w32thread.c
View File

@ -129,7 +129,13 @@ int avcodec_thread_init(AVCodecContext *s, int thread_count){
ThreadContext *c;
uint32_t threadid;
if(!(s->thread_type & FF_THREAD_SLICE)){
av_log(s, AV_LOG_WARNING, "The requested thread algorithm is not supported with this thread library.\n");
return 0;
}
s->thread_count= thread_count;
s->active_thread_type= FF_THREAD_SLICE;
if (thread_count <= 1)
return 0;

6
libavformat/utils.c
View File

@ -930,6 +930,12 @@ static void compute_pkt_fields(AVFormatContext *s, AVStream *st,
/* do we have a video B-frame ? */
delay= st->codec->has_b_frames;
presentation_delayed = 0;
// ignore delay caused by frame threading so that the mpeg2-without-dts
// warning will not trigger
if (delay && st->codec->active_thread_type&FF_THREAD_FRAME)
delay -= st->codec->thread_count-1;
/* XXX: need has_b_frame, but cannot get it if the codec is
not initialized */
if (delay &&

11
libavutil/internal.h
View File

@ -210,4 +210,15 @@
type ff_##name args
#endif
/**
* Returns NULL if a threading library has not been enabled.
* Used to disable threading functions in AVCodec definitions
* when not needed.
*/
#if HAVE_THREADS
# define ONLY_IF_THREADS_ENABLED(x) x
#else
# define ONLY_IF_THREADS_ENABLED(x) NULL
#endif
#endif /* AVUTIL_INTERNAL_H */