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Frame-based multithreading framework using pthreads

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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 Michael Niedermayer
parent 8a278ad30d
commit b38f008ea6
11 changed files with 1068 additions and 10 deletions
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5
doc/APIchanges
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@ -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
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@ -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
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@ -1691,6 +1691,7 @@ 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();

88
libavcodec/avcodec.h
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@ -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
@ -1027,6 +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;\
\
/**\
* frame timestamp estimated using various heuristics, in stream time base\
@ -1246,6 +1264,10 @@ 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.
@ -1499,6 +1521,9 @@ 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.
*/
@ -1508,6 +1533,8 @@ 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.
*/
@ -1811,6 +1838,7 @@ 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
@ -2835,6 +2863,44 @@ typedef struct AVCodecContext {
*/
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;
/**
* Current statistics for PTS correction.
* - decoding: maintained and used by libavcodec
@ -2897,6 +2963,26 @@ 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 */

59
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;
@ -532,6 +538,14 @@ 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);
@ -543,7 +557,7 @@ int attribute_align_arg avcodec_open(AVCodecContext *avctx, AVCodec *codec)
avctx->pts_correction_last_pts =
avctx->pts_correction_last_dts = INT64_MIN;
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;
@ -674,13 +688,18 @@ 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;
picture->best_effort_timestamp = guess_correct_pts(avctx,
picture->pkt_pts,
picture->pkt_dts);
@ -809,6 +828,7 @@ 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. */
@ -1070,6 +1090,8 @@ 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);
}
@ -1270,3 +1292,30 @@ 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 */