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* Copyright (c) 2004 Michael Niedermayer <>
* 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
* 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
//#define DEBUG
#include "avcodec.h"
#include <windows.h>
#include <process.h>
typedef struct ThreadContext{
AVCodecContext *avctx;
HANDLE thread;
HANDLE work_sem;
HANDLE job_sem;
HANDLE done_sem;
int (*func)(AVCodecContext *c, void *arg);
int (*func2)(AVCodecContext *c, void *arg, int, int);
void *arg;
int argsize;
int *jobnr;
int *ret;
int threadnr;
static unsigned WINAPI attribute_align_arg thread_func(void *v){
ThreadContext *c= v;
int ret, jobnr;
//printf("thread_func %X enter wait\n", (int)v); fflush(stdout);
WaitForSingleObject(c->work_sem, INFINITE);
// avoid trying to access jobnr if we should quit
if (!c->func && !c->func2)
WaitForSingleObject(c->job_sem, INFINITE);
jobnr = (*c->jobnr)++;
ReleaseSemaphore(c->job_sem, 1, 0);
//printf("thread_func %X after wait (func=%X)\n", (int)v, (int)c->func); fflush(stdout);
ret= c->func(c->avctx, (uint8_t *)c->arg + jobnr*c->argsize);
ret= c->func2(c->avctx, c->arg, jobnr, c->threadnr);
if (c->ret)
c->ret[jobnr] = ret;
//printf("thread_func %X signal complete\n", (int)v); fflush(stdout);
ReleaseSemaphore(c->done_sem, 1, 0);
return 0;
* Free what has been allocated by avcodec_thread_init().
* Must be called after decoding has finished, especially do not call while avcodec_thread_execute() is running.
void avcodec_thread_free(AVCodecContext *s){
ThreadContext *c= s->thread_opaque;
int i;
for(i=0; i<s->thread_count; i++){
c[i].func= NULL;
c[i].func2= NULL;
ReleaseSemaphore(c[0].work_sem, s->thread_count, 0);
for(i=0; i<s->thread_count; i++){
WaitForSingleObject(c[i].thread, INFINITE);
if(c[i].thread) CloseHandle(c[i].thread);
if(c[0].work_sem) CloseHandle(c[0].work_sem);
if(c[0].job_sem) CloseHandle(c[0].job_sem);
if(c[0].done_sem) CloseHandle(c[0].done_sem);
static int avcodec_thread_execute(AVCodecContext *s, int (*func)(AVCodecContext *c2, void *arg2),void *arg, int *ret, int count, int size){
ThreadContext *c= s->thread_opaque;
int i;
int jobnr = 0;
assert(s == c->avctx);
/* note, we can be certain that this is not called with the same AVCodecContext by different threads at the same time */
for(i=0; i<s->thread_count; i++){
c[i].arg= arg;
c[i].argsize= size;
c[i].func= func;
c[i].ret= ret;
c[i].jobnr = &jobnr;
ReleaseSemaphore(c[0].work_sem, count, 0);
for(i=0; i<count; i++)
WaitForSingleObject(c[0].done_sem, INFINITE);
return 0;
static int avcodec_thread_execute2(AVCodecContext *s, int (*func)(AVCodecContext *c2, void *arg2, int, int),void *arg, int *ret, int count){
ThreadContext *c= s->thread_opaque;
int i;
for(i=0; i<s->thread_count; i++)
c[i].func2 = func;
avcodec_thread_execute(s, NULL, arg, ret, count, 0);
int avcodec_thread_init(AVCodecContext *s, int thread_count){
int i;
ThreadContext *c;
uint32_t threadid;
s->thread_count= thread_count;
if (thread_count <= 1)
return 0;
c= av_mallocz(sizeof(ThreadContext)*thread_count);
s->thread_opaque= c;
if(!(c[0].work_sem = CreateSemaphore(NULL, 0, INT_MAX, NULL)))
goto fail;
if(!(c[0].job_sem = CreateSemaphore(NULL, 1, 1, NULL)))
goto fail;
if(!(c[0].done_sem = CreateSemaphore(NULL, 0, INT_MAX, NULL)))
goto fail;
for(i=0; i<thread_count; i++){
//printf("init semaphors %d\n", i); fflush(stdout);
c[i].avctx= s;
c[i].work_sem = c[0].work_sem;
c[i].job_sem = c[0].job_sem;
c[i].done_sem = c[0].done_sem;
c[i].threadnr = i;
//printf("create thread %d\n", i); fflush(stdout);
c[i].thread = (HANDLE)_beginthreadex(NULL, 0, thread_func, &c[i], 0, &threadid );
if( !c[i].thread ) goto fail;
//printf("init done\n"); fflush(stdout);
s->execute= avcodec_thread_execute;
s->execute2= avcodec_thread_execute2;
return 0;
return -1;
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