【ffmpeg学习】Tutorial 04: Spawning Threads 将解析线程与视频解码线程分开

来源：互联网发布：新加坡股票行情软件编辑：程序博客网时间：2024/04/28 00:00

http://blog.csdn.net/ashqal/article/details/17722935

环境

FFmpeg：2013年9月9日 github master版本

SDL：SDL2

系统：macos 10.8 64位

ffmpeg编译参数：

[plain] view plaincopy

./configure --cc=clang --disable-everything --enable-libfdk_aac --enable-libmp3lame --enable-protocol=file --enable-protocol=file --enable-decoder=aac --enable-decoder=aac --enable-decoder=mp3 --enable-encoder=libmp3lame --enable-encoder=libfdk_aac --enable-demuxer=aac --enable-demuxer=mp3 --enable-muxer=adts --enable-muxer=mp3 --enable-parser=aac --enable-decoder=flv --enable-decoder=h264 --enable-decoder=mpeg4 --enable-demuxer=avi --enable-demuxer=flv --enable-demuxer=h264 --enable-muxer=mp4 --enable-muxer=flv

代码源自

http://dranger.com/ffmpeg/tutorial04.html

修改后版本

[cpp] view plaincopy

// tutorial04.c
// A pedagogical video player that will stream through every video frame as fast as it can,
// and play audio (out of sync).
//
// This tutorial was written by Stephen Dranger (dranger@gmail.com).
//
// Code based on FFplay, Copyright (c) 2003 Fabrice Bellard,
// and a tutorial by Martin Bohme (boehme@inb.uni-luebeckREMOVETHIS.de)
// Tested on Gentoo, CVS version 5/01/07 compiled with GCC 4.1.1
//
// Use the Makefile to build all the samples.
//
// Run using
// tutorial04 myvideofile.mpg
//
// to play the video stream on your screen.
#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <libavformat/avio.h>
#include <libswscale/swscale.h>
#include <libavutil/avstring.h>
#include <SDL2/SDL.h>
#include <SDL2/SDL_thread.h>
#ifdef __MINGW32__
#undef main /* Prevents SDL from overriding main() */
#endif
#include <stdio.h>
#include <math.h>
#define SDL_AUDIO_BUFFER_SIZE 1024
#define MAX_AUDIO_FRAME_SIZE 192000
#define MAX_AUDIOQ_SIZE (5 * 16 * 1024)
#define MAX_VIDEOQ_SIZE (5 * 256 * 1024)
#define FF_ALLOC_EVENT (SDL_USEREVENT)
#define FF_REFRESH_EVENT (SDL_USEREVENT + 1)
#define FF_QUIT_EVENT (SDL_USEREVENT + 2)
#define VIDEO_PICTURE_QUEUE_SIZE 1
typedef struct PacketQueue {
AVPacketList *first_pkt, *last_pkt;
int nb_packets;
int size;
SDL_mutex *mutex;
SDL_cond *cond;
} PacketQueue;
typedef struct VideoPicture {
//SDL_Texture *texture;
AVFrame* rawdata;
//SDL_Overlay *bmp;
int width, height; /* source height & width */
int allocated;
} VideoPicture;
typedef struct VideoState {
AVFormatContext *pFormatCtx;
int videoStream, audioStream;
AVStream *audio_st;
PacketQueue audioq;
uint8_t audio_buf[(MAX_AUDIO_FRAME_SIZE * 3) / 2];
unsigned int audio_buf_size;
unsigned int audio_buf_index;
AVFrame audio_frame;
AVPacket audio_pkt;
uint8_t *audio_pkt_data;
int audio_pkt_size;
AVStream *video_st;
PacketQueue videoq;
VideoPicture pictq[VIDEO_PICTURE_QUEUE_SIZE];
int pictq_size, pictq_rindex, pictq_windex;
SDL_mutex *pictq_mutex;
SDL_cond *pictq_cond;
SDL_Thread *parse_tid;
SDL_Thread *video_tid;
char filename[1024];
int quit;
AVIOContext *io_context;
struct SwsContext *sws_ctx;
} VideoState;
/* Since we only have one decoding thread, the Big Struct
can be global in case we need it. */
VideoState *global_video_state;
void packet_queue_init(PacketQueue *q) {
memset(q, 0, sizeof(PacketQueue));
q->mutex = SDL_CreateMutex();
q->cond = SDL_CreateCond();
}
int packet_queue_put(PacketQueue *q, AVPacket *pkt) {
AVPacketList *pkt1;
if(av_dup_packet(pkt) < 0) {
return -1;
}
pkt1 = av_malloc(sizeof(AVPacketList));
if (!pkt1)
return -1;
pkt1->pkt = *pkt;
pkt1->next = NULL;
SDL_LockMutex(q->mutex);
if (!q->last_pkt)
q->first_pkt = pkt1;
else
q->last_pkt->next = pkt1;
q->last_pkt = pkt1;
q->nb_packets++;
q->size += pkt1->pkt.size;
SDL_CondSignal(q->cond);
SDL_UnlockMutex(q->mutex);
return 0;
}
static int packet_queue_get(PacketQueue *q, AVPacket *pkt, int block)
{
AVPacketList *pkt1;
int ret;
SDL_LockMutex(q->mutex);
for(;;) {
if(global_video_state->quit) {
ret = -1;
break;
}
pkt1 = q->first_pkt;
if (pkt1) {
q->first_pkt = pkt1->next;
if (!q->first_pkt)
q->last_pkt = NULL;
q->nb_packets--;
q->size -= pkt1->pkt.size;
*pkt = pkt1->pkt;
av_free(pkt1);
ret = 1;
break;
} else if (!block) {
ret = 0;
break;
} else {
SDL_CondWait(q->cond, q->mutex);
}
}
SDL_UnlockMutex(q->mutex);
return ret;
}
int audio_decode_frame(VideoState *is) {
int len1, data_size = 0;
AVPacket *pkt = &is->audio_pkt;
for(;;) {
while(is->audio_pkt_size > 0) {
int got_frame = 0;
len1 = avcodec_decode_audio4(is->audio_st->codec, &is->audio_frame, &got_frame, pkt);
if(len1 < 0) {
/* if error, skip frame */
is->audio_pkt_size = 0;
break;
}
if (got_frame)
{
data_size =
av_samples_get_buffer_size
(
NULL,
is->audio_st->codec->channels,
is->audio_frame.nb_samples,
is->audio_st->codec->sample_fmt,
1
);
memcpy(is->audio_buf, is->audio_frame.data[0], data_size);
}
is->audio_pkt_data += len1;
is->audio_pkt_size -= len1;
if(data_size <= 0) {
/* No data yet, get more frames */
continue;
}
/* We have data, return it and come back for more later */
return data_size;
}
if(pkt->data)
av_free_packet(pkt);
if(is->quit) {
return -1;
}
/* next packet */
if(packet_queue_get(&is->audioq, pkt, 1) < 0) {
return -1;
}
is->audio_pkt_data = pkt->data;
is->audio_pkt_size = pkt->size;
}
}
void audio_callback(void *userdata, Uint8 *stream, int len) {
VideoState *is = (VideoState *)userdata;
int len1, audio_size;
while(len > 0) {
if(is->audio_buf_index >= is->audio_buf_size) {
/* We have already sent all our data; get more */
audio_size = audio_decode_frame(is);
if(audio_size < 0) {
/* If error, output silence */
is->audio_buf_size = 1024;
memset(is->audio_buf, 0, is->audio_buf_size);
} else {
is->audio_buf_size = audio_size;
}
is->audio_buf_index = 0;
}
len1 = is->audio_buf_size - is->audio_buf_index;
if(len1 > len)
len1 = len;
memcpy(stream, (uint8_t *)is->audio_buf + is->audio_buf_index, len1);
len -= len1;
stream += len1;
is->audio_buf_index += len1;
}
}
static Uint32 sdl_refresh_timer_cb(Uint32 interval, void *opaque) {
SDL_Event event;
event.type = FF_REFRESH_EVENT;
event.user.data1 = opaque;
SDL_PushEvent(&event);
return 0; /* 0 means stop timer */
}
/* schedule a video refresh in 'delay' ms */
static void schedule_refresh(VideoState *is, int delay) {
SDL_AddTimer(delay, sdl_refresh_timer_cb, is);
}
void video_display(VideoState *is,SDL_Renderer* renderer,SDL_Texture* texture) {
SDL_Rect rect;
VideoPicture *vp;
//AVPicture pict;
float aspect_ratio;
//int w=0, h=0, x=0, y=0;
//screen->w;
//int i;
//renderer->w;
vp = &is->pictq[is->pictq_rindex];
if(vp->rawdata) {
if(is->video_st->codec->sample_aspect_ratio.num == 0) {
aspect_ratio = 0;
} else {
aspect_ratio = av_q2d(is->video_st->codec->sample_aspect_ratio) *
is->video_st->codec->width / is->video_st->codec->height;
}
if(aspect_ratio <= 0.0) {
aspect_ratio = (float)is->video_st->codec->width /
(float)is->video_st->codec->height;
}
//screen->h;
// h = screen->h;
// w = ((int)rint(h * aspect_ratio)) & -3;
// if(w > screen->w) {
// w = screen->w;
// h = ((int)rint(w / aspect_ratio)) & -3;
// }
// x = (screen->w - w) / 2;
// y = (screen->h - h) / 2;
rect.x = 0;
rect.y = 0;
rect.w = vp->width;
rect.h = vp->height;
//SDL_SetRenderDrawColor(renderer, 120, 0, 0, 255);
//SDL_RenderFillRect(renderer, &rect);
SDL_UpdateTexture( texture, &rect, vp->rawdata->data[0], vp->rawdata->linesize[0] );
SDL_RenderClear( renderer );
SDL_RenderCopy( renderer,texture , &rect, &rect );
SDL_RenderPresent( renderer );
//SDL_DisplayYUVOverlay(vp->bmp, &rect);
}
}
void video_refresh_timer(void *userdata,SDL_Renderer* renderer,SDL_Texture* texture) {
VideoState *is = (VideoState *)userdata;
// vp is used in later tutorials for synchronization
//VideoPicture *vp;
if(is->video_st) {
if(is->pictq_size == 0) {
schedule_refresh(is, 1);
} else {
//vp = &is->pictq[is->pictq_rindex];
/* Now, normally here goes a ton of code
about timing, etc. we're just going to
guess at a delay for now. You can
increase and decrease this value and hard code
the timing - but I don't suggest that ;)
We'll learn how to do it for real later.
*/
schedule_refresh(is, 30);
/* show the picture! */
video_display(is,renderer,texture);
/* update queue for next picture! */
if(++is->pictq_rindex == VIDEO_PICTURE_QUEUE_SIZE) {
is->pictq_rindex = 0;
}
SDL_LockMutex(is->pictq_mutex);
is->pictq_size--;
SDL_CondSignal(is->pictq_cond);
SDL_UnlockMutex(is->pictq_mutex);
}
} else {
schedule_refresh(is, 100);
}
}
void alloc_picture(void *userdata,SDL_Renderer* renderer) {
VideoState *is = (VideoState *)userdata;
VideoPicture *vp;
vp = &is->pictq[is->pictq_windex];
if(vp->rawdata) {
// we already have one make another, bigger/smaller
//SDL_DestroyTexture(vp->texture);
//vp->texture = NULL;
av_free(vp->rawdata);
//SDL_FreeYUVOverlay(vp->bmp);
}
// Allocate a place to put our YUV image on that screen
// vp->texture = SDL_CreateYUVOverlay(is->video_st->codec->width,
// is->video_st->codec->height,
// SDL_YV12_OVERLAY,
// screen);
vp->width = is->video_st->codec->width;
vp->height = is->video_st->codec->height;
AVCodecContext *pCodecCtx = NULL;
pCodecCtx = is->video_st->codec;
AVFrame* pFrameYUV = avcodec_alloc_frame();
if( pFrameYUV == NULL )
return;
int numBytes = avpicture_get_size(PIX_FMT_YUV420P, pCodecCtx->width,
pCodecCtx->height);
uint8_t* buffer = (uint8_t *)av_malloc(numBytes*sizeof(uint8_t));
avpicture_fill((AVPicture *)pFrameYUV, buffer, PIX_FMT_YUV420P,
pCodecCtx->width, pCodecCtx->height);
vp->rawdata = pFrameYUV;
//SDL_CreateTexture(renderer, SDL_PIXELFORMAT_IYUV, SDL_TEXTUREACCESS_STREAMING, vp->width, vp->height);
SDL_LockMutex(is->pictq_mutex);
vp->allocated = 1;
SDL_CondSignal(is->pictq_cond);
SDL_UnlockMutex(is->pictq_mutex);
}
int queue_picture(VideoState *is, AVFrame *pFrame) {
VideoPicture *vp;
//AVCodecContext *pCodecCtx;
/* wait until we have space for a new pic */
SDL_LockMutex(is->pictq_mutex);
while(is->pictq_size >= VIDEO_PICTURE_QUEUE_SIZE &&
!is->quit) {
SDL_CondWait(is->pictq_cond, is->pictq_mutex);
}
SDL_UnlockMutex(is->pictq_mutex);
if(is->quit)
return -1;
// windex is set to 0 initially
vp = &is->pictq[is->pictq_windex];
/* allocate or resize the buffer! */
if(!vp->rawdata ||
vp->width != is->video_st->codec->width ||
vp->height != is->video_st->codec->height) {
SDL_Event event;
vp->allocated = 0;
/* we have to do it in the main thread */
event.type = FF_ALLOC_EVENT;
event.user.data1 = is;
SDL_PushEvent(&event);
/* wait until we have a picture allocated */
SDL_LockMutex(is->pictq_mutex);
while(!vp->allocated && !is->quit) {
SDL_CondWait(is->pictq_cond, is->pictq_mutex);
}
SDL_UnlockMutex(is->pictq_mutex);
if(is->quit) {
return -1;
}
}
/* We have a place to put our picture on the queue */
if(vp->rawdata) {
//SDL_LockYUVOverlay(vp->bmp);
/* point pict at the queue */
// pict.data[0] = vp->bmp->pixels[0];
// pict.data[1] = vp->bmp->pixels[2];
// pict.data[2] = vp->bmp->pixels[1];
//
// pict.linesize[0] = vp->bmp->pitches[0];
// pict.linesize[1] = vp->bmp->pitches[2];
// pict.linesize[2] = vp->bmp->pitches[1];
// Convert the image into YUV format that SDL uses
sws_scale
(
is->sws_ctx,
(uint8_t const * const *)pFrame->data,
pFrame->linesize,
0,
is->video_st->codec->height,
vp->rawdata->data,
vp->rawdata->linesize
);
// SDL_Rect rect;
// rect.x = 0;
// rect.y = 0;
// rect.w = vp->width;
// rect.h = vp->height;
//printf("%d,%d\n",rect.w,rect.h);
//SDL_UpdateTexture( vp->texture, &rect, pFrameYUV->data[0], pFrameYUV->linesize[0] );
//av_free(pFrameYUV);
//SDL_UnlockYUVOverlay(vp->bmp);
/* now we inform our display thread that we have a pic ready */
if(++is->pictq_windex == VIDEO_PICTURE_QUEUE_SIZE) {
is->pictq_windex = 0;
}
SDL_LockMutex(is->pictq_mutex);
is->pictq_size++;
SDL_UnlockMutex(is->pictq_mutex);
}
return 0;
}
int video_thread(void *arg) {
VideoState *is = (VideoState *)arg;
AVPacket pkt1, *packet = &pkt1;
int frameFinished;
AVFrame *pFrame;
pFrame = avcodec_alloc_frame();
for(;;) {
if(packet_queue_get(&is->videoq, packet, 1) < 0) {
// means we quit getting packets
break;
}
// Decode video frame
avcodec_decode_video2(is->video_st->codec, pFrame, &frameFinished,
packet);
// Did we get a video frame?
if(frameFinished) {
//printf("video_thread\n");
if(queue_picture(is, pFrame) < 0) {
break;
}
}
av_free_packet(packet);
}
av_free(pFrame);
return 0;
}
int stream_component_open(VideoState *is, int stream_index) {
AVFormatContext *pFormatCtx = is->pFormatCtx;
AVCodecContext *codecCtx = NULL;
AVCodec *codec = NULL;
AVDictionary *optionsDict = NULL;
SDL_AudioSpec wanted_spec, spec;
if(stream_index < 0 || stream_index >= pFormatCtx->nb_streams) {
return -1;
}
// Get a pointer to the codec context for the video stream
codecCtx = pFormatCtx->streams[stream_index]->codec;
if(codecCtx->codec_type == AVMEDIA_TYPE_AUDIO) {
// Set audio settings from codec info
wanted_spec.freq = codecCtx->sample_rate;
wanted_spec.format = AUDIO_S16SYS;
wanted_spec.channels = codecCtx->channels;
wanted_spec.silence = 0;
wanted_spec.samples = SDL_AUDIO_BUFFER_SIZE;
wanted_spec.callback = audio_callback;
wanted_spec.userdata = is;
if(SDL_OpenAudio(&wanted_spec, &spec) < 0) {
fprintf(stderr, "SDL_OpenAudio: %s\n", SDL_GetError());
return -1;
}
}
codec = avcodec_find_decoder(codecCtx->codec_id);
if(!codec || (avcodec_open2(codecCtx, codec, &optionsDict) < 0)) {
fprintf(stderr, "Unsupported codec!\n");
return -1;
}
switch(codecCtx->codec_type) {
case AVMEDIA_TYPE_AUDIO:
is->audioStream = stream_index;
is->audio_st = pFormatCtx->streams[stream_index];
is->audio_buf_size = 0;
is->audio_buf_index = 0;
memset(&is->audio_pkt, 0, sizeof(is->audio_pkt));
packet_queue_init(&is->audioq);
SDL_PauseAudio(0);
break;
case AVMEDIA_TYPE_VIDEO:
is->videoStream = stream_index;
is->video_st = pFormatCtx->streams[stream_index];
packet_queue_init(&is->videoq);
is->video_tid = SDL_CreateThread(video_thread, "video_thread",is);
is->sws_ctx =
sws_getContext
(
is->video_st->codec->width,
is->video_st->codec->height,
is->video_st->codec->pix_fmt,
is->video_st->codec->width,
is->video_st->codec->height,
PIX_FMT_YUV420P,
SWS_BILINEAR,
NULL,
NULL,
NULL
);
break;
default:
break;
}
return 0;
}
int decode_interrupt_cb(void *opaque) {
return (global_video_state && global_video_state->quit);
}
int decode_thread(void *arg) {
VideoState *is = (VideoState *)arg;
AVFormatContext *pFormatCtx = NULL;
AVPacket pkt1, *packet = &pkt1;
int video_index = -1;
int audio_index = -1;
int i;
AVDictionary *io_dict = NULL;
AVIOInterruptCB callback;
is->videoStream=-1;
is->audioStream=-1;
global_video_state = is;
// will interrupt blocking functions if we quit!
callback.callback = decode_interrupt_cb;
callback.opaque = is;
if (avio_open2(&is->io_context, is->filename, 0, &callback, &io_dict))
{
fprintf(stderr, "Unable to open I/O for %s\n", is->filename);
return -1;
}
// Open video file
if(avformat_open_input(&pFormatCtx, is->filename, NULL, NULL)!=0)
return -1; // Couldn't open file
is->pFormatCtx = pFormatCtx;
// Retrieve stream information
if(avformat_find_stream_info(pFormatCtx, NULL)<0)
return -1; // Couldn't find stream information
// Dump information about file onto standard error
av_dump_format(pFormatCtx, 0, is->filename, 0);
// Find the first video stream
for(i=0; i<pFormatCtx->nb_streams; i++) {
if(pFormatCtx->streams[i]->codec->codec_type==AVMEDIA_TYPE_VIDEO &&
video_index < 0) {
video_index=i;
}
if(pFormatCtx->streams[i]->codec->codec_type==AVMEDIA_TYPE_AUDIO &&
audio_index < 0) {
audio_index=i;
}
}
if(audio_index >= 0) {
stream_component_open(is, audio_index);
}
if(video_index >= 0) {
stream_component_open(is, video_index);
}
if(is->videoStream < 0 || is->audioStream < 0) {
fprintf(stderr, "%s: could not open codecs\n", is->filename);
goto fail;
}
// main decode loop
for(;;) {
if(is->quit) {
break;
}
// seek stuff goes here
if(is->audioq.size > MAX_AUDIOQ_SIZE ||
is->videoq.size > MAX_VIDEOQ_SIZE) {
SDL_Delay(10);
continue;
}
if(av_read_frame(is->pFormatCtx, packet) < 0) {
if(is->pFormatCtx->pb->error == 0) {
SDL_Delay(100); /* no error; wait for user input */
continue;
} else {
break;
}
}
// Is this a packet from the video stream?
if(packet->stream_index == is->videoStream) {
packet_queue_put(&is->videoq, packet);
} else if(packet->stream_index == is->audioStream) {
packet_queue_put(&is->audioq, packet);
} else {
av_free_packet(packet);
}
}
/* all done - wait for it */
while(!is->quit) {
SDL_Delay(100);
}
fail:
if(1){
SDL_Event event;
event.type = FF_QUIT_EVENT;
event.user.data1 = is;
SDL_PushEvent(&event);
}
return 0;
}
int main(int argc, char *argv[]) {
SDL_Event event;
VideoState *is;
struct SDL_Window *pScreen;
struct SDL_Renderer *pRenderer;
is = av_mallocz(sizeof(VideoState));
if(argc < 2) {
fprintf(stderr, "Usage: test <file>\n");
exit(1);
}
// Register all formats and codecs
av_register_all();
if(SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER)) {
fprintf(stderr, "Could not initialize SDL - %s\n", SDL_GetError());
exit(1);
}
// Make a screen to put our video
//#ifndef __DARWIN__
// screen = SDL_SetVideoMode(640, 480, 0, 0);
//#else
// screen = SDL_SetVideoMode(640, 480, 24, 0);
//#endif
pScreen = SDL_CreateWindow("audio & video", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 672,376, SDL_WINDOW_OPENGL);
if(!pScreen) {
fprintf(stderr, "SDL: could not set video mode - exiting\n");
exit(1);
}
//SDL_Window *windows = pScreen;
//pScreen->windowed;
pRenderer = SDL_CreateRenderer(pScreen, -1, 0);
SDL_Texture* texture = SDL_CreateTexture(pRenderer, SDL_PIXELFORMAT_IYUV, SDL_TEXTUREACCESS_STREAMING, 672, 376);
av_strlcpy(is->filename, argv[1], 1024);
is->pictq_mutex = SDL_CreateMutex();
is->pictq_cond = SDL_CreateCond();
schedule_refresh(is, 40);
is->parse_tid = SDL_CreateThread(decode_thread,"parse_thread", is);
if(!is->parse_tid) {
av_free(is);
return -1;
}
for(;;) {
SDL_WaitEvent(&event);
switch(event.type) {
case FF_QUIT_EVENT:
case SDL_QUIT:
is->quit = 1;
/*
* If the video has finished playing, then both the picture and
* audio queues are waiting for more data. Make them stop
* waiting and terminate normally.
*/
SDL_CondSignal(is->audioq.cond);
SDL_CondSignal(is->videoq.cond);
SDL_Quit();
return 0;
break;
case FF_ALLOC_EVENT:
alloc_picture(event.user.data1,pRenderer);
break;
case FF_REFRESH_EVENT:
video_refresh_timer(event.user.data1,pRenderer,texture);
break;
default:
break;
}
}
SDL_DestroyTexture(texture);
return 0;
}