http://www.ffmpeg.org/download.html
http://doc.okbase.net/leixiaohua1020/archive/110977.html //视频
http://blog.csdn.net/leixiaohua1020/article/details/46890259 //音频
安装：
sudo apt-get install mercurial
hg clone https://hg.libsdl.org/SDL SDL2.0
该安装包不包括SDL_image , SDL_ttf, SDL_mixer
SDL播放视频的代码流程如下所示。
初始化:
SDL_Init(): 初始化SDL。
SDL_CreateWindow(): 创建窗口（Window）。
SDL_CreateRenderer(): 基于窗口创建渲染器（Render）。
SDL_CreateTexture(): 创建纹理（Texture）。
循环渲染数据:
SDL_UpdateTexture(): 设置纹理的数据。
SDL_RenderCopy(): 纹理复制给渲染器。
SDL_RenderPresent(): 显示。
上篇文章分析了该流程中的第4个函数SDL_CreateTexture()。本文继续分析该流程中的第5个函数SDL_UpdateTexture()。
1 { 2 SDL_Window *screen; 3 SDL_Renderer* sdlRenderer; 4 SDL_Texture* sdlTexture; 5 SDL_Rect sdlRect; 6 7 if(SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER)) { 8 printf( "Could not initialize SDL - %s ", SDL_GetError()); 9 return -1; 10 } 11 12 screen = SDL_CreateWindow("Simplest ffmpeg player's Window", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 13 screen_w, screen_h, 14 SDL_WINDOW_OPENGL); 15 16 sdlRenderer = SDL_CreateRenderer(screen, -1, 0); 17 //IYUV: Y + U + V (3 planes) 18 //YV12: Y + V + U (3 planes) 19 sdlTexture = SDL_CreateTexture(sdlRenderer, SDL_PIXELFORMAT_IYUV, SDL_TEXTUREACCESS_STREAMING,pCodecCtx->width,pCodecCtx->height); 20 21 #if 0 22 SDL_UpdateTexture( sdlTexture, NULL, pFrameYUV->data[0], pFrameYUV->linesize[0] ); 23 #else 24 SDL_UpdateYUVTexture(sdlTexture, &sdlRect, 25 pFrameYUV->data[0], pFrameYUV->linesize[0], 26 pFrameYUV->data[1], pFrameYUV->linesize[1], 27 pFrameYUV->data[2], pFrameYUV->linesize[2]); 28 #endif 29 SDL_RenderClear( sdlRenderer ); 30 SDL_RenderCopy( sdlRenderer, sdlTexture, NULL, &sdlRect); 31 SDL_RenderPresent( sdlRenderer ); 32 SDL_Delay(40); 33 }
音频：
typedef struct SDL_AudioSpec
{
int freq; /**< DSP frequency -- samples per second */
SDL_AudioFormat format; /**< Audio data format */
Uint8 channels; /**< Number of channels: 1 mono, 2 stereo */
Uint8 silence; /**< Audio buffer silence value (calculated) */
Uint16 samples; /**< Audio buffer size in samples (power of 2) */
Uint16 padding; /**< Necessary for some compile environments */
Uint32 size; /**< Audio buffer size in bytes (calculated) */
SDL_AudioCallback callback; /**< Callback that feeds the audio device (NULL to use SDL_QueueAudio()). */
void *userdata; /**< Userdata passed to callback (ignored for NULL callbacks). */
} SDL_AudioSpec audio;
SDL_OpenAudio（）; 打开音频
SDL_PauseAudio(0); play
SDL_MixAudio(stream,audio_pos,len,SDL_MIX_MAXVOLUME);
播放音频的例子
1 #include <stdio.h> 2 #include "SDL2/SDL.h" 3 4 //Buffer: 5 //|-----------|-------------| 6 //chunk-------pos---len-----| 7 static unsigned char *audio_chunk; 8 static unsigned int audio_len; 9 static unsigned char *audio_pos; 10 11 /* Audio Callback 12 * The audio function callback takes the following parameters: 13 * stream: A pointer to the audio buffer to be filled 14 * len: The length (in bytes) of the audio buffer 15 * 16 */ 17 void fill_audio(void *udata,unsigned char *stream,int len){ 18 //SDL 2.0 19 SDL_memset(stream, 0, len); 20 if(audio_len==0) /* Only play if we have data left */ 21 return; 22 len=(len>audio_len?audio_len:len); /* Mix as much data as possible */ 23 24 SDL_MixAudio(stream,audio_pos,len,SDL_MIX_MAXVOLUME); 25 audio_pos += len; 26 audio_len -= len; 27 } 28 int main(int argc, char* argv[]) 29 { 30 //Init 31 if(SDL_Init(SDL_INIT_AUDIO | SDL_INIT_TIMER)) { 32 printf( "Could not initialize SDL - %s ", SDL_GetError()); 33 return -1; 34 } 35 //SDL_AudioSpec 36 SDL_AudioSpec wanted_spec; 37 wanted_spec.freq = 44100; 38 wanted_spec.format = AUDIO_S16SYS; 39 wanted_spec.channels = 2; 40 wanted_spec.silence = 0; 41 wanted_spec.samples = 1024; 42 wanted_spec.callback = fill_audio; 43 44 if (SDL_OpenAudio(&wanted_spec, NULL)<0){ 45 printf("can't open audio. "); 46 return -1; 47 } 48 49 FILE *fp=fopen("output.pcm","rb+"); 50 if(fp==NULL){ 51 printf("cannot open this file "); 52 return -1; 53 } 54 55 int pcm_buffer_size=4096; 56 char *pcm_buffer=(char *)malloc(pcm_buffer_size); 57 int data_count=0; 58 //Play 59 SDL_PauseAudio(0); 60 61 while(1){ 62 if (fread(pcm_buffer, 1, pcm_buffer_size, fp) != pcm_buffer_size){ 63 // Loop 64 fseek(fp, 0, SEEK_SET); 65 fread(pcm_buffer, 1, pcm_buffer_size, fp); 66 data_count=0; 67 } 68 printf("Now Playing %10d Bytes data. ",data_count); 69 data_count+=pcm_buffer_size; 70 //Set audio buffer (PCM data) 71 audio_chunk = (unsigned char*) pcm_buffer; 72 //Audio buffer length 73 audio_len =pcm_buffer_size; 74 audio_pos = audio_chunk; 75 76 while(audio_len>0)//Wait until finish 77 SDL_Delay(1); 78 } 79 free(pcm_buffer); 80 SDL_Quit(); 81 return 0; 82