实战ffmpeg与sdl实现最简单的视频播放器

流程&＃xff1a;
解复用->解码->yuv->交给纹理->交给渲染器->播放。
其中前三步使用ffmpeg实现&＃xff0c;后三步用sdl实现。

#include
#include #include
#include
#include // compatibility with newer API
#if LIBAVCODEC_VERSION_INT < AV_VERSION_INT(55,28,1)
#define av_frame_alloc avcodec_alloc_frame
#define av_frame_free avcodec_free_frame
#endifint main(int argc, char *argv[]) {int ret &＃61; -1;AVFormatContext *pFormatCtx &＃61; NULL; //for opening multi-media fileint i, videoStream;AVCodecContext *pCodecCtxOrig &＃61; NULL; //codec contextAVCodecContext *pCodecCtx &＃61; NULL;struct SwsContext *sws_ctx &＃61; NULL;AVCodec *pCodec &＃61; NULL; // the codecerAVFrame *pFrame &＃61; NULL;AVPacket packet;int frameFinished;float aspect_ratio;AVPicture *pict &＃61; NULL;SDL_Rect rect;Uint32 pixformat; //for renderSDL_Window *win &＃61; NULL;SDL_Renderer *renderer &＃61; NULL;SDL_Texture *texture &＃61; NULL;//set defualt size of window int w_width &＃61; 640;int w_height &＃61; 480;if(argc < 2) {//fprintf(stderr, "Usage: command \n");SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Usage: command ");return ret;}if(SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER)) {//fprintf(stderr, "Could not initialize SDL - %s\n", SDL_GetError());SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Could not initialize SDL - %s\n", SDL_GetError());return ret;}//Register all formats and codecsav_register_all();// Open video fileif(avformat_open_input(&pFormatCtx, argv[1], NULL, NULL)!&＃61;0){SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Failed to open video file!");goto __FAIL; // Couldn&＃39;t open file}// Retrieve stream informationif(avformat_find_stream_info(pFormatCtx, NULL)<0){SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Failed to find stream infomation!");goto __FAIL; // Couldn&＃39;t find stream information}// Dump information about file onto standard errorav_dump_format(pFormatCtx, 0, argv[1], 0);// Find the first video streamvideoStream&＃61;-1;for(i&＃61;0; i<pFormatCtx->nb_streams; i&＃43;&＃43;) {if(pFormatCtx->streams[i]->codec->codec_type&＃61;&＃61;AVMEDIA_TYPE_VIDEO) {videoStream&＃61;i;break;}}if(videoStream&＃61;&＃61;-1){SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Din&＃39;t find a video stream!");goto __FAIL;// Didn&＃39;t find a video stream}// Get a pointer to the codec context for the video streampCodecCtxOrig&＃61;pFormatCtx->streams[videoStream]->codec;// Find the decoder for the video streampCodec&＃61;avcodec_find_decoder(pCodecCtxOrig->codec_id);if(pCodec&＃61;&＃61;NULL) {SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Unsupported codec!\n");goto __FAIL; // Codec not found}// Copy contextpCodecCtx &＃61; avcodec_alloc_context3(pCodec);if(avcodec_copy_context(pCodecCtx, pCodecCtxOrig) !&＃61; 0) {SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn&＃39;t copy codec context");goto __FAIL;// Error copying codec context}// Open codecif(avcodec_open2(pCodecCtx, pCodec, NULL)<0) {SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Failed to open decoder!\n");goto __FAIL; // Could not open codec}// Allocate video framepFrame&＃61;av_frame_alloc();w_width &＃61; pCodecCtx->width;w_height &＃61; pCodecCtx->height;win &＃61; SDL_CreateWindow( "Media Player",SDL_WINDOWPOS_UNDEFINED,SDL_WINDOWPOS_UNDEFINED,w_width, w_height,SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE); if(!win){SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Failed to create window by SDL"); goto __FAIL;}renderer &＃61; SDL_CreateRenderer(win, -1, 0);if(!renderer){SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Failed to create Renderer by SDL"); goto __FAIL;}pixformat &＃61; SDL_PIXELFORMAT_IYUV;texture &＃61; SDL_CreateTexture(renderer,pixformat, SDL_TEXTUREACCESS_STREAMING,w_width, w_height);// initialize SWS context for software scalingsws_ctx &＃61; sws_getContext(pCodecCtx->width,pCodecCtx->height,pCodecCtx->pix_fmt,pCodecCtx->width,pCodecCtx->height,AV_PIX_FMT_YUV420P,SWS_BILINEAR,NULL,NULL,NULL);pict &＃61; (AVPicture*)malloc(sizeof(AVPicture));avpicture_alloc(pict, AV_PIX_FMT_YUV420P, pCodecCtx->width, pCodecCtx->height);// Read frames and save first five frames to diskwhile(av_read_frame(pFormatCtx, &packet)>&＃61;0) {// Is this a packet from the video stream?if(packet.stream_index&＃61;&＃61;videoStream) {// Decode video frameavcodec_decode_video2(pCodecCtx, pFrame, &frameFinished, &packet);// Did we get a video frame?if(frameFinished) {// Convert the image into YUV format that SDL usessws_scale(sws_ctx, (uint8_t const * const *)pFrame->data,pFrame->linesize, 0, pCodecCtx->height,pict->data, pict->linesize);SDL_UpdateYUVTexture(texture, NULL, pict->data[0], pict->linesize[0],pict->data[1], pict->linesize[1],pict->data[2], pict->linesize[2]);// Set Size of Windowrect.x &＃61; 0;rect.y &＃61; 0;rect.w &＃61; pCodecCtx->width;rect.h &＃61; pCodecCtx->height;SDL_RenderClear(renderer);SDL_RenderCopy(renderer, texture, NULL, &rect);SDL_RenderPresent(renderer);}}// Free the packet that was allocated by av_read_frameav_free_packet(&packet);/*SDL_Event event;SDL_PollEvent(&event);switch(event.type) {case SDL_QUIT:goto __QUIT;break;default:break;}*/}__QUIT:ret &＃61; 0;__FAIL:// Free the YUV frameif(pFrame){av_frame_free(&pFrame);}// Close the codecif(pCodecCtx){avcodec_close(pCodecCtx);}if(pCodecCtxOrig){avcodec_close(pCodecCtxOrig);}// Close the video fileif(pFormatCtx){avformat_close_input(&pFormatCtx);}if(pict){avpicture_free(pict);free(pict);}if(win){SDL_DestroyWindow(win);}if(renderer){SDL_DestroyRenderer(renderer);}if(texture){SDL_DestroyTexture(texture);}SDL_Quit();return ret;
}