最简单的基于FFMPEG的AVDevice的例子

/** * 最简单的基于FFmpeg的AVDevice例子（读取摄像头） * Simplest FFmpeg Device (Read Camera) * * 雷霄骅 Lei Xiaohua * leixiaohua1020@126.com * 中国传媒大学/数字电视技术 * Communication University of China / Digital TV Technology * http://blog.csdn.net/leixiaohua1020 * * 本程序实现了本地摄像头数据的获取解码和显示。是基于FFmpeg * 的libavdevice类库最简单的例子。通过该例子，可以学习FFmpeg中 * libavdevice类库的使用方法。 * 本程序在Windows下可以使用2种方式读取摄像头数据： * 1.VFW: Video for Windows 屏幕捕捉设备。注意输入URL是设备的序号， * 从0至9。 * 2.dshow: 使用Directshow。注意作者机器上的摄像头设备名称是 * “Integrated Camera”，使用的时候需要改成自己电脑上摄像头设 * 备的名称。 * 在Linux下则可以使用video4linux2读取摄像头设备。 * * This software read data from Computer's Camera and play it. * It's the simplest example about usage of FFmpeg's libavdevice Library. * It's suiltable for the beginner of FFmpeg. * This software support 2 methods to read camera in Microsoft Windows: * 1.gdigrab: VfW (Video for Windows) capture input device. * The filename passed as input is the capture driver number, * ranging from 0 to 9. * 2.dshow: Use Directshow. Camera's name in author's computer is * "Integrated Camera". * It use video4linux2 to read Camera in Linux. * */ #include "stdafx.h" extern "C" { #include "libavcodec/avcodec.h" #include "libavformat/avformat.h" #include "libswscale/swscale.h" #include "libavdevice/avdevice.h" //SDL #include "sdl/SDL.h" #include "sdl/SDL_thread.h" }; //Output YUV420P #define OUTPUT_YUV420P 0 //'1' Use Dshow //'0' Use VFW #define USE_DSHOW 0 //Show Device void show_dshow_device(){ AVFormatContext *pFormatCtx = avformat_alloc_context(); AVDictionary* options = NULL; av_dict_set(&options,"list_devices","true",0); AVInputFormat *iformat = av_find_input_format("dshow"); printf("Device Info=============\n"); avformat_open_input(&pFormatCtx,"video=dummy",iformat,&options); printf("========================\n"); } //Show Device Option void show_dshow_device_option(){ AVFormatContext *pFormatCtx = avformat_alloc_context(); AVDictionary* options = NULL; av_dict_set(&options,"list_options","true",0); AVInputFormat *iformat = av_find_input_format("dshow"); printf("Device Option Info======\n"); avformat_open_input(&pFormatCtx,"video=Integrated Camera",iformat,&options); printf("========================\n"); } //Show VFW Device void show_vfw_device(){ AVFormatContext *pFormatCtx = avformat_alloc_context(); AVInputFormat *iformat = av_find_input_format("vfwcap"); printf("VFW Device Info======\n"); avformat_open_input(&pFormatCtx,"list",iformat,NULL); printf("=====================\n"); } int main(int argc, char* argv[]) { AVFormatContext *pFormatCtx; int i, videoindex; AVCodecContext *pCodecCtx; AVCodec *pCodec; av_register_all(); avformat_network_init(); pFormatCtx = avformat_alloc_context(); //Open File //char filepath[]="src01_480x272_22.h265"; //avformat_open_input(&pFormatCtx,filepath,NULL,NULL) //Register Device avdevice_register_all(); //Show Dshow Device show_dshow_device(); //Show Device Options show_dshow_device_option(); //Show VFW Options show_vfw_device(); //Windows #ifdef _WIN32 #if USE_DSHOW AVInputFormat *ifmt=av_find_input_format("dshow"); //Set own video device's name if(avformat_open_input(&pFormatCtx,"video=Integrated Camera",ifmt,NULL)!=0){ printf("Couldn't open input stream.（无法打开输入流）\n"); return -1; } #else AVInputFormat *ifmt=av_find_input_format("vfwcap"); if(avformat_open_input(&pFormatCtx,"0",ifmt,NULL)!=0){ printf("Couldn't open input stream.（无法打开输入流）\n"); return -1; } #endif #endif //Linux #ifdef linux AVInputFormat *ifmt=av_find_input_format("video4linux2"); if(avformat_open_input(&pFormatCtx,"/dev/video0",ifmt,NULL)!=0){ printf("Couldn't open input stream.（无法打开输入流）\n"); return -1; } #endif if(avformat_find_stream_info(pFormatCtx,NULL)<0) { printf("Couldn't find stream information.（无法获取流信息）\n"); return -1; } videoindex=-1; for(i=0; i<pFormatCtx->nb_streams; i++) if(pFormatCtx->streams[i]->codec->codec_type==AVMEDIA_TYPE_VIDEO) { videoindex=i; break; } if(videoindex==-1) { printf("Couldn't find a video stream.（没有找到视频流）\n"); return -1; } pCodecCtx=pFormatCtx->streams[videoindex]->codec; pCodec=avcodec_find_decoder(pCodecCtx->codec_id); if(pCodec==NULL) { printf("Codec not found.（没有找到解码器）\n"); return -1; } if(avcodec_open2(pCodecCtx, pCodec,NULL)<0) { printf("Could not open codec.（无法打开解码器）\n"); return -1; } AVFrame *pFrame,*pFrameYUV; pFrame=avcodec_alloc_frame(); pFrameYUV=avcodec_alloc_frame(); uint8_t *out_buffer=(uint8_t *)av_malloc(avpicture_get_size(PIX_FMT_YUV420P, pCodecCtx->width, pCodecCtx->height)); avpicture_fill((AVPicture *)pFrameYUV, out_buffer, PIX_FMT_YUV420P, pCodecCtx->width, pCodecCtx->height); //SDL---------------------------- if(SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_TIMER)) { printf( "Could not initialize SDL - %s\n", SDL_GetError()); return -1; } int screen_w=0,screen_h=0; SDL_Surface *screen; screen_w = pCodecCtx->width; screen_h = pCodecCtx->height; screen = SDL_SetVideoMode(screen_w, screen_h, 0,0); if(!screen) { printf("SDL: could not set video mode - exiting:%s\n",SDL_GetError()); return -1; } SDL_Overlay *bmp; bmp = SDL_CreateYUVOverlay(pCodecCtx->width, pCodecCtx->height,SDL_YV12_OVERLAY, screen); SDL_Rect rect; //SDL End------------------------ int ret, got_picture; AVPacket *packet=(AVPacket *)av_malloc(sizeof(AVPacket)); //Output Information----------------------------- printf("File Information（文件信息）---------------------\n"); av_dump_format(pFormatCtx,0,NULL,0); printf("-------------------------------------------------\n"); #if OUTPUT_YUV420P FILE *fp_yuv=fopen("output.yuv","wb+"); #endif struct SwsContext *img_convert_ctx; img_convert_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height, PIX_FMT_YUV420P, SWS_BICUBIC, NULL, NULL, NULL); //------------------------------ while(av_read_frame(pFormatCtx, packet)>=0) { if(packet->stream_index==videoindex) { ret = avcodec_decode_video2(pCodecCtx, pFrame, &got_picture, packet); if(ret < 0) { printf("Decode Error.（解码错误）\n"); return -1; } if(got_picture) { sws_scale(img_convert_ctx, (const uint8_t* const*)pFrame->data, pFrame->linesize, 0, pCodecCtx->height, pFrameYUV->data, pFrameYUV->linesize); #if OUTPUT_YUV420P int y_size=pCodecCtx->width*pCodecCtx->height; fwrite(pFrameYUV->data[0],1,y_size,fp_yuv); //Y fwrite(pFrameYUV->data[1],1,y_size/4,fp_yuv); //U fwrite(pFrameYUV->data[2],1,y_size/4,fp_yuv); //V #endif SDL_LockYUVOverlay(bmp); bmp->pixels[0]=pFrameYUV->data[0]; bmp->pixels[2]=pFrameYUV->data[1]; bmp->pixels[1]=pFrameYUV->data[2]; bmp->pitches[0]=pFrameYUV->linesize[0]; bmp->pitches[2]=pFrameYUV->linesize[1]; bmp->pitches[1]=pFrameYUV->linesize[2]; SDL_UnlockYUVOverlay(bmp); rect.x = 0; rect.y = 0; rect.w = screen_w; rect.h = screen_h; SDL_DisplayYUVOverlay(bmp, &rect); //Delay 40ms SDL_Delay(40); } } av_free_packet(packet); } sws_freeContext(img_convert_ctx); #if OUTPUT_YUV420P fclose(fp_yuv); #endif SDL_Quit(); av_free(out_buffer); av_free(pFrameYUV); avcodec_close(pCodecCtx); avformat_close_input(&pFormatCtx); return 0; }