ffmpeg编程读取摄像头信息，保存为裸yuv420p、yuyv422视频流

#include <QCoreApplication> extern "C" { #include "libavcodec/avcodec.h" #include "libavformat/avformat.h" #include "libswscale/swscale.h" #include "libavdevice/avdevice.h" } //等于命令： //ffmpeg -list_devices true -f dshow -i dummy //Show Dshow 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"); qDebug("========Device Info=============\n"); avformat_open_input(&pFormatCtx,"video=dummy",iformat,&options); printf("================================\n"); } //Show Dshow 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"); } //Show AVFoundation Device void show_avfoundation_device(){ AVFormatContext *pFormatCtx = avformat_alloc_context(); AVDictionary* options = NULL; av_dict_set(&options,"list_devices","true",0); AVInputFormat *iformat = av_find_input_format("avfoundation"); printf("==AVFoundation Device Info===\n"); avformat_open_input(&pFormatCtx,"",iformat,&options); printf("=============================\n"); } #define USE_DSHOW 1 int main(int argc, char *argv[]) { QCoreApplication a(argc, argv); int i, videoindex; av_register_all(); avformat_network_init(); avdevice_register_all();//Register Device //列出设备 show_dshow_device(); AVFormatContext *pFormatCtx = avformat_alloc_context(); #if USE_DSHOW AVInputFormat *ifmt=av_find_input_format("dshow"); //摄像头的名字 /* ========Device Info============= [dshow @ 03d020a0] DirectShow video devices [dshow @ 03d020a0] "Integrated Camera" [dshow @ 03d020a0] DirectShow audio devices [dshow @ 03d020a0] "楹﹀厠椋庨樀鍒?(Realtek High Definit ================================* */ /* 如果在Linux下： AVInputFormat *ifmt=av_find_input_format("video4linux2"); if(avformat_open_input(&pFormatCtx,"/dev/video0",ifmt,NULL)!=0){ printf("Couldn't open input stream.\n"); return -1; */ //if(avformat_open_input(&pFormatCtx, "video=Integrated Camera",ifmt,NULL)!=0) if(avformat_open_input(&pFormatCtx, "video=EasyCamera",ifmt,NULL)!=0) { printf("Couldn't open input stream.\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.\n"); return -1; } #endif if(avformat_find_stream_info(pFormatCtx, NULL)<0) { printf("Couldn't find stream information.\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; } } //打印音视频设备的信息 printf("videoindex=%d\n", videoindex); av_dump_format(pFormatCtx, 0, 0, 0); if(videoindex==-1) { printf("Couldn't find a video stream.\n"); return -1; } AVCodecContext *pCodecCtx=pFormatCtx->streams[videoindex]->codec; AVCodec *pCodec=avcodec_find_decoder(pCodecCtx->codec_id); if(pCodec==NULL) { printf("Codec not found.\n"); return -1; } if(avcodec_open2(pCodecCtx, pCodec, NULL)<0) { printf("Could not open codec.\n"); return -1; } AVFrame *pFrame;//*pFrameYUV; pFrame=av_frame_alloc(); //pFrameYUV=av_frame_alloc(); //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); int ret, got_picture; AVPacket *packet=(AVPacket *)av_malloc(sizeof(AVPacket)); char strName[512]={0}; sprintf(strName, "e:/video/output_%d_%d.yuyv422", pCodecCtx->width, pCodecCtx->height); FILE *fp=fopen(strName,"wb"); //这里已经需不要了 // struct SwsContext *img_convert_ctx= sws_getContext(pCodecCtx->width, pCodecCtx->height, // pCodecCtx->pix_fmt, //从摄像头中肚读出的原始格式为：yuyv422 // pCodecCtx->width, pCodecCtx->height, // PIX_FMT_YUV420P, SWS_BICUBIC, // NULL, NULL, NULL); ///这里打印出视频的宽高 printf("w= %d h= %d\n",pCodecCtx->width, pCodecCtx->height); //return -1; ///我们就读取100张图像 for(int i=0;i<100;i++) { //读入到 packet if(av_read_frame(pFormatCtx, packet) < 0) { break; } if(packet->stream_index==videoindex) { // packet ---> pFrame ret = avcodec_decode_video2( pCodecCtx, pFrame, //输出 &got_picture, packet //输入 ); if(ret < 0){ printf("Decode Error.\n"); return -1; } if(got_picture) { /* sws_scale(img_convert_ctx, (const uint8_t* const*)pFrame->data, //输入源 pFrame->linesize, 0, pCodecCtx->height, pFrameYUV->data, //目的 pFrameYUV->linesize); printf("%d\n", i); int y_size=pCodecCtx->width*pCodecCtx->height; fwrite(pFrameYUV->data[0],1,y_size, fp); //Y fwrite(pFrameYUV->data[1],1,y_size/4,fp); //U fwrite(pFrameYUV->data[2],1,y_size/4,fp); //V */ // yuyv422 一帧存储为 2倍 的 w×h 个字节 printf("%d\n", i); int y_size=pCodecCtx->width*pCodecCtx->height; fwrite(pFrame->data[0],1,y_size*2, fp); } } av_free_packet(packet); } //sws_freeContext(img_convert_ctx); fclose(fp); //av_free(out_buffer); //av_free(pFrameYUV); avcodec_close(pCodecCtx); avformat_close_input(&pFormatCtx); printf("finish\n"); return a.exec(); }