利用ffmpeg使用v4l2读取视频，并用h264

#include"getVideoThread.h" #include <QTimer> #include <QDateTime> #include <QDebug> GetVideoThread::GetVideoThread() { m_isRun = false; pFormatCtx = NULL; out_buffer = NULL; pFrame = NULL; pFrameYUV = NULL; pCodecCtx = NULL; m_pause = false; mH264Encoder = new H264Encoder(); } GetVideoThread::~GetVideoThread() { } void GetVideoThread::setQuantity(int value) { mH264Encoder->setQuantity(value); } ErroCode GetVideoThread::init(char* videoDevName) { AVCodec *pCodec = NULL; AVDictionary *options = NULL; // av_register_all(); // avformat_network_init(); // avdevice_register_all(); //Register Device pFormatCtx = avformat_alloc_context(); AVInputFormat *ifmt = av_find_input_format("video4linux2"); //使用video4linux2 //QString videoDevOption = QString("video=%1").arg("/dev/video1"); if(ifmt==NULL) { qDebug()<<"Couldn't find_input_format.\n"; return VideoOpenFailed; } av_dict_set(&options, "video_size", "320x240", 0); if(avformat_open_input(&pFormatCtx,videoDevName,ifmt,&options)!=0){ qDebug()<<"Couldn't open input stream video.（无法打开输入流）\n"; return VideoOpenFailed; } videoindex=-1; pCodecCtx = NULL; for(i=0; i<pFormatCtx->nb_streams; i++) if(pFormatCtx->streams[i]->codec->codec_type==AVMEDIA_TYPE_VIDEO) { videoindex=i; //pCodecCtx = pFormatCtx->streams[videoindex]->codec; //qDebug("pCodecCtx->width=%d,pCodecCtx->height=%d\n",pCodecCtx->width,pCodecCtx->height); break; } if(videoindex==-1) { printf("Didn't find a video stream.（没有找到视频流）\n"); return VideoOpenFailed; } pCodecCtx = pFormatCtx->streams[videoindex]->codec; pCodec = avcodec_find_decoder(pCodecCtx->codec_id); if(pCodec == NULL) { printf("video Codec not found.\n"); return VideoDecoderOpenFailed; } if(avcodec_open2(pCodecCtx, pCodec,NULL)<0) { printf("Could not open video codec.\n"); return VideoDecoderOpenFailed; } pFrame=avcodec_alloc_frame(); pFrameYUV=avcodec_alloc_frame(); 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); qDebug("pCodecCtx->width=%d,pCodecCtx->height=%d\n",pCodecCtx->width,pCodecCtx->height); //*************** // int Screen_W = GetSystemMetrics(SM_CXSCREEN); //获取屏幕宽高 // int Screen_H = GetSystemMetrics(SM_CYSCREEN); // mH264Encoder->setWidth(640,480); //设置编码器的宽高 mH264Encoder->setWidth(pCodecCtx->width,pCodecCtx->height); return SUCCEED; } void GetVideoThread::deInit() { if (out_buffer) { av_free(out_buffer); out_buffer = NULL; } if (pFrame) { av_free(pFrame); pFrame = NULL; } if (pFrameYUV) { av_free(pFrameYUV); pFrameYUV = NULL; } if (pCodecCtx) avcodec_close(pCodecCtx); avformat_close_input(&pFormatCtx); avformat_free_context(pFormatCtx); } void GetVideoThread::startRecord() { m_isRun = true; start(); mH264Encoder->startEncode(); } void GetVideoThread::stopRecord() { m_isRun = false; } //FILE *fp = fopen("out.yuv","wb"); void GetVideoThread::run() { struct SwsContext *img_convert_ctx = NULL; int y_size = 0; int yuvSize = 0; if (pCodecCtx) { int numBytes = avpicture_get_size(AV_PIX_FMT_YUV420P, pCodecCtx->width,pCodecCtx->height); out_buffer = (uint8_t *) av_malloc(numBytes * sizeof(uint8_t)); avpicture_fill((AVPicture *) pFrameYUV, out_buffer, AV_PIX_FMT_YUV420P,pCodecCtx->width, pCodecCtx->height); img_convert_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height, AV_PIX_FMT_YUV420P, SWS_BICUBIC, NULL, NULL, NULL); //------------------------------ y_size = pCodecCtx->width * pCodecCtx->height; yuvSize = avpicture_get_size(pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height); ///理论上 这里的 size = y_size * 3 / 2 } int ret, got_frame; AVPacket *packet=(AVPacket *)av_malloc(sizeof(AVPacket)); qint64 firstTime = QDateTime::currentMSecsSinceEpoch(); m_getFirst = false; qint64 timeIndex = 0; bool m_saveVideoFileThread = true; while(m_isRun) { if (av_read_frame(pFormatCtx, packet)<0) { qDebug()<<"read failed!"; msleep(10); continue; } if (m_pause) { av_free_packet(packet); msleep(10); continue; } if(packet->stream_index==videoindex) { qint64 time = 0; if (m_saveVideoFileThread) { if (m_getFirst) { qint64 secondTime = QDateTime::currentMSecsSinceEpoch(); time = secondTime - firstTime + timeIndex; } else { firstTime = QDateTime::currentMSecsSinceEpoch(); timeIndex = 0; m_getFirst = true; } } ret = avcodec_decode_video2(pCodecCtx, pFrame, &got_frame, packet); if(ret < 0) { printf("video Decode Error.（解码错误）\n"); return; } if(got_frame && pCodecCtx) { /// 转换成YUV420 sws_scale(img_convert_ctx, (const uint8_t* const*)pFrame->data, pFrame->linesize, 0, pCodecCtx->height, pFrameYUV->data, pFrameYUV->linesize); if (m_saveVideoFileThread) { uint8_t * picture_buf = (uint8_t *)av_malloc(yuvSize); memcpy(picture_buf,pFrameYUV->data[0],y_size); memcpy(picture_buf+y_size,pFrameYUV->data[1],y_size/4); memcpy(picture_buf+y_size+y_size/4,pFrameYUV->data[2],y_size/4); // fwrite(picture_buf,1,y_size*3/2,fp); // av_free(picture_buf); mH264Encoder->inputYuvBuffer(picture_buf,yuvSize,time); //将yuv数据添加到h.264编码的线程 } } } else { qDebug()<<"other"<<packet->stream_index; } av_free_packet(packet); msleep(20); } sws_freeContext(img_convert_ctx); qDebug()<<"record stopping..."; m_pause = false; deInit(); mH264Encoder->stopEncode(); qDebug()<<"record finished!"; }