C++_QT_ffmpeg网络摄像头初学者.zip

#include "videothread.h" #include <QImage> #include <QTime> #include <QCoreApplication> #include <QEventLoop> #include <QDebug> VideoThread::VideoThread() { } void VideoThread::run() { AVFormatContext *pFormatCtx; int i, videoindex; AVCodecContext *pCodecCtx; AVCodec *pCodec; AVFrame *pFrame, *pFrameRGB; unsigned char *out_buffer; AVPacket *packet; int ret, got_picture; struct SwsContext *img_convert_ctx; AVDictionary *optionsDict = NULL; av_dict_set(&optionsDict, "rtsp_transport", "tcp", 0); av_dict_set(&optionsDict, "stimeout", "2000000", 0); av_dict_set(&optionsDict, "framerate", "20", 0); std::string strResp = "rtsp://admin:admin@192.168.1.89/11"; //char filepath[] = "D:\\QtProjects\\video\\1.mp4"; //初始化编解码库 av_register_all();//创建AVFormatContext对象，与码流相关的结构。 avdevice_register_all(); avformat_network_init(); pFormatCtx = avformat_alloc_context(); //初始化pFormatCtx结构 if (avformat_open_input(&pFormatCtx, strResp.c_str(), NULL, &optionsDict) != 0) //if (avformat_open_input(&pFormatCtx, filepath, NULL, NULL) != 0) { qDebug("Couldn't open input stream.\n"); return ; } //获取音视频流数据信息 if (avformat_find_stream_info(pFormatCtx, NULL) < 0){ qDebug("Couldn't find stream information.\n"); return ; } videoindex = -1; //nb_streams视音频流的个数，这里当查找到视频流时就中断了。 for (i = 0; i < pFormatCtx->nb_streams; i++) if (pFormatCtx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO){ videoindex = i; break; } if (videoindex == -1){ qDebug("Didn't find a video stream.\n"); return ; } //获取视频流编码结构 pCodecCtx = pFormatCtx->streams[videoindex]->codec; //查找解码器 pCodec = avcodec_find_decoder(pCodecCtx->codec_id); if (pCodec == NULL){ qDebug("Codec not found.\n"); return ; } //用于初始化pCodecCtx结构 if (avcodec_open2(pCodecCtx, pCodec, NULL) < 0){ qDebug("Could not open codec.\n"); return ; } //创建帧结构，此函数仅分配基本结构空间，图像数据空间需通过av_malloc分配 pFrame = av_frame_alloc(); pFrameRGB = av_frame_alloc(); //创建动态内存,创建存储图像数据的空间 //av_image_get_buffer_size获取一帧图像需要的大小 out_buffer = (unsigned char *)av_malloc(av_image_get_buffer_size(AV_PIX_FMT_RGB32, pCodecCtx->width, pCodecCtx->height, 1)); av_image_fill_arrays(pFrameRGB->data, pFrameRGB->linesize, out_buffer, AV_PIX_FMT_RGB32, pCodecCtx->width, pCodecCtx->height, 1); packet = (AVPacket *)av_malloc(sizeof(AVPacket)); //初始化img_convert_ctx结构 img_convert_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height, AV_PIX_FMT_RGB32, SWS_BICUBIC, NULL, NULL, NULL); //获取帧率 AVStream *stream=pFormatCtx->streams[0]; int frame_rate=stream->avg_frame_rate.num/stream->avg_frame_rate.den;//每秒多少帧 qDebug() << "frame_rate:" << frame_rate; //av_read_frame读取一帧未解码的数据 while (av_read_frame(pFormatCtx, packet) >= 0){ //如果是视频数据 if (packet->stream_index == videoindex){ //解码一帧视频数据 ret = avcodec_decode_video2(pCodecCtx, pFrame, &got_picture, packet); if (ret < 0){ qDebug("Decode Error.\n"); return ; } if (got_picture){ sws_scale(img_convert_ctx, (const unsigned char* const*)pFrame->data, pFrame->linesize, 0, pCodecCtx->height, pFrameRGB->data, pFrameRGB->linesize); QImage img((uchar*)pFrameRGB->data[0],pCodecCtx->width,pCodecCtx->height,QImage::Format_RGB32); QImage image = img.copy(); //把图像复制一份 传递给界面显示 emit sendGetFrame(image); //发送信号 } } av_free_packet(packet); msleep(0.01); //Delay(10); } sws_freeContext(img_convert_ctx); av_frame_free(&pFrameRGB); av_frame_free(&pFrame); avcodec_close(pCodecCtx); avformat_close_input(&pFormatCtx); }