Recherche avancée

Sur d’autres sites (7866)

• avio_open() function returns -138

  8 avril 2024, par checkright

  When I use ffmpeg4.4.1 to push rtmp to the desktop, the program returns -138 when running avio_open().I use dshow's screen-capture-recorder on the input side. My purpose is to capture the desktop in real time and use rtmp to push the stream.

  


      avdevice_register_all();
    avformat_network_init();

    AVFormatContext* pFmtCtx_In = nullptr;
    AVFormatContext* pFmtCtx_Out = nullptr;
    AVInputFormat*   pInFmt  = nullptr;
    AVDictionary* options = nullptr;
    int nVideoIndex          = -1;
    int              ret     = 0;

    AVCodecParameters* pCodecParam = nullptr;
    AVCodecContext   * pCodecCtx   = nullptr;
    AVCodec          * pCodec      = nullptr;

    AVFrame* pFrame    = av_frame_alloc();
    AVFrame* pFrameRGB = av_frame_alloc();
    AVPacket* pkt      = nullptr;

    pFrame    = av_frame_alloc();
    pFrameRGB = av_frame_alloc();
    pkt       = nullptr;
    img_convert_ctx = nullptr;

    pFmtCtx_In = avformat_alloc_context();
    if(!pFmtCtx_In)
    {
        qDebug() << "create AVFormatContext failed." ;
        return;
    }

    QString urlString = QString("video=screen-capture-recorder");
    const char* rtmpAddress = "rtmp://192.168.0.136:8554/myapp/test";
    
    if(1){
        pInFmt = const_cast(av_find_input_format("dshow"));
        ret = avformat_open_input(&pFmtCtx_In, urlString.toStdString().c_str(), pInFmt, nullptr);
    }else{
        pInFmt = const_cast(av_find_input_format("gdigrab"));
        av_dict_set(&options, "video_device_index", "1", 0);  
        av_dict_set(&options, "offset_x", "1920", 0);
        av_dict_set(&options, "offset_y", "0", 0);
        av_dict_set(&options, "draw_mouse", "1", 0);
        av_dict_set(&options, "video_size", "1920x1080", 0);
        ret = avformat_open_input(&pFmtCtx_In, "desktop", pInFmt, &options);
    }

    if(!pInFmt)
    {
        qDebug() << "find AVInputFormat failed." ;
        return;
    }

    if(ret < 0)
    {
        qDebug() << "open camera failed."<nb_streams; i++){
        if(pFmtCtx_In->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO){
            nVideoIndex = i;
            continue;
        }
    }

    if(nVideoIndex == -1){
        qDebug() << "cannot find video stream." ;
        return;
    }


    pCodecParam = pFmtCtx_In->streams[nVideoIndex]->codecpar;
    pCodec = avcodec_find_decoder(pCodecParam->codec_id);
    if(!pCodec)
    {
        qDebug() << "cannot find codec." ;
        return;
    }

    ret = avformat_alloc_output_context2(&pFmtCtx_Out, NULL, "flv", rtmpAddress);
    //    ret = avformat_alloc_output_context2(&pFmtCtx_Out, NULL, "rtsp", rtmpAddress);
    if (ret < 0) {
        qDebug() << "cannot avformat_alloc_output_context2." ;
        return ;
    }

    for (int i = 0; i < pFmtCtx_In->nb_streams; i++) {
        AVStream *outStream = avformat_new_stream(pFmtCtx_Out, pFmtCtx_In->streams[i]->codec->codec);
        if (!outStream) {
            qDebug() << "cannot outStream." ;

            return ;
        }

        ret = avcodec_parameters_copy(outStream->codecpar, pFmtCtx_In->streams[i]->codecpar);
        if (ret < 0) {
             qDebug() << "cannot avcodec_parameters_copy." ;
            return ;
        }
        outStream->codec->codec_tag = 0;
    }
  
    av_dump_format(pFmtCtx_Out, 0, rtmpAddress, 1);

    ret = avio_open(&pFmtCtx_Out->pb, rtmpAddress, AVIO_FLAG_WRITE);
    if (ret < 0) {
        qDebug() << "cannot avio_open." <code>

  


  An error occurs here.According to the data, the problem occurs at the input end, and the input end can display the desktop normally. How can I make it run successfully ? How do I need to modify the above code ?

  


• FFmpeg : avcodec_open2 returns "Permission denied" (-13)

  24 avril 2019, par maxest

  I wanted to open an encoder, H264, C++, Android. This :

  encoderH264 = avcodec_find_encoder(AV_CODEC_ID_H264);

  works. This one :

  codecContext = avcodec_alloc_context3(encoderH264);

  also works. But I get error "Permission denied" (-13) on that :

  avcodec_open2(codecContext, encoderH264, NULL);

  I’d suppose that my FFmpeg lib does support H264 encoding as avcodec_find_encoder returns valid value (when I used some other FFmpeg lib this function returned null).

  Any ideas ?

• Google Analytics Sampling : Why It Matters and How to Avoid It

  21 octobre 2024, par Daniel Crough — Analytics Tips

  When marketing decisions rely on website analytics, accuracy matters.
  However, Google Analytics and other analytics platforms sample data to
  generate reports, which can sometimes misrepresent the true data trends.

  Read More