c++ - 使用gstreamer将jpeg混合到mkv

情况:

当我尝试将jpeg多路复用到mkv文件时，我将得到一个大小为零的文件。我必须将解析器和多路复用器之间的编码和解码元素放在正确的输出。当我用相同的代码混合h264视频时，我会得到正确的视频文件，这意味着缓冲区的时间设置应该可以(持续时间和pts参数)。无论如何，错误的缓冲区设置后文件的大小都不为零。
Matroskamux在水槽垫上仅要求“宽度”和“高度”功能具有“图像/jpeg”功能，但看起来这还不够。 Jpegparse提供正确的值，并且在手动设置此功能后，该程序也无法运行。

管道示例:

该管道不起作用

appsrc ! "image/jpeg" ! jpegparse ! matroskamux ! filesink location=mjpeg.mkv

但这有效

appsrc ! "image/jpeg" ! jpegparse ! avdec_mjpeg ! x264enc ! matroskamux ! filesink location=mjpeg.mkv

代码示例:

工作代码，但具有重新编码

    app = new _App();

    app->src = (GstAppSrc*)gst_element_factory_make ("appsrc", "source");

    if(IsH264Frame(codecType))
        app->parser = gst_element_factory_make("h264parse", "parser");
    else if(codecType == IMAGE_MJPEG_FRAME)
        app->parser = gst_element_factory_make("jpegparse", "parser");

        //additional code
    app->decoder = gst_element_factory_make("avdec_mjpeg", "decoder");
    app->encoder = gst_element_factory_make("x264enc", "encoder");

    app->muxer = gst_element_factory_make("matroskamux", "muxer");
    app->sink = (GstAppSink*)gst_element_factory_make ("filesink", "sink");


    if (!app->pipeline || !app->src || !app->decoder || !app->encoder || !app->muxer || !app->sink || !app->parser)
        return;



    app->bus = gst_pipeline_get_bus (GST_PIPELINE (app->pipeline));
    g_assert(app->bus);
    gst_bus_add_watch (app->bus, (GstBusFunc) BusMessage, this);


    gst_bin_add_many (GST_BIN (app->pipeline), (GstElement*)app->src, app->decoder, app->encoder, app->muxer, app->sink, app->parser
        ,NULL);


            /*          SETUP ELEMENTS          */


    g_object_set(app->src,
        "stream-type", 0,
        "format", GST_FORMAT_BUFFERS,
        "is-live", true,
        "block", true,
        NULL);

    if(IsH264Frame(codecType)){

        g_object_set(app->src, "caps", gst_caps_new_simple("video/x-h264",
            NULL), NULL);

    } else if(codecType == IMAGE_MJPEG_FRAME) {

        g_object_set(app->src, "caps", gst_caps_new_simple("image/jpeg",
            "framerate",GST_TYPE_FRACTION,(int)framerate,1,
            NULL), NULL);

        //additional code

        g_object_set(app->decoder, "caps", gst_caps_new_simple("video/x-raw",
            NULL), NULL);

        g_object_set(app->encoder, "caps", gst_caps_new_simple("video/x-h264",
            NULL), NULL);

    }


    g_signal_connect(app->src, "need-data", G_CALLBACK(StartFeed), this);
    g_signal_connect(app->src, "enough-data", G_CALLBACK(StopFeed), this);


    g_object_set (app->sink,
        "location", GenerateFileName().c_str(),
        "buffer-mode", 0,
        NULL);


      /*            LINKING         */


    GstPad *padDecSrc, *padMuxSink, *parserSrc,
    GstPadTemplate *mux_sink_pad_template;

    mux_sink_pad_template = gst_element_class_get_pad_template (GST_ELEMENT_GET_CLASS (app->muxer), "video_%u");
    padMuxSink = gst_element_request_pad (app->muxer, mux_sink_pad_template, NULL, NULL);

    parserSrc = gst_element_get_static_pad (app->parser, "src");
    padEncSrc = gst_element_get_static_pad (app->encoder, "src");


    if(!gst_element_link( (GstElement*)app->src,  app->parser))
            return;

    if(IsH264Frame(codecType)){

        if(gst_pad_link (parserSrc, padMuxSink) != GST_PAD_LINK_OK)
            return;

    } else if(codecType == IMAGE_MJPEG_FRAME){

        //additional code
        if(!gst_element_link( app->parser,  app->decoder))
            return;

        if(!gst_element_link( app->decoder,  app->encoder))
            return;

        if(gst_pad_link (padDecSrc, padMuxSink) != GST_PAD_LINK_OK)
            return;

    }

    if(!gst_element_link( app->muxer,  (GstElement*)app->sink))
        return;


            /*          PLAY            */


    GstStateChangeReturn ret = gst_element_set_state (app->pipeline, GST_STATE_PLAYING);

    if (ret == GST_STATE_CHANGE_FAILURE)
    {
        gst_object_unref (app->pipeline);
        return;
    }

问题:

我做错了什么？有解决这个问题的想法吗？

最佳答案

我通过将appsrc属性“格式”从GST_FORMAT_BUFFERS更改为GST_FORMAT_TIME解决了此问题。缓冲区上的正确时间戳是不够的。