无法将元素添加到 BIN，在 "pad-added" 的回调函数中

Question

我想创建一个动态管道，它需要根据读取文件".ts"进行修改

在读取中，文件i可能只有一个视频流，也可能有两个视频流，或者也可能有文本数据。

如果文件有两个视频，那么如果我添加两个videosinks和一个appsink用于文本数据，那么我就无法播放视频。

然后，我尝试在回调函数中添加该元素，然后无论何时文本数据来，它都不工作。

我附上了代码。

void uuCMediaPlayer::DemuxLinking(GstElement *Demux, GstPad *DeMuxPad, gpointer data)
{
    uuCMediaPlayer* pObjPlayer = (uuCMediaPlayer *)data;
    int linkFlag = 0;
    char* pad_name = gst_pad_get_name(DeMuxPad);
    UU_PRINT("Player :: In dynamic ADDING PAD %s", pad_name);
    if(g_str_has_prefix(pad_name, "metadata"))
    {
        if(!gst_bin_add(GST_BIN(pObjPlayer->mpPlayerPipe), pObjPlayer->mpMetaSink))
        printf"Failed to Add Meta Sink !!");
        printf(" Player :: In dynamic ADDING Meta PAD %s", pad_name);
        GstPad *metasink = gst_element_get_static_pad(pObjPlayer->mpMetaQueue, "sink");
        if(GST_IS_PAD(DeMuxPad) && GST_IS_PAD(metasink))
        {
            if(gst_pad_link(DeMuxPad, metasink) != GST_PAD_LINK_OK)
            {
                UU_PRINT( "Player ::Failed to Link Demux with Meta Queue !!");
                pObjPlayer->mRunFlag = 0;
            }
            else
            {

                    gst_element_link_many(pObjPlayer->mpMetaQueue, pObjPlayer->mpMetaCapsFilter,
                        pObjPlayer->mpMetaKlvParse, pObjPlayer->mpMetaParseCapsFilter,
                        pObjPlayer->mpMetaSubParse, pObjPlayer->mpMetaSink, NULL);
                    //gst_bin_add_many(GST_BIN(pObjPlayer->mpPlayerPipe), pObjPlayer->mpMetaSink, NULL);
            }
        }
        else
        {
            UU_PRINT( "Player ::Failed to Link Demux with Meta Queue !!");
            pObjPlayer->mRunFlag = 0;
        }
    }
else if(g_str_has_prefix(pad_name, "video"))
{
    UU_PRINT("Player :: In dynamic ADDING VIDEO PAD %s", pad_name);
    if((!pObjPlayer->mDlLinkFlag) && (!linkFlag))
    {
        GstPad *dlsink = gst_element_get_static_pad(pObjPlayer->mpDlQueue, "sink");
        if(GST_IS_PAD(DeMuxPad) && GST_IS_PAD(dlsink))
        {
            if(gst_pad_link(DeMuxPad, dlsink) != GST_PAD_LINK_OK)
            {
                UU_PRINT( "Player :: Failed to Link Demux with DL Video Queue !!");
                pObjPlayer->mRunFlag = 0;
            }
            else
            {
                /** adding elements to bin */
                 gst_bin_add_many(GST_BIN(pObjPlayer->mpPlayerPipe), pObjPlayer->mpDLVideoDecoder,
                    pObjPlayer->mpDLVideoParse, pObjPlayer->mpDLVideoSink,
                    NULL);
                gst_element_link_many(pObjPlayer->mpMetaQueue, pObjPlayer->mpDLVideoDecoder,
                    pObjPlayer->mpDLVideoParse, pObjPlayer->mpDLVideoSink,
                    NULL);
            }
        }
        else
        {
            UU_PRINT( "Player :: Failed to Link Demux with DL Video Queue !!");
            pObjPlayer->mRunFlag = 0;
        }
    }
    else if((!pObjPlayer->mIrLinkFlag) && (!linkFlag))
    {
        GstPad *dlsink = gst_element_get_static_pad(pObjPlayer->mpIrQueue, "sink");
        if(GST_IS_PAD(DeMuxPad) && GST_IS_PAD(dlsink))
        {
            if(gst_pad_link(DeMuxPad, dlsink) != GST_PAD_LINK_OK)
            {
                UU_PRINT( "Player :: Failed to Link Demux with DL Video Queue !!");
                pObjPlayer->mRunFlag = 0;
            }
            else
            {
                pObjPlayer->mIrLinkFlag = 1;
                linkFlag = 1;
            }
        }
        else
        {
            UU_PRINT( "Player :: Failed to Link Demux with DL Video Queue !!");
            pObjPlayer->mRunFlag = 0;
        }
    }
    else
        UU_PRINT("Player :: Ignoring the Video Stream !!");
}

代替

pObjPlayer->mDlLinkFlag = 1;
                linkFlag = 1;

我将视频解码器和xvimagesink元素添加到管道bin。,

我尝试将tsdemux与视频解码器连接，然后连接xvimagesink。

但是视频没有播放。如果我在回调函数之外添加这些，那么它会工作得很好。

Answer 1

我在使用gst1-java-core java绑定时遇到了类似的问题。我必须在pad回调中添加到管道中的箱子上调用play()。我不确定在你的非java代码中确切的方法调用是什么。

也许https://groups.google.com/d/msg/gstreamer-java/Zvf-3ZAhAwg/fekxcsJDCAAJ上讨论的其他元素会帮助你取得进展。