Appsink freezing my pipeline

[Paul Stuart]

Hi,
Still stuck on the same problem with appsink freezing my pipeline. If I 
replace appsink with fakesink in the code below, it runs fine. If I 
leave it as appsink, I get a frame out to my display and then everything 
freezes.

 I'm posting a snippet of my code below, maybe I'm doing something 
goofy? The premise is that I've got a pipeline with a tee, one path off 
the tee goes to the display, and the other tee goes to my JPEG capture. 
Code for the JPEG capture bin with the appsink is below. Any suggestions 
would be greatly appreciated.



void GStreamerJpegBin::makeLink(GstElement *pipeline, GstElement 
*videoSrcTee){

    GstElement *queue;
    GstPadLinkReturn  retVal;
    GstPad *sinkpadvideo, *srcpadvideo;
    gchar *name;

    /* first thing we want to do is add an appsink to the tee off of our 
video source, and later
       we will build up a pipeline to capture a single JPEG image */
   
    // create new bin to stuff our queue and appsink into
    appSinkBin = gst_bin_new (NULL);
    queue   = gst_element_factory_make ("queue", NULL);
    appSink = gst_element_factory_make ("appsink", NULL);

    // only allow three frames to queue up at a time in our appsink 
APPSINK_MAX_BUFFERS = 3
    gst_app_sink_set_max_buffers (GST_APP_SINK(appSink), 
APPSINK_MAX_BUFFERS);
    gst_app_sink_set_drop (GST_APP_SINK(appSink), true);
   
    // make queue leaky
    g_object_set(G_OBJECT(queue), "leaky", 2, NULL);
   
    // test for existence
    if (NULL == queue)
        g_error ("Couldn't create a queue\n");
    if (NULL == appSink)
        g_error ("Couldn't create an appsink\n");
   
    // add them into the bin
    gst_bin_add_many(GST_BIN(appSinkBin), queue, appSink, NULL);
    // link the internals of the appSinkBin
    if(gst_element_link(queue, appSink)){
        printf("MADE LINK FROM QUEUE TO APPSINK\n");
    }else {
        printf("LINK FROM QUEUE TO APPSINK FAILED\n");
    }

    // get a new src pad from the tee element
    srcpadvideo = gst_element_get_request_pad (videoSrcTee, "src%d");
    name = gst_pad_get_name (srcpadvideo);
    g_print ("DEBUG: A new pad %s was created\n", name);
    g_free (name);
   
    // get the sink pad on our queue
    sinkpadvideo = gst_element_get_static_pad(queue, "sink");
     
    // create a ghost pad on the bin to link the queue sink pad to the 
bin sink pad
    gst_element_add_pad(appSinkBin, gst_ghost_pad_new("videosink", 
sinkpadvideo));
   
    // we can unref our copy now that it has been added
    gst_object_unref(GST_OBJECT(sinkpadvideo));

   
    // set the new bin to PLAYING (not sure if I need to do this)
    //gst_element_set_state(appSinkBin, GST_STATE_PLAYING);
       
   
    // add the bin into our pipeline
    gst_bin_add(GST_BIN(pipeline), appSinkBin);
   
   
    // Link src pad of tees to sink pads of bin with filtered caps
    GstCaps *capsFilter  = gst_caps_new_simple ("video/x-raw-yuv",
          "format", GST_TYPE_FOURCC, GST_MAKE_FOURCC ('N', 'V', '1', '2'),
          "width", G_TYPE_INT, 736,
          "height", G_TYPE_INT, 480,
          NULL);
   
    sinkpadvideo = gst_element_get_pad(appSinkBin, "videosink");
    retVal = gst_pad_link(srcpadvideo, sinkpadvideo);
    gst_caps_unref (capsFilter);
    if(0 == retVal){
        g_print("DEBUG: MADE LINK FROM TEE TO APP SINK BIN\n");
    }else {
        g_print("DEBUG: LINK FROM TEE TO APP SINK BIN FAILED: %d\n", 
retVal);
    }
   

    // change state of main pipeline to playing
    //gst_element_set_state (pipeline, GST_STATE_PLAYING);
    gst_object_unref(GST_OBJECT(sinkpadvideo));
    gst_object_unref(GST_OBJECT(srcpadvideo));
   
    // store some elements for use in our glib callbacks
    JpegCapMgr.appSink      = appSink;
    JpegCapMgr.mainPipeline = pipeline;
   

    //createJpegEncPipeline();
 
}


Mike Mitchell wrote:
> Perhaps each branch of the Tee should have a queue like below. You 
> might also consider the sync=false on your display. 
>
> v4l2src--tee--queue--display
>                  |
>                  --queue--appsink
> *
> *
> *Mike Mitchell*
>
>
> On Fri, Oct 7, 2011 at 11:35 AM, Paul Stuart <Paul_Stuart at seektech.com 
> <mailto:Paul_Stuart at seektech.com>> wrote:
>
>     Hi,
>      I have a pipeline (defined in code) that looks roughly like:
>
>     v4l2src---queue--tee--display
>                      |
>                      --queue--appsink
>
>     So, basically tee'ing off the stream after the video source to
>     split it between the display and the appsink.
>
>     I have set appsink to drop buffers after the maximum number of
>     queued buffers is met.
>
>     If I replace appsink with fakesink, my pipeline runs fine, but
>     when I use appsink, I get a frame through to the display and then
>     the whole thing freezes.
>
>     Would one expect this to work? Maybe I am missing some fundamental
>     understanding of tee's and appsink.
>
>     Thanks,
>     Paul
>
>
>
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>