CODEWITHSUNDEEP
pluginsgstreamer
Kranti
Kranti

Reputation: 192

GStreamer - Sample Plugin

I am a newbie in gstreamer and trying to develop a sample plugin for captions decoding.

I have downloaded the gStreamer Plugin template: based on this information.

When I launched the plugin from command line, it is working fine.

I wrote a sample application to verify the plugin. But now, I am facing a problem in setting pipeline state to PLAYING. Below is the code snippet

Any inputs would be of great help.

Thanks in advance, Kranti

gst_init(NULL, NULL);

loop = g_main_loop_new (NULL, TRUE);

g_print("\n Gstreamer is Initialized and Created the loop ");

pipeline = gst_pipeline_new ("pipeline");

source = gst_element_factory_make ("filesrc", "source");

filter = gst_element_factory_make ("myfilter", "testfilter");

sink = gst_element_factory_make ("fakesink", "sink");

if((NULL != pipeline) && (NULL != source) && (NULL != filter) && (NULL != sink))
{
    g_print("\n Successfully created the factory elements ");

    g_object_set(G_OBJECT (source), "location", fileName, NULL);
    g_print("\n Set the file name \n");

    g_object_set(G_OBJECT (filter), "silent", 1, NULL);
    g_print("\n Set the silent type \n");

    /* we add a message handler */
    bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline));
    bus_watch_id = gst_bus_add_watch (bus, bus_call, loop);
    gst_object_unref (bus);
    g_print("\n Created bus and a monitor to watch it");

    gst_bin_add_many(GST_BIN(pipeline), source, filter, sink, NULL);
    gst_element_link_many(source, filter, sink);
    g_print("\n Added and Linked the factory elements");

    g_signal_connect (filter, "pad-added", G_CALLBACK (on_pad_added), filter);

    g_print ("Now reading: %s\n", "test.txt");
    g_print ("Setting the pipeline state to PLAYING ");
    ret = gst_element_set_state (pipeline, GST_STATE_PLAYING);
    if(ret == GST_STATE_CHANGE_FAILURE)
    {
        g_print("\n Failure in setting pipeline state to PLAYING \n");
    }

    else
    {
        g_print("\n Successfully set the pipeline state to playing \n");
    }
}

else
{
    g_print("\n Failure in creating factory elements");
}

Upvotes: 1

Views: 4613

Answers (1)

Kranti
Kranti

Reputation: 192

After trying with few examples on gstreamer elements, found the problem.

Apart from filesrc, filter, fakesink:: If I add 'decoder' element also to the pipeline, then I am able to change the state to PLAYING

But why is that required - I am still trying to figure it out

And sometimes, the name used to create pipeline is also causing problems: Better to use some unique name rather than pipeline in gst_pipeline_new ("pipeline");

Upvotes: 1

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