gstreamer C API

[R C]

ever had that situation where you have been looking for an answer and 
right after you ask, you find it?


so,  thanks..  but never mind.


Ron

On 5/31/19 5:02 PM, R C wrote:
>
> Hello,
>
>
> I have been playing with the "basic tutorial" C API a bit, and can 
> create a stream in c code. However, when the strea is running, how can 
> I quit/terminate that stream?
>
>
> For example,  basic tutorial 3:
>
>
> After creating a pipeline, one can start it. Then there's a loop that 
> listens for msgs from the 'bus', in a loop. Whenever there is a msg, 
> the loop runs through a switch, and and listens for a new msg again.
>
> I want to create "some sort of event"  that terminates that loop (for 
> example existence (or not) of a lock file.).
>
> (or can I create a handler, set an option, that will make 
> gst_element_get_bus(..)  return, even if there isn't a msg, with an 
> empty msg or so?  (I am fairly sure, gst_element_get_bus, is not 
> returning and only will if there is a msg waiting.)
>
>
> Here's a/the code snippet from the basic tutorial 3 example:
>
>   /* Start playing */
>   ret = gst_element_set_state (data.pipeline, GST_STATE_PLAYING);
>   if (ret == GST_STATE_CHANGE_FAILURE) {
>     g_printerr ("Unable to set the pipeline to the playing state.\n");
>     gst_object_unref (data.pipeline);
>     return -1;
>   }
>
>   /* Listen to the bus */
>   bus = gst_element_get_bus (data.pipeline);
>   do {
>     msg = gst_bus_timed_pop_filtered (bus, GST_CLOCK_TIME_NONE,
>         GST_MESSAGE_STATE_CHANGED | GST_MESSAGE_ERROR | GST_MESSAGE_EOS);
>
>     /* Parse message */
>     if (msg != NULL) {
>       GError *err;
>       gchar *debug_info;
>
>       switch (GST_MESSAGE_TYPE (msg)) {
>         case GST_MESSAGE_ERROR:
>           gst_message_parse_error (msg, &err, &debug_info);
>           g_printerr ("Error received from element %s: %s\n", 
> GST_OBJECT_NAME (msg->src), err->message);
>           g_printerr ("Debugging information: %s\n", debug_info ? 
> debug_info : "none");
>           g_clear_error (&err);
>           g_free (debug_info);
>           terminate = TRUE;
>           break;
>         case GST_MESSAGE_EOS:
>           g_print ("End-Of-Stream reached.\n");
>           terminate = TRUE;
>           break;
>         case GST_MESSAGE_STATE_CHANGED:
>           /* We are only interested in state-changed messages from the 
> pipeline */
>           if (GST_MESSAGE_SRC (msg) == GST_OBJECT (data.pipeline)) {
>             GstState old_state, new_state, pending_state;
>             gst_message_parse_state_changed (msg, &old_state, 
> &new_state, &pending_state);
>             g_print ("Pipeline state changed from %s to %s:\n",
>                 gst_element_state_get_name (old_state), 
> gst_element_state_get_name (new_state));
>           }
>           break;
>         default:
>           /* We should not reach here */
>           g_printerr ("Unexpected message received.\n");
>           break;
>       }
>       gst_message_unref (msg);
>     }
>   } while (!terminate);
>
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