[gst-devel] how to make gstreamer run in separate thread

[Alexey Chernov]

Thank you guys for support, I finally managed to make gstreamer process 
callbacks in separate thread. The solution was to set bus handler with 
gst_bus_set_sync_handler() instead of gst_bus_add_watch() as wl2776 proposed, 
special thanks for him. So here're some things which I found out from this 
case:
1. Qt actually dispatches glib events and no additional g_main_loop_run() is 
necessary for Qt applications.
2. Qt seems to create separate glib context for glib objects which are created 
in separate QThread objects.
3. To make callbacks be called in separate thread where the certain gst 
objects were created you need to set them as a handler with 
gst_bus_set_sync_handler() to make them processed in the context of certain 
objects and not in the main context.

Stefan is right that it's often unnecessary to run gst part of application in 
its own thread, but in some cases especially when performance depends on some 
drivers of special hardware (tuners, cameras etc.) it could be useful to 
separate threads.