Deleting a MediaPlayer requires stopping the pipeline and deleting it; the call to gst_element_set_state (pipeline_, GST_STATE_NULL); is however hanging. Running this in a separate thread seems to fix the problem. It is not 100% sure however if the gst_object_unref ( GST_OBJECT (pipeline_) ); will be thread safe and not crashing...
2 new callbacks (PlayFastForward, PlaySpeed), modified Seek callback to take target time in seconds (instead of ratio of duration). Integrating this in Input Mapping GUI and Session saving.
All Stream report failure with logs, read in InfoVisitor for Sources. ImGuiVisitor for Sources also detect failure of source and its stream.
Cleanup of unused includes and functions.
The case of MISSING_PLUGINS for audio in gst discoverer should not prevent from decoding video stream in media. The failure of discoverer should only be in absence of video stream.