QT Video error under Linux

[dresco]

The recent move to the Qt 5 MultiMedia framework appears to be causing a problem for Fedora 19.

The symptom is a hang in QVideoWidget() with the following output;

(GoldenCheetah:905): GLib-GObject-WARNING **: cannot register existing type `GstObject'

(GoldenCheetah:905): GLib-CRITICAL **: g_once_init_leave: assertion `result != 0' failed

(GoldenCheetah:905): GLib-GObject-CRITICAL **: g_type_register_static: assertion `parent_type > 0' failed

(GoldenCheetah:905): GLib-CRITICAL **: g_once_init_leave: assertion `result != 0' failed

(GoldenCheetah:905): GStreamer-CRITICAL **: gst_element_class_set_details_simple: assertion `GST_IS_ELEMENT_CLASS (klass)' failed

(GoldenCheetah:905): GStreamer-WARNING **: static caps 0x7fff8c71af90 string is NULL

(GoldenCheetah:905): GStreamer-CRITICAL **: gst_mini_object_unref: assertion `mini_object != NULL' failed

(GoldenCheetah:905): GStreamer-WARNING **: static caps 0x7fff8c71af10 string is NULL

(GoldenCheetah:905): GStreamer-CRITICAL **: gst_mini_object_unref: assertion `mini_object != NULL' failed

(GoldenCheetah:905): GStreamer-WARNING **: static caps 0x7fff8c71af90 string is NULL

(GoldenCheetah:905): GStreamer-CRITICAL **: gst_mini_object_unref: assertion `mini_object != NULL' failed

This appears be caused by Qt WebKit pulling in gstreamer 1.0, instead of gstreamer 0.10 that Qt MultiMedia wants.

I've been able to replicate the same error with the Qt5 videowidget sample app, by adding the following line to the makefile;

#LIBS          = $(LIBS) -lQt5WebKitWidgets -lQt5WebKit 

Not sure where to go from here though!..

[liversedge]

I'm going to make QT video optional - so you can build with VLC -or- QT video from QT5 onwards.
Will get fixed alongside #938.

[liversedge]

Updated code to allow GC_VIDEO_xxx where xxx is one of;
QT5 - use QT libs and native backend on win/linux with qt > 5.2.1
VLC - use VLC libs on win/linux (any qt version)
QUICKTIME - use QT on Mac (default on Mac)
NONE - do nothing

applied and tested in the following commits: fde9809 ddfdb78 and caa0b21

SO TO FIX THIS ISSUE BEST TO CONTINUE USING VLC ON FEDORA