[Development] Video playback on Ubuntu 16.04

[Massimo Callegari]

Hi everyone,

is it just me or QtMultimedia 5.6.0 video playback is quite broken on Ubuntu 16.04 ?

I think the reason is that Qt 5.6.0 (and 5.7.0 as well) are still built against gstreamer 0.10, which is quite obsolete now.
In fact, I built Qt 5.7.0 myself with gstreamer 1.0 and video playback works as expected.

On Ubuntu 16.04, gst 1.0 is the default, and even if I install the available gst 0.10 packages, video playback still doesn't work, displaying a colorful number of error messages such as:

10:03:11:massimo:player > ./player 
Cannot connect to server socket err = No such file or directory
Cannot connect to server request channel
jack server is not running or cannot be started
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for 4294967295, skipping unlock
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for 4294967295, skipping unlock
GStreamer; Unable to pause - "file:///home/massimo/Scaricati/Star Trek Trailer 3 HD 720p (720p).mp4"
GStreamer; Unable to pause - "file:///home/massimo/Scaricati/Star Trek Trailer 3 HD 720p (720p).mp4"
Warning: "No decoder available for type 'video/x-h264, stream-format=(string)avc, alignment=(string)au, level=(string)3.1, profile=(string)main, codec_data=(buffer)014d401fffe10016674d401fe88028022d0800001f480005dc0078c1889001000468ebef20, width=(int)1280, height=(int)544, framerate=(fraction)45000/1877, pixel-aspect-ratio=(fraction)1/1'."


Problem is that gst 0.10 plugins-bad/ugly packages are not available anymore on 16.04. There is only gstreamer0.10-plugins-good.

My request is: can you please consider to drop gst 0.10 and build by default with gstreamer 1.0 ?
At least for Qt 5.7.0, even though since Qt 5.6 is a LTS and Ubuntu 16.04 is a LTS, I would say Qt 5.6.1 should bring this change too.

In the end, it's easier for a Ubuntu 14.04 user to install gst 1.0 rather than for a Ubuntu 16.04 user to install gst 0.10.

Thanks,
Massimo