The play video interface displays blank screen on resume

[Pat McGowan]

[Procedures]
1.Play a video from video screen
2.Press power key during launch media player
3.Press power key again and unlock the DUT
4.Check the video play view

[Expect results]
The video should playback normal
[Actual results]
The audio and progress bar display normal, but the Playback view display blank
or
the entire screen is blank with backlight
or
the DUT resumes right away and then the screen is blank when unlocked
or
the entire screen is black and does not respond to input but everything is running

[Reproduce]
Need to press the button just as the app is starting

[Jean-Baptiste Lallement (jibel)]

A black overlay is displayed on top of the greeter, and the phone stops responding to user input. If I connect with adb and kill mediaplayer, the overlay disappears and reveals the greeter.

[Jim Hodapp (jhodapp)]

That's interesting, I couldn't reproduce this yesterday but thanks to your comment I realized it might be because I was testing with the device connected to USB (and thus charging). The wakelocks behave differently in this situation. I'll try to reproduce again.

[Jim Hodapp (jhodapp)]

Verified that this is only reproducible when the device is not plugged in and charging.

[Jim Hodapp (jhodapp)]

The issue is that mediaplayer-app is missing the app suspend signal and so it fails to call pause. This results in the player playing when the screen is locked but the surface texture for rendering video not instantiating correctly. The fix will involve something to ensure that mediaplayer-app is able to consistently signal media-hub to pause playback before the system goes to sleep.

[Jim Hodapp (jhodapp)]

Same problem as this bug: https://bugs.launchpad.net/ubuntu/+source/camera-app/+bug/1398436

[Jim Hodapp (jhodapp)]

Also see bug: https://bugs.launchpad.net/ubuntu/+source/unity8/+bug/1309915