[Interest] qmediaplayer on raspberry stretch (and modified stretch)

[maitai]

Hello,

I have an application running on Raspberry/Stretch supposed to play some 
wav files. On RPI basically for sound you can choose between HDMI or 
Jack output. Stretch by default does not come with pulseAudio, so it is 
only Alsa.

Actually there is no problem with a "pure" Stretch installation, and 
QMediaPlayer plays the sound where it should, according to the system 
setting HDMI or Jack. If you set QT_DEBUG_PLUGINS=1 you can see an error 
concerning pulseAudio (which is normal since not installed), but it 
plays the sound nonetheless.

Unfortunately some users do not run a pure Stretch, but a special 
distrib (openPlotter) based on Stretch (again without pulseAudio). And 
when running there, the sound is always directed to HDMI, and never to 
the jack. All other applications (not qt-based) play the sounds on the 
Jack, but qt for some reason always plays it on hdmi. All messages from 
QT_DEBUG_PLUGINS are exactly the same, as well as the list of sound 
devices, default, etc.

I have tried many things (including installing pulseAudio), with no 
luck.

Any clue where to search?

Thanks
Philippe.