[mythtv] #13351: Add OpenGL ES configurability/autodetection

[Peter Bennett]

On 11/27/18 7:31 AM, Piotr Oniszczuk wrote:
>
>> Wiadomość napisana przez Stuart Auchterlonie <stuarta at squashedfrog.net> w dniu 27.11.2018, o godz. 13:01:
>>
>>> 2.Working myth when OS provides _only_ OpenGL ES
>>>
>> I thought we already had this on embedded platforms
>> such as the rpi?
> Well - correct me if I’m wrong:
>
> For rpi we need to distinguish 2 cases:
> 1) GL provider is by brcm BLOBS
> 2) GL provides is by FOSS software (mesa 18+)
>
> Ad1)
> In this case afaik there is no GL Desktop at all, as there is no possibility to build Qt with OpenGL Desktop.
> IIRC this is because low-level api provided by brcm blobs are not compatible with Qt GL integration sub-layer.
> By this on brcm blobs we have only 2 options for painting in myth:
> -EGLFS (if Qt build correctly for this)
> -Qt
>
> Ad2)
> Mesa 18+ is able to provide GL (via v3d vc4) at Desktop GL and GLES levels.
> This works perfectly and I have rpi fully working with OpenGL Desktop.
> GLES however is not possible due: https://github.com/MythTV/mythtv/blob/9c940817da8aa001219bbded26b26f12a7b364b7/mythtv/configure#L6566
> With #13351 have fully working GLES on rpi (including 2G accell via glamour and GL playback).
> SD plays nicely - but for HD rpi’s cpu is too weak...
> To get HD playback we need video decode hw accell - and afaik only solution is v4l2 m2m.
> (OpenMAX IL is not option due low-level api provided by brcm blobs incompatibility).
>
On the raspberry pi builds that I do with mythtv-light, opengl is 
disabled except for one small place. It uses opengl es for the OSD. This 
is a hybrid setup. The main GUI uses qt under x11, but the playback uses 
openmax full screen api and the playback OSD uses the full-screen opengl es.

I will test your patches with all of the builds and see if everything works.

Peter