[vlc-devel] [PATCH v4] linux: kernel mode setting (KMS) vout plugin

[Juha-Pekka Heikkilä]

Thomas Guillem kirjoitti 29.6.2018 klo 16.12:
> 
> 
> On Thu, Jun 28, 2018, at 14:33, Juha-Pekka Heikkila wrote:
>> On 26.06.2018 16:08, Thomas Guillem wrote:
>>> Hello,
>>>
>>> This plugin is well written. This is a very good start for DRM support into VLC. Personally, I would love to have OpenGL support with DRM, by using our OpenGL vout with a DRM window plugin and the EGL DRM extension.
>>>
>>
>> I was earlier talking with Remi about this, I see this kind of change as
>> 'v3' of this plugin..as in v1 is this bare bones working on with the
>> basics. If there are special nuances found in some platform which I
>> don't have access it will be easier to hunt down and fix problems. V2 is
>> where mix in DRM features which can make a difference. At least with
>> scaling done on display HW can be made gains on power usage as well as
>> performance and its all totally free. V3 would be where add features
>> which start to change things. Though, I still don't know what is the
>> benefit of having OpenGL here? Remi tried to explain it to me but I
>> understood from him the gain is limited because DRM is full screen only.
> 
> We prefer having a GL, D3D (or VK soon) based vout in order to apply GPU filters, like the one used to render 360° videos for example.
> A vout without shaders won't be capable to render such videos in a good way.
> 
>>
>>> I was able to test it and have one remarks:
>>>
>>> Why do you set the DRM master mode (drmSetMaster()) ?
>>> It forces to run VLC as root. I tried to remove this part and was able to run your plugin as a normal user (with video group perm).
>>>
>>> Maybe you should not fail if drmSetMaster fails ?
>>>
>>
>> I had chitty chatty with my friend who know how DRM rights management
>> work and it turn out I can just drop the request for becoming drm
>> master, these rights are given automatically for my process or otherwise
>> I get error on one of my drm requests. This will also drop need for
>> root. I still need to try on how it work out in reality.
> 
> So, I can remove this master part and push ? Agree ?
> 

Agree. Let me know after you've pushed.

/Juha-Pekka