[vlc-devel] [PATCH v4 1/7] libvlc: allow selecting the video hardware acceleration

Steve Lhomme robux4 at ycbcr.xyz
Mon Mar 16 09:52:40 CET 2020

On 2020-03-13 16:45, Rémi Denis-Courmont wrote:
> Le perjantaina 13. maaliskuuta 2020, 14.28.32 EET Steve Lhomme a écrit :
>> Pass a string matching one of the decoder device strings.
> That's moving the problem. Now somebody hard-codes a string value, ends up
> breaking portability to other platforms or to future versions. And this is not
> a theoretical problem. I've seen a number of LibVLC app devs device to force
> acceleration on or off under false impressions.
> If you make a LibVLC app for embedded devices, then sure, by all means, fine
> tune hardware acceleration, or really anything you want, to the hardware.
> Though that probably does not belong in the official upstream.
> But if you're not doing "embedded", but just regular software for installation
> on hardware not in your control, then you really should not touch this. LibVLC
> might not know perfectly well what acceleration to use or not to use, but it
> knows better than you.

I agree with everything you said. That doesn't mean we should not 
provide an API for those who want to tweak things. It would be like 
saying we remove the --dec-dev option in VLC because users are stupid 
and might use it incorrectly.

There are already these warnings in the function documentation:
* Not all videos might be decoded through the selected mode depending on 
* hardware and the source material.
* Selecting an unsupported mode for the platform or video source will 
* in the video being decoded/processing in software.

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