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

[Steve Lhomme]

On 2020-03-16 17:41, Rémi Denis-Courmont wrote:
> Le maanantaina 16. maaliskuuta 2020, 10.52.40 EET Steve Lhomme a écrit :
>> 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.
> 
> Yes it does mean exactly that. We have plenty enough support issues caused  by
> APis that are actually useful or are necessary for backward compatibility, not
> to add foot guns.
> 
>> It would be like
>> saying we remove the --dec-dev option in VLC because users are stupid
>> and might use it incorrectly.
> 
> No, that's very different. There is zero forward/backward/cross compatibility
> warranties with the command line.

I counted 201 instances of add_obsolete_bool/string/integer() in the 
code. 69 just in libvlc-module.c

That's code that is there to pretend the code does something it used to 
when in fact it does nothing.