[vlc-devel] [PATCH 00/17] Restart the display module on format changes

[Romain Vimont]

On Sun, Nov 22, 2020 at 11:08:33AM +0200, Rémi Denis-Courmont wrote:
> Le perjantaina 20. marraskuuta 2020, 16.44.50 EET Steve Lhomme a écrit :
> > The display may be able to cope with the
> > change but in case it doesn't we need to restart the display.
> 
> That's not how we usually solve that problem. As was already mentioned at the 
> last workshop, we already have a simple and robust solution for that, that has 
> been used for years. The display requests up-front whatever format is most 
> convenient, and lets the the filter chains figure insert any necessary 
> conversion.

That's stupid to add a converter if a filter outputs a format that can
be handled directly by the vout display.

The display sometimes do not have a "most convenient format". For
example, the OpenGL display doesn't care if it receives I420, NV12 or
RGBA for example. Adding a converter to match the decoder format (which
is meaningless) is a pure waste.

Moreover, it breaks use cases like a filter producing hardware pictures
(opaque) that could be consumed directly by the vout display.

The display should not even know what the format produced by the decoder
is, what matters is the format of the pictures it actually receives.

Regards