[vlc-devel] [PATCH v2 1/3] video_output: don't use the private pool for the blend picture

[Steve Lhomme]

On 2020-08-19 22:23, Rémi Denis-Courmont wrote:
> Le lundi 17 août 2020, 17:32:59 EEST Steve Lhomme a écrit :
>> Create one on the fly each time. We don't need to preallocate some
>> pictures if we're never going to use them. Also we don't to know the target
>> format in advance.
> 
> Allocating pictures repeatedly might be slow though. It might be safer to
> allocate a small (really private) pool when the display cannot blend.

The advantage of not using a pool is that in push you have to care if 
the format changes in the middle. The direct allocation will always be 
right.

We already have all filters doing a picture_NewFromFormat by default, so 
I don't think it's a stretch to do it here too (it's an different kind 
of filter where the output allocation is done outside of the filter).

Later we can improve this by using a picture pool, but it should be 
improved to handle format changes and with a dynamic size (a filter that 
never use more that 1 or 2 pictures at a time should not allocate 3 or 
more).

So, if anything, this patch fixes the vd->source format changes that is 
currently not handled when blending.