[vlc-devel] [RFC 0/1] Let decoders decide over DPB size.

[Julian Scheel]

Am 24.08.13 12:43, schrieb Rémi Denis-Courmont:
> Le vendredi 23 août 2013 20:52:58 Julian Scheel a écrit :
>>> I don't mind specifying the DPB count in the decoders, as it would be
>>> architecturally cleaner than doing so in the core. But I dislike the
>>> notion
>>> that it would be used to promote indirect rendering over direct rendering.
>>>
>>> Regardless, your patch seems incomplete / under-implemented.
>>
>> I would see some need of extension for the vdpau plugin to announce it's
>> actually required dpb size.
>
> I don't see that. For VDPAU, pictures are just picture_t structures. The DPB
> size is overestimated, but the overhead is negligible.

That overhead is not negligible if you can not be sure to have enough 
memory for the upper limit of the decoder. If you have hardware which 
only supports some profiles this might not be the case. Admittedly this 
is not the case for any hardware whose drivers implements VDPAU as of now.

>> Would you see any other decoder modules that
>> would actually required the picture pool to include dpb as of now?
>
> Almost all decoders would need to be updated to set their respective DPB size
> explicitly.

What about keeping a default of 2, as it is with the current code, and 
let the decoders explicitly override when needed? -> 18 for H264 
decoders, 3 for VP*.

-Julian