[VDPAU] VP8 support in the VDPAU interface

[Younes Manton]

On Fri, Mar 2, 2012 at 7:29 PM, Stephen Warren <swarren at nvidia.com> wrote:
> Younes Manton wrote at Wednesday, February 29, 2012 3:38 PM:
> ...
>> Pretty much. You also have to watch out for the fact that every key
>> frame can specify a new frame size, and the decoder is expected to
>> scale all frames to the video's natural dimensions as required.
>
> The way I've seen this handled in APIs before is that the application
> allocates all surfaces and decoder objects based on the maximum size
> expected from the stream, and when a smaller picture is encountered,
> everything can just use a smaller section of the surfaces. That way,
> no dynamic re-allocation is required mid-stream.

True, unless you have stricter requirements imposed on you by your
hardware. But I guess decoders can create and keep scratch surfaces
around internally in that case.

> That said, how common is this feature? IIRC, one of the formats VDPAU
> already theoretically supports this feature but we haven't seen any
> demand to expose it in VDPAU due to lack of practical uses of it.
>
> --
> nvpublic
>

I don't have any numbers, but resizing is enabled by default in
Google's reference encoder, for what that's worth. Given that it's the
only functional encoder out there at the moment, and given VP8's focus
on web and streaming, I would expect it to be more common than not at
lower bit rates. That's just my intuition though...