[XviD-devel] reduced resolution VOPs (rrv) and all sort of things

Marco Al xvid-devel@xvid.org
Sat, 7 Dec 2002 00:38:52 +0100


Marc FD wrote:

> someone else wrote:

>> B-VOP are not subject to
>> rrv coding (I wonder why...).

They are less relevant to realtime coding, and since rrv/drc is only part of the
advanced realtime simple profile ...

> for me it makes sense...
> for low motion, where you can notice a lot of
> details, bvops have very accurate prediction
> and they'll never be used as references.
> for high motion, reduced-ivops will contain
> a _lot_ of texture data (many intraMBs and
> complex interMBs) so scaling the texture
> will reduce a lot the texture data to encode,
> but it'll be somehow better than using too
> big quantizers, because following frames
> will have better prediction.
>
> i'm totally wrong or it makes sense ?

The theory is that the motion is such that no good prediction can be made at
all, the information encoded in RRVs is supposed not to "live" long enough for
you to notice the difference.

Ideally you would look ahead to see how much the next (couple of) frame(s) will
change, if there is a very high total distortion (or an i-frame) coding the
present VOP at reduced resolution might make sense.

Marco