Re:Putting x264 developer's technical analysis of WebM into ...
by astrange on Saturday May 22, 2010 @10:41PM
(#1371619)
> though he does make a few minor technical blunders
Such as?
> I mean he says it's better than H.264 baseline. If you're watching it on an iPod or iPhone then that's the only profile they support. In other words Android phones will have better maximum quality video than Apple's. Is that part getting overlooked somehow?
"Better" doesn't mean "much better"; a better residual coder is useful, but H.264 has better reference frame system - On2 seems to love idiosyncratic systems which aren't as good - and much more flexible adaptive quantization. Which is the basis of x264's psy optimizations, so the same (fundamentally good) ideas probably can't be implemented as well.
> It's only a matter of time and at least the Xiph guys have experience of doing exactly this on a similar codebase and they've been working on VP8 for weeks already.
IIRC Theora barely implemented rate-distortion optimizations in the first place, let alone Psy-RD - you have to get that out of the way before you can do the really interesting things.
However, I don't think VP8 uses the weird Hilbert coding of the older system, so it might be easier to implement all of that. Besides, you can just copy it from x264.
Such as?
> I mean he says it's better than H.264 baseline. If you're watching it on an iPod or iPhone then that's the only profile they support. In other words Android phones will have better maximum quality video than Apple's. Is that part getting overlooked somehow?
"Better" doesn't mean "much better"; a better residual coder is useful, but H.264 has better reference frame system - On2 seems to love idiosyncratic systems which aren't as good - and much more flexible adaptive quantization. Which is the basis of x264's psy optimizations, so the same (fundamentally good) ideas probably can't be implemented as well.
> It's only a matter of time and at least the Xiph guys have experience of doing exactly this on a similar codebase and they've been working on VP8 for weeks already.
IIRC Theora barely implemented rate-distortion optimizations in the first place, let alone Psy-RD - you have to get that out of the way before you can do the really interesting things. However, I don't think VP8 uses the weird Hilbert coding of the older system, so it might be easier to implement all of that. Besides, you can just copy it from x264.