[FFmpeg-devel] donation for snow

Jason Garrett-Glaser darkshikari
Thu Nov 6 19:30:58 CET 2008


On Thu, Nov 6, 2008 at 10:04 AM, Lars T?uber <lars.taeuber at gmx.net> wrote:
> Good evening.
>
> On Tue, 4 Nov 2008 21:10:48 +0100 Michael Niedermayer <michaelni at gmx.at> wrote:
>> On Tue, Nov 04, 2008 at 11:38:34AM -0800, Jason Garrett-Glaser wrote:
>> > Motion estimation in Snow is still more advanced than x264 in some
>> > respect; Snow has iterative ME, x264 doesn't.
>>
>> yes but iterative ME is slow and some say, being too slow ...
>
> Is this true for encoding only or for decoding to? I don't care for encoding speed, decoding speed is by far more important. But other users might think very different.
Encoding only, and personally I'd say its not too slow at all; its
just really slow in Snow because the optimal comparison metric for
Snow is the forward wavelet transform, which is not assembly optimized
at all (only the decoding transform is).

>> > > Ive no doubt that snow could beat x264 given a few determined and smart
>> > > developers
>> > I highly, highly doubt this, assuming you stick to the basic current
>> > idea of Snow.  I don't doubt that you or I could make a better format
>> > than H.264 if I tried--there are dozens of places one could make
>> > improvements--but what I do doubt is the ability to make a better
>> > format *using overlapped wavelet*, since thousands of people have
>> > tried that for something on the order of two decades and failed
>> > miserably.
>>
>> I had no intent to stick to wavelets once someting else had been implemented
>> that work better, actually i was aware that existing wavelets with existing
>> ntropy coders perform poorly on inter frames before even writing the wavelet
>> code.
>
> Then what about using wavelets for intra frames only and other algorithms for the inter frames?

Because ordinary wavelets are even worse for intra coding than for
inter, since they don't have spatial prediction.

There are some ideas floating around in the realm of directional
wavelets and so forth, but nobody's come up with anything that can
beat spatial prediction yet, at least as far as I know.

Dark Shikari




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