[theora] I'm almost very impressed with theora 1.1 beta 3

[Basil Mohamed Gohar]

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On 09/16/2009 09:59 PM, Jim Darby wrote:
> Firstly I have to say that having just tried out theora 1.1 beta 3
> the improvement over the previous 1.0 is amazing. In my very
> subjective view it looks like the same quality for about half the
> bitrate and that's amazingly impressive. The results have for the
> most part been excellent and my congratulations to all concerned
> for there very hard work.
>
> There is (for me) only one serious problem remaining. As Monty
> points out in http://web.mit.edu/xiphmont/Public/theora/demo.html
> there is an issue with flat colour surfaces and gentle gradients.
> This is most annoying! For example, a video I was encoding the
> other day has a floor area that's pretty much just a plain polished
> black. When watching this there was very noticeable blocking
> artefacts on the floor that because of their nature proved very
> distracting.
>
> Is there any work going on in this area? It seems that even upping
> the bitrate significantly fails to solve this problem. Or are there
> any tweaks I can perform to help?
>
> Many thanks and keep up the good work!
>
> Jim.
Jim,

I've noticed the same thing myself, and it is quite distracting.  The
improvements in the high-frequency portions of a frame are phenomenal,
to say the least, but as you've pointed-out, in the more smooth areas,
blocking becomes quite obvious.

This, along with general encoder & decoder performance, are two areas
which, if improved, would make Theora quite competitive with MPEG4 ASP
and even H.264/AVC (at least in some areas).  In my informal (soon to
be formal, hopefully) testing, I found clips where Theora actually
exceeded the performance of H.264 (via the libx264 encoder in FFmpeg).

It's amazing, really.  Most other codecs would require a new,
incompatible version of a codec to get the kinds of improvements that
Theora has seen.  Kudos to the devs, really.  I wish them all the best
in their continued pursuit of a truly free (as in freedom) video codec.

- -- 
      Basil Mohamed Gohar
abu_hurayrah at hidayahonline.org
http://www.basilgohar.com/blog
basilgohar on irc.freenode.net
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