[theora] Thusnelda Video Quality

Gregory Maxwell gmaxwell at gmail.com
Mon Mar 30 11:23:25 PDT 2009

On Mon, Mar 30, 2009 at 12:22 PM, Jason Self <jason.self at gmail.com> wrote:
> Wow.
> Let me say that again, just in case you missed it.
> Wow.
> The quality looks to be on par with what I get out of H.264, but
> Theora has the added benefit of free and open source software with no
> patent worries so I can use it with a clean conscience. Thanks,
> everyone.

I think we can comfortably say that the new behaviour doesn't suck.

But lets not allow our enthusiasm to make us sloppy: There is still
significant room for improvement.  If it is now as good as H.264 it
is likely that Theora only compares so well at particular (lower)
bitrates or against particular H.264 encoders.

Full H.264 is a more modern, more complex, more CPU hungry format. If
it doesn't edge out against Theora then there is a flaw in the H264 encoder.

*However* that edge isn't necessarily a big one. Most users don't care
about and won't notice a small difference in quality. (I'd suggest
your claim that Theora is as good is demonstrating that). … but loud
proclamations that Theora is as good are going to invite the people who
do care about those small differences to make a disproportionate
amount of noise.

Theora's strength is and will remain that it is free of encumbrance,
it's just that now (or soon) many more applications can enjoy that
advantage without a huge compromise in quality/bitrate.

I'd really prefer that the public sees this as "Theora: Free as always,
and now better quality." rather than "Theora: Still Not always as good as
H.264.".  Realistic expectations are important.

In particular, Theora's quality is limited on the high end and will
likely remain that way unless there is a non-backwards compatible
revision to the forma. It seems that as soon as you say 'quality'
people jump to doing high bitrate comparisons.

Don't let someone try to drag you into a comparison of 4mbit/sec
standard def video with Theora vs H.264. Thats not what Theora is
intended for and Dirac does that much better than Theora. If you
really don't care much about bitrate (i.e. movie copying rather than
webcasting), then you should be looking at Dirac rather than Theora. (While
Theora does low bitrates better than Dirac does)

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