[theora-dev] litheora encoding speed, was: Ogg files incompatible

[Basil Mohamed Gohar]

On 02/12/2010 05:13 PM, Id Kong wrote:
> > Date: Fri, 12 Feb 2010 11:19:10 -0500
> > From: xiphmont at xiph.org
> >
> >
> > There's a better way than using an old libtheora. We anticipated the
> > need for continued compatability with VP3 and the new encoder can be
> > run in VP3 compat mode. In this mode it will not use any features
> > that weren't available in VP3. This obviously penalizes efficiency,
> > but it does work.
>
> I was wondering what that VP3 compatibility constant was for!  It all
> makes sense now...
> Thank you very much.  My videos now work in every respect!  It's a
> shame about the efficiency but it's better than not having video at all...
>
> Actually, I have another (hopefully final) issue to deal with
> involving a different kind of efficiency.  My application is encoding
> in real time and was computationally expensive to begin with, even
> before libtheora!  Obviously libtheora adds enormous CPU time, perhaps
> even more than the original application alone!
> How much effort was put into computational efficiency for libtheora?
>  Do you think there's much room for improvement?  Do you (or anyone,
> please!) think you know somewhere that can improved in this regard?
> Thank you so much...
Performance optimization is definitely a priority for the Theora devs
(amongst which I am not...yet, but I don't mind speaking for them!), but
quality has been as well.  Real-time encoding of Theora is not currently
as important for most uses as final quality and efficiency are, because,
for the most part, videos are going to be encoded once and then used
many times thereafter, so encoding time isn't such a big factor in
usability.

Incidentally, libtheora is still faster than, for example, x264 is for
encoding, and decoding Theora video with libtheora is likewise faster
than decoding H.264 video.  At least, this has been my personal
experience with my own personal test samples.
>
> >
> > Plenty of people are using the new spec, but ffmpeg was very very late
> > to the party.
>
> I'm sorry, I thought that ffmpeg was "it."  I mean, does anyone not
> use it?  What's the alternative?  I get the impression that integrated
> video encoding is not commonly needed so people just used these
> established command line utilities...
I think Monty's reply before this post addressed your concern.  ffmpeg
is "it" for certain things, but Theora development and support have not
been as much a priority for the core ffmpeg developers as has been, say,
support for H.264.  I do not think they are against it, so to speak,
they just don't care much for it.  I'm sure if someone else put in the
work, they'd accept it, though, which has been the case for most of the
recent Theora improvements, if I'm not mistaken.
>
> Of course, many thanks to Tim, who answered all my initial questions...
And thank you for choosing a free-as-in-freedom format for your video
needs!  The world appreciates your decision!