[theora] Indexing Ogg files for faster seeking

[Chris Pearce]

On 07/11/09 20:46, Jason Self wrote:
>
> Here's a 30 second clip of something I grabbed from television for
> testing. ffmpeg2theora won't create an index because it claims that
> the file has no duration. That isn't necessarily a reflection on the
> indexing process, but it might be nice if ffmpeg2theora's handling of
> the file could be improved so that it knows the duration and could
> then index it.
Yeah, for some reason that's beyond me at the moment, we can't get the 
duration of that file. I wonder if we could get timing information when 
running in --two-pass mode and get the duration that way?

>   Other video encoders (such as HandBrake, which also
> makes use of the FFmpeg project) provide the duration so I hope that
> it's doable.
>
> http://aws.bluehome.net/test.mpg
>
> I also ran into another file that I received an error about
> miscalculating the index or something. Unfortunately, it seems that
> I've since deleted that file. I will see if I can recreate the problem.
>    

A testcase would very helpful. :) I'm actually kinda worried about 
hitting this error,  it could be caused by us getting an incorrect 
duration, and that sounds like fun to fix.


Chris P.