[theora] Add an intro to a theora file without re-encoding?

[yorn at gmx.net]

> Hi again Yorn,
> 
> I still have a problem with oggSilence... When I ask for a 6s duration,
> I get 05.942s instead.
>       $ ogginfo silence.ogg
>   11.
>       Processing file "silence.ogg"...
>   12.
>        
>   13.
>       New logical stream (#1, serial: 2864fb0a): type vorbis
>   14.
>       Vorbis headers parsed for stream 1, information follows...
>   15.
>       Version: 0
>   16.
>       Vendor: Xiph.Org libVorbis I 20070622 (1.2.0)
>   17.
>       Channels: 2
>   18.
>       Rate: 48000
>   19.
>        
>   20.
>       Nominal bitrate: 112.000000 kb/s
>   21.
>       Upper bitrate not set
>   22.
>       Lower bitrate not set
>   23.
>       User comments section follows...
>   24.
>               ENCODER=oggVideoTools 0.8
>   25.
>       Vorbis stream 1:
>   26.
>               Total data length: 616 bytes
>   27.
>               Playback length: 0m:05.942s
>   28.
>               Average bitrate: 0.829257 kb/s
>   29.
>       Logical stream 1 ended

What is not completely clear to me is the output of oggzinfo

Does it print the granual position of the last packet as playback length? If so, this is not the duration of the file, is it? I believed, the granual position for vorbis starts with 0 and is the "beginning" of the samples that are encoded within this packet.

Or am I wrong?

-Yorn