[vorbis] Rgenerating headers

[Peter Maersk-Moller]

Hi

Segher Boessenkool wrote:
> Michael Smith wrote: 
>       > >So, back to my question - is there any reason why you shouldn't 
>       > >be able to completely regenerate the header packets/frames 
>       > >from what I have outlined ? 
>       > Unfortunately, yes. This requires that the _client_ have the encoder 
>       > as well. Worse, it requires that the client have _exactly_ the same 
>       > version of the encoder as the server. 
>       Worse still, some encoders generate their headers partly based on the 
>       actual audio encoded, not based only on the encoder settings. 

Which encoders. The ones from Xiph I have been using generate the headers
before audio data is available - and thanks for that.

>       Which is a good thing really (better compression). 

That was what I thought Vorbis did until I started using it.
Then I also realised that 5 secs, or 5000 secs if you like,
almost never will or can be representative for anything.
Just turn on the radio and listen for 5 secs and then try
to see if it will be representative for what you will
hear 60 secs or 600 secs later.

Kind regards
------------------------------------------------------------------------------
Peter Maersk-Moller
------------------------------------------------------------------------------
Ogg/Vorbis support for MPEG4IP and YUV12, XviD, AVI and MP4 for
libmpeg2. See http://www.maersk-moller.net/projects/
------------------------------------------------------------------------------
--- >8 ----
List archives:  http://www.xiph.org/archives/
Ogg project homepage: http://www.xiph.org/ogg/
To unsubscribe from this list, send a message to 'vorbis-request at xiph.org'
containing only the word 'unsubscribe' in the body.  No subject is needed.
Unsubscribe messages sent to the list will be ignored/filtered.