[Vorbis] Sharing encoders

[David Baelde]

Hi list,

I'm developping quite a complex system (namely liquidsoap,
http://savonet.sf.net project) which involves encoding many WAV
streams. Sometimes, all the streams are the same -- but it cannot be
known statically. For example, some user runs a radio which has three
channels, one playing hiphop music, one playing reggae music, the
third one switching from one of the two first to another. We're trying
to figure out how to improve the system, by sharing the encodings --
the system currently separately encodes the three channels.

Now for two more precise questions.

1) Suppose two outputs A and B are using the same vorbis encoder on
the same stream, and A wants to switch to some other stream. A needs
to flush its encoder. Is there any risk of simply flushing the
encoder, from the point of view of B ? For B, the stream doesn't stop,
and the encoder shouldn't be reset.

2) Another problem: A plays some stream using encoder E, and wants to
switch to another stream, also used by B through encoder F. From the
point of view of A, can I safely concatenate the output of E and F ? I
guess no, but is it enough to impose that F has just been reset (and E
flushed) ?

I hope this is not too unclear ;) I would greatly appreciate any help,
or link to related questions. Providing these features would be really
great.

I'm also available for more explainations.

Thanks.
--
David