Is it possible to turn a mp3 or a mpc into a ogg without decoding?
Thanks

If you mean without having the big intermediate .wav file then: yes, have a look at xcLAME at robertos http://www.inf.ufpr.br/~rja00/index.html

But of course the decode step is still there. It's just done on the fly.

To transcode without decoding, the formats must be similar like for example MP2 <-> MPC. MPC, MP3 and OGG are too far apart.

/Erik

You can't transcode one format into another.
Even it is not possible to transcode from
MP2 to MP1. The formats must be so similar
that the formats must be designed for lossless
transcoding.

You need the same transform, the the same
blocking, the same channel coupling, the same
quantization.

ok. I was a bit mislead about mpc then... What kind of transcoding is it you mention here?

http://www.uni-jena.de/~pfk/mpp/sv8/profile.html

/Erik

SV8 can have 4 submodes, 3 are currently defined.

- SV7 mode
- SV8 mode
- MPEG Layer 2 mode
- reserved

This costs 77 bps. SV7 transcoded SV8 and
Layer II transcoded SV8 has a fully different
stream syntax, but uses the same lossy transforms
as SV7 and Layer II, so lossless transcoding
is possible (Layer II -> SV8 also saves a
lot of space and can be converted back).

If Layer II were designed carefully this
would also possible form Layer I -> Layer II
transcoding and Layer II would also benefits
from that for highly transient music, were
Layer I is better than Layer II is better than
layer III.

just to clarify, those are the proposed specifications for streamversion 8, while we are still on streamversion 7.