On Thu, Jun 14, 2012 at 08:55:59AM +0200, Gerd Hoffmann wrote: > Hi, > > >> I suspect there is no way around resampling support though. We'll need > >> it for compatibility reasons, so sound keeps working if only one side is > >> able to operate at 48 kHz. > > > > The ability to resample OTOH probably isn't a silly thing to have, and > > can be fairly easily set up as an inline filter that is switched out > > if you really don't need it. > > > > Just to be clear about this though, there is actually no reason that > > both sides of the link need to use the *same* sample rate, even without > > a resampler. > > > > For instance you can perfectly well push an 8kHz stream into opus, and > > decode that as a 48kHz stream at the other end, or vice versa, without > > resampling, for any integer fraction of 48k down to 8. Or just because > > one end needs to resample from 44.1 to 48, it doesn't prevent the other > > side from still natively using 48k etc. > > Ah, ok, so opus is different from mp3 here. So you could "reample" > using opus? i.e. have one side feed 44.1 into opus encoder, then send > opus over the wire, have the other side decode 48 kHz from opus? >From 44.1 you'd still need to externally resample to one of 8, 12, 16, 24, or 48k - but you can put any of those rates in, and take any of those out again without them needing to be the same. So only endpoints actually needing an 'oddball' rate would need a resampler to get them, they wouldn't force the other end to also support and use that rate as well. > Is that true for celt 0.5.1 too btw? Unfortunately no. For celt you compose your own 'mode' and that mode essentially defines the bitstream. Different modes make different bitstreams so you need to decode with the same mode you encoded with. For opus, the emphasis on "everything should be interoperable" came to the fore, so from the user visible side there is only one mode, that supports multiple rates/frame sizes/channel counts. Ron _______________________________________________ Spice-devel mailing list Spice-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/spice-devel