On Fri, Jun 15, 2012 at 11:17:34AM +0200, Gerd Hoffmann wrote: > Hi, > > > 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. > > Ok, so we must resample 44.1 anyway before encoding. > > >> 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. > > Ok, so it's easiest to simply not touch celt. > > So, how to go forward? spice-server gets a 44.1 stream from qemu today. > I think we should switch that to 48k. Needs changes in the sound > interface and in qemu. spice-server needs to be able to handle both old > (44.1) and new (48k) qemu. spice-server also needs to be able to handle > clients with different capabilities (possibly even at the same time if > multiclient is enabled, not sure multiclient support covers the sound > channel though). No sound channel for multiclient. > > So we'll need resampling support for both 44.1 -> 48k and 48k -> 44.1. > In the end we'll have the following cases, at the server side: > > old qemu, no caps [-> 44.1 pcm] > pass through pcm audio data as-is > > new qemu, no caps [-> 44.1 pcm] > resample 48k -> 44.1 > > old qemu, cap_celt > encode 44.1 celt > > new qemu, cap_celt > resample 48k -> 44.1, encode 44.1 celt > > old qemu, cap_opus > resample 44.1 -> 48k, encode opus > > new qemu, cap_opus > encode opus > > We might want to add: > > new qemu, cap_pcm48k > pass through pcm audio data as-is > > Long-term (new spice-server, new qemu, clients supporting opus) we'll > operate at 48k on the whole chain without resampling needed in the > spice-server. > > Client side is easy, we just decode stuff and pass it on to pulseaudio > to deal with it. > Sounds like a good plan. > cheers, > Gerd > _______________________________________________ > Spice-devel mailing list > Spice-devel@xxxxxxxxxxxxxxxxxxxxx > http://lists.freedesktop.org/mailman/listinfo/spice-devel _______________________________________________ Spice-devel mailing list Spice-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/spice-devel