Re: FW: Loss concealment with SBC codec

"Brad Midgley" <[email protected]>
Newsgroups gmane.linux.bluez.devel
Message-ID <[email protected]>
Hey

> I'm not a codec guru, but my experience with SBC has not been wonderful.

the codec settings may make a difference here. 4 subband-encoded audio
sounds better. There are also parts of the code we will target for
better numerical accuracy once some bugfixes are complete.

for devel-related issues, see http://wiki.bluez.org/wiki/SBC

> (Does the Bluetooth stack have a feature to swallow SBC coded material
> directly, rather than insisting that the client decode SBC to raw, then the
> audio service re-codes raw to SBC?)

yes. If you use gstreamer, you can separate a2dp transmission from the
codec. It can accept sbc coded material and with a gstreamer patch it
can accept mp3 material (provided your headset has an mp3 decoder).

> > If the CRC8 is wrong, does sbc_decode function conceals the lost frame? If
> > not, did you hear anything about a packet loss concealment algorithm for
> > SBC? Any work on that?

there is no attempt at packet loss concealment, but we're not opposed
to the idea :)

-- 
Brad

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