[pulseaudio-discuss] [WIP] Passthrough support

[Arun Raghavan]

On Mon, 2011-03-14 at 13:43 -0500, pl bossart wrote:
> > I forced support for pulse1.0 it by hand in config.h and found the
> > same problem with the headset. Trying to figure out the differences
> > with my initial patches. there must be a step missing.
> 
> ok, found a solution, see diff attached. For some reason the
> setup_ad2p() did both the SBC and MPEG configuration. Adding a test
> for the mode solves the issue, probably there was a buffer overflow or
> something bad.

Thanks! I was getting around to this view as well - the
set_configuration seems to be failing because we're trying to set MPEG
caps on the SBC seid.

> playing with SBC and MPEG works fine now, meaning that the negotiation
> works well depending on the payload.
> but when I try to go back to PCM/SBC the second time I get the
> following assert in pulseaudio (see gst log below)
> E: module-bluetooth-device.c: Assertion 'u->write_memchunk.length ==
> u->block_size' failed at
> modules/bluetooth/module-bluetooth-device.c:1519, function
> a2dp_process_render(). Aborting.
> 
> I'll let you debug this one, should be easier :-)

:) ack.

> Other things I noticed: the volume is much higher in passthrough mode,
> maybe we need to find a way to set the volume on the headset to match
> the volume used for PCM. Also I heard some high-frequency modulations,
> typically coding noise, maybe there's still something fishy during the
> mp3 decode part.

I get this sort of thing on, as far as I can tell, one channel as well.
I figured the decoder on the CSR chip wasn't that great.

Cheers,
Arun