Arun Raghavan <arun.raghavan at collabora.co.uk> writes: > On Mon, 2012-12-17 at 21:49 +0000, Neil Jerram wrote: > [...] >> - load module-echo-cancel >> >> - do "paplay -d >> alsa_output.platform-soc-audio.0.analog-stereo.echo-cancel >> /media/card/Documents/audio/ogg/Do\ They\ Know\ It\'s\ Christmas.ogg" >> in one terminal >> >> - do "parecord -d >> alsa_input.platform-soc-audio.0.analog-stereo.echo-cancel >> --file-format=wav > record1.wav" in another terminal >> >> - speak into the microphone. > > In general, to start with, you should pick a recording of voice rather > than music since that's the sort of echo that is designed to be > cancelled. I've noticed varying degrees of success for music with speex > and much better success with the webrtc canceller, but starting with the > basics is better. Good point, thanks, I'll do that. Also I realise now that I really want the entire process of in-call audio routing to be running at 8000 only - because that's all I need for voice, and because I presume that should take less power than involving higher rates. Overall, for this phone, I have two audio scenarios. - In-call audio, which can/should all be handled at 8000. - Media playback outside calls, which I think should be at 44.1 kHz for best quality. Is it possible for a single instance of PulseAudio to switch between those scenarios. If not, I think I can pretty easily stop and restart PulseAudio when the scenario changes. (I'm guessing from your and Tanu's other replies to me that I might need to restart with different default-sample-rate settings, to get the best outcome and performance for my two scenarios.) Thanks, Neil