Subject: Re: Recording silence is definitely not golden
To: None <darcy@netbsd.org>
From: Nathan J. Williams <nathanw@wasabisystems.com>
List: current-users
Date: 11/22/2005 13:30:01
"D'Arcy J.M. Cain" <darcy@NetBSD.org> writes:

>  - your dmesg output

relevant bits:

auich0 at pci0 dev 31 function 5: i82801DB/DBM (ICH4/ICH4M) AC-97 Audio
auich0: interrupting at irq 11
auich0: ac97: Analog Devices AD1981B codec; headphone, 20 bit DAC, no 3D stereo
auich0: ac97: ext id 601<AC97_22,AMAP,VRA>

auich0: measured ac97 link rate at 48003 Hz, will use 48000 Hz
audio0 at auich0: full duplex, mmap, independent


>  - your "mixerctl -a" output

outputs.master=127,127
outputs.master.mute=off
outputs.mono=255
outputs.mono.mute=on
outputs.mono.source=mixerout
outputs.headphones=255,255
outputs.headphones.mute=off
inputs.speaker=255
inputs.speaker.mute=off
inputs.phone=191
inputs.phone.mute=on
inputs.mic=191
inputs.mic.mute=on
inputs.mic.preamp=off
inputs.mic.source=mic0
inputs.line=191,191
inputs.line.mute=off
inputs.cd=191,191
inputs.cd.mute=off
inputs.video=255,255
inputs.video.mute=off
inputs.aux=191,191
inputs.aux.mute=off
inputs.dac=191,191
inputs.dac.mute=off
record.source=mic
record.volume=240,240
record.volume.mute=off

(this is how it boots up. Turning up inputs.mic and inputs.mic.preamp
help, since I'm recording from an actual microphone, but isn't
strictly necessary).

>  - your "audioctl -a" output

6 crash-test-dummy:nathanw>audioctl -a
name=ICH4 AC97
version=0x01
config=auich0
encodings=slinear_le:16,slinear_be:16*,ulinear_le:16*,ulinear_be:16*,mulaw:8*,alaw:8*
properties=full_duplex,mmap,independent
full_duplex=0
fullduplex=0
blocksize=1600
hiwat=40
lowat=1
monitor_gain=0
mode=
play.rate=8000
play.channels=1
play.precision=8
play.encoding=mulaw
play.gain=127
play.balance=32
play.port=0x0
play.avail_ports=0x0
play.seek=0
play.samples=0
play.eof=0
play.pause=0
play.error=0
play.waiting=0
play.open=0
play.active=0
play.buffer_size=65536
record.rate=8000
record.channels=1
record.precision=8
record.encoding=mulaw
record.gain=240
record.balance=32
record.port=0x1
record.avail_ports=0x7
record.seek=0
record.samples=120800
record.eof=0
record.pause=0
record.error=0
record.waiting=0
record.open=0
record.active=0
record.buffer_size=65536
record.errors=0


>  - what commands you use to record

audiorecord -F wav -v 255 -t 5 test.wav

Something is funny if I don't use -t and ^C the program instead; it
seems like I lose the last fractional "block".

        - Nathan