Subject: kern/16385: recording on uaudio causes noise
To: None <email@example.com>
From: None <firstname.lastname@example.org>
Date: 04/17/2002 12:31:31
>Synopsis: recording on uaudio causes noise
>Arrival-Date: Tue Apr 16 20:32:00 PDT 2002
>Originator: IWAMOTO Toshihiro
>Release: NetBSD 1.5ZC
System: NetBSD miyuki.my.domain 1.5ZC NetBSD 1.5ZC #67: Sat Apr 6 00:59:23 JST 2002
Recording on uaudio causes noise. I supppose this is due to
rev. 1.54 of uaudio.c, but I don't have time to look at it.
Another problem is that playing sound on the device switches
it to monaural recording mode.
Use a Roland UA-3 (at /dev/sound1) with the following script.
This causes impulse noises every 100~200 samples.
audioctl -f /dev/audioctl1 -w record=8000,1,8,mulaw
audioctl -f /dev/audioctl1 -w record=44100,2,16,slinear play=44100,2,16,slinear
dd if=$dev of=$2 count=$l
To invoke the second problem, run the above script first and
play some mp3 with madplay on the same device.
Then running the recording script generates a monaural recording