This output is captured when running periods_min=4.
[root@axis /mnt/flash/root]1335# arecord -v -r 16000 -c1 -Daudiosource0 -fS16_LE /tmp/in.wav Recording WAVE '/tmp/in.wav' : Signed 16 bit Little Endian, Rate 16000 Hz, Mono Direct Snoop PCM Its setup is: stream : CAPTURE access : RW_INTERLEAVED format : S16_LE subformat : STD channels : 1 rate : 16000 exact rate : 16000 (16000/1) msbits : 16 buffer_size : 8000 period_size : 2000 period_time : 125000 tstamp_mode : NONE period_step : 1 avail_min : 2000 period_event : 0 start_threshold : 1 stop_threshold : 8000 silence_threshold: 0 silence_size : 0 boundary : 2097152000 Hardware PCM card 0 'X4 AIC3104 Dual' device 0 subdevice 0 Its setup is: stream : CAPTURE access : MMAP_INTERLEAVED format : S16_LE subformat : STD channels : 2 rate : 16000 exact rate : 16000 (16000/1) msbits : 16 buffer_size : 8192 period_size : 2000 period_time : 125000 tstamp_mode : ENABLE period_step : 1 avail_min : 2000 period_event : 0 start_threshold : 1 stop_threshold : 1073741824 silence_threshold: 0 silence_size : 0 boundary : 1073741824 appl_ptr : 0 hw_ptr : 0
-----Original Message----- From: alsa-devel-bounces@alsa-project.org [mailto:alsa-devel-bounces@alsa-project.org] On Behalf Of Jaroslav Kysela Sent: den 14 mars 2011 11:08 To: Magnus Olsson Cc: alsa-devel@alsa-project.org Subject: Re: [alsa-devel] Dsnoop-plugin buffer sizes
On Mon, 14 Mar 2011, Magnus Olsson wrote:
Hi,
I'm having issues with garbage data in my audio stream, which I believe is caused by incorrect buffer sizes somewhere in the audio pipeline. The garbage occurs periodically and is always constant in length. This problem only triggers when I use the dsnoo-plugin. If running directly towards the device, the audio stream is fine (no garbage). I've not tested if this occurs with any other plugin.
I'm using Dsnoop to capture a mono stream from a stereo device using arecord, arecord -v -r 16000 -c1 -Daudiosource0 -fS16_LE /tmp/in.wav (where audiosource0 is my dsnoop-device, bound to channel 0)
The verbose info from arecord shows me that ALSA has correctly created the Dsnoop device, with a "buffer_size" of 8000. It also shows that it has opened my Hardware device in MMAP-mode, with a "buffer_size" of 8192.
Show us this output from 'arecord -v'.
Jaroslav
----- Jaroslav Kysela perex@perex.cz Linux Kernel Sound Maintainer ALSA Project, Red Hat, Inc.
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