crackling microphone

[GitHub issues - reopened]

alsa-project/alsa-plugins issue #10 was reopened from riddicc:

Hi!

When I send a 800Hz sine wave with rate 12345 to pcm.outmic and
when I arecord from pcm.micend at rate 8000 with 1 channel ([/etc/asound.conf](https://github.com/alsa-project/alsa-plugins/files/4597703/etc-asound-conf.txt)),
then I get a lot of tiny little gaps (see attachment) and a lot of messages like "overrun!!! (at least 0.014 ms long)" (the "ms" vary from 0.008 to 0.043; and arecord continues to record) and sometimes even this error: "arecord: xrun:1672: read/write error, state = RUNNING" (it causes arecord to terminate).

1. > speaker-test -D outmic -t sine -f 800 -c2 -r 12345
2. > arecord -D micend -r 8000 -c 1 -f S16_LE /tmp/bla.wav

twinkle makes even bigger gaps, when I let it use pcm.micend as microphone...
But with hw:Generic,0,0 as mic device twinkle works fine...
https://github.com/LubosD/twinkle/issues/207

"samplerate_best" and "samplerate_order" seems to make it worse...

How can I fix that?

Thx.

Bye.

![audacity screenshot](https://user-images.githubusercontent.com/33246439/81384628-7ad51080-9101-11ea-849d-6afb14bf1307.png)

Issue URL     : https://github.com/alsa-project/alsa-plugins/issues/10
Repository URL: https://github.com/alsa-project/alsa-plugins