Re: [ecasound] Garbage at end of playback: ecasound or alsa broken?

From: Knut Petersen <>
Date: Sat Jul 20 2013 - 15:02:34 EEST

On 20.07.2013 11:57, Julien Claassen wrote:
> Hello Knut!
> No idea yet, who's to blame. but have you tried repeating the experiment
> with another tool. You can use audacity, so you can use the GUI.

Audacity is even more broken. Thatīs true for the version from opensuse (2.03),
and itīs true for the current development code,

If I mark that 1s of audio described in the original post, a lot of audio is missing at the
beginning and a bit of audio is missing at end. In total only about 460 msec of audio
is captured, 540 msec is lost.

Audacity currently does not playback correctly with non-memory-mapped alsa devices.
But thatīs another story ;-(

> There are other recording applications. Or you might even try with the alsa utilities
> aplay and arecord. this will require two console or terminals.

If I put

     arecord -f cd -D hw:0,0 -d 2 testarec.wav &
     aplay testin.wav -D hw:0,0

into a script I get a perfect recording: 47 msec silence, exactly 1s of audio data,
silence up to the end of the file. Well, that result seems to indicate that I found an
ecasound bug. Unless itīs some alsa code unused by aplay ;-)

> You might also try the same experiment with JACK, if you're not averse to it.

In the best case that could only mask the bug.

> I did digitise a few tapes and prelistened to the volume and audio quality.
> So it's not a problem in general.
Half a second silence at the end of the audio masks the bug. Because of that I agree that
itīs not a general problem, most people will never notice it. But itīs still a bug.


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Received on Sun Jul 21 00:15:02 2013

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