[alsa-devel] [ecasound] Garbage at end of playback: ecasound or alsa broken?
Knut_Petersen at t-online.de
Sat Jul 20 14:02:34 CEST 2013
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. That´s true for the version from opensuse (2.03),
and it´s 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 that´s 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 it´s 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
it´s not a general problem, most people will never notice it. But it´s still a bug.
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