> 
> Coincidentally, I just finished doing some coding for PyAudio and
> (py)alsaaudio on Debian 7/Wheezy, though I don't use PulseAudio.
> I also found that PyAudio has pops and clicks characteristic of
> Xruns (overruns and/or underruns), while AlsaAudio does not.
> (FWIW, I decided to use AlsaAudio rather than PyAudio, though I
> coded my program with a constant that makes it trivial to switch
> between the two.)

Yes, I've noticed this problem with PyAudio with other soundcards as well.
> 
> In another reply, Bill Unruh suggested routing the output through
> the line input of another card.  That is a very good idea and may
> give you an idea of what's happening with the pops and clicks in
> the middle of the file with PyAudio.

Thank you and Bill for the suggestion, I did that and it looks like
there is a DC offset before and after the sound starts playing, you
can see it on this graph:

https://dl.dropboxusercontent.com/u/1162239/before_pyaudio.pdf

this was obtained by playing a 500-ms 1 kHz pure tone with 10-ms
fade in and 10-ms fade out (not obvious from the figure but the fade
in and fade out is there) with aplay

after I "prime" the soundcard by playing some sounds with pyaudio,
the graph obtained by playing the same sound with aplay looks like this instead:

https://dl.dropboxusercontent.com/u/1162239/after_pyaudio.pdf

Sam

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