[aubio-user] [peterparker at fastmail.com: some questions]

[Peter P.]

Hi list, hi Paul,

I already sent this to contact at aubio.org last week. I am
including it below (with one of the questions slightly modified to
reflect my current state of knowledge). Thank you for any ideas and
please excuse a possible cross-posting.

--------------------------->

Hi,

I found out that aubiocut will write its output file as 16bit Signed
Integer PCM regardless of the encoding of the input file (24bit
signed-integer, 8bit unsigned-integer). Am I correct?

I was surprised that aubiocut takes wav files with more than 2 channels
and writes wav files with the correct number of
 channels to disk again. Are all these channels considered in the
analysis?

Could aubiocut receive its input audio data from stdin instead from a
file? This would make pre-processing/integration with SoX super easy
without having to write temporary files (see sox manpage for examples).

I am trying to use aubiocut to give me timestamps of onsets, but would
prefer to do the cutting/splicing in SoX. For this I am using the onset
times in samples rather than in seconds. If I multiply an onset time
from aubiocut by the sampling rate of the file I am getting non-integer
values. For example: 0.1866 * 44100 = 8229.1
All seems to be fine just truncating the .1 sample, but I am curious
about the origins of that .1 fraction.

The Debian manpage is possibly ambigous about the default threshold
value. Both 0.1 and 0.3 are given.

What would a use-case be for the --cut-until-nslices option? I would
like to use it to get larger and less slices of audio. In order for this
to work would it be possible to have aubiocut --cut-until-nslices post
the values for that to the console (instead of every slice)?

Thank you for all answers and these great tools!
best, Peter