[linux-audio-user] sample-rate/bit-depth wav converter

Eric Dantan Rzewnicki rzewnickie at rfa.org
Mon Oct 10 10:31:38 EDT 2005


On Sun, Oct 09, 2005 at 11:03:32PM +0400, Andrew Gaydenko wrote:
> Eric,
> 
> Thanks! 
> 
> Are there any quality differences in comparison with sndfile-xyz tools?

If you use the resample-hq option ecasound uses libsamplerate, which I
think is used by sndfile-resample since Erik de Castro Lopo is the
author of both libsndfile and libsamplerate. I'm pretty sure ecasound
uses libsndfile for most sound file handling, though I'm not 100% sure
whether that includes sample width changes. Anyway, the syntax from man
ecasound:

Resample - access object of different sample rates 
Object type 'resample' can be used to resample audio object's audio data
to match the sampling rate used in the active chainsetup. For example,
ecasound -f:16,2,44100 -i resample,22050,foo.wav -o /dev/dsp, will
resample file from 22.05kHz to 44.1kHz and write the result to the
soundcard device. Child sampling rate can be replaced with keyword
'auto'. In this case ecasound will try to query the child object for its
sampling rate. This works with files formats such as .wav which store
meta information about the audio file format. To use 'auto' in the
previous example, ecasound -f:16,2,44100 -i resample,auto,foo.wav -o
/dev/dsp.

If ecasound was compiled with support for libsamplerate, you can use
'resample-hq' to use the highest quality resampling algorithm available.
To force ecasound to use the internal resampler, 'resampler-lq'
(low-quality) can be used.

> Andrew
> ======= On Sunday 09 October 2005 22:47, Eric Dantan Rzewnicki wrote: =======
> ...
> > //info
> > sndfile-info foo.wav
> > 
> > //resample
> > sndfile-resample -to 48000 -c 0 foo.wav bar.wav
> > 
> > //convert to 16 bit
> > sndfile-convert -pcm16 bar.wav baz.wav
> 
> ecasound can also perform these operations.
-- 
Eric Dantan Rzewnicki  |  Systems Administrator
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