[alsa-devel] aplay\arecord compare utility

[Ricard Wanderlof]

On Mon, 26 Feb 2018, Ricard Wanderlof wrote:

> On Fri, 23 Feb 2018, Muni Sekhar wrote:
> 
> >  [ Please keep me in CC as I'm not subscribed to the list]
> > 
> > I?m using an alsa utilities(aplay & arecord) for sound loopback
> > testing. From Linux host , sending & receiving the wav file.
> > 
> > At end I want to compare the sent & received wav file. Does Linux has
> > any utility to support this one?
> 
> If the wav headers are identical, you can just use cmp or diff. Otherwise, 
> you can extract the raw audio using sox, which gives you files with just 
> the audio samples in them, and then you can use cmp or diff to compare 
> them. It won't work though if the files aren't actually identical, for 
> instance if there is an offset of a couple of samples in one compared to 
> the other.
> 
> If I had to compare two wav files which were offset by a small number of 
> samples, I'd open them in Audacity, manually align them, then sum the 
> result, write to a new file and verify that the file just contained zeros.

(Sorry, pressed enter a bit too fast there)...

... align them, _invert_one_of_them_, then sum the result, write to a new 
file and verify that the file just contains zeros.

/Ricard
-- 
Ricard Wolf Wanderlöf                           ricardw(at)axis.com
Axis Communications AB, Lund, Sweden            www.axis.com
Phone +46 46 272 2016                           Fax +46 46 13 61 30