On 01/01/13 19:18, Robin Gareus wrote:
On 01/01/2013 07:07 PM, Brent Busby wrote:
First off, Happy New Year to all! :)
Can anyone recommend a quick way of seeing the differences highlighted
visually between two channels in a stereo sample...sort of like a
graphical 'diff' for waveforms?
I think I may have some Akai MPC2000 samples that somehow were saved by
the Akai as mono samples even though they actually contain two channels
and are really stereo:
Using 'sndfile-info' on them reports them as mono, but it's just looking
at the 22nd byte in the file, which should contain 0x00 or 0x01 to say
if it is mono or stereo. The file contains 0x00 in that location, so
sndfile-info believes that it's mono because the file header says so.
However, if I flip the bit in a hex editor and resave the file, now I
can load the file in a sample editor and it seems to have two channels
which play at double speed. I'm still not positive I'm hearing stereo
(if I am, it's very subtle), but I'm definitely seeing two channels
visually, and I know this sample was sampled on the Akai in stereo.
Any way to do a graphical comparison that will highlight even small
channel waveform differences?
Invert the phase of one channels (volume *=-1) and downmix to mono. If
both channels are identical it'll result in a flat zero line.
I'd use rezound for that, but pretty much any soundfile editor should do.
You could probably also do it with sox and diff (possibly script it for
many files..):
sox mystery_file.wav c1.wav remix 1
sox mystery_file.wav c2.wav remix 2
diff c1.wav c2.wav
If mystery_file.wav had exact same channels diff will just exit with no
output (exit code 0) otherwise it will output something like: Binary
files c1.wav and c2.wav differ (and exit code 2)
Lorenzo.
_______________________________________________
Linux-audio-user mailing list
Linux-audio-user@xxxxxxxxxxxxxxxxxxxx
http://lists.linuxaudio.org/listinfo/linux-audio-user
