Re: [solved] Convert multichannel raw file to wav

Jan Stary <[email protected]> writes:

>>  $ pacat --record -d
>> alsa_input.usb-BEHRINGER_UMC404HD_192k-00.analog-surround-40 --channels=4
>> --channel-map=aux0,aux1,aux2,aux3 --file-format=wav dump.wav
>> 
>>  Warning: failed to write channel map to file.
>>
>> and in fact the resulting file seems not to be as accurate as the one I get
>> creating first the raw file and then converting it to wav via sox.
>
> In what way is the converted file more "accurate"?


We have now two different methods to produce the wav 4-channel audio file: the
first we call output2.wav we got with:

 $ pacat --record -d alsa_input.usb-BEHRINGER_UMC404HD_192k-00.analog-surround-40 --channels=4 --channel-map=aux0,aux1,aux2,aux3 > dump2.raw

 $ sox -t raw -r 44100 -e signed-integer -L -b 16 -c 4 dump2.raw output2.wav

and the second we call dump.wav simply with:

 $ pacat --record -d alsa_input.usb-BEHRINGER_UMC404HD_192k-00.analog-surround-40 --channels=4 --channel-map=aux0,aux1,aux2,aux3 --file-format=wav dump.wav

Now, using sox I split each of them in four single channels and observe, or
hear, that in the first method those single channels are better separate: I can
say so because one of my microphones is an ugly 6-dollar bad thing I bought
just for experiment and I can recognize it: it's a sensation but very clear but
difficult here to explain: however pacat alerts us with its message:

 Warning: failed to write channel map to file.

so the second methods is not good unless we manage to eliminate that message,
but the first method seems very good with just one step more.

Thanks,

Rodolfo