Re: Recording specific channels

On May 13 09:26:10, [email protected] wrote:
> On May 12 22:56:45, [email protected] wrote:
> > If someone needs files from 1:35 to 3:15 we just give them 1 to 4.
> > They combine them (with no seam at 2pm) [...] We routinely combine files
> > into larger segments and we need them to be seamless.
> 
> Ah, right, that's what you mean by "sample perfect". Let's try:
> 
> $ sox -n sine.wav synth 10
> $ sox sine.wav part%n.wav trim 0 5 : newfile : trim 0 5
> $ soxi sine.wav part*.wav
> 
> On my machine, that's 480000 split into 240000 + 240000 exactly
> when I said 5s out of 10s.

On the contrary, this is not sample perfect:
a line in my crontab, starting a recording of one minute every minute.

* * * * * /Users/hans/bin/rec -q /tmp/file-`date +\%s`.wav trim 0 00:01:00

This does indeed record each minute of audio into
an appropriately named file, but the transition is not seamless
(as verified by playing a song longer than one minute).

But if you change this to record your "predefined blocks"
of a couple of hours, then perhaps overlaping a few samples
will not matter if the seams are at silent times.
Or you could record whole days, restarting at, say, 3 am.

Jan