[LAU] rubberband and batch processing

[Chris Cannam]

On 06/06/2008, Dave Phillips <dlphillips at woh.rr.com> wrote:
> I want to convert an entire directory of 80 bpm loops to 100 bpm loops.
> Alas, rubberband does not have a nice simple "change to tempo X"
> function (AFAICT)

No, it doesn't.  I might well add one (well, "change from tempo X to
Y" -- I don't intend to make it calculate the current tempo) for the
next release.

>  1. What formula should I use for either the -t or -T options ?

-t 0.8 or -T 1.25

>  2. How do I use rubberband to process the whole directory ?
>
>  Actually I can figure out #2, but I'm open to suggestions for the most
>  efficient shell script. I'd like to keep the names and append "-100" so
>  that "80bpm-loop.wav" becomes "80bpm-loop-100.wav".

I would probably use a loop somewhat like

for x in *.wav; do
    rubberband -t 0.8 "$x" "${x%%.wav}-100.wav"
done

(caution: untested, assumes bash).


Chris