Fractional BPM in Change Tempo effect

[Gale Andrews]

[Topic split from http://forum.audacityteam.org/viewtopic ... 63#p215663]

I cheat by entering the length or BPM values in Effect > Change Tempo.

The Quick Calculator is more accurate.
For example, according to "Change Tempo", from 45 to 33.3333 = -26.667 (tempo values are truncated to integers).

Oh yes I remember someone was going on that he wanted fractional BPM support in that effect (length is not truncated).

Should Change Tempo not prevent non-integer BPM input, or better, support fractional BPM?


Gale

[steve]

Should Change Tempo not prevent non-integer BPM input, or better, support fractional BPM?

I've sent you a patch for fractional BPM support, though note that SoundTouch is not very accurate so allowing fractional BPM does not mean that you will be able to achieve super-accuracy in the stretch length.

[Gale Andrews]

Thanks for the patch. It compiled on Windows, but seemed like the old behaviour, even though I removed the build directory first. I'll have to try it again.

On Ubuntu, it seems fine - a change on a second decimal place BPM affects the outcome length.

How about rounding the displayed length to three decimal places, like BPM?


Gale

[steve]

How about rounding the displayed length to three decimal places, like BPM?

That may be implying greater accuracy than is actually achieved by SoundTouch. When applied to a 30 second audio clip the returned audio is likely to be a few milliseconds out - even hundredths of a second may be a little ambitious.

[Gale Andrews]

It's OK now on Windows.


Gale