Time Track accessibility

[Polarus]

Hi everyone, new in this forum but using Audacity since 2004, nice work, respect!

I have question: could anyone with knowledge implement resampling methot of time scale? Or is there any plugin which can work same as this effect but with resampling instead? I would like to speed up a piece of music across the time, but by giving starting and ending point in percentage or BPM scale.
Thanks in advance for advice and / or helo!
Patrick.

[jjulie]

Hi everyone!

I'm also interested in implementing this function into the software.
Many thanks!
Julie

[kozikowski]

Playback software will not play a song with variable sampling. The software will see music like that as a damaged file.

Koz

[steve]

See "Time Tracks" http://manual.audacityteam.org/o/man/time_tracks.html
Currently this works OK for small changes in speed, but becomes quite jumpy for larger changes. This feature has been considerably improved in the development build and the improved version should be available in Audacity 2.0.3 (due for release early 2013)

[Polarus]

I mean same method like in "change speed..." so you can speed up changing both tempo and pitch without artifacts and make it variable. Logic Pro 9 and Abletonn has this feature so it is possible.

[steve]

I mean same method like in "change speed..." so you can speed up changing both tempo and pitch without artifacts and make it variable.

In that case you need the "Sliding Time Scale / Pitch Shift..."

Resampling changes both pitch and tempo.

[Polarus]

Ok, it seams to work as I expected. But in Sliding time scale I could select only portion of audio and then apply it, how I have to put these points and envelope with keyboard and screen reader? I am visually impaired (blind) person... It seams impossible...

[steve]

how I have to put these points and envelope with keyboard and screen reader?

Sorry I don't understand what you mean, "Sliding Time Scale / Pitch Shift" does not use envelope points.

"Time Track" does use envelope points and is unfortunately one of the features in Audacity that is not accessible from the keyboard, but you said that you wanted the pitch to remain unchanged so "Time Track" will not do what you want. Time Track works by variable rate resampling, and that changes both pitch and speed.

[Polarus]

No no no, we misunderstood. I want changing tempo with pitch together, so time track would work fine if I would be able to put these points by keyboard, screen reader, selection or anything but accessible.

Btw. Thank you for fast replies! I would be very thankfull if accessibility of time track would be solved too.
Best regards.

[steve]

I want changing tempo with pitch together,

Fortunately you can also do that with "Sliding Time Scale / Pitch Shift" (and this effect should be accessible from the keyboard).

As an example, to create a variable resample effect from the original sample rate to half the resample rate, the effect needs to slow down the tempo to half speed and lower the pitch frequencies to half of their original frequency. In other words we are lowering both the tempo and the pitch from "normal" (0 %) to half (minus 50 %).

The important thing for getting the pitch and tempo to change by the same amount (as happens with variable rate resampling) is that the pitch % settings need to be set the same as the tempo % settings.