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Automating something

Posted: Thu Feb 04, 2010 11:31 pm
by tilling
I'm trying to figure out how to automate something I will do a lot.

I record Spanish lessons over Skype. I have the audio as two tracks: one is me, one is my teacher.
I want to speed up the sections where I am speaking. My Spanish is slow and halting, and could probably be
sped up by 2x without any difficulty.
Presumably I would have to get Audacity to:

(1) Select each range where his track is silent.
(2) Select BOTH tracks for those ranges.
(3) Speed up each of those ranges.

I know how to do Change Tempo, and I know where the Silence Finder is (but not the Silence Selector :),
nor how to "tell" Audacity to pick both tracks (by hand I click on the other track while hitting "shift").

BTW I notice that if I select BOTH tracks and use Truncate Silence, it seems to throw off the synch...anything I can do about that?

Re: Automating something

Posted: Fri Feb 05, 2010 1:21 am
by kozikowski
In Audacity, Batch Processing is called Chains. I can't find any instructions for Chains. I know there are some and Chains in 1.3 has gotten quite a bit better in later versions. I'm going to keep looking. That's the search term.

Koz

Re: Automating something

Posted: Fri Feb 05, 2010 1:37 am
by billw58
In Audacity 1.3.12 (and possibly 1.3.11 - I can't check right now but I will...) under the Analyze menu there is "Sound Finder".
http://manual.audacityteam.org/index.ph ... find_sound

If you run this effect on your track it will put region labels on each section of your track. Now you can: with the cursor in your track, click on a region label to select the audio in your track spanned by that region; shift-up-arrow (assuming the teacher's track is above yours) to extend the selection; run the Change Tempo effect (which changes speed without affecting pitch) - since both tracks are selected, they will stay in sync. Repeat as needed. That's about the extent the automation I can think of for this project.

-- Bill

Re: Automating something

Posted: Fri Feb 05, 2010 3:21 am
by kozikowski
Can you chain that?

Koz

Re: Automating something

Posted: Fri Feb 05, 2010 4:05 am
by billw58
kozikowski wrote:Can you chain that?
No - it's a Nyquist effect.

It wouldn't matter anyway. Chains are mostly about batch processing files, although they can be used to apply a "chain" of effects to a selection in a project. The key point is that they are applied to a selection - there is no way to "loop" a chain or tell it to operate on every labelled region.

-- Bill

Re: Automating something

Posted: Fri Feb 05, 2010 6:38 am
by kozikowski
See original question...

<<<I'm trying to figure out how to automate something I will do a lot.>>>

Can we assume turn Audacity loose and go for coffee?

Koz