Re: [ecasound] Automated volume change

From: Kai Vehmanen <kvehmanen@email-addr-hidden>
Date: Sat Sep 03 2005 - 11:03:21 EEST

On Fri, 2 Sep 2005, Luis Pablo Gasparotto wrote:

> I would like to know if there's some way to change, as an example, the volume
> (-ea) parameter in a certain time position.
> Example:
> ecasound -i:test.wav -ea:100
> and I would like -ea:120 at the 5 seconds position.

Yes, see ecasound(1) and the -klg operator, the general linear envelope.
To implement your example:

ecasound -i:test.wav -ea:100 -klg:1,100,120,3,0,0,4,0,5,1

IOW, you define three change points (0,0), (4,0) and (5,1),
where (x,y) => x=position-secs, y=value-between-0.0...1.0.

With simple cases you can also use the more straightforward
linear envelopes. For example you can achieve the above with:

ecasound -i:test.wav -ea:100 -kl2:1,100,120,4,1

This creates the same effect, -ea stays at 100% until pos=4sec, where it
starts to increasing, and at pos=4+1sec, -ea should be 120%, where it
stays until end of processing.

> May I do it using -km?

That'd also work, but then you need to setup an external MIDI controller.

  links, my public keys, etc at
SF.Net email is Sponsored by the Better Software Conference & EXPO
September 19-22, 2005 * San Francisco, CA * Development Lifecycle Practices
Agile & Plan-Driven Development * Managing Projects & Teams * Testing & QA
Security * Process Improvement & Measurement *
Ecasound-list mailing list
Received on Sat Sep 3 12:15:05 2005

This archive was generated by hypermail 2.1.8 : Sat Sep 03 2005 - 12:15:05 EEST