On my hard drive a couple of wav recordings of classical concerts are waiting eagerly being split into the individual pieces and to be saved as ogg respectively mp3 files.
I’m using Audacity for the task, a famous open source audio editing software.
The tasks requires the following steps:
- Remove audio in front of the first piece.
- Remove audio past the final applause of the audience.
- Fade out the applause.
- Normalize both channels independently due to mike differences.
- Add silence between the pieces.
- Fade in the hum caused by the audience in front of each piece.
- Fade out the hum at the end of each piece.
- Create text markers for each piece containing the name of the compser, the name of the piece and the like.
- Let Audacity do the job by splitting and exporting the audio material based on the text markers.
I searched a possibility to ease steps 5 through 7. I found a code snippet by edgar-rft. He politely granted the permission to reuse the Nyquist plugin code, so I slightly modified it to get my job done.
Installation and Usage
- Download dual-fade.ny.zip and extract it.
- Move the resulting file dual-fade.ny to the plug-ins folder of your Audacity installation.
- (Re)start Audacity and load some audio data.
- Select some of the audio.
- From the menu effects, choose the command »Dual-Fade«.
That’s it. The first third of the selected audio will be faded out, the second third will appear as silence, and the last third will be faded in. The complete fade follows a three-stage envelope with linear segments (using pwl, »piece-wise linear functions«):
BTW: I also found the Fade+ plugin by Steve Daulton which uses bezier curves to apply some smoother fading curves instead of the usual linear one. In case you do not only want to fade noise but real audio pieces, I’d recommend to check whether it gives you pleasant results.