DoudouLinux CD

A quick investigations on several packages included in DDL showed that some of them are using audio files sampled in 44.1kHz. Although children may hear sounds up to 16 kHz, computers will often not play sounds upper than 10 kHz. We can then decrease the sample rate to 22kHz. Moreover many sound files are recorded stereo. We can then switch them to mono.

So we propose the following:

1. write a script to list audio files of a DDL system with path, sample rate, number of channels and file size, it should be OGG or WAV files
2. evaluate what could be shrunk
3. write a script that is able to backup the chosen files for later restoration, at DDL installation on HD or USB key for example
4. write a script that shrinks these files if not already done, then stores the shrunk version in a given folder
5. write a script that put shrunk files in config/chroot_local-includes/ at CD build time