the itjerk

my adventures with technology

Monthly Archives: October 2008

open source audio


Since acquiring a 500GB hard drive, I've set to the task of ripping "some" of my CD collection into digital audio files for use with my Squeezebox and Nuforce Icon amplifier. Fortunately, this coincided with the discovery of the Sansa Clip and two firmware upgrades (the latest V01.01.30A) that provide native playback for Ogg and FLAC files.

Like MP3 and AAC, Ogg is a lossy (compressed) media format; however, unlike MP3 and AAC, it is completely free of patent restrictions and royalties. Music encoded with a "q" value of 6 is similar to a 192kps MP3 file, but smaller in size and better in sound quality. FLAC, another open format, stands for "Free Lossless Audio Codec". A CD ripped into FLAC is 50% smaller than the original WAV source, yet there's no compromise in quality – it is true lossless audio.

Most Linux distributions include the libogg / libvorbis / vorbis-tools software by default. Xiph.org has Ogg codecs for both the Mac and Windows operating systems. FLAC software can be found at its site on Sourceforge.net. Admittedly, hardware support is the drawback; the iPod requires Rockbox firmware to play either format. But I'd like to think of it as another reason to support Slimdevices and Sandisk for doing the right thing!

I use Grip to rip my CDs to FLAC and then force-save metadata tags with EasyTag. Grip can also rip directly into Ogg (I use a "q" value of 6). Two notes: Do not write ID3v2 tags to FLAC files because Oggenc – which converts the files – won't recognize the Flac format. Also, OGG files should be written with ID3v1 tags, with Western ISO-8859-1 character set. First, this insures Oggenc will preserve the metadata during conversion, and secondly the Sansa Clip will be able to play the tracks in the correct order (yes, it has a little bug).

Of course, a 500GB drive has no problem storing hundreds of CDs in the FLAC format. But a little 2GB audio player? Converting all the FLAC files in a single directory to Ogg can be on the command line with Oggenc:

$ find . -name "*.flac" -exec oggenc -q 6 '{}' ;

That's it! No patent restrictions, no royalties, and professional sound quality.

On the Web:
Play Ogg
Vorbis
Xiph.org
FLAC @ Sourceforge

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