Converting CDA to MP3 files on the Mac

Question

How do I covert CDA audio files to MP3 format on the Mac?

The CDA files have already been ripped and are sitting on my computer. Could I just change the filename extension from .cda to .mp3?

Solution

CDA is something of a misnomer. According to the top Google result, CDA files are a shortcut to a track on an audio CD. Another source provides a slightly less obvious version of the same assessment. From the first link:

File Description:
Shortcut to a track on an audio CD; plays the referenced track on the CD when opened; therefore, the CD must be in the CD-ROM drive for the shortcut to work correctly.

CDA files do not contain actual audio data; songs "ripped" from an audio CD are usually saved as uncompressed .AIF or .WAV files.

"CDA files" are an attempt to provide a files-on-a-filesystem concept to something that has no filesystem. Audio CDs are burned in tracks of a specific kind of PCM data -- stereo, 16-bit, 44.1 kHz. When you put the CD in a CDROM drive, modern operating systems display the tracks as a list of CDA or CDDA files. If you copy these CDA files to your desktop, what you get is shortcuts to the tracks -- not the tracks themselves.

Consider this. CD audio data takes up approximately 10 MB per minute. So check the filesize of your CDA files. If they're around 4 kB each, you have shortcuts. If they actually take up 10s or 100s of MB, you have PCM data.

• If you have shortcuts, you'll need to get the CD in order to have anything to convert to MP3. iTunes can rip CDs and encode them to MP3s.
• If you have actual audio data files, iTunes can probably convert those too. You might need to rename the files ".wav" or ".aif" for importing into iTunes.

If you were on Windows, I'd recommend Exact Audio Copy aka EAC to do the ripping and LAME to do the encoding. I don't use OSX so I can't recommend another ripper aside from iTunes, though I'm sure LAME is available for OSX if you just need an encoder.

Comments

[quack quixote]

if these are ".cda" files on a CD disc, they're not really "files" -- you're trying to rip an audio CD. if these are ".cda" files on the hard drive, they're probably really WAV files (44.1kHz, 16-bit, stereo PCM).

[Simon Hughes]

@quack - on disk. Should I just change the file name? Would that help?

[quack quixote]

@Moshe: yes, Audacity can use LAME. Audacity is a sound editor that can use LAME as a plugin for MP3 encoding; neither is required to use the other. Audacity+LAME can certainly encode PCM data to MP3, if PCM is what you have. i don't know if Audacity has ripping capabilities if you need to rip a CD.

[Simon Hughes]

The CDA files are on mac, ripped already. I think audacity is rhe way to go here. Thank you.