CDfs
CDfs is a virtual Linux file system that provides access to individual data and audio tracks on compact discs. A compact disc mounted with the "cdfs" driver appears as a collection of files, each representing a single track. It supports the following track types:
- Red Book audio: Appears as a CDA file; reading from it will start the media player reading from the tracks. The CDA files aren't actual music files, they are 'shortcuts' to the invisible tracks on the audio CD.
- White Book video: Appears as a playable MPEG-1 file containing audio and video streams.
- Yellow Book data:
- Apple HFS: Appears as a mountable HFS file system image (sans partition table).
- ISO 9660: Each session appears as a mountable ISO image file.
- El Torito boot image: Appears as a floppy image file.
Cdfs is not included in the mainline Linux kernel, but is distributed instead as a series of kernel patches.
On other Unices and operating systems such as Windows, cdfs can be the name of the ISO 9660 file system driver.
Contents
Usage
Note: Most of the following is taken directly from the official website (with modifications).
- If you mount the CD with the cdfs file system, you get the two sessions as files:
mount -t cdfs -o ro /dev/cdrom /mnt/cdfs
ls -l /mnt/cdfs total 33389 -r--r--r-- 1 root root 33503232 2007-04-20 19:36 sessions_1-1.iso -r--r--r-- 1 root root 34121728 2007-04-20 19:36 sessions_1-2.iso
- These files can then be mounted loop back:
mount -t iso9660 -o loop /cdfs/sessions_1-1.iso /mnt/loop1 mount -t iso9660 -o loop /cdfs/sessions_1-2.iso /mnt/loop2
and the file a can be accessed in both sessions
ls -l /mnt/loop1 total 9889 -r-xr-xr-x 1 root root 10104236 2007-04-20 17:34 a ls -l /mnt/loop2 total 2 -r-xr-xr-x 1 root root 2 2007-04-20 19:16 a -r-xr-xr-x 1 root root 2 2007-04-20 19:19 b
The file system also allows you to access data on faulty multi session disks, e.g. disk with multiple single sessions instead of a multi session (for instance created with mkisofs without the proper -C parameters).
track-?.wav: an audio file. The file starts with a WAV-header and can be copied or played (by copying it to the audio device), e.g.:
mount -t cdfs -o ro /dev/cdrom /mnt/cdfs
ls -l /mnt/cdfs total 0 -r--r--r-- 1 root root 42973392 2007-04-20 18:01 track-1.wav -r--r--r-- 1 root root 65164512 2007-04-20 18:01 track-2.wav -r--r--r-- 1 root root 71743056 2007-04-20 18:01 track-3.wav -r--r--r-- 1 root root 66940272 2007-04-20 18:01 track-4.wav
sox /mnt/cdfs/track-1.wav -t ossdsp /dev/dsp
proc
Note: The following is an example.
cat /proc/cdfs [cdfs 2.6.19] CD (discid=XXXXXXXX) contains 10 tracks: Track 1: audio track (track-01.wav), [ 0 - 20987], length= 4:39 Track 2: audio track (track-02.wav), [ 20988 - 39988], length= 4:13 ...
