View Full Version : Do mp3 Data Disks Have Error Correction?
ulTRAX
07-19-2006, 04:56 PM
Audio CDs have 2-3 layers of error correction/concealment that make them resistant to scratches. The data is interleaved so it can be reconstructed should there be a minor scratch
One of the reasons encode some low quality audio sources at 128kbs when 64kbs would be sufficient is based upon suspicion that if I archived a higher bit rate mp3 file onto a data disk... the bigger file might be more resistant to scratches than a more compressed one.
But I'm not sure if there IS any error correction on a mp3 disk as there is a standard CD.
Does anyone know?
Thanks!
Spoon
07-20-2006, 04:34 AM
An mp3 cd is just an ordinary data cd, which has much more error correction than audio cds.
ulTRAX
07-20-2006, 04:49 PM
An mp3 cd is just an ordinary data cd, which has much more error correction than audio cds.
I can see error correction in the OS that copies an mp3 disk... and in NTFS which writes a file to disk. Some compressed files like RAR an include a recovery record...
But what I don't understand is what sort of intrinsic error correction do ALL mp3 have that would make allow them to recover data lost to a scratched disk?
And if what you say is true, then would you say that a file at a higher bitrate would be more resistant to scratches/degradation of media than the same file at a lower bitrate?
LtData
07-20-2006, 05:08 PM
See here for more information on data CD error correction: http://en.wikipedia.org/wiki/Cross-Interleaved_Reed-Solomon_Coding
ulTRAX
07-22-2006, 06:47 PM
See here for more information on data CD error correction: http://en.wikipedia.org/wiki/Cross-Interleaved_Reed-Solomon_Coding
Thanks. I know about the error correction used in CDs and it was designed not just to protect against scratches but because it was thought it'd be too expensive to produce perfect disks in the first place.
But mp3 were never designed to for the same purpose as audio CDs. It's an audio track in a video standard that's taken on a life of its own.
So when mp3s are burned to disk... do they have any intrinsic error correction? It would seem the interleaved error correction makes it most resistent to scratches. Perhaps there's nothing inherent in the standard but it's burned to disk by the burning software to ANY data CD.
LtData
07-22-2006, 10:21 PM
Actually, I believe that even data CDs use the CIRC error correction. Remember, mp3 CDs are just data CDs that happen to be all mp3s.
gameplaya15143
08-02-2006, 01:34 PM
There is no such thing as an 'mp3 cd', there is no standard for it. They are just data CDs with MP3s on them, nothing more. The only additional error protection that the MP3s could have is MP3's own CRC's. So if you want the MP3s themselves to have error protection, encode them with error protection.
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