While copying from a TDK DVD DL to HD, I got: Cannot copy XXXXX : Data error (cyclic redundancy check). what does it mean? Is the disc bad? Files copied on 2nd attempt. But should I junk the disc and burn files to another one, or was this a hardware issue? I do not verify burns anymore as I felt it was a waste of time.
The cyclic redundancy check error (CRC) means that the error correction system in your computer has found a major difference between the sums of data both horizontally (parity inner error) and in the column checks (parity outer error) and any additional redundant information added to the data. Because nothing adds up properly to correct the error, it can't interpret what the information is supposed to be. (Error correction is designed to determine an incorrect sum of data to pinpoint exactly what part is wrong and then to reconstruct the correct information from other sums of data.) In this case the error is too big to fix. It could mean the disc is bad, that there was transient debris at some point on the disc that fell off, that the recording on the disc is not the best, or that there was a transfer problem. Run a quality check on the disc to see if there is a spike in error rates somewhere. On DL discs the spike is usually at the layer break. If you do find a big spike, record the video onto another DL disc and check the recording afterwards. (Recording data onto DL discs is not a good idea. Video is more forgiving.)
