11 Sep
2010
11 Sep
'10
11:41 a.m.
Charles Dickman wrote:
I know the error correction is better on
the audio disk than the data disks,
Alexander Schreiber wrote:
It isn't. CD-ROMs add another layer of error
correction on top of what is
already used for audio CDs, so the error correction for CD-ROMs is
better.
Only for Yellow Book Mode 1 or Mode 2 form 1. Mode 2 form 2 does not
have L3 error correction. Admittedly Mode 2 is extremely rare now.
However, audio CDs are far less troubled by errors -
at worst, you'll
hear
some annoying sound artefacts from the damaged
sectors, whereas with a
CD-ROM data errors means that you can't read (parts of) the afflicted
file
or directory.
It's more complicated than that. While CD-Audio (Red Book) doesn't have
the L3 error correction of CDs, it does still have interleave, so
defects beyond the correction capability of the L1+L2 error correction
will almost never drop two consecutive samples. There may, however, be
runs in which every other sample is missing. In this case, the player
uses "error concealment" by interpolating between the samples to either
side of the missing one(s). This results in a momentary drop in the
audio bandwidth, but is usually not noticeable.
When there are errors that result in multiple consecutive lost samples,
the player will mute the audio, which was considered to be less
unpleasant than playing digital noise. However, when there are rapidly
alternating segments of good samples and multiple consecutive lost
samples, it can end up sounding like digital nose anyhow.
Eric