slimpy;150929 Wrote: > Cd players always need to read data from the cd in realtime. In case of > a bad disc, scratches etc. the player might not be able to extract the > data quick enough. In order not to interrupt playback it uses automatic > error correction. It guesses what the missing bits could be. Quite true.
slimpy;150929 Wrote: > Ripping on a pc however is not bound to this constraint as there is no > demand for uninterrupted data flow. This means that hard to read parts > of a cd can be read at a slower rate. I've seen rates drop to 0.1x of > the normal playback speed. You're misinterpreting what's going on here. Yes, ripping software can re-read in an attempt to get clean data after an uncorrectable error. However, the 0.1x rates you have seen refer to the average read speed over the track (or disc) compared to realtime. When the software re-reads the faulty sector, it is still constrained by the capabilities of the hardware CD drive, and in fact many modern CD and DVD ROM drives have a minimum read speed higher than 1x. A minimum speed of 4x is not unusual. So in fact what's going on is the ripping software is reading the failed block over & over again, but still at fairly high speed. slimpy;150929 Wrote: > In most cases you will get a cleaner file from a pc rip than from > recording the digital ouput from a cd player. In most cases, there are no uncorrectable errors on the disc, and you get the same data whether you rip or record the SPDIF. And in that case, ripping is obviously more convenient. In those cases where there are uncorrectable errors, the re-reading strategy often fails to improve matters. If a disc is damaged, reading it again doesn't make the damage go away. So then you're at the mercy of whatever concealment technique is provided by the hardware and/or software. And in these cases some CD players *might* do a better job than the ripping method. -- cliveb Performers -> dozens of mixers and effects -> clipped/hypercompressed mastering -> you think a few extra ps of jitter matters? ------------------------------------------------------------------------ cliveb's Profile: http://forums.slimdevices.com/member.php?userid=348 View this thread: http://forums.slimdevices.com/showthread.php?t=29202 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
