mauidan Wrote: > "Of course I acknowledge that CDs do exist which cannot be read without > error. They may be damaged, or they may have been mastered/pressed > badly. But in my experience, playing such a CD on an audio CD player > and recording the SPDIF output often gives a better result than letting > EAC "do its magic." - cliveb > > I'm still waiting for cliveb to explain what "magic" EAC is going to > perform if you've recorded a signal with ECCs. My apologies for not explicitly answering your question earlier. On 26th June opaqueice posted something in response which sort of summed up what EAC does when it detects an uncorrectable error. I posted a slight clarification on 27th, and thought that between them those two posts covered it. But clearly I was wrong to think that, so....
Let's consider what happens when a CD has an uncorrectable error, ie. enough bad symbols in a data block that even after C2 CIRC processing, they cannot be corrected. When being read by an audio CD player, the incorrect data is interpolated. In other words, the CD player "makes up" some replacement data that it hopes will provide a seamless join between the preceding and following correct data. Very often, such an interpolation works very well. This isn't what EAC does. The reading drive reports an uncorrected C2 error, and EAC starts re-reading the same block over & over again, in the hope that the error will go away. But in most cases the error *doesn't* go away. My experience is that if EAC detects an uncorrectable error, it rarely pops out the other side of this process having eliminated it. And the normal result is an audible "tick" in the extracted WAV file. I have yet to see any evidence that EAC performs error concealment through interpolation in the way that audio players do. Even CDROM drives that have error interpolation capability (eg. my Plextor PX712A) are not utilised fully by EAC. I recently ripped a brand new CD that had uncorrectable errors, and only Plextools was able to get a clean result, precisely because it apparently knows how to instruct the drive to deploy its interpolation algorithm. EAC could not produce a tick-free result in any mode (secure, fast or burst). -- cliveb ------------------------------------------------------------------------ cliveb's Profile: http://forums.slimdevices.com/member.php?userid=348 View this thread: http://forums.slimdevices.com/showthread.php?t=24957 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
