Add option to consider subcode descyncs as bad sectors

[Sazpaimon]

For damaged discs, subcode desyncs is more often than not a sign that the drive is reading the wrong sectors. There should be an option to not save these reads until the desync goes away.

[ehw]

to add to this, couldn't you do a msf sequence check for data tracks that store that info to ensure that the sector being returned is in sequence with what comes before and after?

to add some context - we were dumping a disc and noticed that a single sector in the data track that fell out of sequence got returned and was used to replace all the bytes that had been read for a bad sector during refine mode. redumper acknowledged the subcode desync, but because the sector data being returned had no c2 errors or edc/ecc errors, it replaced the bytes and changed the sector header for the affected sector. the sector that was being refined wasn't necessarily surrounded by more erroneous sectors, and one of the drives reported a low c2 error bit count for it too.

i wonder if there's something that can be done to handle situations like this?

[ehw]

adding an additional note - we're seeing that its more likely that you will have subcode desyncs made in error if the read speeds are set too low.

this issue is more apparent when redumper returns both a subcode desync and a successful correction in the same pass in a given sector.

(i have no idea where the rumor that reading discs at slow speeds helps with bad discs came from but thats being proven false every day)