Option to check AccurateRip DB checksums before ripping

[drjaska]

Hey,

I have come across a few slightly scratched discs which have "Unreported loss of streaming/other error in read" for some tracks according to cdparanoia when they are read. When whipper reads these discs' tracks they are read repeatedly until a pair of reads lands on the same checksum.

For tracks which have just a few checksums they flicker between it's not impossible to keep reading the whole disc in an attempt to check whether or not a read matches the AccurateRip DB checksums or not. But for tracks which have hundreds of these the odds are astronomical to get a pair to land on the correct checksum.

Could it be possible to allow whipper to check AccurateRip DB checksums before reading the disc's tracks for their content and allow just a single read to be passed in the case that it matches the AccurateRip DB checksum?

This would save some time for tracks which flicker between just a few checksums, while for tracks which have hundreds of checksums it would essentially enable fishing for just a singular good read from the damaged disc.

PS. Thanks for the great software!

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[drjaska]

From what I can tell we have a cue table when we begin ripping. We can use this cue table to fetch the responses from AccurateRip before ripping any tracks. While ripping we can calculate the AR checksums for each track we rip and rerip in the case that the checksums do not match, and do this without ripping the track a second time for testing the checksum.

I just have not at all pieced together how to do that with code yet. Many of the class methods do not clearly state the information they expect to have as pre-requisites and there are nested and nested data structures all over the place making it very hard to piece together the code for any even a bit larger functions.