Par2Par: p2p PAR2 sharing for CD rip repair

[bhoar]

Re: Par2Par: p2p PAR2 sharing for CD rip repair

It's a neat idea, but there are lots of missing questions...

What chunk size would you propose? Would track boundaries be involved or no? What percentage of missing data would the service need to store? And who would provide it?

The storage aspect is troubling me...unless...hmm.

Ah. I could see it working better if it were a P2P network that autogenerated the necessary parity based on the currently stored/verified disc images of participants, but also prevented users from downloading more than some %age of parity data. Whether that would increase or decrease the legal risks, I am not sure.

-brendan

[EliC]

Re: Par2Par: p2p PAR2 sharing for CD rip repair

I understand. I was just pointing out how if this argument was carried to the extreme even hashes could be illegal. Maybe the best way to do it would simply be having some sort of plugin architecture and someone could provide the plugin to the ripper.

This could be made even more legit by storing the par2 files only with the name and track # based on the disc ID key and NOT providing any mechanism to search for the par files except having the original disc and using that to calculate the disc ID key.

[LtData]

Re: Par2Par: p2p PAR2 sharing for CD rip repair

I agree with you totally on the moral side and would LOVE to have this. I'm just playing devil's advocate, that's all.

[EliC]

Re: Par2Par: p2p PAR2 sharing for CD rip repair

you could argue that you could potentially do the same thing with a hash. Say you know that only one bit is wrong and you know what the correct crc checksum is, you could change the bit and keep re-calculating the crcs until they match, then you must have the correct data. Its all very grey when it comes to the law, but I think clearly its within any moral boundries as you clearly must have 99+% of the original data for the par2 to do any good.

[LtData]

Re: Par2Par: p2p PAR2 sharing for CD rip repair

My point is the file that is downloaded doesn't contain any real data itself, correct. However, it is used to create the rest of the missing file. It could possibly be seen that the file you downloaded "contains" copyrighted data and is therefore illegal.

However, as you said, a lawyer would need to address this and I am also no lawyer.

Also, I do think this is a good idea for when you just can't get a CD to rip properly.

[EliC]

Re: Par2Par: p2p PAR2 sharing for CD rip repair

that would be the case if you just downloaded the missing part, but I would think that since the par2 file requires the rest of the file and is a mathmatic algorithm to rebuild the data based on the data you have that there would not be a copyright violation. Clearly a lawyer would need to address this and I am no lawyer.

[LtData]

Re: Par2Par: p2p PAR2 sharing for CD rip repair

Unfortunately, repairing the files involves rebuilding data you do not have available, therefore it could be seen that you are "downloading" data to complete your songs and therefore violating copyright law. With the RIAA being so... yea... these days, it is a big risk.

[EliC]

I mentioned this idea before and would like to bring it up again. With the goal of making the next iteration of dMC the ultimate and most popular CD Ripper I would like to re-suggest a feature that no other ripper has:

Data Repair/Recovery via PAR2 files

No matter how good a ripper is it cannot recover lost data (ie label side scratches...). The idea would be that users would alot a certain amount of disc space for the storage and sharing of PAR2 files created from their rips. The PAR2 files contain no music data and without the wav file could not be used to re-create the music. When a user attempts to rip a track with unrecoverable errors as much of the wav is ripped as possible. Then the system would use a unique disc identifier to search a p2p network (or central server is someone wanted to host it) for the par2 file to repair the rip. The CRC of the repaired file would then be compared with the AR db for a final check.

The system would require an original pressed cd with the same number of tracks with matching lengths per track, and matching AR checksums for accurately ripped tracks. Because the par2 files contain no music data (esentially its just metadata) and the original disc/ripped wav would be required, there should be no legal issues.