Guide to Proper Lossless Rips

Well, the only thing i have done to the file is move it from one HDD to another. From SATA to PATA.

Now i have read somewhere else that this sort of thing could be hardware related, something like bad transfer between HDD's, something wrong with the mobo, bad drivers, overclocking, bad sectors on HDD's etc etc, but i am really not sure.

When it comes to .rar files, i ocasionally have CRC errors. No, wait, scratch that. Recently, a lot of CRC errors. Maybe there is a connection. Im not really good with these sorts of things.

There has to be, if you get frequent CRC errors and the like, somewhere down the line data corruption is occuring. I'd suggest making some RARs and transferring them to see if a faulty connection (or HDD) is the problem. Trust me, from what I've heard so far, corrupted FLAC files is the least of your worries. Try to figure out if it's the PATA or SATA HDD (or the connection between the two), then you can find out what to do next.

Well i dont know what to make of this. I tried compressing an album that was in wav and cuting/pasting it from HDD to HDD to check if some CRC error poped up. There were no errors.

Then i compressed an album that was in flac, did the same thing, cuting/pasting it from HDD to HDD. The first transfer got me a CRC error right away.

I don't know what to do next, maybe checking the HDD's with some scanning program? What are some good HDD scanning programs?

Quote:

Trust me, from what I've heard so far, corrupted FLAC files is the least of your worries.

Please elaborate. Is it that bad?

Originally Posted by YoMan

Well i dont know what to make of this. I tried compressing an album that was in wav and cuting/pasting it from HDD to HDD to check if some CRC error poped up. There were no errors.

Then i compressed an album that was in flac, did the same thing, cuting/pasting it from HDD to HDD. The first transfer got me a CRC error right away.

I don't know what to do next, maybe checking the HDD's with some scanning program? What are some good HDD scanning programs?



Please elaborate. Is it that bad?

WAV files have no CRC information whatsoever. Meaning if one or 99% of the file is corrupted, you won't know (unless the header is bad as well).
With RARs and FLAC files you can tell if file corruption has happened (the non-malicious kind at least), but with WAVs and files that have little or no error checking (and critical system files). It seems either the new HDD is bad or the transfer sucks. In either case it's worthy of concern. Try making files (not just transferring them) on the SATA HDD and see what happens when you cut and paste it to a new folder, hopefully it should be fine; if not, your hard drive could be bad.

BTW: WAV files only report a bad CRC when Windows detects an error from the source disk (like from a stratched CD or bad floppy).

Okey, here is what i have done:

1. Compressed a flac album into one .rar file using winrar.

2. Move that file around old folders/new folders/different HDD's (I have 3 in this case) and tried to unpack and test it if its got any CRC errors.

3. The result: nothing, no CRC's errors whatsoever. My guess is that this thing happens randomly because i can't seem to find any pattern here. Sometimes it gets an error, sometimes it don't.

But why are errors such a big problem with flac files opposed to say mp3 files?

And a little humor to close off this post:

As i type this i see that my google ads read:

1. Corrupt File?
Free Registry scan, fix errors and improve PC performance. Try it now

2. Fix Corrupt Files Fast
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I thought it was kind of funny

Originally Posted by YoMan

Okey, here is what i have done:

1. Compressed a flac album into one .rar file using winrar.

2. Move that file around old folders/new folders/different HDD's (I have 3 in this case) and tried to unpack and test it if its got any CRC errors.

3. The result: nothing, no CRC's errors whatsoever. My guess is that this thing happens randomly because i can't seem to find any pattern here. Sometimes it gets an error, sometimes it don't.

But why are errors such a big problem with flac files opposed to say mp3 files?

And a little humor to close off this post:

As i type this i see that my google ads read:

1. Corrupt File?
Free Registry scan, fix errors and improve PC performance. Try it now

2. Fix Corrupt Files Fast
All Corrupt Files Fixed Instantly Free Scan, Repair 100% Guaranteed

I thought it was kind of funny

being lossless, FLAC files depend on perfect (or very near perfect) file integrity for decoding, mp3 files have very good fault tolerance to corruption (due to their nature to be streamed), they just skip ahead to the next decodable frame.

What I do to guard my FLAC files against corruption is I use a program called QuickPar to make PAR2 recovery files for the FLACs. Then I burn the FLACs, the recovery files and a QuickPar installer all together to a DVD.

I have QuickPar set up to make its recovery files 20% of the size of the original data. Probably overkill... I think the default is 10%.

I use SFVs to keep check on my FLACs and keep more than just a single DVD back-up, but also all of my music is on two EXT HDDs that are only used for storing the music...

They are also read-only access!

I don't get why people use simple checksum tools for their own data. If you find corrupt files, what can you do but re-rip or re-download them? Seems kind of pointless to me.

I'd rather sacrifice some storage space to be able to actually recover corrupted files.

Originally Posted by ArrowHead

What I do to guard my FLAC files against corruption is I use a program called QuickPar to make PAR2 recovery files for the FLACs. Then I burn the FLACs, the recovery files and a QuickPar installer all together to a DVD.

I have QuickPar set up to make its recovery files 20% of the size of the original data. Probably overkill... I think the default is 10%.

Have you tested the robustness of QuickPar? I'd like to see how much you can corrupt a file before it becomes unreadable.

I used to make par2 files when I backed up music to guard from inevitable CRC errors. But then I realized I was killing my self trying to make them; very time/space consuming. I just gave up. I probably *should* do it for rarer things but for just downloads in general, it's just too much effort.

Originally Posted by Eleo

I used to make par2 files when I backed up music to guard from inevitable CRC errors. But then I realized I was killing my self trying to make them; very time/space consuming. I just gave up. I probably *should* do it for rarer things but for just downloads in general, it's just too much effort.

Doesn't sound too much of a waste of space to me. 10% backup of 4GB of files is 409.6MB.

Still takes a great deal of time to deal with.

Maybe if their was a tool that allowed me to drag and drop several folders and just make par2 files and move them somewhere. Then I could just go ahead and make par2 files for all the stuff I've already backed up and future stuff as well.

But I instead always have to drag/drop chunks of flac files, logs and cues, artwork, etc. Then there's sometimes multiple discs and such; subdirectories. I just got done backing up 200GB worth of lossless and grew tired after making par2 files for the 20th DVD or so. I thought, forget it, if some stuff get's CRC errors on it then so be it. Maybe I'll make par2 files later for rarer stuff (presumably VGM since 99% of the lossless music community doesn't have or share any.)

To help myself I've bought more reliable (expensive) media; as I have most generally gotten CRC errors on cheaper, more generic media. Ideally I'd get some Taiyo Yuden discs, but right now I am using Ritek/Ridata and Verbatim.

EDIT: Also let's not forget that DVDs have a certain amount of error correction native to their design.

Anyone have a Philips DVD+-RW (DVD8801) drive? That's one of the drives that my new PC came with, but don't see it listed at the offset site. The other drive a LG DVD-ROM (GDR-8164B) is listed though...

BTW, any ideas if these are decent drives?

You might have to detect the read offset in a more manual way.

You can do this by ripping a WAV with your LG drive using its correct read offset. Then, rip the same track with your Philips drive, configured with no offset, to WAV. Then you can use EAC's WAV comparison (Tools > Compare WAVs) to see if there are missing or duplicate samples between them.

I believe if there are duplicate samples then your Philips drive would be reading too early; you want to take the number of sample differences and create a positive offset from that. If there are missing samples then your drive is reading too late, you want to take the difference in samples and create a negative offset from that.

Or it might actually be vice-versa of what I said (positive for missing samples, negative for dupe samples). Keep playing around with it until WAVs ripped from both drives are identical (ie no difference in samples).

Will give it a try I guess. Thanks...

If you have the right CDs, you can find the read offset by using AccurateRip. If you CD-ROM is in the database, it'll automatically set the offset, if not you'll need three CDs on the offset list (which is over 20,000; compared to the 100ish that EAC uses internally).

Oh, I thought it was a no-go with AccurateRip unless your drive was in the database. Finding 3 CDs can be a bitch, though, as there are different pressings of certain CDs, so even though it says Nirvana - In Utero will work, your copy of it might not work and can't be used for detection.

Thanks for the help guys! It ended up being the same offset that they use on their other DVD-RW drives though. Tested both using the offset and not doing so, it worked, so...

Hopefully, I'll find the write offset soon enough!