Bug?

[mathmat]

Hi. As I'm very curious as to how AccurateRip works, I decided to do an experiment to see what would happen.

I ripped "Dark Side of the Moon" on my old computer (I think the drive offset was 102, but I'm not 100% sure) with iTunes a few years back and this is the AccurateRip result I got. I call it "Test 1."

Pink Floyd - Dark Side Of The Moon (Test 1) [AccurateRip DiscIDs: 009-000F86F4-0072C539-710A1109 009-000F85B4-0072BE5A-6F0A1109]
Track 1: AccurateRip Verified Confidence 143, Pressing Offset -893 [ARv2 CRC 277D87CB] C:\Users\A\Desktop\Dark Side Test\Dark Side Of The Moon (Test 1)\01 Speak To Me_Breathe.m4a
Track 2: AccurateRip Verified Confidence 143, Pressing Offset -893 [ARv2 CRC 63547C5D] C:\Users\A\Desktop\Dark Side Test\Dark Side Of The Moon (Test 1)\02 On The Run.m4a
Track 3: AccurateRip Verified Confidence 144, Pressing Offset -893 [ARv2 CRC 1740BA5D] C:\Users\A\Desktop\Dark Side Test\Dark Side Of The Moon (Test 1)\03 Time.m4a
Track 4: AccurateRip Verified Confidence 140, Pressing Offset -893 [ARv2 CRC 3A6FC960] C:\Users\A\Desktop\Dark Side Test\Dark Side Of The Moon (Test 1)\04 The Great Gig In The Sky.m4a
Track 5: AccurateRip Verified Confidence 146, Pressing Offset -893 [ARv2 CRC 59E1676D] C:\Users\A\Desktop\Dark Side Test\Dark Side Of The Moon (Test 1)\05 Money.m4a
Track 6: AccurateRip Verified Confidence 144, Pressing Offset -893 [ARv2 CRC 7EEB700C] C:\Users\A\Desktop\Dark Side Test\Dark Side Of The Moon (Test 1)\06 Us And Them.m4a
Track 7: AccurateRip Verified Confidence 143, Pressing Offset -893 [ARv2 CRC E277234D] C:\Users\A\Desktop\Dark Side Test\Dark Side Of The Moon (Test 1)\07 Any Colour You Like.m4a
Track 8: AccurateRip Verified Confidence 144, Pressing Offset -893 [ARv2 CRC C4DCCAB3] C:\Users\A\Desktop\Dark Side Test\Dark Side Of The Moon (Test 1)\08 Brain Damage.m4a
Track 9: AccurateRip Verified Confidence 144, Pressing Offset -893 [ARv2 CRC 3EB4CFBC] C:\Users\A\Desktop\Dark Side Test\Dark Side Of The Moon (Test 1)\09 Eclipse.m4a

I then ripped the same exact CD with my new computer (I believe the drive offset is 48) and I got this result. I call it "Test 2."

Pink Floyd - Dark Side Of The Moon (Test 2) [AccurateRip DiscIDs: 009-000F86F4-0072C539-710A1109 009-000F85B4-0072BE5A-6F0A1109]
Track 1: AccurateRip Verified Confidence 143, Pressing Offset -947 [ARv2 CRC 277D87CB] C:\Users\A\Desktop\Dark Side Test\Dark Side Of The Moon (Test 2)\01 Speak To Me_Breathe.m4a
Track 2: AccurateRip Verified Confidence 143, Pressing Offset -947 [ARv2 CRC 63547C5D] C:\Users\A\Desktop\Dark Side Test\Dark Side Of The Moon (Test 2)\02 On The Run.m4a
Track 3: AccurateRip Verified Confidence 144, Pressing Offset -947 [ARv2 CRC 1740BA5D] C:\Users\A\Desktop\Dark Side Test\Dark Side Of The Moon (Test 2)\03 Time.m4a
Track 4: AccurateRip Verified Confidence 140, Pressing Offset -947 [ARv2 CRC 3A6FC960] C:\Users\A\Desktop\Dark Side Test\Dark Side Of The Moon (Test 2)\04 The Great Gig In The Sky.m4a
Track 5: AccurateRip Verified Confidence 146, Pressing Offset -947 [ARv2 CRC 59E1676D] C:\Users\A\Desktop\Dark Side Test\Dark Side Of The Moon (Test 2)\05 Money.m4a
Track 6: AccurateRip Verified Confidence 144, Pressing Offset -947 [ARv2 CRC 7EEB700C] C:\Users\A\Desktop\Dark Side Test\Dark Side Of The Moon (Test 2)\06 Us And Them.m4a
Track 7: AccurateRip Verified Confidence 143, Pressing Offset -947 [ARv2 CRC E277234D] C:\Users\A\Desktop\Dark Side Test\Dark Side Of The Moon (Test 2)\07 Any Colour You Like.m4a
Track 8: AccurateRip Verified Confidence 144, Pressing Offset -947 [ARv2 CRC C4DCCAB3] C:\Users\A\Desktop\Dark Side Test\Dark Side Of The Moon (Test 2)\08 Brain Damage.m4a
Track 9: AccurateRip Verified Confidence 144, Pressing Offset -947 [ARv2 CRC 3EB4CFBC] C:\Users\A\Desktop\Dark Side Test\Dark Side Of The Moon (Test 2)\09 Eclipse.m4a

As you can see, the Disc IDs, the confidence values, and the CRCs all were identical. The only difference was the offsets, but they were the same for each track for each rip.

Then I decided to do a little "mix and match." I took tracks 2, 3, 5, and 6 from Test 1 (1st rip) and tracks 1, 4, 7, 8, and 9 from Test 2 (2nd rip) so I'd have the whole album, which I call "Test 3." (This was NOT another rip. Just taking some tracks from the 1st rip and combining them with the remaining tracks from the 2nd rip.) I then did a PerfectTUNES check and this is the result I got:

Pink Floyd - Dark Side Of The Moon (Test 3) [AccurateRip DiscIDs: 009-000F86F4-0072C539-710A1109 009-000F85B4-0072BE5A-6F0A1109]
Track 1: AccurateRip Verified Confidence 143, Pressing Offset -947 [ARv2 CRC 277D87CB] C:\Users\A\Desktop\Dark Side Test\Dark Side Of The Moon (Test 3)\01 Speak To Me_Breathe.m4a
Track 2: AccurateRip Verified Confidence 126, Pressing Offset +571 [ARv2 CRC AC131AAB] C:\Users\A\Desktop\Dark Side Test\Dark Side Of The Moon (Test 3)\02 On The Run.m4a
Track 3: AccurateRip Verified Confidence 144, Pressing Offset -893 [ARv2 CRC 1740BA5D] C:\Users\A\Desktop\Dark Side Test\Dark Side Of The Moon (Test 3)\03 Time.m4a
Track 4: Track InAccurate C:\Users\A\Desktop\Dark Side Test\Dark Side Of The Moon (Test 3)\04 The Great Gig In The Sky.m4a
Track 5: AccurateRip Verified Confidence 125, Pressing Offset +571 [ARv2 CRC 98366636] C:\Users\A\Desktop\Dark Side Test\Dark Side Of The Moon (Test 3)\05 Money.m4a
Track 6: AccurateRip Verified Confidence 144, Pressing Offset -893 [ARv2 CRC 7EEB700C] C:\Users\A\Desktop\Dark Side Test\Dark Side Of The Moon (Test 3)\06 Us And Them.m4a
Track 7: AccurateRip Verified Confidence 123, Pressing Offset +517 [ARv2 CRC 6C5C8321] C:\Users\A\Desktop\Dark Side Test\Dark Side Of The Moon (Test 3)\07 Any Colour You Like.m4a
Track 8: AccurateRip Verified Confidence 144, Pressing Offset -947 [ARv2 CRC C4DCCAB3] C:\Users\A\Desktop\Dark Side Test\Dark Side Of The Moon (Test 3)\08 Brain Damage.m4a
Track 9: AccurateRip Verified Confidence 144, Pressing Offset -947 [ARv2 CRC 3EB4CFBC] C:\Users\A\Desktop\Dark Side Test\Dark Side Of The Moon (Test 3)\09 Eclipse.m4a

I don't understand what happened with Test 3. It's obviously in the AccurateRip database. The Disc IDs are identical to those of Test 1 and Test 2. Tracks 1, 3, 6, 8, and 9 are identical in confidence, offset, and CRC to the values they have in Test 2, Test 1, Test 1, Test 2, and Test 2 respectively. This is expected.

But then what happened with tracks 2, 4, 5, and 7? The confidence and offsets and CRCs were different than the corresponding values in Test 1 and Test 2! And track 4 came back as Inaccurate! Yet they are the same tracks, bit for bit, as those in Test 1, Test 2, Test 1, and Test 2 respectively.

How is it that 5 tracks came back identical to their corresponding earlier checks, yet 4 were completely different, with one of those being Inaccurate? I'm clearly getting contradictory results. (Like I said, this was not a new rip. They are the identical files that were tested prior.)

If anybody can help explain what happened here I'd be very grateful.

Thanks!

P.S. This actually occurred with a few CDs. I got identical results with all the CDs I did this test with. I just posted Dark Side of the Moon.

[dbfan]

Re: Bug?

Because to match it has to use parts from the previous file, mixing files will mess this process.

[garym]

Re: Bug?

Because to match it has to use parts from the previous file, mixing files will mess this process.

to clarify, he means by "previous file" he means prior track from the same CD. So once you mix and match tracks from different rips, this interjects errors in the process, as, for example, track 3 and track 4 are not from the same rip. And if the perfecttunes testing of Track 4 relies on track 3, but track 3 was from a different rip, then the problem you see occurs. Note, this is why PerfectTunes can only perform an AccuraterRip match on a complete album, not on an individual track basis.

[mathmat]

Re: Bug?

to clarify, he means by "previous file" he means prior track from the same CD. So once you mix and match tracks from different rips, this interjects errors in the process, as, for example, track 3 and track 4 are not from the same rip. And if the perfecttunes testing of Track 4 relies on track 3, but track 3 was from a different rip, then the problem you see occurs. Note, this is why PerfectTunes can only perform an AccuraterRip match on a complete album, not on an individual track basis.

Hi garym. Happy New Year. Thanks for your answer. I figured this was likely the reason. The interesting thing is that if I didn't know what I did, I would see a log that would suggest a track that came back inaccurate, but in reality was accurate!

Also, one of the other CDs I did this with, the 1st rip all the tracks had an offset of 102, and the tracks from the 2nd rip also all had offsets of 102, and the results came back fine. I'll post that log:

Cream - The Very Best Of Cream (AL) [AccurateRip DiscIDs: 020-00336753-02FBEC1D-3710D514]
Track 1: AccurateRip Verified Confidence 44, Pressing Offset +102 [ARv2 CRC 19464A99] C:\Users\A\Desktop\Lossless CD Rips\Other\The Very Best Of Cream (AL)\01 Wrapping Paper.m4a
Track 2: AccurateRip Verified Confidence 43, Pressing Offset +102 [ARv2 CRC E1134EE5] C:\Users\A\Desktop\Lossless CD Rips\Other\The Very Best Of Cream (AL)\02 I Feel Free.m4a
Track 3: AccurateRip Verified Confidence 43, Pressing Offset +102 [ARv2 CRC 3CFCA856] C:\Users\A\Desktop\Lossless CD Rips\Other\The Very Best Of Cream (AL)\03 N.S.U..m4a
Track 4: AccurateRip Verified Confidence 43, Pressing Offset +102 [ARv2 CRC 8CF269A9] C:\Users\A\Desktop\Lossless CD Rips\Other\The Very Best Of Cream (AL)\04 Sweet Wine.m4a
Track 5: AccurateRip Verified Confidence 43, Pressing Offset +102 [ARv2 CRC C4C1917B] C:\Users\A\Desktop\Lossless CD Rips\Other\The Very Best Of Cream (AL)\05 I'm So Glad.m4a
Track 6: AccurateRip Verified Confidence 43, Pressing Offset +102 [ARv2 CRC FC7C0F85] C:\Users\A\Desktop\Lossless CD Rips\Other\The Very Best Of Cream (AL)\06 Spoonful.m4a
Track 7: AccurateRip Verified Confidence 43, Pressing Offset +102 [ARv2 CRC C9EEC728] C:\Users\A\Desktop\Lossless CD Rips\Other\The Very Best Of Cream (AL)\07 Stange Brew.m4a
Track 8: AccurateRip Verified Confidence 43, Pressing Offset +102 [ARv2 CRC 98AC1EE3] C:\Users\A\Desktop\Lossless CD Rips\Other\The Very Best Of Cream (AL)\08 Sunshine Of Your Love.m4a
Track 9: AccurateRip Verified Confidence 43, Pressing Offset +102 [ARv2 CRC 7D1C284B] C:\Users\A\Desktop\Lossless CD Rips\Other\The Very Best Of Cream (AL)\09 Tales Of Brave Ulysses.m4a
Track 10: AccurateRip Verified Confidence 43, Pressing Offset +102 [ARv2 CRC 0EE0EFA2] C:\Users\A\Desktop\Lossless CD Rips\Other\The Very Best Of Cream (AL)\10 Swlabr.m4a
Track 11: AccurateRip Verified Confidence 43, Pressing Offset +102 [ARv2 CRC 363EADAC] C:\Users\A\Desktop\Lossless CD Rips\Other\The Very Best Of Cream (AL)\11 We're Going Wrong.m4a
Track 12: AccurateRip Verified Confidence 43, Pressing Offset +102 [ARv2 CRC B7A59B38] C:\Users\A\Desktop\Lossless CD Rips\Other\The Very Best Of Cream (AL)\12 White Room.m4a
Track 13: AccurateRip Verified Confidence 43, Pressing Offset +102 [ARv2 CRC FE9CF03D] C:\Users\A\Desktop\Lossless CD Rips\Other\The Very Best Of Cream (AL)\13 Sitting On Top Of The World.m4a
Track 14: AccurateRip Verified Confidence 43, Pressing Offset +102 [ARv2 CRC 80DFB51C] C:\Users\A\Desktop\Lossless CD Rips\Other\The Very Best Of Cream (AL)\14 Politician.m4a
Track 15: AccurateRip Verified Confidence 42, Pressing Offset +102 [ARv2 CRC D5DE3A2C] C:\Users\A\Desktop\Lossless CD Rips\Other\The Very Best Of Cream (AL)\15 Those Were The Days.m4a
Track 16: AccurateRip Verified Confidence 43, Pressing Offset +102 [ARv2 CRC 9752ADE7] C:\Users\A\Desktop\Lossless CD Rips\Other\The Very Best Of Cream (AL)\16 Born Under A Bad Sign.m4a
Track 17: AccurateRip Verified Confidence 42, Pressing Offset +102 [ARv2 CRC 3E51B203] C:\Users\A\Desktop\Lossless CD Rips\Other\The Very Best Of Cream (AL)\17 Deserted Cities Of The Heart.m4a
Track 18: AccurateRip Verified Confidence 42, Pressing Offset +102 [ARv2 CRC CEAEABC4] C:\Users\A\Desktop\Lossless CD Rips\Other\The Very Best Of Cream (AL)\18 Crossroads.m4a
Track 19: AccurateRip Verified Confidence 43, Pressing Offset +102 [ARv2 CRC F5F1BB3C] C:\Users\A\Desktop\Lossless CD Rips\Other\The Very Best Of Cream (AL)\19 Anyone For Tennis.m4a
Track 20: AccurateRip Verified Confidence 42, Pressing Offset +102 [ARv2 CRC 89FD1285] C:\Users\A\Desktop\Lossless CD Rips\Other\The Very Best Of Cream (AL)\20 Badge.m4a

Here tracks 14 and 15 were from a different rip. But the logs of the original 2 rips that I mixed and matched from were identical. Confidence, offsets, and CRCs. Also, the mix and match log was identical to the logs from the 2 rips. So all 3 logs were identical to each other.

So it would seem that it's the different offsets from the 2 rips that are causing the strange log in Dark Side of the Moon. Is that correct?

I'm assuming, also, that in this case of the Cream CD, the because the offsets are all the same, the corresponding tracks from each rip are bit for bit identical, hence mixing and matching doesn't make a difference. Is that correct?

[garym]

Re: Bug?

I'm assuming, also, that in this case of the Cream CD, the because the offsets are all the same, the corresponding tracks from each rip are bit for bit identical, hence mixing and matching doesn't make a difference. Is that correct?

Happy New Year to you too! Your thoughts above are probably correct. But I'm no expert on the mechanics of AccurateRip. All I know is that it is the only tool of its kind for doing comparisons of bitperfect rips across different physical CDs ripped on different machines. So for now it's all I have for confirming my rips are as perfect as possible.

p.s. I don't fully understand aerospace engineering and all the ins and outs of how airplanes work. But I still get on airplanes all the time because they are the best bet I have for long distance travel until something else is invented.

[mathmat]

Re: Bug?

I looked at the other logs that I did this experiment with and it seems to support my theory on the offsets. That is, if a track (B) in the "mix and match" follws a track (A) from the same rip, track B corresponds to the rip it came from. And if a track (B) from one rip follows a track (A) from the other rip, I get the unusual results above for that track B. (Assuming the offsets are different.)

Would it be ok if I sent you a PM? I have a question I'd love to ask you that I think you can help me with. Thanks.

[garym]

Re: Bug?

I looked at the other logs that I did this experiment with and it seems to support my theory on the offsets. That is, if a track (B) in the "mix and match" follws a track (A) from the same rip, track B corresponds to the rip it came from. And if a track (B) from one rip follows a track (A) from the other rip, I get the unusual results above for that track B. (Assuming the offsets are different.)

Would it be ok if I sent you a PM? I have a question I'd love to ask you that I think you can help me with. Thanks.

sure, PM me.