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iTunes does not rip accurate audio data - Page 3

post #31 of 199
1/29/08 at 12:26am
Quote:
Originally Posted by IPodPJ View Post
ALAC isn't lossless. If it were, the file data (and therefore how it sounds) would be identical to the verified, extracted audio data that EAC grabs from a CD.
No, this is absolutely wrong. You are changing two variables (the encoder and the ripping software) and then reaching an incorrect conclusion about the encoder. You need to change just one variable.

Rip a song in iTunes to .wav. Then convert that same track to ALAC. Bit compare them in Foobar. I guarantee you they will be identical.
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post #32 of 199
1/29/08 at 12:29am
Thread Starter 
Quote:
Originally Posted by servoled View Post
That assumes the input data was identical, see my post above.

If you really want to test it, start with a WAV file, encode the WAV file using ALAC, and then compare the resulting ALAC file to the original WAV file.
What's the point of that? Why would Apple make a lossless compression format that their own music software can't rip accurately? The whole purpose of a media server program ripping lossless files is to do so from an original CD, not to have to make a WAV file first with different audio extraction software.

Yes, you could be correct. Perhaps it's not the codec, perhaps it's iTunes itself. But since ALAC is a propietary Apple format and iTunes is their propietary media management software, if neither one of them work properly it is pointless to use that compression format.
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post #33 of 199
1/29/08 at 12:30am
Thread Starter 
Quote:
Originally Posted by Febs View Post
Rip a song in iTunes to .wav. Then convert that same track to ALAC. Bit compare them in Foobar. I guarantee you they will be identical.
Yes, I've already said that. I know THEY will be identical. But what good are two identical files that don't match the actual data on the CD?

See my above post.
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post #34 of 199
1/29/08 at 12:31am
this guys nuts man ALAC is lossless and no you can't hear the differance...
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post #35 of 199
1/29/08 at 12:31am
Quote:
Originally Posted by IPodPJ View Post
Yes, I've already said that. I know THEY will be identical.
And yet that didn't stop you from creating this thread.
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post #36 of 199
1/29/08 at 12:32am
The problem would appear to be not with the ALAC compression, but with the iTunes ripping process.

Try this:
Rip a track with EAC, use iTunes to compress that track to ALAC. Compare it to the original wav.
Are they the same?

Then try:
Rip a track with EAC. Rip the same track with iTunes. Don't compress either. Compare the wav files.
Are they the same?

Edit: Doh, too slow...
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post #37 of 199
1/29/08 at 12:35am
Thread Starter 
Quote:
Originally Posted by Febs View Post
And yet that didn't stop you from creating this thread.
Ok, I'll modify the thread title to reflect that.
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post #38 of 199
1/29/08 at 12:37am
Quote:
Originally Posted by IPodPJ View Post
What's the point of that? Why would Apple make a lossless compression format that their own music software can't rip accurately? The whole purpose of a media server program ripping lossless files is to do so from an original CD, not to have to make a WAV file first with different audio extraction software.

Yes, you could be correct. Perhaps it's not the codec, perhaps it's iTunes itself. But since ALAC is a propietary Apple format and iTunes is their propietary media management software, if neither one of them work properly it is pointless to use that compression format.
ALAC works perfectly fine. The iTunes ripper on the other hand is probably not the best out there, but its good enough for the vast majority of people who would rather have a close enough rip quickly than take the time to rip it correctly. I've never tested either EAC or iTunes on ripping accuracy, but I'll give it a try and post the results.
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post #39 of 199
1/29/08 at 12:41am
Thread Starter 
Quote:
Originally Posted by servoled View Post
ALAC works perfectly fine. The iTunes ripper on the other hand is probably not the best out there, but its good enough for the vast majority of people who would rather have a close enough rip quickly than take the time to rip it correctly. I've never tested either EAC or iTunes on ripping accuracy, but I'll give it a try and post the results.
The iTunes ripper is not close. It's not even close to close. The audio difference is obvious. Try it and you'll see. 16.9 million samples being different proves that it's not even close to the original audio data on the CD. This also explains why so much of my music library seems to have distortion when none is present on the CD.

But yes, I guess it's good enough for most since the vast majority of iTunes users use 128kbit MP3 files anyway. But we are on Head-Fi because we want the purest audio experience possible. I wouldn't post a thread about audio quality on the Apple website, however Apple should be made aware that iTunes for PC is total garbage. I love the interface but it's pointless for me to use if the audio quality stinks. And I won't even get into the horrible quality of audio playback in iTunes since that has been discussed in numerous threads already.
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post #40 of 199
1/29/08 at 12:47am

del


Edited by servoled - 4/11/11 at 7:48pm
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post #41 of 199
1/29/08 at 12:50am
I ripped a track to .wav using EAC and then ripped the same track using iTunes and had similar results as what servoled posted:

Quote:
Comparing:
"C:\MED_Docs\Music\The Eagles\Their Greatest Hits\01 Take It Easy 4.wav"
"C:\MED_Docs\Music\01 Take It Easy 2.flac"
differences found: 18672320 sample(s), starting at 0.5926984 second(s), peak: 0.0189819 at 0.9886621 second(s), 2ch
I suspect that it is a volume difference and just did an experiment that suggests that this is the case. I'm going to try something else and report back.
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post #42 of 199
1/29/08 at 12:51am
A lossless rip will not neccesarily be bit-accurate with the original CD file UNLESS you do a secure bit-accurate rip. That is not a problem with the codec but a problem with the ripping software. Bit accurate (secure) rips can be time consuming so for most software it is not the default option. This is the case with dbpoweramp. But if you do secure rips with it you will get identical results when comparing the FLAC rip to the original CD. I know as I did extensive (approx. 30 random CD's) comparisons of FLAC encoded to rips to the original CD files. I can't comment on itunes and ALAC as I do not use either one.
As far as the compression levels for FLAC the reason for the options is historical. On older computing platforms high compression (-8) rips could take inordinately and painfully long times. that is rarely the case today with modern computing platforms (fast CPU's and gobs of RAM).
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post #43 of 199
1/29/08 at 12:56am
If your rips aren't accurate using iTunes, all you have to do is go to...

PREFERENCES/ADVANCED/IMPORTING

...and check the box that says USE ERROR CORRECTION.

That'll solve your problem.

See ya
Steve
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post #44 of 199
1/29/08 at 12:59am
Quote:
Originally Posted by Febs View Post
I suspect that it is a volume difference and just did an experiment that suggests that this is the case. I'm going to try something else and report back.
Bingo.

In EAC, go to "EAC Options" --> "Normalize," and make sure that the "normalize to" option is unchecked.

Comparison of iTunes rip with EAC rip with the "normalize" option unchecked in EAC:

Quote:
Comparing:
"C:\MED_Docs\Music\01 Take It Easy 3.wav"
"C:\MED_Docs\Music\The Eagles\Their Greatest Hits\01 Take It Easy 4.wav"
No differences in decoded data found.
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post #45 of 199
1/29/08 at 12:59am

del


Edited by servoled - 4/11/11 at 7:49pm
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