EAC-combined read / write sample offset correction-help

@ y-y , I agree that the read offset is all you need for what you want to do.

I want to address the AccurateRip.dll which should have been installed with EAC.
I tested with my version of EAC in my Program Files folder & when I took this file out of the "C:\Program Files\Exact Audio Copy " folder . The " Use AccurateRip with this drive " checkbox became Grey. As soon as I pasted it back in the box became white & could be checked.
My conclusion is you need to :
Uninstall EAC , reboot & install a new download of EAC .
The reason is I think your install of EAC has became corrupt.
If it hadn’t the Accurate rip would be working.

I’m still confused.
But anyway thanks for the help.
I wish things could be simpler …

I’m surprised you’re still confused…Especially since you’ve asked the exact same ?'s and have received some great help…
http://forum.dbpoweramp.com/showthread.php?t=24224
http://www.digital-inn.de/exact-audio-copy-english/41835-please-help-eac-installation-cache-offset-accuraterip-test-copy-secure-mode.html
http://www.hydrogenaudio.org/forums/index.php?showtopic=89632

And in case you didn’t really follow the guides here’s another link.
http://wiki.hydrogenaudio.org/index.php?title=EAC_Options

Are you by any chance using EAC in ’ Beginners mode’ ?..Cus if you are, some features are disabled and hidden, that includes offset correction which is set for you automagically…Read the info provided in links…

[QUOTE=t0nee1;2597836]Are you by any chance using EAC in ’ Beginners mode’ ?..Cus if you are, some features are disabled and hidden, that includes offset correction which is set for you automagically [/QUOTE]

@ t0nee1 . I didn’t even think of that . I never used “beginners mode” . Is there any way to go to “Expert” mode other than using the “Configuration” wizard again ?
Apparently y-y has the offset/speed tab .

@ y-y , Follow the steps at # 4 to check out your drive.

http://blowfish.be/eac/Burn/burn.html

Even if the procedure aboves says you can rip to .FLAC then convert don’t.
Rip to uncompressed .WAV on both the rips necessary.
If you leave the “read sample offset correction” at +6 & that is correct for your drive . The " Compare WAVs " window will be blank .
You also need to leave the " Write samples offset" in the “Writer” tab at “0” . For this test write.
If the " Compare WAVs " window stays blank then the correct write offset is “0”.
The correct “combined read / write sample offset correction” value is the “read” offset + the “write” offset .
I used both this method & I had a CD that was in the database too . One just verified the other. The results were the same.
I hope this helps .

[QUOTE=t0nee1;2597836]I’m surprised you’re still confused…Especially since you’ve asked the exact same ?'s and have received some great help…
http://forum.dbpoweramp.com/showthread.php?t=24224
http://www.digital-inn.de/exact-audio-copy-english/41835-please-help-eac-installation-cache-offset-accuraterip-test-copy-secure-mode.html
http://www.hydrogenaudio.org/forums/index.php?showtopic=89632

And in case you didn’t really follow the guides here’s another link.
http://wiki.hydrogenaudio.org/index.php?title=EAC_Options

Are you by any chance using EAC in ’ Beginners mode’ ?..Cus if you are, some features are disabled and hidden, that includes offset correction which is set for you automagically…Read the info provided in links…[/QUOTE]

With all due respect
I know what I wrote down where and when.
You should not be surprised at all because after all the Threads I have wrote i did not received an answer whether I can use the read offset without affecting the quality and accuracy of extraction. Even after I burn these files. (Quality and accuracy of the songs on my computer)
And whether the use of read offset only will make any damage.
I do not write again the same questions because I’m bored, but just because I do not understand or because I did not get an unequivocal answer.
Believe me, I first who want to end these Threads, to solve the problem and not to bother anyone.
Believe me I have no more power to it.im Sick of it. Maybe I should surrender and give up. And leave things unresolved with concern that the project I’m doing (a lot of money invested in the project ) just will be ruined.

But I thank you for your help anyway.

jonathan.

@ y-y

[QUOTE=y-y;2597854]And whether the use of read offset only will make any damage.[/QUOTE]
If what you have found at http://accuraterip.com/driveoffsets.htm for your drive is the correct read offset using it will produce the closest rip your drive is capable of.
The read offset only effects the “read” or rip of the CD . At that point you have an exact a rip as your drive is capable of.
Where the “write” offset comes into the process is when you write or burn the rip back to a CD disc with your drive. If the “write” offset is set incorrectly then the burn will be offset incorrectly.
I hope this doesn’t confuse you.
If the “read” offset is incorrectly set then the offset of the rip will be offset by that much . This means if you burn from that rip it will be incorrect on the burn . This assumes that the “write” offset is correct for your drive.
To add to the mix there are drives that are supposed to be better for ripping CDs . I suppose they are. I don’t have one of those & that is why I went to the trouble to set mine as best as I could.
Also any rip & burn is not going to give you exactly what is on a pressed commercial CD. Only the “master” mold can do that by pressing a new CD.

[QUOTE=cholla;2597857]@ y-y

If what you have found at http://accuraterip.com/driveoffsets.htm for your drive is the correct read offset using it will produce the closest rip your drive is capable of.
The read offset only effects the “read” or rip of the CD . At that point you have an exact a rip as your drive is capable of.
Where the “write” offset comes into the process is when you write or burn the rip back to a CD disc with your drive. If the “write” offset is set incorrectly then the burn will be offset incorrectly.
I hope this doesn’t confuse you.
If the “read” offset is incorrectly set then the offset of the rip will be offset by that much . This means if you burn from that rip it will be incorrect on the burn . This assumes that the “write” offset is correct for your drive.
To add to the mix there are drives that are supposed to be better for ripping CDs . I suppose they are. I don’t have one of those & that is why I went to the trouble to set mine as best as I could.
Also any rip & burn is not going to give you exactly what is on a pressed commercial CD. Only the “master” mold can do that by pressing a new CD.[/QUOTE]

Finally …
So you’re saying that if i use only “read offset” without “combined read / write sample offset correction” to read cds when i burn with WMP that’s will affect only the burned cd and will not affect at all on the extracted files Quality or accuracy that were Extracted by me from the original cd?

Everything will be exactly the same with the extracted files. only the accuracy of the burned cd will not be accurate because I have not defined the write offset on EAC?

:cool:

If the “read” offset is all that is used & it is the correct one for your drive . Then the “rip” will be as exact as your drive was capable of ripping. These files will remain on your hard drive & will be the same no matter what software you use to burn them to a CD.
Any "write " correction would need to be made in the writing(burning) software. If no write offset setting is made for the drive it will use the setting that is in it’s firmware.
I’m not sure of this but it is my understanding that the “write” offset in EAC will only be used if the “write” (burn) is done by EAC.
Other software would use whatever write offset their settings have if any. I’ve never burned a CD with WMP so I can’t say it has any setting for offset.
ImgBurn is my preferred burner & it doesn’t have any settings for offset. Since my drive has a “0” write offset the results are the same as if I used EAC’s writer. IMO ImgBurn is a better writer though.

[QUOTE=cholla;2597868]If the “read” offset is all that is used & it is the correct one for your drive . Then the “rip” will be as exact as your drive was capable of ripping. These files will remain on your hard drive & will be the same no matter what software you use to burn them to a CD.
Any "write " correction would need to be made in the writing(burning) software. If no write offset setting is made for the drive it will use the setting that is in it’s firmware.
I’m not sure of this but it is my understanding that the “write” offset in EAC will only be used if the “write” (burn) is done by EAC.
Other software would use whatever write offset their settings have if any. I’ve never burned a CD with WMP so I can’t say it has any setting for offset.
ImgBurn is my preferred burner & it doesn’t have any settings for offset. Since my drive has a “0” write offset the results are the same as if I used EAC’s writer. IMO ImgBurn is a better writer though.[/QUOTE]

If someone disagrees with the honorable member of this forum this is the time to say it.

This shoud be enough to confuse most it does me . I’m not giving any of these as accurate examples . Draw your own conclusions.

People are obsessive /compulsive about this subject. A lot more than I am. Keep in mind the offset sample is microseconds . I thought I would post some thoughts from a few other forums to prove this . They even refer back to the cdfreaks(club.myce forum.

What if I tell you that I have done an experiment
with industrial CD encoders and found your
reference point is 30 samples off from
the real absolute zero?

If you mean the drive used for the experiment, it was this : http://ch.twi.tudelft.nl/~sidney/fpga/sanyo.jpg
The “GND EFM” plug outputs the pits and lands seen at the CD’s surface.

The pits and lands are recorded with this : http://ch.twi.tudelft.nl/~sidney/fpga/fpga.jpg

…Then analyzed in the computer.

Read more : http://forum.cdfreaks.com/showthread.php?t=111913#post726955

IpseDixit does not rely on any factory offset. He looks at the raw digital data from the CD and builds up all the relationship between the time codes and the user data, until he finds, starting from the pits and lands themselves, the exact binary sample that is in relation with an exact time code.

I’ve talked to Rich Wall, at DCA (Doug Carson and Associates),
THE optical disc encoder company (www.dcainc.com),
he allowed me to disclose about the offset experiment:
he prepared a DDP file (Disc Descriptor Protocol) for me
where 1st byte of 00: 02.00 was !00 and encoded it
in a MIS VIII encoder (http://www.dcainc.com/products/MIS/MIS_V8/),
then captured signal from LBR (Laser Beam Recorder) into a bitstream
in a raw reading file, discovering encoder places main channel’s 1st byte
aligned into channel frame 00: 02.00, then came genial Mr. Sidney Cadot
(http://ch.tudelft.nl/~sidney/) with his FPGA audio readout system
(http://club.cdfreaks.com/showthread.php?t=111913 ), made with an
old drive which precisely returns such !00 when asked for 00:02.00,
Then I concluded when I saw such drive in Wiethoff’s database having
a +30 samples offset correction.

IpseDixit has likely discovered where the “absolute zero” is on a theoretically perfect audio CD, and it’s 30 samples (or 120 bytes or 5 frames) before where Andre thought it was.

  • The AccurateRip database is based on Andre’s offset values, so reading using the new offsets in EAC makes AccurateRip unusable.
  • Spoon and Andre, for good reason, don’t want to start over with AccurateRip.
  • This really shouldn’t matter to anyone, because a) CD’s themselves are manufactured with varying start points anyway, even with the same title, b) standard audio CD players are nowhere near as precise as we’re talking about, and c) we’re talking about 680 freaking milliseconds
  • There are always perfectionists and preservationists in the world, so many people are still upset about this.

DrazardX had the exact same idea I did. Couldn’t the following work? (Forgive me if this is wrongheaded; I primarily live on a Mac and have not yet been able to try all this out on a PC.)

  • Rip CD in EAC using the new corrected offsets to bin/cue
  • Add 120 nulls to the end of the bin (I don’t know enough about the bin format to know for sure if it is a linear dump of sectors; if not, then we could get the WAV instead as DrazardX did or perhaps tweak the cue sheet).
  • Remove the first 120 bytes, and save them somewhere if by some chance they’re not all null
  • Virtually mount the modified image and let AccurateRip check it out
  • If AccurateRip likes it, then put the 120 back on the beginning and remove the 120 from the end, and convert it to FLAC or AAC or whatever floats your boat.

It seems like this ought to allow the uberpurists to both rip with the “accurate” offsets and still check them with AccurateRip. As I said, I’ve been unable to try yet – but would this work?

I ripped the same track with both Andre’s offset and the new one.
Andre’s (old) = +97 (CRC=B8954265)
New = +67 (CRC=6E1701B7)

Luckily for me the first track began and ended with plenty of null samples.

I was going to be messing with the raw audio data, so I used wvunpack to decode my WavPacks to raw audio with the command (-mr).

Then, I opened up my hex editor (XVI32) and the old rip (Andre’s offset) (.raw). Then I added 120 bytes (=30 samples) to the beginning of the file and removed 120 bytes from the end. (I knew I was on the right track when I did a CRC hash in XVI32 and it matched the CRC from the new rip (6E1701B7))

After saving the new file, I encoded it to FLAC with the command (-V -8 --endian=little --sign=signed --channels=2 --bps=16 --sample-rate=44100). Then I decoded it to wav, and then encoded it back to WavPack. The original MD5 stored in both this new file and the one made from the new offset were exactly the same (2E4284CD29FEF1E0C19DD3D02658B289).

So, by using this method you can fix someone’s rip with a wrong offset simply with a hex editor. Although, if the samples in the end of each track are not null, you would have to do this with the album as one large wav. There is also the chance that some bytes may be missing from thier wrong offset, so it’s always important to check the beginning and end for null samples.

y-y I/we gave you some good advise(IMO)…Not sure what you mean by a “lot of money invested in the project” but frankly I really would try out dBpoweramp for it’s simplicity in setting up, and it’s trialware…20 days free(I think)…Trust me when I say this, it is really that much easier to set up, especially when you’re not gettin it…Other then that, it’s all I got for ya…
T. out:cool:

Okay,
I decided to read and write cds using the combined read / write sample offset correction.
I see no reason why not.

  • How do I make the test that will determine what is the combined read / write sample offset correction of my DVD RW? link?
    -combined read / write sample offset correction is used both to read and write cds?
    -combined read / write sample offset correction is used also to write cds with a software that is not EAC? for example WMP?
    -lets say that my read offset correction is : 6 + and my write offset correction is:- 6 and I use combined read / write sample offset correction.when reading a cd EAC will use 6+ offset? when writing a cd EAC will use -6 offset?
    -combined read / write sample offset correction exist To avoid filling every time the right offset for reading or writing? or for another reason?
    – If I extract a cd using the right combined read / write sample offset correction the extraction will be accurate as possible?

jonathan.

Okay,
I decided to read and write cds using the combined read / write sample offset correction.
I see no reason why not.

Exactly…

  • How do I make the test that will determine what is the combined read / write sample offset correction of my DVD RW? link?
    -combined read / write sample offset correction is used both to read and write cds?
    -combined read / write sample offset correction is used also to write cds with a software that is not EAC? for example WMP?

http://www.exactaudiocopy.de/en/index.php/support/faq/offset-questions/

-lets say that my read offset correction is : 6 + and my write offset correction is:- 6 and I use combined read / write sample offset correction.when reading a cd EAC will use 6+ offset? when writing a cd EAC will use -6 offset?
-combined read / write sample offset correction exist To avoid filling every time the right offset for reading or writing? or for another reason?

Your combined read/write offset is 0 based on what you’ve provided…Remember combined= read offset+ write offset

Here’s another hopefully helpful link/thread.
http://www.digital-inn.de/exact-audio-copy-english/41650-rip-w-eac-burn-something-else-what-offset.html

As t0nee1 has posted & I agree with him there are many programs that will do a good rip. Most of us(including myself) couldn’t hear the difference between a CD ripped with EAC & one of those.
Here is a list of some I’ve used:
EAC
dBpoweramp CD Ripper
Audio Grabber
CDEX
I haven’t used Nero for this but It will do it.
The point is rip a few CD’s with various programs . Burn to disc with various programs . Then just listen to them played on a good player with a good amp. Let you hearing be your guide as to what sounds the best.
That being said I did try to answer you questions below to the best of my knowledge.

[QUOTE=y-y;2597966] - How do I make the test that will determine what is the combined read / write sample offset correction of my DVD RW? link?[/QUOTE]
Read my post again here:


Follow the instructions on the blowfish guide with the ones I added.

[QUOTE=y-y;2597966] -combined read / write sample offset correction is used both to read and write cds? [/QUOTE]
Yes

[LEFT]A read made with EAC will have the combined offset in the files it writes to your hard drive . This will actually be the [B]Read offset . [/B][/LEFT]
It is permanently written in those files. When they are written to a disc the files will be offset on the burned disc. Whether EAC or other software is used.
If you use EAC to do the write then the combined read / write sample offset will be used again. This time it will actually be the [B]Write offset .[/B]
If you use another program to do the write(burn) it will not have a write offset to use . [B]Unless it has an option for this in it’s settings.[/B]

[QUOTE=y-y;2597966]-combined read / write sample offset correction is used also to write cds with a software that is not EAC? for example WMP? [/QUOTE]
Most other CD ripping programs don’t have a place to set either offset.
It is my understanding that the settings made in EAC only work when EAC is the program used. The EAC settings are not [B]GLOBAL[/B] for your OS or permanent for your drive.
EAC uses the AccurateRip formula for calculating offset . That is why they work together.

[QUOTE=y-y;2597966]-lets say that my read offset correction is : 6 + and my write offset correction is:- 6 and I use combined read / write sample offset correction.when reading a cd EAC will use 6+ offset? when writing a cd EAC will use -6 offset? [/QUOTE]
If your drive had this configuration & it probably [B]doesn’t [/B]the combined read / write sample offset would be 0 (zero) because you add the read & write together to get the combined read / write sample offset .

[QUOTE=y-y;2597966] combined read / write sample offset correction exist To avoid filling every time the right offset for reading or writing? or for another reason?[/QUOTE]
I’m not sure I understand the question . If you make this setting in EAC it is permanent until you change it . It works as long as you use EAC . Again it is not global.

[QUOTE=y-y;2597966]-- If I extract a cd using the right combined read / write sample offset correction the extraction will be accurate as possible? [/QUOTE]
Yes if what EAC uses the AccurateRip formula for calculating offset is correct .
As in my post above there is a lot of discussion & opinions on this.

There’s also iTunes which does a pretty good job as does f2k, MediaMonkey…Many just get too caught up in the I want a perrrrrfect rip, when in most cases the other alternatives do a pretty good/decent job…

case closed.

thanks.

Not quite ready to close the case as I think this will help others.

The instructions at the EAC site are somewhat confusing.
You have to wonder when they contain this;

[B](I hope this is correct)[/B]

How do I determine the combined read/write offset?
The combined read/write offset is only valid for the special combination of exactly one reading drive and exactly one writing drive. If you use another reading, you would most probably need a different combined offset. To determine this offset, you would need to write a CD-R/CD-RW. At first prepare WAV files you want to write to the CD. Then write it to a CD (either with any burning program, or with EAC using write offset 0). Do not delete the written WAV files. Afterwards you have to extract one or more tracks from the freshly burned CD, using the specific reader and using read offset 0. Of course you should not overwrite the original WAV files. Now you have to use the WAV Compare feature in EAC to compare the first WAV (original) with the second (reextracted one). Usually EAC will report either missing samples or extreneous samples. The number that is reported by that will be your combined offset, only be changed to positive or negative. If your original file has extreneous (repeated) samples or the copied file has missing samples the offset should be positive, otherwise it should be negative. [B] (I hope this is correct) [/B] To double check the found offset, use that offset as sample offset for reading. Now The reextracted file and the original should be the same without missing or extreneous samples.

I will try to break it down.

To determine this offset, you would need to write a CD-R/CD-RW. At first prepare WAV files you want to write to the CD.

By " Preparing the WAV files " . I have to assume that this means by reading with EAC after setting the read offset in the EAC Drive options to O(zero).
For this read(rip) . This makes the read offset of these WAV files the same amount of your drives combined read/write offset offset. This will determine the correct combined read/write offset when the test process is finished.

Then write it to a CD (either with any burning program, or with EAC using write offset 0).

This would be to a blank CD -R . It is correct for EAC & other software if that software doesn’t have an offset option. If it does the setting needs to be 0(zero). Write with the first ripped WAV files preferably with the same drive.

Do not delete the written WAV files.

These are the WAV files ripped with 0(zero) offset from an original pressed CD.

Afterwards you have to extract one or more tracks from the freshly burned CD, using the specific reader and using read offset 0. Of course you should not overwrite the original WAV files.

This is correct . Only one file is usually necessary . To add to this it should be read (extracted or ripped) from the same drive with EAC read offset still set at 0(zero) . Use a seperate folder for the new WAV files . This helps to keep them from getting mixed up.

Of course you should not overwrite the original WAV files.

Follow this advice . That is why a new seperate folder is necessary . If you don’t change the directory in EAC it will overwrite the original files. I haven’t done this for a while but EAC may give the option not to overwrite & save to a different folder.

Now you have to use the WAV Compare feature in EAC to compare the first WAV (original) with the second (reextracted one).

This is correct as far as it goes.
You need to open the original (first ripped) WAV first. Then the exact same title WAV from the burned CD that you read(ripped or extracted) to the seperate folder [B]second[/B].

Usually EAC will report either missing samples or extreneous samples.

Correct but if the window is blank the offset is 0(zero).

The number that is reported by that will be your combined offset

If you set the read to 0(zero) & the write to 0(zero) as in my extra instructions above what you get is your drives [B]combined read/write offset[/B] offset .

If your original file has extreneous (repeated) samples or the copied file has missing samples the offset should be positive, otherwise it should be negative.

This means;
If your original file has extreneous (repeated) samples or the copied file has missing samples the offset should be positive. This would be positive by the amount of samples .

If your original file has missing samples or the copied file has extreneous (repeated) samplesthe offset should be negative. This would be negative by the amount of samples .

(I hope this is correct) To double check the found offset, use that offset as sample offset for reading. Now The reextracted file and the original should be the same without missing or extreneous samples

This is not exactly correct all of the time . The offset determined by this process will always be the [B]combined read/write offset[/B]. That is where you should put the determined offset. The reason is in the process there is no way to tell if the drive also has a Write offset . If it does then it makes any read from a write it has done offset by that amount. From that point I don’t know how or if EAC can determine which is correct for the read or write from the combined read/write offset.
Here is my example of this & I’m not sure it is correct .
Take a drive that actually has a +6 read offset & a -6 write offset . The process above would show the combined read/write offset as 0(zero) .
When really any read that drive does will have a +6 offset & any write it does will have a - 6 offset.
Only by knowing the read & write offsets separately & putting those values in EAC separately could you be sure of an exact a copy as possible .
In the example drive EAC would treat the drive as if the read was 0(zero) & the write was 0(zero) . When that would be wrong . So all the reads & writes of the example drive wouldn’t actually be corrected by EAC.

My results:
According to Accurate rip my drive is supposed to be a +6 read offset.
I did several tests . When EAC is set to 0(zero) read & 0(zero) on my drive & I use the procedure above.
When the .WAV files are compared they show to be identical with no offset samples.
If my drive was actually +6 offset there should be either 6 repeated samples on the original extracted side or 6 missing samples on the burned rextracted side.
This is not the result I got.
When I did set the read to +6 read offset . I then got the 6 repeated samples on the original extracted side.
When I did set the read to +12 read offset . I then got the 12 repeated samples on the original extracted side.
So my drive’s read offset is 0(zero) maybe & what ever I change it to on the +(plus) side in EAC it will be that when compared with the 0(zero) read offset .WAV .
The "Create Offset Test CD " also come up with 0(zero) when tested with the “Detect read sample offset correction” button.

I haven’t yet tested but with the one drive. I intend to test my two other drives & see if I can determine if (zero) is correct for my main drive.
That still won’t be 100% sure but should let me know if it is off somewhere. Too bad drive manufacturers who could actually determine this don’t give that information on the drives they sell.

As a side note dBpowerAMP CD Ripper must automatically use AccurateRip to check for a drives offset . When it rips the offset is +6 .