WAV=>CD=>EAC=>(exact same) WAV

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WAV=>CD=>EAC=>(exact same) WAV

2004-07-05 17:21:15

I'm trying to burn a WAV and then be able to extract with EAC or any other program and have the exact same WAV. I tried with Nero but I beleive it converted the song even though it was already a WAV, when I extracted it it was completely different it was at least 1Mb smaller. The I thought Windows would be dumber (I was not in my 5 senses), and tried the built-in burner, obviously Bill did some kind of conversion in WMP to my song. How can i burn it as-it-is?

WAV=>CD=>EAC=>(exact same) WAV

Reply #1 – 2004-07-05 17:54:17

I assume that you've already disabled all options you can think of that'd change the files, EAC's normalizing during reextration for example.
Be sure to use the correct write offset, if you're writing with EAC.
Then reextract using the correct read offset correction.If you're using another program than EAC for writing, use the correct combined read/write offset correction.
Be also sure that all your wavs can be divided into CD sectors (1 sector=588 samples), otherwise your writer lengenths/shortens the wavs.
These two things are absolutely neccessary.

edit: And yes, what you want to do is possible.I do it all the time.

WAV=>CD=>EAC=>(exact same) WAV

Reply #2 – 2004-07-05 18:32:04

perfectionist:

Can you explain me thoroughly how to do it. I'm a newbie to audio extraction, who do I set the offset? And how can I check if my WAV can be divided into CD sectors?

WAV=>CD=>EAC=>(exact same) WAV

Reply #3 – 2004-07-05 18:46:01

I'm only a little bit precise, not perfect.
Please visit this thread again in some days, I've no time for a long explanation at the moment, sorry.

WAV=>CD=>EAC=>(exact same) WAV

Reply #4 – 2004-07-05 19:03:51

OK, thanks a lot.

WAV=>CD=>EAC=>(exact same) WAV

Reply #5 – 2004-07-05 19:27:11

if the sizes of the WAV files are different, then it's because your burning program is doing something wrong, like adding pauses between tracks.

You would have to select 0 seconds pauses.

Apart from that, the source WAV has been directly extracted from CD?

Because, if size is not multiple of 588 samples, then it's normal...
All tracks in a CD-DA disc must have a multiple of 588 samples.

WAV=>CD=>EAC=>(exact same) WAV

Reply #6 – 2004-07-05 20:28:08

Check out:

http://users.pandora.be/satcp/tutorials.htm

Particularly the sections entitled "The Truth About Offsets", "Determining The Offsets Part I", and "Determining the Offsets Part II".

WAV=>CD=>EAC=>(exact same) WAV

Reply #7 – 2004-07-07 16:49:01

So, I'm back again.
First, welcome to HA, epinhao!

As you can see from the tutorial, there's a lot that you have to know about offset issues until you can create an exact copy of an audio CD. I consider it to be very difficult for a newbie, much more than just EAC-ripping and archieving with a lossless codec on HDD or data CDs. (That's what many HA members, including myself, seem to do.) I'll try to make it as easy as possible.

After you've installed EAC, you should first run the setup wizard. It'll give you the correct settings for secure mode. Follow EAC's instructions and let it apply the characteristics which it has found.

not necessary for wav=>audio CD=>exact (same) wav:
The second thing is to determine your drive's read offset. Use a CD from the EAC key list disc given in "EAC.txt" (comes with EAC). Perform "detect read offset" in the drive options/offset and let EAC apply the detected read offset correction value. You should now be able to create really perfect extractions. (the track on the CD is really the same as the created wav file)

As for the writing issue:
You need to know your writer's combined read/write offset. Therefore you let EAC write an offset test CD. The function is available in the writer's drive options/writer. Use write offset 0 (important!). Using this CD, determine now your writer's combined read/write offset correction value (the same function as above).
After you've written your audio CD with Nero (write at least three tracks), use this offset value for reextraction with your writer.
Be sure to disable "delete leading and trailing silence" in the EAC options.
Extract only tracks from the middle of the burned CD. Strange things can happen at the beginning of first and at the end of last tracks.
If you've written gaps on the CD ( Nero's default setting: it does), perform "detect gaps" and then choose "leave out gaps". Alternatively, you can tell Nero to write without gaps. (I don't remember how to do it exactly, you can find it in its help feature.)
The files should now be identical to the original wavs. You can also compare using EAC's "wav compare" function. It will tell you in which way the files are different. For example, "0,0021... longer", if you've added a gap etc.

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And how can I check if my WAV can be divided into CD sectors?

As minix already said, audio CDs are divided into sectors.
1 sector=1frame=1/75 sec=1/75 sec * 44100 samples/sec=588 samples
The wav files have to consist of an integer number of frames, otherwise they will probably be lengthened by adding some null samples. If the wav files are direct (unchanged) extrations from CD, this issue is irrelevant. They should consist of an integer number of frames.

Possibly you still don't know what offsets are. Offsets are time shifts between a drive's actual reading/writing position and the position it should read/write. You can find information in EAC's "faq.txt". I just had a quick look at the tutorial, but the offset pictures seem to be a great thing.

WAV=>CD=>EAC=>(exact same) WAV

Reply #8 – 2004-07-07 19:16:03

Thanks a lot precisionist I managed to do it with your help, I just had some difficulties with gaps, but I burned a CD without gaps and I had no problem extracting the tracks perfectly, I didn't had problems with the first track but with the last one. Would you recommend me burning some dummy tracks?

WAV=>CD=>EAC=>(exact same) WAV

Reply #9 – 2004-07-13 14:24:42

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Would you recommend me burning some dummy tracks?

I don't understand this question, could you please explain a bit more ?

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I didn't had problems with the first track but with the last one.

This can have several reasons. Probably your writer isn't able to overwrite into lead out and has a negative write offset. What is your writer ? Only Teac and Plextor writers are said to be able to do that.

It is also (additionally?) possible that your writer, or the drive you've used for reextraction, isn't able to overread into lead out and has a negative read offset. If you performe the detection for the read offset correction, EAC also reports the overreading capability (if I remember correctly).

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