Ripping a image, good or bad? Options

[damagician]

I recently read somewhere that you shouldn't really rip from an image stored on the hard disk as it may lose some quality. I'm a little unsure if that is the case and would just like someone to clarify for me. The reason I ask is I have Alcohol 120% and am able to create an image and then rip the image with EAC faster than I can rip the cd with EAC in the first place. Also I am able to create an image of a couple of really badly scratched cd's which I was having trouble ripping with EAC.

So basically is there a degredation in quality when using Alcohol?

[Jan S.]

Alcohol doesn't have secure ripping as EAC does.
So yes. If you rip with alcohol you won't know if the cd is read correctly. Reading with EAC afterwards doesn't do anything to the quality.
But ripping with EAC in the first place ensures that the rip is as good as possible.

[damagician]

Aha, thanks for clearing that up for me Jan

This post has been edited by damagician: Nov 14 2005, 23:58

[Ludwig von Koopa]

That is incorrect. Alcohol, with default settings, will make a perfect image or no image at all. If even a single byte cannot be read (audio or otherwise), the image will not be written.

I have used Alcohol to "rescue" badly scratched audio cds. On my worst cd, it read the disk at 0.2x real-time (which can take literally hours) through the scratched part, and it ended up being a successful, perfect image.

There is also the possibility that you will wait hours, have a 98% complete image, and than reach a truly unreadable sector, and have the image writing terminated. But it was worth a try.

I use EAC all the time, but if EAC ever gives errors upon completion, you can try to make an Alcohol image, put the image in a vitual drive, and read from the virtual drive with EAC (in burst mode now).

[damagician]

Yep, that's exactly what I was wanting to know as I have had this exact problem and Alcohol read the disk much faster and provided a better rip than did EAC but I was a bit worried as I had read that I would lose quality by ripping from an image.

Well thanks people for putting my mind at rest.

[dreamliner77]

Alcohol's DAE routines are not secure.

[LANjackal]

Alcohol's DAE routines are not secure.

Correct me if I'm wrong, but as far as I know, Alcohol doesn't even do DAE. It just extracts raw data and dumps it to an image file. At the same time, there's no mention anywhere in its documentation or on its forums about secure ripping.

ISObuster will image copy protected CDs perfectly (you get another copy protected CD as output, but as it's a clone of the first, the restrictions are effectively reset).

EAC's the best option unless you're really interested in extracting the multimedia sessions that are present on some discs, in which case Alcohol, PlexTools (proprietary .pxi format that's not very compatible with other stuff) or ISObuster might be better options.

[dreamliner77]

You're right. Alcohol does not explictly do DAE, but this is the end result that you're after. The error corrections routines in EAC are better suited to DAE than the image ripping capabilities of Alcohol.

[krazy]

That is incorrect. Alcohol, with default settings, will make a perfect image or no image at all. If even a single byte cannot be read (audio or otherwise), the image will not be written.

No.
Data CD's, which Alcohol is designed for, have robust error-correction information. Audio CD's do not, and so require special techniques to ensure correct data extraction.
This has been discussed before: http://www.hydrogenaudio.org/forums/index....showtopic=34293

I have used Alcohol to "rescue" badly scratched audio cds. On my worst cd, it read the disk at 0.2x real-time (which can take literally hours) through the scratched part, and it ended up being a successful, perfect image.

If you extracted twice, compared the files, and found them to be bit-identical then you may have extracted a 'perfect image'. However it will be more through luck than anything specific to Alcohol.

[=trott=]

So could you say that:
1) rip with alcohol, but configure it to abort upon encountering an error
2) if alcohol had errors, try again with EAC

would give succesful rips ?

[boojum]

The simple answer as so many have discovered is to do audio extraction with EAC.

This post has been edited by boojum: Nov 15 2005, 08:02

[krazy]

So could you say that:
1) rip with alcohol, but configure it to abort upon encountering an error
2) if alcohol had errors, try again with EAC

would give succesful rips ?

No, you couldn't, for the reasons outlined in the thread linked above.