Why do I need to use EAC to rip discs?

Dave964

Well-known Member
All of my CDs are ripped to a desktop PC, and I used EAC for it. I've seen the reasons why EAC is recommended, and that this should result in a more accurate rip.

However - I had a friend visiting over Christmas and he pointed out a flaw in this argument which I couldn't argue with, so I'd like somebody to explain it to me.

Even cheap CD drives in PCs must be able to read the data accurately without using something like EAC. If they didn't, they couldn't possibly install / run software from CDs. With computer software, you can't possibly read data that is "mostly" right - if you did, it simply wouldn't run.

So why should audio CDs be any different? Why do I need some flashy ripping program to make sure the CD is ripped accurately at a digital level when the PC is perfectly capable of getting it right for software CDs?

I'd be genuinely interested if somebody can explain this.
 

Member 7321

Active Member
Most applications the rip CD's read the data and include the errors on the disc that may come from finger prints and scratches. They also only do jitter correction.

EAC, in conjunction with AccurateRip will read the data multiple times and compare with the AccurateRip database which is made up of data from other people who have also ripped the same CD. This means that the data you are ripping can be compared to other others and the most accurate version of the data can be saved to your HDD.

HTH but if it doesn't then Google is your friend ;)
 

Dave964

Well-known Member
Most applications the rip CD's read the data and include the errors on the disc that may come from finger prints and scratches. They also only do jitter correction.

EAC, in conjunction with AccurateRip will read the data multiple times and compare with the AccurateRip database which is made up of data from other people who have also ripped the same CD. This means that the data you are ripping can be compared to other others and the most accurate version of the data can be saved to your HDD.

HTH but if it doesn't then Google is your friend ;)

That's the argument I've heard before - and the reason I used EAC. But I think you've missed the point I was making.

If I am installing COD4 from a CD, it's done 100% accurately. It doesn't need to look up an online database of other people who've installed it to make sure it installs correctly. And that can have fingerprints on it just as much as an audio CD.

So what's the difference?
 

Member 7321

Active Member
I see your point.

I don't know more than what I have put above so I am sure somebody else more knowledgeable might be able to shed some light.

The only thing I can think of (and I am guessing here) is that there is better error correction built in to the way data CD's are written and read compared to red book audio CD's
 

amcluesent

Well-known Member
CD-ROM use the ISO 9660 standard which as much error detection and correction. CD-ROM also don't have to be read in real-time, unlike a music CD.
 

KoThreads

Well-known Member
I use CDEX. The FLAC files I have are fine. It too does error checkng but it's quicker and when your ripping loads of CD's spare time counts. However I'm trying to backup all my CD's so I can put them away and have some space. I wasn't going to do them all but thought I may as well, but it's taking forever.
 

ro53ben

Well-known Member
The answer is - you're right. EAC and accurate rip, for the most part, it not required at all and offers no advantage.

An ISO9660 compliant disc is the same whether it's music or data. If a data CD gets damaged, be it dirt or a scratch, you can't read that data. You can lose MBs of data as a result and, if damage, your software will not install from the disc. To avoid this, the drive will read and re-read the disc to try and do what it can to read the data properly. If not, you get a CRC error and your data may be unrecoverable. This situation is quite common on cheap blank media where the dyes expires prematurely.

In the case of a CD player, audio playback is real time. If you're just playing a CD in this way and dirt on damage on the disc can cause it to skip when you get buffer under-run. The good areas around the damage will play just fine however unlike the case of a data files filling a whole disc where you may not be able to recover anything.

When ripping a disc, it isn't treated as an audio CD - the disc is treated as pure data. It's read of byte by byte and, as you're not dependent on real-time, any bad reads can be re-read - just like it can when installing software.

The difference is that a damaged software CD is damaged for life, no comeback. A damaged audio CD that can't be read, however, can be compared to others using the aforementioned online database. If accurate rip can't read your disc, but thousands of other have already submitted their data of that section of disc, instead of giving up and drawing a blank; the software can download a good sample of the data and use that instead of the bad data on your disc. End result, uninterrupted rips.

So, in summary, the data doesn't make the reading any more accurate. It doesn't do a better effort with your CD drive. But it can substitute bad data for good from the online database.

In real life, I think most music lovers are quite kind to their media and put the CD back in the case when they no longer need it. I've owned a CD player for 20 years and I've only ever had one scratched disc - I dropped it on a tarmac driveway when getting out of a car. All my others read just fine and EAC offers zero advantage to me.
 
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Autopilot

Distinguished Member
EAC offers other advantages too, such as excellent gap detection and jitter correction. It's lots of little things that make the whole benefit from using EAC, which makes it the riper of choice for people who want the absolute maximum possible quality rips without compromise. And it's not just obvious big scratches, things like UV damage take their toll over the years.

But while i respect it as a great piece of software and appreciate the fact some people are complete perfectionists, i would say that DBpowerAMP, while having a few quirks, is by far the best all-round ripping package. I would recommend it to the vast majority of people i know over EAC these days.
 
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amcluesent

Well-known Member
>if accurate rip can't read your disc, but thousands of other have already submitted their data of that section of disc, instead of giving up and drawing a blank; the software can download a good sample of the data<

Please provide a reference to substantiate that assertion.
 

mrspoon

Novice Member
AccurateRip validates tracks (through CRCs), it does not send another persons audio data to someone else.
 

ro53ben

Well-known Member
In that case, EAC has even less value than I perceived. It can't rip the data any better but will know when it's failed :)
 

Autopilot

Distinguished Member
In that case, EAC has even less value than I perceived. It can't rip the data any better but will know when it's failed :)

Which can be incredibly useful, unlike iTunes which would just leave you with silent gaps/distortions and none-the-wiser until you come to listen to them.
 

ro53ben

Well-known Member
Which can be incredibly useful, unlike iTunes which would just leave you with silent gaps/distortions and none-the-wiser until you come to listen to them.

Can you prove that?

I've ripped around 350GB of data in Apple Lossless using iTunes...never happened.
 

amcluesent

Well-known Member
>It can't rip the data any better but will know when it's failed<

Any better than what?

EAC can be configured to rip in 'Secure Mode' where it will retry reads to recover data while adjusting drive speeds etc.

Once it reports that the data can't be read accurately, you have choice of obtaining another CD or setting EAC to use burst mode and interpolate the missing samples from the music either side of the missing section.

EAC provides control for those who actually understand how to use the tool.
 

ro53ben

Well-known Member
>It can't rip the data any better but will know when it's failed<

Any better than what?

EAC can be configured to rip in 'Secure Mode' where it will retry reads to recover data while adjusting drive speeds etc.

Once it reports that the data can't be read accurately, you have choice of obtaining another CD or setting EAC to use burst mode and interpolate the missing samples from the music either side of the missing section.

EAC provides control for those who actually understand how to use the tool.

I don't believe any of this is significantly better than enabling error correction in iTunes. Ripping a scratches CD in iTunes can take quite some time whilst it engages in very similar error correction techniques.

So, to answer your question, any better than iTunes.
 

Autopilot

Distinguished Member
Can you prove that?

I've ripped around 350GB of data in Apple Lossless using iTunes...never happened.

Back before iTunes became a bloated idiocentric mess, and when i was pretty new to the whole digital music lark, i tried to use iTunes to rip a load of CD's. Some had minor scratches, barley visible, but they where enough to completely throw a spanner in iTunes works. Either it just froze or left gaps in tracks. iTunes error correction is, from what i have read, mainly there to stop iTunes hanging and get on with ripping rather than actually fixing problems.

And without systems like Accuraterip it does even know if it has actually encountered an error in some cases. Some of the errors produce artefacts that, if you buy what you read on more audiophile forums, might not audible unless you have a very high end system - not that that would really effect me. An extension in the length of ripping time is probably just your optical drive slowing down because the drive itself is struggling - it does not necessarily mean it is actually going back to read sectors that might be bad because the Accuraterip data indicates it might be wrong.

Anyway, so i then found Audiograbber and then CDeX, which worked pretty well. Then eventually i got on EAC and used it for years. However, with the advent of album art and the large collections requiring perfect tags DBpowerAMP is my ripper of choice.

I'm sure iTunes must have a better ripping engine now, but DBpowerAMP is far superior in every other area, and free for the basic version, so why use iTunes? Not only that, but they have there own MP3 encoder, and i would only ever use LAME for MP3 ripping. It does not do FLAC either. There was a good article on Hydrogen Audio on why iTunes ripping and encoding engine was not as good as others, i will try and dig it out. But TBH, it was pretty hard core tech and went over my head for the most part.

So i love my iPod's and have nothing against Apple, and i do agree that with perfect CD's iTunes is probably more than adequate and a lot of this theory about jitter etc might make bugger all difference - but why on earth would i ever use it to rip and tag my music? Can you give me one good reason to stop using the absolutely excellent and free tools i use now which give me complete freedom?

So my answer to the OP's original question could be; why not?
 
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ro53ben

Well-known Member
So i love my iPod's and have nothing against Apple, and i do agree that with perfect CD's iTunes is probably more than adequate - but why on earth would i ever use it to rip and tag my music? Can you give me one good reason to stop using the absolutely excellent and free tools i use now which give me complete freedom?

I find it quite an excellent ripping and tagging tool, personally. It can edit tags in a perfectly adequate way and, if tags are managed carefully whilst ripping, the "batch management" tools in the other music managers are never required. Making all the Abba ABBa ABBA etc. tags into one ABBA tag across all tags is arguably as easy in iTunes. The big music management tools have some excellent powerful features, but as I carefully managed my tags as I ripped my music, I've never had a need for them. The only exception was album art which was always supported in iTunes, but it provided no way of downloading the art. For a while now it has, and it will automatically download the art for me which is another benefit.

It's now the only tool I use and it's also free.
 

mrspoon

Novice Member
Take a CD you do not like, rub it on a concrete floor, getting plenty of scratches on it. Rip in iTunes, it will not report anything wrong with the CD (your damaged audio files will be present there for your listening pleasure), rip in an AccurateRip supported program - it will report error free, or containing errors, the difference is night and day.

...and before you say 'none of my CDs have a scratch', rip 1000 CDs and I would guess around 50 would have tracks with an error - even a single sample beng out of place, AccurateRip is there to detect and report that. Rippers can use that information to retry ripping (some secure rippers might try a single section 200 times, and it might recover the data on the 200th try).

Secure Ripping is not for everyone, just those who really want 100% correct ripping without even a single error, ie have the same audio that was put onto the glass master CD.
 
G

Globex

Guest
Lots of wrong, wrong information in this thread.

There's a significant difference between data CDs and audio CDs. Audio CDs are not ISO9660 and do not have the same degree of error correction.

Data CDs use 2048 bytes per sector for data. Since a CD sector has 2352 bytes, the remaining 304 bytes are used for error correction. This is why you can install software or copy data from a CD and know you're getting a bit-for-bit 100% copy (unless there's a serious read error, in which case it can be easily detected and reported to you by the OS).

Audio CDs do not have error correction. All 2352 bytes per sector are used for audio data. This means not only that audio CDs are much, much more prone to read errors (since data can't reliably be replaced), but it's also not a simple process to detect a read error. The designers of the audio CD knew this, and for that reason audio CD players (including software players) are designed to be able to interpolate data that sounds close enough to the real thing even when small amounts of wrong data are read. But this interpolated data doesn't necessarily match what's on the CD.

Extracting CD audio is not the same as copying a file off of a data CD. Audio CDs don't even have a file system (like data CDs ISO9660), despite modern operating systems faking it. A good CD ripper has to go through a rather involved process to ensure the data being ripped accurately represents the data on the disc, since there's no information on the disc itself to aid it in this process, as there is on a data CD. Some software's "secure" mode (such as iTunes or WMP) simply trusts modern CD drives' error reporting functions (which are not generally reliable). EAC's secure mode will read a given sector as many times as necessary to conclude that the data ripped is accurate. The Windows/Mac built-in ripping capability attempts no error validation at all.

This is why EAC/CDex/cdparanoia/etc are necessary. It is absolutely wrong and ignorant to state that these programs do nothing beyond what the OS is capable of. EAC offered and offers serious advantages, even ignoring the AccurateRip feature, which is a relatively recent addition.
 
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