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After dozens of blind A/B tests, it is clear that AL and AIFFs differ slightly in playback. The AL file almost always sounds better. Is iTunes/QT decoding AL files and massaging gain and EQ? I can deal with that and wait for better decoders/players as long as the quality of the audio data is identical to AIFF or WAV, and we know (?) that it is (see below). I would love to save big $$$ on disk space, but I will NEVER rip from CD again.Tests: WAV->AL->WAV tests (wav file encoded with Apple Lossless then converted back to wav) demonstrate that the two files are identical (I used a simple UNIX diff command to confirm others' results using more sophisticate tools).
Follow Ups:
First I am a little confused. If you are not ripping from CD then how are you getting AL or AIFF files?If you do not have the option in the IMPORTING settings of iTunes set to Error Correction on CD reading. Then I can agree with your statement. You have to have this to rip from CD or error tracks will drive you crazy.
If you are downloading then converting to AL... well that is a waste of time as you already have thrown out too much information to recover it.
I did spend a ton of time before converting my lib from AIFF to AL and found no difference in output between an AIFF and AL file on playback.
Rather than start a new thread, let me try to hijack this one sideways.I'm working on a project for the iPod, and have been ripping some CDs to have tunes to listen to. So far I use AAC at 320k. I haven't had a chance to do any kind of A/B really, but would prefer lossless coding.
Am I right that AIFF is kinda sorta another "flavor" of CD data-in other words, it's uncompressed "perfect" data, though the exact file format is not Red Book? And the file size is about as big as the CD?
And Apple Lossless is another variation on WinZip/StuffIt/Meridian Lossless Packing type schemes? Which Windows Media and RealPlayer won't support, much as I think iTunes doesn't support their lossless formats?
I don't see an option in iTunes 4.5 to use lossless coding, where is that?
How will the AL files size compare to 320k AAC? About twice as big, depending on the music?
To access Apple Lossless in iTunes 4.5, select Preferences, then Importing, then "Apple Lossless Encoder". Any CDs you now rip will be in Apple Lossless format. I've compared these to AIFF files (by converting back) and they are bit-for-bit identical and therefore should sound the same. Unlike AAC, you can (at a later date) convert these back to AIFF (or WAV) and then to any other non-lossy format with no loss of information.I've ripped nearly 29 days of music (about 170GB) and the files have an average of 542kbs, which is a compression ratio of 2.6. All my music is classical which I gather compresses better than rock. I found 320kbs AAC excellent on my iPod but the difference in sizes between this and what I'm getting with Apple Lossless no longer warrants keeping lossy files.
The more complex an image or sound file, the better it compresses. So classical listeners may benefit from ALE, whereas lossy algorithms favor popular music. That's good news. Do you know of any databases for tagging classical music? The Gracenote CDDB is atrocious and although my partner loves to edit tags to comply with his own cataloguing system, it's just going to be too much work (1000 Bach tracks, 7000 total classical and growing).
I enter all my tags manually too. It's a lot of work, but iTunes does text completion which helps. Also I merge all tracks of a single piece of music first. So a symphony is a single file. You can see details of the schema I use below. I should finally finish ripping my CD collection this weekend. About 200GB for 700-800 CDs, all in Apple Lossless format.
Stephen
...and read all the options. I didn't notice that before.Classical has more silent passages, maybe that's why it compresses more. I'm not convinced by my own argument, though.
And now you're just waiting for Apple to release a 200GB iPod? :-)
"Classical has more silent passages, maybe that's why it compresses more."I think the harmonic structure and high-frequency content comes into play as well.
"And now you're just waiting for Apple to release a 200GB iPod? :-)"
I would settle for a 250GB bus-powered pocket firewire drive. These max out at 80GB at the moment, AFAIK.
Stephen
The best I can dig up is that Apple Lossless Encoder is based on AAC encoding, but that may be people's impressions because the file type is the same. A lossless, proprietary compression is applied to what I guess is a compression-less (exact copy) AAC. I arrive at this because if you don't have QuickTime 6.5.1 or higher, iTunes will still encode/decode ALE -- only it ain't ALE, it's AAC at a high setting.After much testing, it is my conclusion that ALE is just as good as WAV or AIFF, at 50% space savings. However, I will probably live to regret my decision to encode with ALE.
Please post with anything you discover about origins of ALE. I have done listening and file comparison tests, but would love to be able to explain this lossless compression to myself and others in some kind of context.
I'm supposing that, like WinZip and MLP (Meridian Lossless Packing), Apple Lossless Encoder codes patterns in the digital data to reduce space.But I'm not sure if that answers the question about the origin of ALE. Do you mean why did Apple come out with that? (=to fight WMA Lossless, and because storage gets cheaper every year). Or are you wondering if the AAC engine is used for the compression? (I kinda doubt it. I asked Dolby if they used pattern compression as part of Dolby Digital, and what I got out of their answer was "no, because you couldn't do that fast enough at the time, and the process is just totally different").
I would love to know FOR SURE that ALE follows Stuffit/ZIP/MLP (and standard lossless compression theory) and not some "almost as good" scheme, just for piece of mind. Apple has decided to treat ALE files as AACs most likely for convenience. They are of the same file type, so it could follow that ALE uses a lossless algorithm to compress to the same file type as the lossy AAC. I know there is an ALE encoder separate from AAC, but is there a different player, or merely a new AAC player that handles ALE files?Again, iTunes 4.5 -- without QT 6.5.1 -- acted as though it was encoding and playing ALE files, when it wasn't.
Guys,First AL is not based on AAC. AL is like Zip for audio files. What goes in comes out.
John Atkinson and several others as myself have done tests. AIFF-> AL-> AIFF and the first and the last compare right up. That would indicate that the files are kept in tack. I also did some major listening before I took my entire AIFF lib and converted it too AL.
Yes you can with the latest iPod update use AL files on your iPod. They do sound the best to me and at least then I know I have the exact copy and not one that sounds about the same on the iPod.
At CES last year when I released the Cosecant USB DAC. I talked to a ton of people that had iPods. Everyone was using AIFF then. I am sure next year it will be AL. Thanks Apple, saved me 5G's on my iPod and Hardisk.
FYI 2 things to not if you convert....
1) Converting AAC to AL is worthless the file will be larger and will not contain any more info.
2) You will have to delete all the AIFF when you have converted them. This means any playlists you have with those files in it disapear.
Ok how to convert....
Select a list of songs that are AIFF (I guess also WAV would work).
Go into Preferences-> Importing and select Apple Losless
Go to Advanced-> Convert
The selected files will be duplicated into AL format. When done simply delected the selected list (AIFF files). Notice the improved disk space :)
I suspect the engine is totally different from the AAC engine, and they just bundled everything together for simplicity. Anyway, somewhere in this thread, another poster checked that you can go AIFF--> ALE --> AIFF and the AIFFs are bit for bit identical. So it is truly lossless.
Response to Gordon Rankin - hope this helps clarify:AIFFs are ripped from CD with iTunes. The error correction feature of iTunes is amazing, but does pose the question: HOW does it correct errors? One way is by creating new data to replace unreadable data. I love having tracks resurrected by iTunes' error correction, but I am also trying to make exact copies, which by definition cannot include new data.
My blind A/B listening tests -- lots of them, lots of ears -- have demonstrated a difference between AL and AIFF files in iTunes playback. Very subtle, and usually for the best. All that says is that the players alter the data in some way. The players are no doubt trying to optimize playback by tweaking EQ and levels. Not a crime, but with AL you don't even have a choice of players.
This is all rather academic, and perhaps most files are not affected at all by either error correction or a player's "optimization." But since a file can be affected by both, my DAC cannot be said to be receiving a copy of the source file, let alone an exact copy of the track on the original CD. A player that simply passes the data along to my DAC without weighing in on how it should sound would be ideal.
When error correcting is on then when the computer reads a track that is bad then it goes back and re-reads that until it is read correctly. Otherwise it is imported with an error.Had a customer do an entire library with this off. Had to go back and start over.
As far as output, you might want to go into the Preferences-> effects and turn off the Sound Enhancer and see if you notice a difference.
If you set the options right it does pass the data as is.
Otherwise it enhances it like it wants too.
there should not be the need for error correction on a proper rip unless the CD is seriously scratched. I have used EAC to duplicate most of my CD collection to black media, and withing about 500 CDs, I have had only 2 CDs that needed any additional "investigation" of suspect areas. One of these CDs was a crappy pressing (Russian made) with a visible hole in the reflective layer, the other had been completely scratched up by children so that no regular player would even load it anymore. All other CDs were extraced with 100% confidence in overlapping reads.Perhaps Itunes calls the overlapping reads error correction, while in EAC the error correction is a very time consuming process. I think each suspect sector will be read up to 80 times before it fills in some data it extracts, or fails.
Another thing I noticed is that you really need a CD reader that is well suited for the extraction. Among the 12 odd PCs I have access to, only those with very recent MSI or LiteOn CD-ROMs were really good, while some slightly older drives lacked some features EAC likes to see for good extraction. The good drives will rip a CD at about 8-11X (these are generally 52x drives) while the bad ones will spend 1+ hour on the same CD and report tons of errors.
Read up on what EAC does - Itunes is cute for MP3 ripping, because it does have a great CD database that knows pretty much every CD I ever fed into it. However, it's rather fuzzy about what it really does in terms of quality extraction. I may do a test one day and do a binary comparison of an EAC-ripped file with a file Itunes pulled. One thing I didn't see in Itunes was the ability to rip into an image file with cue sheet to then write the CD as a perfect dupe, not having to spend any time on gap times between songs, etc. Since I don't create samplers from my CDs, rather dupe them to better media, Itunes remains a computer-only type tool for me, creating compressed files for playback on crappy computer speakers or headphones. Don't really care about lossless or rip quality when I listen there.
Peter,First off EAC does error correction in that it will re-read a track that was read with error. This happens not because of the quality of the disk but the speed at which it can be read.
In iTunes you can see the actual speed at which it rips. On some cd I can get 15x (24x drive) and some only 5.2x (average). If error checking is off then they read all out. Faster but with significant errors.
As far as quality I give iTunes a major edge. First off the Apple Lossless is so cool it saves space but retains 100% of the quality. It's free and it's completely integrated. Don't give Apple and MP3 face if you have not even looked into it.
I have a HUSH PC (fanless heat pipe technology) setup with everything MusicMatch, EAC, XP PRO etc...
My little iBook kicks the shit out the PC any day of the week.
I can see the actual speed EAC rips at. Same master CD will error correct and re-read at les than 1X on one drive, while it flies through many times without a single retry on another drive, averaging 12X at the end of the read.Where do you give ITunes the edge? Like I said, the only reason I use it is for crappy computer audio. I don't CARE what that sounds like as long as it's tolerable. I use EAC for the critical duping of crappy master CD pressings to much better sounding 1X written black CD-Rs for my audio setup where I actually listen to the music. I'd never dare to hook up a computer to that system to play back AIFF or whatever files.as for your Ibook - good for you. I just turned a $4600 G3 laptop into a toy for my kids, as it has been teh biggest waste of money in my life, spending the first year more in the shop than in my hands, and after the warranty ran out it pretty much died gradually. I haven't used a Mac since, and I don't miss it.
Anyway - for critical listening, ANY of these things are crap. That's not what I use EAC for. My battery powered DAC on my modded CD transport will kick the shit out of any iBook any day.
So much for today's section in "My Mac is better than your PC" pissing contests.
Peter
How'd you spend $4600 on a G3 laptop? And that was in 1990's dollars, too! I don't know about your system, but replacing a transport with a computer is what most of us seem to be concerned with. The Cosecant USB DAC that Gordon uses is a gem and I wish I had one myself. Plus it's powered by the bus, so he can do critical listening even when he runs out of batteries. I use S/PDIF from my Mac to my DAC via a USB interface. Check out wavelength's site and the joys of eliminating crappy transports and their attendant problems with one good rip.Your battery powered DAC on your modded CD transport will not kick anything out of a silent iBook serving data to one of the most thoughtfully crafted DACs I've ever seen/heard. Heck, the iBook's battery powered, which seems to count for something with you -- and you can even use it to look stuff up on the Internet, maybe learn a thing or two.
Peter,First off why do you say they sound bad? I have had the best results with my Cosecant and no longer even use a CD transport.
http://www.wavelengthaudio.com/Cosecant.html
Sure the Analog outputs are crap look who they are servicing. That's why I designed the Cosecant because the computer is a great vehicle but needs better output.
Peter I designed PC for years have some 300K plus in the field plus about 32 ISA/PCI boards. I know PC's and MAC's better than most.
For Audio, MAC's are just better. Look at any recording studio, they are almost all MAC's. FOR A REASON.
I think I have one of the best PC setups you can get:
http://www.hushtechnologies.com/
Loaded to the hilt with MusicMatch PRO, EAC, XP PRO, 1G mem, 240G drive.
This is definately the quitest PC I can find and it works great.
But why should I have to use more than one program to do the same thing I can do with iTunes.
And for that matter why whould I have to put up with non-intutitve OS like Windows when all I want to do is play good music.
The problem with PRO PC people is that they have not even taken a look at anything else.
Apple makes it soo easy to do all this stuff. It's fast, it's fanless and all the software you need is free and already installed. They prompt you when new software is available for anything you have on your system.
I prefer it because I have seen the best of both.
As far as your transport and your dac, glad to hear it. But USB is error free and there is no need for jitter problems as it is all async to the data rate. My TentLabs modified 47 Labs and my SPDIF dac sounds great too. But both are in the closet collecting dust.
Why... the computer just has so much more too offer without any of the problem areas.
"The problem with PRO PC people is that they have not even taken a look at anything else."I currently have 3 Macs here, have owned (and used) many before since 1990, with shifting perferences depending on where I got more done. I work with media all day long, and currently I get more done on the PC. Doesn't mean it can't be done on the other platform.
however, I LISTEN to music on a non-PC setup because the gizmo stuff it simply isn't needed to enjoy music. When at work, most of the apps I need to use don't even exisit on the mac, or are rather expensive. Usually I work more with video, and working in the streaming area, I don't use the computer for high-end stuff - just compressed internet delivery. At that level, I care more about multi-format compatibility and a tool that delivers to the 95% market share that's out there using PCs. Try encoding a multi-bitrate WindowsMedia stream on a Mac for example.
Anyway - we probably misunderstand each other here as to what we use the computers for in the audio arena. I use PCs to edit/produce, and if I listen to music, it's in a noisy office environment where 12 computers and disk arrays are making a total racket to begin with. that's where MP3 is fine with me. At home, when listening to MUSIC, it's a quiet tweaked transport, a battery powered DAC, a tube preamp, and some Magnepan speakers in a room that except for lights has no other electronics in it. It works, sounds fabulous, and doesn't need a security patch every 2 weeks ;-)
I am assuming that you are using a Mac. It does not suprise me that the two formats might sound different. There is a lot going on in the software layer of programs like iTunes. Can you describe the sonic differences?In the PC format, where there are many different software players available, sonic quality varies a lot, even among lossless playback formats.
Ideally, the data on a CD should be copied exactly to HD as (let's say) a .WAV file. The player should do nothing more than shuttle that data to a DAC, at which point we leave this topic of discussion. It seems to be that, surprise, the ideal is unusual, maybe unheard of. Even with the same DAC converting from software players, my computer's CD drive as well as its own transport, you cannot expect identical results when playing the "same" file from CD and iTunes/.WAV. The CD transports both have jitter and other issues. The computer's CD transport in conjunction with verification checksums gives you a good copy, but even there data is lost or altered due to damage, power spikes, sunspots, acts of god, etc. or "error correction" is applied (software's informed and well-intentioned guess as to what data should be there). Then your player gets into the game and offers its take on what your "exact copy" should sound like.It's maddening. Can anyone tell me why a CD-> AIFF-> AL-> AIFF sounds different than CD-> AIFF?
Well, in a computer, much more happens to a Wav or Aiff file as it gets to the dac. There is a lot of processing, and I think most software player designers can't resist tweaking the sonic result to taste a bit. There has never been a sonic purist approach to design in these software players as far as I can tell.As far as "It's maddening. Can anyone tell me why a CD-> AIFF-> AL-> AIFF sounds different than CD-> AIFF?"
That would be a quandry if both Aiffs compare equally bit by bit.
One test you might want to do, is compare two identical Aiffs (one named differently). While this might seem a bit odd, it might help you discover an aberation in your approach.
Of course, the ultra-paranoid might suspect some new sophisticated type of watermarking that comparators can't pick up.
... to recommend any software for use when storing CDs on a HD (for greatest sonic integrity)?
Big J.
for Windows I prefer CDex for ripping, and save as flac files, a lossless format.
are there any issues worth considering when compressing and expanding CD files? Are all lossless compressors alike?
Big J.
I have not heard any difference in sonics amoung lossless formats. Ape compression is poular, but ape files have in the past tended to be not very robust, that is the files have gotten corrupt if you move them from hard drive to hard drive etc. I myself had that happen with APE files. Ape might have fixed that though.At VRS, we like FLAC because it's well supported on many operating systems and seems to have a bright future, and is a robust format.
"Can anyone tell me why a CD-> AIFF-> AL-> AIFF sounds different than CD-> AIFF?"It can't. I've verified the Apple Lossless compression myself and it works as advertised. The only difference between the two AIFF files produced above would be their locations on hard disk. If however you're comparing hard disk playback to that directly from the original CD (in the computer drive) there could well be differences.
Stephen
> After dozens of blind A/B tests, it is clear that AL and AIFFs
> differ slightly in playback. The AL file almost always sounds
> better. Is iTunes/QT decoding AL files and massaging gain and EQ?Apparently it's doing something if you're certain about the conclusion of your blind tests. Though, if you think about it, it should have nothing to do with the encoding scheme. The decoder has just taken it upon itself to mess with the playback of that particular file format.
> I can deal with that and wait for better decoders/players as long
> as the quality of the audio data is identical to AIFF or WAVEither a data encoding scheme is or is not lossless. From your conversion experiments apparently AL is lossless. Which really shouldn't be much of a surprise.
I dunno, I'd be disturbed if the only means of playback of a particular encoding scheme was messing with the output. Even if you think it sounds better to you. Next year's version 5.0 or whatever of the playback software may not sound so good to your ears. I'd much prefer that they sound identical when played back by the same means.
> I would love to save big $$$ on disk space, but I will NEVER rip
> from CD againYep, you should be future proof as long as you're satisfied with redbook. You could change from that lossless encoding to another one or to raw WAV or AIFF formats at will. Or create mp3 or mp4 or whatever new lossy codec comes along for portable players.
If you really want to think you'll never rip again, make sure you've got everything backed up to some very large-capacity media such as DVD-R.
Thanks James L for the excellent points.Culprit -- the decoder -- can be taken out of the equation by storing AL, but listening to "reconstituted" WAVs or AIFFs. A script can do this on the fly (convert playlist or part thereof, play, delete after use). I am leaning towards making a go with iTunes' AL decoder as it is since the difference in playback is a small one -- a color change really. Less of a difference than switching interconnects between DAC and preamp. My next test will be to compare WAVs as played by different players on the same system. This will help satisfy my curiosity about how much, if at all, the player can alter the end results with "raw" files.
Storage and backup: redundancy in my active array plus offsite to HD should hold me. As I upgrade over the years, these 2 copies will be stable enough. With new drives every 2 or 3 years, I don't need the stability/durability of DVD (which after all is not much of an improvement over CD size-wise). My gargantuan 800GB of music data will no doubt fit in my cell phone or my state-issued Loyalty Card within a decade, and I'll have backups in my car and toaster. And those hated CDs will always be with the 8-tracks and vinyl in Mom's basement.
may be the key. If the decompression is indeed lossless, assembling the data in the system memory, rather than reconstituting it from an optical drive (hard drive) may be significant - lower jitter, timing anomalies etc.? Combine this with a usb NONOS DAC and *now* you're talking!
Big J.
Pardon a dumb question, but you say you "will never rip from CD again." Do you mean that you are giving up on doing this kind of thing for now? Or is there another way to get music off a CD and into iTunes without ripping it? I thought the term "ripping" meant simply copying the music files off a CD and onto a hard drive of some sort through a program like iTunes?I haven't tried the Lossless format yet, but my external hard drive is crowding up so I was going to try it on a few CDs before I bought a larger hard drive. Right now I use the AIFF format.
I'll re-phrase: I never want to rip the same CD twice. By maintaining exact copies (AIFFS, WAVs), we have the luxury of trying any lossy compression codec that comes down the pike, always starting with pristine audio data. Those who rip to lossy compression like mp3 cannot reap the benefits of better lossy compression (e.g., AAC) or lossless compression. Once that first lossy encoding happens, audio data (quality) is lost forever and it's back to the (shudder) CD and ripping all over again. Let's all be thankful that disk prices are plummeting and lossless compression codecs are a reality.
nt
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