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AAC Put To The Test

timothy posted more than 10 years ago | from the musical-ambitions dept.

Music 353

technology is sexy writes "Following the increasing popularity of AAC in online music stores and the growing amount of implementations in software and hardware, the format is now being put to the test. How well does Apple's implementation fare against Ahead Nero, Sorenson or the Open Source FAAC at the popular bitrate of 128kbps? Find out for yourself and help by submitting the results. You can find instructions on how to participate here. The best AAC codec gets to face MP3, MP3Pro, Vorbis, MusePack and WMA in the next test. Previous test results at 64kbps can be found here."

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353 comments

Isn't AAC used for its DRM features? (-1, Offtopic)

SHEENmaster (581283) | more than 10 years ago | (#6157087)

If so, why should I care about its quality?

Even if I'm not interested in the round, my bets are on Ogg Vorbis for the next round. Ogg rules! (Even if the iPod with Linux is too slow to play them.)

Re:Isn't AAC used for its DRM features? (0, Troll)

Rai (524476) | more than 10 years ago | (#6157121)


Isn't AAC used for its DRM features?

If so, why should I care about its quality?


It's kinda like owning a card that can do 160mph, but only allows you to drive on roads with speed bumps every 20 feet.

Re:Isn't AAC used for its DRM features? (0)

Anonymous Coward | more than 10 years ago | (#6157240)

Well thats just for your own safety. I wouldn't want to go any faster than 30 or 40 mph on my card.

Re:Isn't AAC used for its DRM features? (1)

BJH (11355) | more than 10 years ago | (#6157271)

Shit, my card only gets 10 megapixels an hour.

Re:Isn't AAC used for its DRM features? (0)

Anonymous Coward | more than 10 years ago | (#6157336)

Yeah and you can't drive it down roads with speed bumps every 20 feet, can you?

Re:Isn't AAC used for its DRM features? (1, Insightful)

2nd Post! (213333) | more than 10 years ago | (#6157135)

Well, if you don't care about the quality, why the heck does it matter if Ogg has good or bad quality?

All it needs to be is open and unencumbered, right?

Well, the AAC produced by Apple Quicktime isn't DRM burdened, even if it does have some patent stuff attached.

Re:Isn't AAC used for its DRM features? (1)

Knife_Edge (582068) | more than 10 years ago | (#6157158)

Oh sure, just smack down the Ogg guy, like always happens when the format is mentioned here. As if a free and open audio codec were such a terrible idea... Incidentally it sounds pretty good too.

Sorry (3, Informative)

2nd Post! (213333) | more than 10 years ago | (#6157516)

That was a flippant answer to his seeming flippant post.

I like Ogg fine. It is my codec of choice, except of course that no one bothers to support it for my OS of choice, OS X.

There's no good Ogg encoders that can interface with iTunes and support Unicode (yet, of course)
There's no Ogg codec for Quicktime on OS X 10.2.6 (yet, of course)

I much prefer Ogg, ideologically, but it's not something I can actually *live* with, because the support isn't there.

I have 100% support for MP3 and AAC.

Yes, I believe in fighting for causes I believe in. Right now Ogg is not one of those causes; maybe later. Right now I'm more concerned with my friends, my mortgage, and my state of unemployment, sorry.

patent and the possibility of DRM (3, Insightful)

SHEENmaster (581283) | more than 10 years ago | (#6157201)

Patent encomberment is a serious deal. It means than a legal OSS player is nearly out of the questions. If I can't play the things on my iBook(Linux), iMac(Linux), server(Linux), palmtop(Linux), and at school (OS X) then I won't be using it. Quality is irrelevant at that point.

Ogg Vorbis, because of its openness and mpeg, becase people ignore the patent, are my best two options. AAC is not an option, so its quality means nothing.

Would you rather use a train that can safely travel at 100mph along prelaid tracks that don't follow your route or a car that can safely go 60mph along much more convenient roads?

(Oh yeah, Linux is a rocket car in the analogy because it has to be stuck in there somewhere. Windows is a horse in that it can go anywhere if at a crawling pace while shitting over everything, but a rocket car can go more places...

Re:patent and the possibility of DRM (0)

Anonymous Coward | more than 10 years ago | (#6157251)

I'll take my 160mph card, thank you.

Re:patent and the possibility of DRM (3, Informative)

Anonymous Coward | more than 10 years ago | (#6157421)

Patent encomberment is a serious deal. It means than a legal OSS player is nearly out of the questions.

No. Anybody who wants to can get a license, get the reference code, and write an open source player. (Or encoder, even.) There is no barrier here except cost.

Of course, in order for somebody to do that, to pay for a license I mean, they'd have to literally put their money where their open source mouth is. If it's sufficiently important, this shouldn't be a problem.

Why doesn't some enterprising individual buy a license, write an open source player, and then sell it (source and binary) to Linux users? Okay, maybe that's not a great idea, because my gut tells me that a person who did that would make enough to buy a pizza, but that's about it.

Why doesn't somebody start an open source player kibbutz and take donations? If everbody who wants a Linux player were to send in $10, the costs would be covered easily.

my iBook(Linux), iMac(Linux), server(Linux), palmtop(Linux)

You're running the wrong OS on three out of four of these things. Palmtops should run PalmOS. iBooks and iMacs should run OS X. Linux is not a good solution for any of those things.

Then again, Ogg is not a good solution for compressed audio, either, so maybe I'm seeing a pattern here.

Would you rather use a train that can safely travel at 100mph along prelaid tracks that don't follow your route or a car that can safely go 60mph along much more convenient roads?

You're missing the point of the car analogy. Ogg is a car that doesn't go where you want it to go. There's no Ogg support in QuickTime. There's no Ogg support on the iPod. It simply can't go places that people want to go.

Re:patent and the possibility of DRM (1)

cygnus (17101) | more than 10 years ago | (#6157494)

Ogg Vorbis, because of its openness and mpeg, becase people ignore the patent, are my best two options. AAC is not an option, so its quality means nothing.
oxymoron time. AAC is *part* of MPEG. why is it ok for you to use one patented part of an mpeg standard (MP3) and not another (AAC)?

Re:patent and the possibility of DRM (1)

repetty (260322) | more than 10 years ago | (#6157513)

Lemme guess...

You have a really big Beta tape collection at home.

Re:Isn't AAC used for its DRM features? (-1, Flamebait)

Anonymous Coward | more than 10 years ago | (#6157152)

If you want to live in your own little world, you shouldn't. If you want to use products and services provided by others, you should.

Feel free to continue using whatever codec you like. If you pick an obscure or commercially irrelevant one, however, you should probably just type up a boilerplate and save it somewhere on your computer for convenient posting to Slashdot and elsewhere. Something like this ought to do the trick.
This product and/or service [is lame/is evil/sUx0rs] because it [does not support/does not sufficiently support/does not release the source code that implements their support of] my audio format of choice. Until this product and/or service supports my audio format of choice, I will not buy it. This, of course, spells commercial doom for this vendor.
Feel free to copy that and use it yourself. At least all the words are spelled right and the punctuation is in the right places.

Re:Isn't AAC used for its DRM features? (0)

Anonymous Coward | more than 10 years ago | (#6157195)

Why did this get (instantly) moderated as flamebait? What's the deal there?

Re:Isn't AAC used for its DRM features? (0)

Anonymous Coward | more than 10 years ago | (#6157263)

Truth hurts. It is easier to pretend you didn't have a point than to consider something so dangerous to the fragile psyche of the open source zealot.

All the more reason to read at -1.

Re:Isn't AAC used for its DRM features? (5, Insightful)

Anonymous Coward | more than 10 years ago | (#6157193)

You mean the DRM features that allow me to rip my own CD's to AAC and copy the resultant files to any and all computers or players (that understand them) and play them back?

Or how about the DRM feature that allows me to export bought AAC's to aiff and then convert them to MP3/OGG/AAC/.wav/.au etc and do with them what I please?

True, Apple's TMS is selling AAC's that have a DRM-like "inconvenience protection" on them but it's not _inherent_ to the AAC format, nor does it affect the sound quality vs. file size questions.

(In any case, we _should_ be cheering for any company that's actually trying to give us quite reasonably limited freedom with copyrighted material, while satisfying the RIAA/MPAA etc.)

conversions (1)

SHEENmaster (581283) | more than 10 years ago | (#6157349)

lose quality. If you convert from AAC to MP3 for example, you deal with both the shit from AAC and the shit from MP3.

Re:Isn't AAC used for its DRM features? (0)

Anonymous Coward | more than 10 years ago | (#6157501)

yeah, if you're expanding to AIFF and then re-encoding to mp3 you're better off dropping everything to analog tape and then re-encoding through your line in. the static from your soundcard will be less than the artifacts you get from going AAC>AIFF>MP3

Re:Isn't AAC used for its DRM features? (-1, Flamebait)

Anonymous Coward | more than 10 years ago | (#6157243)

AAC certainly isn't used for it's audio quality. Sucked ass in almost every test.

Re:Isn't AAC used for its DRM features? (-1, Flamebait)

Anonymous Coward | more than 10 years ago | (#6157405)

How the fuck is a question about AAC offtopic?

Fucktards.

I need help [completely OT] (-1, Offtopic)

J.D. Hogg (545364) | more than 10 years ago | (#6157091)

Okay, I'm going to ask one last time and then I'll stop wasting bandwidth. Thanks to those who have already answered.

I'm doing a little art project that involves getting as much spam as I can to a spam hole on yahoomail. I'm looking to get as much 419 nigerian scams, mlm scams, penis enlargement, chain-letters, investments ... mails as possible. I've tried to d/l some of the latest spams received by the spam archive (http://www.spamarchive.org/) and answering it to hook the spammers, but I don't seem to get any, and half of those reply-to addresses are deprecated already. The junk mail filter in my dummy yahoomail account is turned off, but still nothing comes through.

So, if some of you get a lot of spam, could you please respond to a few in my yahoomail's account name to start the syphon ? the address is :

internetnoise@yahoo.com

If you do help me, please don't sign-me up for free newsletters, or horoscopes or things like that : these aren't true spam/scams and I'd like to receive only those.

I'm not trolling by the way, and I know this is OT, but I figured posting something on /. was the best way to jump-start that spam flood I need.

BTW : the above is really my account. If you send a mail to it, I'll respond immediately.

Re:I need help [completely OT] (0)

Anonymous Coward | more than 10 years ago | (#6157254)

I was going to recommend www.spamyousilly.com, but it seems to have died.

Sounds like what you needed.

penis + arse (-1, Troll)

Anonymous Coward | more than 10 years ago | (#6157099)

does not a trip to sweden make...

but it comes close

i prefer just to steal the music (5, Funny)

Anonymous Coward | more than 10 years ago | (#6157105)

this makes the format rather irrelevant.

Re:i prefer just to steal the music (0)

Anonymous Coward | more than 10 years ago | (#6157396)

Isn't this the whole point of Apple's AAC use? It may very well be superior to mp3, though I doubt it.

Even if it's proven to be worse, does anyone think Apple is going to say "we encoded everything in an inferior format because it was the only way to handle DRM"? They'll say it's the best thing since sliced bread even if it sucks..

WTFDAACM ? (0)

Anonymous Coward | more than 10 years ago | (#6157117)

anyone explain what AAC means ?

Re:WTFDAACM ? (2, Informative)

Urthpaw (234210) | more than 10 years ago | (#6157124)

AAC@Everything2 [everything2.com]

Re:WTFDAACM ? (0)

Anonymous Coward | more than 10 years ago | (#6157140)

thank you very much

Re:WTFDAACM ? (2, Funny)

stagmeister (575321) | more than 10 years ago | (#6157515)

THANK YOU for linking to e2!

Now for the next hour - or maybe the next few - I will waste my time going to pages such [everything2.com] as [everything2.com] this [everything2.com].

Once again, thanks!

--Jason

crap in, crap out (5, Interesting)

larry bagina (561269) | more than 10 years ago | (#6157137)

just remember, every codec depends on the quality of what it is encoding. I haven't heard any AAC encoded music myself (i use uncompressed wav or 256khz mp3 myself), but Apple allegedly uses the master recordings to encode their files.

Most mp3s or oggs you find out there are from someone's CD-Rom drive, who knows how the disc looked, or how much jitter there was. I have heard stories of people downloading songs to find a skip or two in the middle, or been an amalgam of two different files accidently spliced together.

I'd hazard a guess that most people that encode with ogg-vorbis do a better ripping and encoding job, though.

Re:crap in, crap out (0, Interesting)

nattt (568106) | more than 10 years ago | (#6157324)

Master recording? They'll use the CD like everyone else.

Jitter? You don't know what you're talking about. Jitter is a phenonema that occurs ONLY in the D to A converter. If you load a program from CD, do you get the wrong bytes because of jitter? If you're going to use an audiophool buzzword, at least understand what it's about beforehand.

Re:crap in, crap out (4, Informative)

Shenkerian (577120) | more than 10 years ago | (#6157391)

Granted it was probably mostly marketing bluster, but Steve Jobs did claim that Apple is encoding the original master recordings when they're available.

Re:crap in, crap out (5, Informative)

larry bagina (561269) | more than 10 years ago | (#6157484)

Cdparanois uses the term "frame jitter" for block skewing. Out of respect for them, i use their terminology.

This is what the cdparanoia faq [xiph.org] has to say about ripping...

I can play audio CDs perfectly; why is reading the CD into a file so difficult and prone to errors? It's just the same thing.

Unfortunately, it isn't that easy. The audio CD is not a random access format. It can only be played from some starting point in sequence until it is done, like a vinyl LP. Unlike a data CD, there are no synchronization or positioning headers in the audio data (a CD, audio or data, uses 2352 byte sectors. In a data CD, 304 bytes of each sector is used for header, sync and error correction. An audio CD uses all 2352 bytes for data). The audio CD *does* have a continuous fragmented subchannel, but this is only good for seeking +/-1 second (or 75 sectors or ~176kB) of the desired area, as per the SCSI spec.

When the CD is being played as audio, it is not only moving at 1x, the drive is keeping the media data rate (the spin speed) exactly locked to playback speed. Pick up a portable CD player while it's playing and rotate it 90 degrees. Chances are it will skip; you disturbed this delicate balance. In addition, a player is never distracted from what it's doing... it has nothing else taking up its time. Now add a non-realtime, (relatively) high-latency, multitasking kernel into the mess; it's like picking up the player and constantly shaking it.

CDROM drives generally assume that any sort of DAE will be linear and throw a readahead buffer at the task. However, the OS is reading the data as broken up, seperated read requests. The drive is doing readahead buffering and attempting to store additional data as it comes in off media while it waits for the OS to get around to reading previous blocks. Seeing as how, at 36x, data is coming in at 6.2MB/second, and each read is only 13 sectors or ~30k (due to DMA restrictions), one has to get off 208 read requests a second, minimum without any interruption, to avoid skipping. A single swap to disc or flush of filesystem cache by the OS will generally result in loss of streaming, assuming the drive is working flawlessly. Oh, and virtually no PC on earth has that kind of I/O throughput; a Sun Enterprise server might, but a PC does not. Most don't come within a factor of five, assuming perfect realtime behavior.

To keep piling on the difficulties, faster drives are often prone to vibration and alignment problems; some are total fiascos. They lose streaming *constantly* even without being interrupted. Philips determined 15 years ago that the CD could only be spun up to 50-60x until the physical CD (made of polycarbonate) would deform from centripetal force badly enough to become unreadable. Today's players are pushing physics to the limit. Few do so terribly reliably.

Note that CD 'playback speed' is an excellent example of advertisers making numbers lie for them. A 36x cdrom is generally not spinning at 36x a normal drive's speed. As a 1x drive is adjusting velocity depending on the access's distance from the hub, a 36x drive is probably using a constant angular velocity across the whole surface such that it gets 36x max at the edge. Thus it's actually spinning slower, assuming the '36x' isn't a complete lie, as it is on some drives.

Because audio discs have no headers in the data to assist in picking up where things got lost, most drives will just guess.

This doesn't even *begin* to get into stupid firmware bugs. Even Plextors have occasionally had DAE bugs (although in every case, Plextor has fixed the bug *and* replaced/repaired drives for free). Cheaper drives are often complete basket cases.

Rant Update (for those in the know):

Several folks, through personal mail and on Usenet, have pointed out that audio discs do place absolute positioning information for (at least) nine out of every ten sectors into the Q subchannel, and that my original statement of +/-75 sectors above is wrong. I admit to it being misleading, so I'll try to clarify. The positioning data certainly is in subchannel Q; the point is moot however, for a couple of reasons.

  1. The SCSI and ATAPI specs (there are a couple of each, pick one) don't give any way to retrieve the subchannel from a desired sector. The READ SUB-CHANNEL command will hand you Q all right, you just don't have any idea where exactly that Q came from. The command was intended for getting rough positioning information from audio discs that are paused or playing. This is audio; missing by several sectors is a tiny fraction of a second.
  2. Older CDROM drives tended not to expect 'READ SUB-CHANNEL' unless the drive was playing audio; calling it during data reads could crash the drive and lock up the system. I had one of these drives (Apple 803i, actually a repackaged Sony CD-8003).
  3. MMC-2 *does* give a way to retrieve the Q subchannel along with user data in the READ CD command. Although the drive is required to recognize the fetaure, it is allowed to simply return zeroes (effectively leaving the feature unimplemented). Guess how many drives actually implement this feature: not many.
  4. Assuming you *can* get back the subchannel, most CDROM drives seem to understand audio discs primarily at the "little frame" level; thus sector-level structures aren't reliable. One might get a reassembled subQ, but if the read began in the middle of a sector (or dropped a little frame in the middle; many do), the subQ is likely corrupt and useless.
As reassembling uncorrupted frames is easy without the subchannel, and corrupted reads likely result in a corrupted subchannel too, cdparanoia treats the subchannel as more trouble than it's worth (during verification).

At least one other package (Exact Audio Copy for Win32) manages to use the subchannel to enhance the Table of Contents information. I don't know if this only works on MMC-2 drives that support returning Q with READ CD, but I think I'm going to revisit using the subchannel for extra TOC information.

Re:crap in, crap out (3, Informative)

Anonymous Coward | more than 10 years ago | (#6157529)

Master recording? They'll use the CD like everyone else.

No. Apple doesn't actually make the compressed recordings they sell on ITMS. The record labels are responsible for doing that themselves. And the labels have access to the original master recordings. Some labels have chosen in some cases to go back to the masters when making their AAC's, though it's not widely known which labels made that choice or which songs were encoded that way.

Re:crap in, crap out (5, Insightful)

Guppy06 (410832) | more than 10 years ago | (#6157522)

"I'd hazard a guess that most people that encode with ogg-vorbis do a better ripping and encoding job, though."

Only because right now you'd have to know a thing or two about the intricacies of digital music to have ever heard the phrase "ogg vorbis." If a big on-line music player were to standardize on this format instead of MP3 and it too becomes the common man's format, you can be sure the quality of ogg files will go down just as well.

Thank iTunes for the skips etc. (2, Informative)

SuperBanana (662181) | more than 10 years ago | (#6157542)

I have heard stories of people downloading songs to find a skip or two in the middle

You can probably thank iTunes for that- I had numerous problems with encoding my CDs. Songs has skips, and more commonly, ended early- often by more than 15-20 seconds. It was extremely irritating.

Curiously, I never had such problems with Xing's AudioCatalyst, an awesome encoder for the Mac(it was, and I think still is, the only encoder for the Mac that can do live encoding from line-in). AudioCatalyst was also exceedingly fast on my powerbook- 4x encoding speed, and the rip of the CD was very, very fast.

If you want perfect rips of the audio to encode from, you don't need masters- you need a CD ripper that doesn't suck, like CDparanoia(although CDparanoia is very slow.)

I use uncompressed wav or 256khz mp3 myself

Assuming you mean 256kbit, that's an absurd waste of disk space- anything over 160 is. In fact, if you look at encodes done by "groups", the most they ever do is 192kbit, and usually only if the material is worth it- ie, it has really good production quality, the music is very nice, etc.

Personally, I wish people would take the disk space to do 160kbit- from most encoders, 128kbit files sound pretty bad on anything better than a $25 set of computer speakers.

Re:crap in, crap out (0)

Anonymous Coward | more than 10 years ago | (#6157581)

Excuse me, but when you're talking about digital music, the quality of a CD-ROM is totally academic.

Most MP3 encoders will use DAE (Digital Audio Extraction) to get the data from the CD. This means that the data they pull is either a perfect copy, or their CD-ROM is screwed. If their CD-ROM was screwed, they wouldn't be able to use if for hardly anything anyway (when dealing with PC data, you have to be bit-perfect).

Somebody who made a nice 256Kbps MP3 from a standard pressed CD would create an MP3 which is just as good as if somebody had done the same with the 'CD Master'.

An honest question - who cares? (3, Interesting)

LeoDV (653216) | more than 10 years ago | (#6157145)

This might get modded Troll, but it's an honest question. Whenever I rip a CD, I encode it into mathematically loseless MP3s, and with the cheapness of disk space these days, I can't stop being amazed at how many people don't do the same. If the quality can be compressed into something loseless from the original digital medium (the CD), then who cares if AAC sounds better than OGG sounds better than WMA sounds better than MP3 at 64 kb/s?

Please enlighten me, I'm actually, honestly, curious.

Re:An honest question - who cares? (0)

Anonymous Coward | more than 10 years ago | (#6157174)

How do you define "mathematically lossless?"

Besides, thinking of music in terms of math misses the point. Listen to the music, before and after encoding. Can you hear a difference? If not, then the encoding is subjectively lossless. That's all that matters.

Of course, "subjectively lossless" means different things to different people, or to the same person on different equipment, or even to the same person over time. That's what makes it subjective.

Re:An honest question - who cares? (1, Insightful)

Anonymous Coward | more than 10 years ago | (#6157196)

mathematically loseless MP3s

Oh really? At what bitrate or setting are you getting the exact same WAV files back out after an encode/decode cycle?

You want lossless, use a lossless codec (like FLAC). MP3 is not designed for that, and can't do it. You might not be able to hear the difference, but that doesn't make it anywhere near mathematically loseless.

Re:An honest question - who cares? (0)

bullitB (447519) | more than 10 years ago | (#6157203)

Whenever I rip a CD, I encode it into mathematically loseless MP3s Uhm...no you don't. The MP3 format doesn't allow for it. Maybe if you used FLAC or MonkeyAudio, but the MP3 format specifies maximum audio frame sizes that make lossless MP3 and impossibility.

Re:An honest question - who cares? (1)

ejdmoo (193585) | more than 10 years ago | (#6157213)

CDs = expensive. mp3s = free!
Disk space = cheap. Bandwith = expensive.

There you have it.

Re:An honest question - who cares? (1)

thefogger (455551) | more than 10 years ago | (#6157219)

Well, that depends on what you consider 'mathematically lossless'. I think that when you encode to mp3 you loose at least a bit of quality.

Cheers, Fogger

Re:An honest question - who cares? (1)

Saint Stephen (19450) | more than 10 years ago | (#6157220)

Same here. I bought 2 250 GB hard drives, and just encode to FLAC. 91 albums (so far) = 26.3 GB. Back up to DVD. Basically, movies today are to music a few years ago: still need to compress em.

I expect by late 2005 I'll have a couple of terabytes and just rip movies unocompressed too.

Re:An honest question - who cares? (1)

PyromanFO (319002) | more than 10 years ago | (#6157445)

You won't be doing that from a DVD. They are compressed from the master in MPEG2.

Re:An honest question - who cares? (4, Informative)

markv242 (622209) | more than 10 years ago | (#6157229)

"...I encode it into mathematically loseless [sic] MP3s..."

Not possible. MP3 by its very nature is a lossy encoding scheme, hence there will always be artifacts when you pass the audio through the encoder. You may not be able to hear the quality change (even after passing the files over and over and over through the encoder) but you will be generating noise.

As far as your original question, it all comes down to file portability. It takes people a bit longer to send a 65 meg wav to their friends, compared to a 6.5 meg mp3.

Re: "lossy encoding scheme" (0)

Anonymous Coward | more than 10 years ago | (#6157545)

You must have meant to say instead 'lossy compression scheme'

It doesn't really make sense to describe an encoding or recording scheme lossy, since that is the nature of recording. Lossless encoding is identical to cloning.

Re:An honest question - who cares? (2, Insightful)

afidel (530433) | more than 10 years ago | (#6157230)

Well it matters because some people are buying shitty 128k aac file from Apple (a LOT aparantly, they have sold almost 4 million tracks already). I too rip to high quality mp3 (~220kbps VBR mp3's from LAME which passed tripple blind with wav and ogg) but I guess it's usefull to know what quality you can expect from this service since Apple will be coming out with iTunes for windows later this year and bringing their online service to the masses.

Not a good test of iTunes service (4, Interesting)

benwaggoner (513209) | more than 10 years ago | (#6157296)

It looks like they're working with 16-bit source, not the 24-bit source that most of the iTunes AAC files are ripped from. So this test, while certainly very interesting, won't be useful to determine the iTunes music store quality.

Re:Not a good test of iTunes service (0)

Anonymous Coward | more than 10 years ago | (#6157313)

This is incorrect. What the test is attempting to measure is the difference in quality of the encoded version vs the original. This is a relative measurement, not an absolute measurement, thus the quality of the original is irrelevant (be it 16bit, 24bit, etc).

Re:An honest question - who cares? (0)

Anonymous Coward | more than 10 years ago | (#6157242)

What's a "mathematically loseless" MP3?

An MP3 that cannot lose?

(Repeat after me kids ... "MP3's are _not_ lossless.")

Re:An honest question - who cares? (4, Informative)

Monkelectric (546685) | more than 10 years ago | (#6157279)

You are grossly misinformed. MP3 and most other audio compression formats perform FFT's and throw away coefficents of the FFT that are least noticeable (thats a gross simplification).

There *are* lossless codecs like FLAC and SHN, but they generally achieve between 10 - 30% compression.

Re:An honest question - who cares? (0)

Anonymous Coward | more than 10 years ago | (#6157298)

MP3s are lossy, period. Try converting your "mathmatically lossless" mp3 to a wav and cmp it with the source. What you need is FLAC, which is actually lossless. There are other lossless formats out ther shorten, monkeys audio etc, but FLAC is best because of its BSD license, streamability, and asymmetric algorithm. There are already a number of hardware flac players, unfortunately no portable yet though.

I care. (5, Interesting)

crapulent (598941) | more than 10 years ago | (#6157490)

I care because I have not fallen for the "golden ears" fallacy. To me, 192kbps ABR lame-encoded sounds exactly like the original. I don't have super expensive speakers attached to the computer, nor do I have a fancy sound card (Creative Live 5.1.) Storing music losslessly is a waste of space to me. Sometimes I like to share music files and it's a heck of a lot easier and others are a heck of a lot more interested in trading compressed music compared to lossless files. And I can put a heck of a lot more of them on a CDR. And should I wish to listem to them in my MP3 player with limited memory, I'm sure as hell not going to use a lossless format.

If YOU want to use up your hard drive space, internet bandwidth, and blank media with huge lossless encoded files, feel free. But don't get all smug and proclaim to not have any idea why anyone would not want to waste their resources.

Oh, and I'm not going to touch that "mathematically lossless" crap, others have covered that already.

aahh... AAC sux, anyway... (4, Funny)

Corporate Drone (316880) | more than 10 years ago | (#6157146)

... especially if they allow Miami, BC, and Syracuse in...

Re:aahh... AAC sux, anyway... (1)

jpt.d (444929) | more than 10 years ago | (#6157209)

Allow an American City, a Canadian Province, and an European city in one?

Re:aahh... AAC sux, anyway... (0)

Anonymous Coward | more than 10 years ago | (#6157325)

Uh that's ACC.... not AAC.

Don't know your sports do you?

DVDA (5, Funny)

Graspee_Leemoor (302316) | more than 10 years ago | (#6157148)

I prefer DVDA.

What hyphen?

graspee

I prefer analog (0, Troll)

ArchieBunker (132337) | more than 10 years ago | (#6157191)

Just remember that digital=loss. You are hearing a representation of the original source material. Its only as good as the sampling and playback.

Re:I prefer analog (0)

Anonymous Coward | more than 10 years ago | (#6157248)

Uhm...you do realize that CDs are a digital format? So with good sampling hardware that can read without jitter or errors, the quality should be the same (with a lossless codec of course).

Re:I prefer analog (1)

Graspee_Leemoor (302316) | more than 10 years ago | (#6157260)

You missed my joke, ArchieBunker. I think the AC below you did too, though he tried to make it himself.

hint, DVDA /= DVD-A.

graspee

Re:I prefer analog (4, Insightful)

rsidd (6328) | more than 10 years ago | (#6157290)

Just remember that digital=loss

Well, any analog medium = much worse loss. LPs and cassette tapes can't approach the dynamic range of a CD. Plus you get noise, which gets worse on repeated playback.

The only lossless music is a live performance. But even then, you may crib about acoustics. Besides, you can't hire Brendel to play live for you whenever you feel like, and even if you could, he may not be in good form every day.

Re:I prefer analog (4, Interesting)

afidel (530433) | more than 10 years ago | (#6157303)

What you prefer the loss of the pits on your LP wearing as the needle passes through the grooves? Yeah spectral analysis shows that after three plays with a high end player the LP has already lost MORE dynamic range then a ADAT recording, and of course in hundreds of plays and a couple generations the digital copy is obviously superior, plus getting vinyl from mail order sucks, I know I DJ and the % of DOA stuff is way too high for my liking (especially if it's a white label or rare import, ususally means I get the insurance $ but never find the music again for a reasonable price). Analog has its place (like scratching, cd's just are not the same) but long term quality is not where it's at.

Re:I prefer analog (0)

Anonymous Coward | more than 10 years ago | (#6157327)

The original joke isn't that funny, there's nothing to get, it's just a reference to orgazmo. But you, not "getting" it, and blabbing about who knows what, that's classic.

Re:DVDA (0)

Anonymous Coward | more than 10 years ago | (#6157222)

when you get to be my age, you have to do DVDA or no one will hire you

Re:DVDA (0)

Anonymous Coward | more than 10 years ago | (#6157368)

BAHAHAHA! I'd completely forgotten about that movie. +8 hilarious.

mod parent up funny (1)

bodrell (665409) | more than 10 years ago | (#6157288)

come on, i KNOW plenty of you slashdotters understand the double entendre.

hint: it has to do with pron.

Files on P2P (-1, Offtopic)

2true (672555) | more than 10 years ago | (#6157173)

Has anyone seen anyonline apple store mp3s on p2p yet?

Apple Store doesn't sell mp3s, you idiot. (-1, Flamebait)

Anonymous Coward | more than 10 years ago | (#6157284)

Did you get the hint? They sell AAC files.

Re:Files on P2P (0)

Anonymous Coward | more than 10 years ago | (#6157294)

What apple store mp3s? No such creature.

Re:Files on P2P (0)

Anonymous Coward | more than 10 years ago | (#6157374)

they're not mp3s. But I ahve seen them available on a p2p network. I didn't try downloading (Windows/BSD, so I can't play them), and my understanding of the format was that you can't play them unless they're shared from your playlist (and you can only share with 3 other people, i think).

Test Page (1, Informative)

Anonymous Coward | more than 10 years ago | (#6157190)

http://rarewares.hydrogenaudio.org/test/

Re:Test Page (0)

Anonymous Coward | more than 10 years ago | (#6157252)

Somebody mod the above message up which links to the test page. It's the official specific page for the test.
Of course, the best would be if the news was edited..

MPEG2-AAC not too bad (2, Interesting)

kungfoolouie (589719) | more than 10 years ago | (#6157202)

I happen to own a Panasonic SV-AV30 (4-in-1), and music management app that comes with it has to options to save in MP3 or MPEG2-AAC. Lately, I have been transcoding the audio from mp3s and cd to 96kbps AAC and the results are surprisingly good. I play it in my car and have not really noticed a much of a difference.

Obviously, the tracks which were bad to begin with will be bad as AACs.

BTW, I have been playing/making music for 14 years and have a pretty good ear when it comes to tone and timbre. Hi-hats on CDs have always bothered me with the lack of warmth and fullness of timbre. So take my word for it if I saw it's not too bad :-)

Don't take 64 Kbps AAC results seriously (5, Informative)

benwaggoner (513209) | more than 10 years ago | (#6157211)

I note that in the 64 Kbps test, they used the AAC-LC encoder from QuickTime 6.0. This was a pretty darn lousy one, lacking any ability to specify a sample rate at a given data rate, and had poor quality. The current version of QuickTime 6.3 (for Windows and MacOS X), has a much improved, more flexible AAC-LC encoder, so if they did that test today AAC would likely rank higher.

If using the Apple encoder, encode in "Better" mode with 16-bit source, and in "Best" mode with source that's more than 16-bits per sample (and hence isn't a CD rip). Support for mastering from 24-bit when running in "Best" is one of the reasons why the AAC-LC files as part of iTunes sound so good.

And that wasn't a dis (2, Informative)

benwaggoner (513209) | more than 10 years ago | (#6157273)

Also, I didn't mean that to be a criticism of the original test. 6.0 was the current version of QuickTime when they did the test, so it looks like a fair test for the state of the technologies at the time.

Pfffft... (5, Funny)

Squirrel of Doom (677325) | more than 10 years ago | (#6157233)

In the Billy and the Boingers' "U Stink But I Luv U" encoding test, the OOP-AAC compression scheme won by a wide margin.

Re:Pfffft... (1)

bodrell (665409) | more than 10 years ago | (#6157312)

Billy and the Boingers sucked compared to Death TÃngüe. No one has repeated such masterpieces as "Leper Lover." And I love the line "Let's run over Lionel Richie with a tank."

You make me sick! (0)

Anonymous Coward | more than 10 years ago | (#6157331)

Wa-oohhhh

Wa-oohhhh

Wa-oohhhh

You make me sick! You really stink!

[Tuba Solo]

But I love youuuuu

Re:Pfffft... (1)

BaronM (122102) | more than 10 years ago | (#6157344)

Oh dear God, I haven't laughed that hard in a while now. I think I still have an original audiosheet that I have no way to play. If anyone actually has a rip of this, please send to jhodge@biglizard.net. Don't worry about copyright, I already own two originals. Joe

Sigh. Not a way to get good results (2, Interesting)

Anonymous Coward | more than 10 years ago | (#6157272)

Please note that the survey's host makes no claims that what he's doing is in any way scientific. Keep that in mind. The reasons why the results are to be taken with a grain of salt:

1. There is no guarantee of clean data - the users are expected to generate their own files. MIstakes happen.
2. The type of user who participates in this (and more likely in the OGG vs AAC coming debate) may have some predisposed bias. There is no way to weed out any placebo effects.
3. There is no way to weed out folks who have tin ears. I don't want some idiot who loves dance forming an opinion about Bach not sounding "boomy" enough

This may fly in the face of the /. crowd, but an open call to the masses to submit their opinions is not science nor does it have any scientific meaning.

Re:Sigh. When will people RTFA and get a clue? (5, Informative)

Anonymous Coward | more than 10 years ago | (#6157416)

First, read this:

http://www.ff123.net/abchr/abchr.html

This describes the program and testing methodology used here, which, btw, is based on widely accepted perceptual testing conventions. And yes, by the scientific community. These are the same techniques used by the scientists that do the research and development on these formats. Please note the references at the bottom of the page.

1. Wrong, the MP4 files are already encoded and created for the user, stored in the .zip files.
2. Wrong, the Hidden Reference (ABC/*HR*, please read the page at the first link), ensures that if the user honestly cannot tell the difference but thinks that one exists (placebo), and rates the original lower than one of the encoded versions, that their results are discarded.
3. This is where the statistics come in. With enough listeners, the "noise" gets weeded out of relevant results. Most past tests using this methodology have been shown to provide highly relevant and fairly uniform results when all the data is factored together.

An open call to the masses is the only way to measure the perception of the masses, and if the test is performed properly (which it is in this case), then it *is* scientific.

Next time, please read up a little more on what is happening before jumping to all sorts of incorrect conclusions.

Re:Sigh. When will people RTFA and get a clue? (0)

Anonymous Coward | more than 10 years ago | (#6157447)

To clarify on point #1, the MP4 files are already provided as are the appropriate decoders and scripts necessary to convert them to a usable state. This does not leave much room for error, certainly not to the degree that would make the test results unreliable. The only way a "mistake" could happen then, if directions were followed (and let's face it, if they can't figure out how to run a script, chances are they can't figure out how to use the testing program either, which makes the issue moot again anyway), is if the users hardware is faulty.

CowboyNeal..... (0)

Anonymous Coward | more than 10 years ago | (#6157275)

...still uses a gramophone, you insensitive clod!

Heise did a public test about them one years ago (4, Informative)

Psychic Burrito (611532) | more than 10 years ago | (#6157395)

Read more about the test here [heise.de] (german link).

With 6000 participants, the double-blind public test results were:

  1. Ogg
  2. WMA
  3. RealAudio
  4. Mp3Pro
  5. MP3
  6. AAC (Sic!)
Of course, this was crazy, with AAC even behind MP3, but these really were the results...

Ratings are nice, but... (2, Informative)

MP3Chuck (652277) | more than 10 years ago | (#6157415)

Why not show spectrum analasys of different songs encoded into the given formats too?

Perhaps I'm just an audio freak, but I would find that a lot more interesting than just ratings [ff123.net].

Re:Ratings are nice, but... (0)

Anonymous Coward | more than 10 years ago | (#6157480)

Because spectrum analysis is useless for determining *audio* quality. What you see visually does not correlate with what you hear, especially when considering that spectrum analysis graphs are highly static, and music and audio coders are of a much more dynamic nature. For example, pre-echo, which is one of the most common artifacts in audio coders, is temporal in nature, and can only really be seen visually on a spectrogram, and even then, only if you zoom in and capture the problem in the exact spot in time that it occurs.

Put simply, visual graphs do not provide you with the correct information. It is like with testing speakers or something where the system is expected to behave relatively similarly throughout time.

Some more 64 and 128 Kbit/s AAC listening results (4, Informative)

florin (2243) | more than 10 years ago | (#6157450)

As was previously mentioned [slashdot.org] on Slashdot, a highly regarded German magazine called C'T dedicated an article to a similar comparison of various audio compression codecs last year.

They created fourteen different .WAV recordings containing 3 short excerpts from various CD music tracks (pop, classical and jazz) that had previously been encoded by 6 popular codecs, each at both 64 Kbit/s and 128 Kbit/s (or as close as possible for VBR-only encoders). For verification of the results, 2 of the recordings came directly from CD and had not gone through any encoding process. Because the .WAV files were all the same size, there was no way for the listener to know which encoder had been used on a particular file. Participants were asked to rank their preferences among these files. The encoders included MP3, MP3PRO, Ogg Vorbis, WMA, RealAudio and AAC.

Over 6000 people downloaded those tracks and submitted their preferences. Unfortunately, the results of that test were only published in print and I haven't been able to find an online version of it. A few noteworthy results are below however.

The percentages indicate how many people put a particular codec at a particular ranking:
MP3 64 KBit/s
1st place: 1 %
2: 1%
3: 1%
4: 1%
5: 2%
6: 4%
7th place: 90%


As might be expected for the oldest codec, almost everyone agreed that the file that had been run through MP3 at 64 Kbit was the worst sounding of all. At 128 KBit however, listeners were clearly divided on whether MP3 sounded worse or better than others:

MP3 128 Kbit/s
1: 11%
2: 14%
3: 15%
4: 15%
5: 16%
6: 16%
7: 14%


Now the AAC results. At 64 Kbit, it was ranked a slightly below average performer:
AAC 64 KBit/s
1: 7%
2: 12%
3: 17%
4: 26%
5: 22%
6: 14%
7: 2%


What's interesting is that at 128 Kbit/s, more people ranked AAC the worst sounding encoder than any other codec in the test including MP3!
AAC 128 KBit/s
1: 11%
2: 11%
3: 13%
4: 12%
5: 14%
6: 14%
7: 26%


Not surprisingly, the files that had been read directly from CD without any encoding steps done in between got the best rankings of all. Ogg Vorbis did very well indeed and came in second overall.

Re:Some more 64 and 128 Kbit/s AAC listening resul (1, Informative)

Anonymous Coward | more than 10 years ago | (#6157543)

First of all there are many different AAC codecs. Second, the AAC codec tested in c't produced slightly lower gain (volume) than other codecs.
It's a known fact that "louder sounds better" in a test situation like this. It should be made sure that the volume of the samples are the same, something they didn't do in the c't test especially when there are lots of unexperienced testers.
Third, the c't test is old already.

Sounds Better != High Fidelity (5, Insightful)

Josuah (26407) | more than 10 years ago | (#6157454)

This experiment is really designed to test which codec overall sounds better to the average user, for an arbitrary and inconsistent range of hardware setups, acoustic environments, and listening preferences (e.g. do I pay more attention to the primary beat or to the background harmony). I wouldn't place any value on this test other than to choose which codec I might choose if I wanted to please the ignorant consumer (a valid market, of course!). It does nothing to address how accurately a codec reproduces the artist's original sound.

I'll put a lot more stock in the Report on the MPEG-2 AAC Stereo Verification Tests [uni-hannover.de] put together by David Meares (BBC), Kaoru Watanabe (NHK), Eric Scheirer (MIT Media Labs) for the ISO. And the other MPEG Audio Public Documents [uni-hannover.de].

How can this possibly be accurate? (3, Insightful)

NeoOokami (528323) | more than 10 years ago | (#6157462)

You're basically asking for a lot of people to submit their opinions. This will show you what the people who participated in it prefer, but it doesn't really reveal much in they way of actual sound quality. Everyone has their own opinions already about which audio codec is supperior. The only way you could rule out the placebo affect is to give the test blind, so that they have no clue which file is which. Even then since the results are being turned in on good faith, you have to accept that some people may simply lie about the results based on their own biases. You'd need an objectional third party to administer a test like this, and even then almost no one would agree on a third party in the end. If someone's favorite format lost they'd just bitch about the test being rigged. The only un arguable test would to actully compare the integrity of the audio to the original via an olliscope or some other device. Audio's not my area of expertise so I could be wrong there. It seems to me it's best to just not worry about it and use what you're happy with. Seeing a test like this wouldn't change my mind really. "Person A liked Audio B encoded with mp3 the best!" It just doesn't seem to hold that much sway over me.

Re:How can this possibly be accurate? (4, Informative)

Anonymous Coward | more than 10 years ago | (#6157569)

It's rather obvious that you haven't bothered to read anything about the test, the program used, etc.

The test *is* blind, and it is based on widely accepted perceptual testing techniques. It uses hidden references (references to the original vs the encoded sample, on a per sample basis in which the user is not aware of which is which, thus if they rate the original as being worse than the encoded version, their result is discarded) as a control. The program devised has been developed by someone who has taken the time to do the proper research, read the appropriate papers and other sources, discuss the idea with developers of many different audio codecs (LAME, Vorbis, PsyTEL AAC, etc). The technique here works, and has been used many times before. It's not simply some amateurish scheme that someone who knew nothing about the appropriate sciences dreamed up simply because he wanted to find out if "Person A liked Audio B".

Re:How can this possibly be accurate? (0)

Anonymous Coward | more than 10 years ago | (#6157609)

It was blind, taking care of the placebo effect. In fact, it was double-blind to take care of the rigging administrator effect. I recommend you read www.ff123.net, especially his page about criticisms to the study. He also explains why an oscilliscope doesn't replace human test subjects in listening experiments.

Easy (0, Troll)

CoughDropAddict (40792) | more than 10 years ago | (#6157541)

It's patented. Therefore it fails the test. If I wanted to put my music in a format that I have to (directly or indirectly) pay licensing fees to encode or decode, I'd use mp3.
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