1437039
story
bullitB writes
"For fans of the world wide patent conspiracy's latest audio format, the latest double blind AAC encoder comparison test results are in. If nothing else, this suggests much of the complaints regarding the iTunes Music Store's lossyness might be unfounded."
Discussion (Score:5, Informative)
A warning to potential HA posters (Score:5, Informative)
go AAC (Score:5, Interesting)
Re:go AAC (Score:1)
Re:go AAC (Score:5, Informative)
http://www.rjamorim.com/test/64test/results.htm
and here
http://www.hydrogenaudio.org/index.php?showtopi
Re:go AAC (Score:2)
Re:go AAC (Score:5, Informative)
FAAC is another AAC codec.
Re:go AAC (Score:2)
Re:go AAC (Score:5, Funny)
Lossy is lossy (Score:5, Interesting)
When will people realise that half the trouble with a lossy format is transcoding? Sure, AAC may sound high-quality when it's in its original format, but when you transcode it to MP3 for your MP3 player, the quality turns to shit. This is inevitably the case when dealing with lossy formats, and why I'd rather buy CDs and rip them to FLAC [sf.net].
Re:Lossy is lossy (Score:1)
Oh, don't have an iPod to play your AACs? Do you have a CD player? Because you can burn them.
(Anybody burned them and then ripped them to mp3 from the CD? I can imagine that would be less lossy than straight transcoding.)
Re:Lossy is lossy (Score:1)
Why would burning AAC's to CD and then ripping to MP3 be any less lossy than straight transcoding?
Considering that all transcoding does is render the AAC data into a waveform and then translate the waveform into MP3, what difference would storing the waveform on some intermediate medium make?
Re:Lossy is lossy (Score:1)
Re:Lossy is lossy (Score:5, Insightful)
if every device was perfect it would be bitwise identical. and what in the world led you to believe otherwise? if you ran it through analog form in some point you might get 'smoother' sound or something but that's just it and self deceit.
that being said, if you buy music for an mp3 player, buy it in mp3. or rip it yourself from a cd, or just get high enough bitrate it doesn't matter for your golden ears if you code it from one format to another.
better yet buy from some independends that are willing to provide both formats. or fuck, just encode good old amiga mods.
Re:Lossy is lossy (Score:4, Insightful)
To load it in your mp3 player?
Re:Lossy is lossy (Score:1)
Re:Lossy is lossy (Score:3, Interesting)
-Half the price, at $200
-Ogg support
-Open source firmware and software, including good Linux support.
-Removable HDD 'back packs', you can buy additional 20GB storage for a reasonable ~$100
-Built in FM radio reciever and broadcaster (very cool)
-Hardware MP3 enocding, you can rec
Re:Lossy is lossy (Score:3, Insightful)
Then I bought an iPod, because it was actually well designed - it had an interface that actually lends itself to playing music. I want an mp3 player that I can change the song on while driving - that is, one that's fast to use, and is forgiving of being put down halfway through a menu and picked up again five minutes later because the traffic got bad.
And, frankly, though I could carry an mp3 player larger than an iPod around, if I don't have to, I'm just as happy no
Re:Lossy is lossy (Score:2)
Because I have a car. Until Apple makes an indash iPod I'm not going to be using AACs anytime soon. I'll stick with my kenwood indash mp3 player.
Re:Lossy is lossy (Score:2)
Somehow I don't think that's a viable solution in a discussion about audio quality.
Re:Lossy is lossy (Score:3, Insightful)
I mean, you're driving. If you're being safe, your sound quality is going to be hampered by the fact that your stereo isn't louder than the sounds your car and the road are making.
Re:Lossy is lossy (Score:2)
a. you're screwing up your tape drive. I destroyed 2 of mine with tape adapters. Not that I'm ever going to use them for anything else than tape adapter but still...
b. There is a wire and a "floating device" to handle while driving.
c. You have to buy a charger for your iPod which I guess is very expensive if you plan on letting it in the car.
Well, I'd say it sounds like temporary DIY.
Re:Lossy is lossy (Score:2)
Re: (Score:2)
Re:Lossy is lossy (Score:2, Insightful)
Unfortunately... (Score:5, Informative)
Too bad, too. I would've loved to have seen how it compared.
Error bars (Score:5, Insightful)
Hence, the conclusions declaring clear winners/losers in these cases are invalid. If 99% confidence intervals were used (which gives a better statistical test), I feel that no clear winners or losers would be drawn.
Be careful with these sort of studies - even though the author has used confidence intervals, he has failed to use them to infer the proper conclusions.
That said, it's awfully nice to see error bars on this sort of website. Simple data points give such a false sense of precision, I find...
Re:Error bars (Score:5, Informative)
Re:Error bars (Score:2)
>the beginning the requirements for a clear winner.
The more comparisons we do, the greater the chance that we made an error in one of our comparisons (you can model this with a binomial distribution fairly trivially). Here, in each graph, there are 10 possible comparisons. The odds of us having a false positive in one of those graphs is around 40.1%. Across multiple studies, like this one, you can imagine the odds that one of our com
Correction (sigh) (Score:2)
That should read "The odds of having a false positive among the tests on any one of those graphs is around 40.1%"
Re:Error bars (Score:2)
>pval correction is used. The method for separating the means
>is a protected Fisher LSD.
Fisher LSD is better than I thought, but you are still going about it the wrong way. The only way the Fisher LSD is protected is if you do the ANOVA first and it shows a significant difference between the groups, then you do the post hoc tests accordingly. Just doing the LSD without doing the ANOVA first to determine a significant difference betwe
Re:Error bars (Score:2)
Re:Error bars (Score:2)
Perspective (Score:5, Insightful)
1) Most people can't tell the difference between formats that are similiar in performance.
2) Some people actually can tell the difference.
3) Some people are just posers who can't tell the difference but say they can.
4) Lastly, most people don't really care as long as it is convenient to use either format.
Sounds good to me (Score:5, Informative)
Re:Sounds good to me (Score:5, Interesting)
This statement irks me to no end. Your wording is better than most others though as you used for your preference.
The thing to remember is that MP3 and AAC are different encodings. Comparing AAC to MP3 (to OGG to WMA...) is not like comparing MP3 algorithms. AAC will throw out different sounds that MP3 will keep, and vice versa. For example, a symbol crash sounds a lot better on an MP3 than it does on a similarly encoded AAC (I use LAME MP3s and iTunes AACs, they might sound different on others). However, vocals are clearer on AAC than MP3. I find overall AAC is superior to MP3, and that's what I have my songs as. However, saying a 192 AAC == 128 MP3 is a bit faulty. Both have their strengths and both have their weaknesses.
Re:Sounds good to me (Score:3, Interesting)
. So I reripped all of my CDs to 128kbps AAC and got more songs onto my 5GB iPod.
Sounds like what I did. Then I played my iPod through my home stereo. Yikes! Now I'm re-ripping to 256 MP3. Like you said, though, it's personal preference and what you're using the files for and everybody's different.
Re:Sounds good to me (Score:2)
Re:Sounds good to me (Score:2)
So you jumped from 192kbps MP3 to 128kbps AAC then back to 256kbps MP3... Did you at least try AAC at higher bitrates?
Sad but true. I didn't do any listening tests outside of headphones the first few times (I know--dumb). After I heard 128 AAC through the home stereo I spent a good chunk of a Saturday comparing formats. AAC beats MP3 at the cheap headphone (or ear clips, in my case) level. However, I was surprised that MP3 beat AAC at the home stereo level. While 256 MP3 VBR isn't as good as uncompre
AAC vs. AAC not the issue (Score:4, Interesting)
I understand Apple trying to keep filesizes to a minumum, but in these days of 3.0 Mbps DSL links to people's apartments and storage prices at absolutely mind-boggling low price points, their logic is becoming less and less understandable with each passing month.
AAC actually sounds like a well-developed and efficient lossy format but let's up the bitrate a bit especially when the price of a physical CD with all the artwork and liner notes along with lossless tracks and the ability to rip them to a lossy format for portable use is only a few dollars more, and in some cases the same price, than an album on the iTMS.
Re:AAC vs. AAC not the issue (Score:1)
Re:AAC vs. AAC not the issue (Score:3, Interesting)
I know they use Akami, land of the infinite bandwidth, but that doesn't mean it's free.
Do you ask a car mechanic... (Score:5, Insightful)
Re:Do you ask a car mechanic... (Score:1)
Re:Do you ask a car mechanic... (Score:1)
But... about AES statement: What hearing conditions and sound material do they use for their tests?
And seems like you possibly know: what is the MAX dynamic range of compressed (AAC, MP3, whatever) sound? WTF, not only that, but I can't find ANY (s/n, distortions, intermodulations, etc) parameters of this conversion. I really can't found that, trying hard. And I have no interest/time(to recall) in calculating by myself, so, if you have something on this, please, share info/link.
Re:Do you ask a car mechanic... (Score:3, Insightful)
And here I was thinking that the whole point of lossy audio compression was about throwing away information that people could not hear. :)
The format that throws away the least audible information (as determined, in fact, by "measuring people's perceptions"), other things (encoder complexity, file size, etc) being equal, is the winner.
Re:Do you ask a car mechanic... (Score:4, Insightful)
However, when I am in my car playing them off my iPod->TapeDeckConvertor, well - all the formats still sound the same.
At home on my expensive stereo, I can easily tell the difference between CD and AAC. The AAC is the one playing off my iPod, and the CD is stored in a corrigated box in the basement...
How do these findings compare with mp3, wmf, etc? (Score:2)
Look at Roberto's previous listening tests (Score:4, Informative)
Which 78s sound best, RCA or Columbia? (Score:2, Informative)
I find the music I've downloaded from iTMS perfectly acceptable; ditto the music I hear on my car's factory-equipment FM receiver. That doesn't mean I can't tell the difference between them and better sound.
Actually, I've been transferring my LP's to CD... and recently I've been converting the CD's to
Its all about the file size (Score:4, Insightful)
In someways your right, people should pick a bit rate/format that works for them and not worry about it. but this is slashdot..
Re:Which 78s sound best, RCA or Columbia? (Score:2)
Many people will use vinyl simply for the reason that it does sound better than a CD. While the sound from a vinyl may not be as accurate as a CD, most people will find that they rather enjoy the distortion caused by the vinyl when compared.
News flash, folks. Many people perfer vinyl to CD... if you have a good record, expensive player, you'll notice that vinyl does sound a lot better as long as those two conditions are met. Of course, the beauty of a CD is
Re:Which 78s sound best, RCA or Columbia? (Score:2)
Re:Which 78s sound best, RCA or Columbia? (Score:2)
Don't use ANOVA here (Score:4, Insightful)
Re:Don't use ANOVA here (Score:2, Insightful)
And ANOVA is a robust method as you've commented, so it's probably reasonable to assume normality. In any case, the raw data is available for any stats weenies to play with, and there are a couple of more conservative methods besides the Fisher LSD readily available to try, if anyone has an uncontrollable urge.
I point you to:
http://ff123.net/friedman/stats.html [ff123.net]
where you can run a non-parametric analysis of the
the comments (Score:3, Interesting)
Results: iTunes wins, with Nero closely behind it, more or less tied. Faac is tied with Nero, and Compaact! and Real are tied just below Faac."
"House (Electronic/Techno)
Results: iTunes and Nero tied at first place, Real and Compaact!tied with Nero, and Faac tied to Real and Compaact!."
They were like that. Did we really need a play by play? Did he think we wouldn't be able to "decipher" these "complex" graphs?
...
Re:the comments (Score:2)
Blind people listen to music, and would probably be very interested in his results (many of them having more acute hearing than we sighted folk). However, they would be unable to decipher or even perceive the graphs. I'm not sure how well their screen readers would deal with "faac" or "compaact!" though.
Re:the comments (Score:2)
;-P
Minor Detail (Score:4, Informative)
Re:Minor Detail (Score:2, Interesting)
What is the difference between a "professional" encoder or decoder product, and a "consumer" encoder or decoder product?
A professional product is purchased for commercial (i.e., revenue generating) purposes. A consumer product is purchased or made available for non-revenue generating purposes. Examples of professional products include broadcast encoders, and high-end audio or audio/video workstation applications. Professional products are t
Objectively comparing formats (Score:3, Insightful)
These kinds of tests comparing codecs always seem to be something involving playing two versions of the song and asking someone which in their opinion sounded better. Isn't there a more quantitative way to measure the effect of the lossy compression? For instance:
In other words, whichever codec introduces the least error into the track in a closed loop encode and decode test did the best job of faithfully reproducing the original signal. No subjective human testing required. You might have to tweak it a bit (say, sum the squares of the error or something) but would an approach like this work to settle the codec debates, or is there a fundamental flaw in this technique?
Re:Objectively comparing formats (Score:2)
You could do a fourier analysis and get the frequencies / phase, but how do you visually compare these when they could be significantly different but sound virtually identical. (and which one is more pleasing and less distracting)
I'm waiting for audiophiles to start comparing and critiquing l
Whoa there! Look at the error bars... (Score:3, Informative)
The issue I have is with the error bars. These are the vertical lines above and below the mean of each encoder. Like the beginning of the report says, "One codec can be said to rated better than another codec with 95% confidence if the bottom of its line segment is at or above the top of the competing codec's line segment." This is very much true for these sorts of statistical tests -- if the error bars overlap, that indicates that the means of the two groups are statistically identical. One could always adjust their confidence interval to a lower percentage, but 95% is quite often the standard.
Note how many of the plots in this test have overlapping error bars. In the first plot, for example, all of the encoders tested have overlapping error bars. The results drawn from this plot should be that no encoder was measurably different than any other encoder -- not that iTunes won, like the results say. (Note: I own a Powerbook G4, and am typing this post on it right now, and I love Apple. I just don't like bad statistics, that's all)
The results given in many of the plots are based strictly on the means of the samples, and not the error bars, which are actually more important in this case. Do not trust them. Interpreting the plots with the logic stated at the beginning of the article is the only statistically sound method (that I know of). I hope this sheds some more light on these tests...
It's all quite ridiculous (Score:2)
Re:iTMS music does NOT sound lossy (Score:3, Informative)
Maybe you don't understand the nature of the tests?
FWIW, with the Norah Jones track 'Creepin In' (not used in this test) I can not only ABX every codec bar musepack, I can also spot the aac and mp3 variants because of the way they degrade.
Being a medical student, I assume you understand basic psychoacoustic principles?
Re:iTMS music does NOT sound lossy (Score:5, Funny)
Did you calibrate the flux capacitor?
Re:iTMS music does NOT sound lossy (Score:5, Informative)
A famous example of this is that for many years scientists could not work out how bees could fly. Their wings were too small, muscles too weak and bodies too heavy. It turned out that bees were able to use previously unknown aerodynamic effects to generate more lift than our previous "knowledge" allowed. Another example is that many birds of prey have visual acuity better than the laws of optics, applied to their eyes, would seem to permit. It turned out that the visual signal processing in their brains is so advanced that birds can actually 'see' features that are below the resolution limit of their eyes.
Similarly, we shouldn't be too dogmatic about what humans can and cannot hear. MP3s (and presumably AACs) compress music by suppressing parts you "can't" hear, not because they're outside your range of hearing but because the brain, assuming those parts should be there, fills in for them even when they're absent.
But it may be that you can't hear something consciously but still tell that it's not there.
For example, there was a news story a week or so back showing that people could somehow tell when a picture had changed by the removal of an item in it, even though consciously they could not explain what the difference was - it just 'felt different'.
So, if someone claims to be able to tell the difference between 1 128Kb AAC and a CD, test that claim in a double-blind experiment. Only when he fails the test can you say he was imagining things.
Re:iTMS music does NOT sound lossy (Score:3, Interesting)
Re:iTMS music does NOT sound lossy (Score:3, Interesting)
Havn't tried double blind but......... (Score:3, Interesting)
I'm not a doctor, but I play one on television (Score:5, Informative)
It is clear you have no idea what you are talking about. Just because you can't tell the difference does not mean others can.
The people who are "able to tell" just happen to have more sensitive hearing. I'm probably not one of them, but I have known several, including someone who cannot listen to CD's because there is a whine on all of them associated with the digital nature (this same guy does not like going into Radio Shack because of the noise made by their security system.)
Just because you are not a sensitive-eared audiophile does not mean everyone has the same cloth-ears as you do.
Re:I'm not a doctor, but I play one on television (Score:4, Interesting)
I'm getting sick of hearing about how Jimmy the cat boy can't listen to CDs, so the rest of the Budweiser crowd has to bow down to his codec choices.
These people are either freaks who feel the need to expound their superiority at any given chance, or audiophiles who feel they're somehow making a difference by making us waste storage space.
At some point you have to choose whether you're listening to the music or the technology used to reproduce it.
Re:I'm not a doctor, but I play one on television (Score:2)
Ok, I don't hear that, but a muted television drives me nuts. Most have a high pitch squeal. Apparently, not everyone can hear it. I don't consider myself an audiophile by any stretch. I'm pretty sure my hearing is moderately damaged from too many close encounters with loud bands in small bars. But a muted tv really irritates me. Even when it's not muted, I can hear it, though it's not so bad.
Anyone else know wha
Re:I'm not a doctor, but I play one on television (Score:5, Informative)
Re:I'm not a doctor, but I play one on television (Score:2)
It will sound as good to me, but not to my super-sensitive-eared friend, whose hearing is bothered by the low digital "resolution" of CD audio, and it causes unpleasant effects for him. I've never noticed the problem myself, just as I never noticed the Radio Shack security system sound that he heard.
Re:I'm not a doctor, but I play one on television (Score:5, Insightful)
Then I heard what good CD players can sound like, and realized that the harshness of CD audio had nothing to do with resolution, and everything to do with component makers cutting corners. Your friend might make the same discovery, if he goes to a good listening room with an open mind.
You may have a point (Score:2)
Re:You may have a point (Score:5, Informative)
Audiophile opinion (Score:4, Interesting)
I used to get my jollies installing the cable the wrong way round on one side. Not one of the audionerds noticed by listening.
Want to know how much flowery crap they can go on with? Take a look here [netsuite.com]. You only have to read the descriptions of a few of those turntables to realise these guys are as wacked out as alien abductees and the guy on the street corner who tells you every morning he has the FBI after him.
Re:Audiophile opinion (Score:4, Insightful)
But this is different. Bear in mind 'CD quality' ('Red Book' audio) has been established as a base line for the last 10 years or so. Lossy compression degrades this quality by variable amounts depending on what codec is used, what the source material is and at what bitrate it is compressed. The reason for so much development on these codecs isn't to find an audio nirvana, but to minimize the loss from the source material.
Re:Audiophile opinion (Score:5, Insightful)
I think that's part of it for many people. We might not hear parts of the music just like we may not "see" parts of a video clip on the first run round, but after 3 years listening to Louis Armstrong direct from CD, hearing him on 128kbit MP3 can be harsh. Humans learn and learn well, and the repitition of that playing guarantees we'll hear things that we're not meant to! or rather, things that we don't need to in order to identify a particular artist and recording. But we don't just listen to something to identify it, we listen to enjoy. That's different.
Most of the time 128kbit is fine for me. 192kbit for the things I'm familiar with.
Re:Audiophile opinion (Score:5, Interesting)
The better you know a subject, the more clearly you can "see" it through a dirty window.
P.S. Most of Louis Armstrong's best stuff was recorded on very harsh-sounding "clay 78s." No matter what format you play his Hot Fives and Hot Sevens singles on, it's going to sound like mush. This is another example: People who listen to a lot of live jazz have no trouble listening through all the ticks, pops, scratches, microphone clipping, bad accoustics, etc. and in their "mind's ear" can hear just how brilliant and beautiful Armstrong's recordings are. Those who don't can barely make out a fuzzy-sounding trumpet in an echo-filled hall, and wonder what all the fuss is about.
Re:Audiophile opinion (Score:3, Informative)
Re:Audiophile opinion (Score:3, Funny)
read the descriptions of a few of those turntables to realise these guys are as wacked out as alien abductees
You think that's insane? Take a look at this review of a freekin power cable [soundstage.com].
Re: (Score:2)
Re:Audiophile opinion (Score:2)
Re:Audiophile opinion (Score:5, Funny)
Ha ha ha! I love the directional cable talk!
As soon as you find someone who starts talking to you about directional audio cables, you must do two things: discount anything else they have ever said to you, and laugh in their faces. While it may seem, to the uninformed, that music 'flows' from the CD / record player out to the speakers, we must always remember that speakers are AC. Alternating current is required to make the speaker cones move in and out.
The real problem is that with all that back and forth motion, the electrons can get very very tired. I recommend that everyone with directional cables should only play their scratchy old LPs for a few minutes each day, lest the electrons in their very expensive cables succumb to extreme fatigue. Come to think of it, the Golden Ear crowd better buy replacements for all their cables once a month -- just in case!
Re:Audiophile opinion (Score:2)
Re:Audiophile opinion (Score:3, Interesting)
Re:iTMS music does NOT sound lossy (Score:5, Insightful)
If I listen to an MP3 or AAC file on my computer with its sound card and speakers (SB Audigy, Boston Accoustics) I can tell the difference between the same (160kbs) MP3 file and a (128k) AAC - the AAC sounds better. I can't tell the difference between the AAC and a WAV file however.
If I move up to my ($$$$) home stereo then I can easily tell the difference between the compressed and non-compressed versions of the same song. AAC still sounds better to me than MP3 however.
The difference here is money and environment, my office is a noisy place with all the computers etc running. My listening room is quiet and I spent a lot of time setting the stereo up so that its at its best.
I have not looked at OOG or any of the other formats so I can't comment on the relative merits of them.
Re:iTMS music does NOT sound lossy (Score:3, Funny)
You, sir, are most certainly not aware of where you are posting that statement. On /., there is little to no precident for needing knowledge of any technology to authoritatively comment on it's merits.
Re:iTMS music does NOT sound lossy (Score:3, Informative)
I mean due to "harmonising".
Furthermore, there exists some "dynamic range compression"
So I have to tell that:
a) if you are listening in APPROPRIATE conditions and on APPROPRIATE sound system (mean amplifyer&speakers&QUET room) you easily can distinguish compressed from flat by dynamic range. Possibly you can't tell what's d
Re:iTMS music does NOT sound lossy (Score:2)
Re:AAC is an aberration that should go away (Score:1)
I'm sticking to musepack. I've got 23000+ tunes (1700 albums-ish) on my home server, but can only casually find ~4-5 tunes which seem degraded from the original. Hardware support would be nice, though.
Re:AAC is an aberration that should go away (Score:5, Informative)
Re:AAC is not a standard format (Score:2)
Re:AAC is not a standard format (Score:4, Insightful)
"I find that the DRM used in the iTunes store is fair, and more or less barely noticeable"
It's far from fair, since it requires the kludgey solution of burning to CD and then ripping to an actual usable format in order to make use of your OWN files on your OWN machines.
If you got a track from iTMS, you MUST have downloaded it with iTunes. Thus, you have a solution for using the original file on your machine (Windows and Mac). Don't complain about the lack of Linux support. It's apple's baby and they can do what they want with it.
I'm not saying you have to like AAC, or support its right to exist, but if you knowingly buy an iTMS track, caveat emptor.
Also, I'd like to know what rights Fairplay has denied you? The right to share music with all your friends? Copyright law already forbids that. Fairplay only enforces it. Your example of AAC to CD to MP3/WMA/etc. claims that you have lost the right to directly convert AAC to another format. I hardly find that overly restrictive, considering the alternatives (only one machine, only one portable music player, limited times burning the track, etc.)
Re:AAC is not a standard format (Score:1)
Re:AAC is not a standard format (Score:2)
What the hell is a "usable format"? I use my mine how I like them just fine. Download and listen from laptop or iPod.
Ohhhh, you meant "usable" in the sense of your own opinion. Nice 'standard' compliance there, chief.