Slashdot Mirror
Hydrogenaudio AAC Listening Test Results
caffeine_monkey writes "Hydrogenaudio's AAC public listening test, previously posted on Slashdot, is now over and the results are in. The test compared five codecs at 128 kbps, including Psytel, Nero, Sorenson Squeeze, QuickTime, and FAAC. The winner? 'QuickTime is a clear winner, performing much better than the competition. Sorenson Squeeze, Psytel AACenc and Nero are tied, with Sorenson slightly higher than the others. Faac is clearly the worst.'"
I have the Ultimate Guide
I'm not Seth.
d'oh. Answering my own question here:
Because AAC is not an encoding format supported by M$ WMA.
- Oisin
PGP KeyId: 0x08D63965
While it may be relevant to have a comparison between different AAC encoders the trial would have much more relevance to real life if it had included ogg and mp3.
A little extra work for a lot more sense in the results.
Have fun
Xander
Slashdot Beta should die a painful death.
Because comparing apples to oranges is never a bright idea. The comparison is between AAC codecs not a few AAC codecs vs WMA.
Do not confuse FAAC and FLAC (the lossless audio format from Xiph).
Btw, why does this test compare only proprietary formats and not free (as speech) formats like Ogg Vorbis or FLAC ?
The following are actual quotes I've read from audiophiles on the net. Enjoy.
"Pulling harmonics together from a jumbled auditory stream to form a coherent harmonic envelope."
"Image outlines were sharply focused in space with believable palpability."
"There was plenty of bass detail to behold."
"The music flows with gusto and verve. It squeezes instrumental images into incredibly palpable outlines."
"...more muscle and definition, and a heart that is pure gold."
"Most preamps when pushed hard change their sonic signature."
"Harmonic colors were somewhat on the dark side."
"By using the $450 gold plated RCA stereo jumper cables for all line-level connections, and the newly available $1200 gold plated XYZ speaker wires, we were able to achieve a distinct improvement in highs and the deepest rich bass lows I have ever heard. A massive improvement over ordinary old copper."
"These cables deliver big time! The sound is surprsingly smooth and spacious, with particularly sweet upper octaves."
"If you connect a ground to the chassis of your power amplifer and use 4 gauge wire connected to a bucket of salt water with a copper coil in it, your mids and highs will be the sweetest you have ever heard. Works with car audio systems too. Place the bucket in the trunk and reduce speed on corners and when braking, to avoid spillage."
"Special wooden resonator disks made in Asia from a special tree, only found in one area. Placing these under EACH of your components, at strategic locations will remove 'unwanted resonances', and DRAMATIC improval tonal quality. The difference is astounding. These disks of wood sell for around $100 to $400 EACH (depending on size)." (See the top of this web page!)
"somewhat fuzzy portrayal of image outlines."
"Harmonic textures ebbed and flowed with startling dynamic nuances and the sort of liquidity and purity one only comes to associate with world-class audio products."
"Harmonic textures are painted slightly gray in color."
"Spatial detail was painted with a fine brush that readily resolved massed voices and the air around individual instruments."
"Image outlines, however, are more precisely focused within the soundstage and in general the Accordance is capable of sketching out a convincing 3-D acoustic impression."
"It felt like I had crawled into a warm and inviting sonic womb."
"Not content with straight S.E.X. (the single-ended experimenter's kit), the Doctor introduces the "69" tapered pipe loudspeaker. Sounds like a recipe for a mind-blowing sonic orgasm."
"The impression of speed and control was strong."
"Bass lines were fleshed out with excellent definition."
"It is less lush sounding than..."
"...force feeding the listener an earful of detail; more accurately, a barrage of in-your-face zingers that becomes almost an instant irritant."
"Each tube brand seems to have a unique flavor of its own."
"Certain busy passages of music get congested."
"... sounds either euphonic or bright."
"The Equilibre ($8,475) - nominally a 60-watt stereo amp."
"It could well explain the sweet sounds that come from using passive preamps straight into the power amplifiers."
"...with an easy-to-drive impedance magnitude."
"Rendition of harmonic colors was suave and smooth, with a believable sugar coating."
"Exposure of low-level detail, even in complex passages, without leaving anything to the imagination."
"The mids are vivid in spades with wave after wave of honey-coated harmonic bliss."
"The midbass region is "fun"
"the upper mids are a bit more laid back than I would like."
"the low bottom end is not there..."
I'm not Seth.
Did you even read the blurb? Quicktime's AAC encoder won.
apple refer to there container format, player and codecs all as quicktime. the story should have arguably refered to it as the quicktime aac codec or possibly the apple quicktime aac codec or even the apple propriatory quicktime aac compression engine
but it just used quicktime and we all knew what it ment
**** lying is wrong even for sleeping dogs
Would I be correct in assuming that it is the QuickTime codec that is used in iTunes? I can't imagine Apple would go to the trouble of writing two different codecs.
"Reality is merely an illusion, albeit a very persistent one " -Albert Einstein
What I'm curious about is, there was some discussion before about the differences between the original AAC encoder that came with QT, and the newer one that now ships with QT 6.3 (and ties to iTunes). The original encoder was said to have sucked. This one, if I'm reading this right, is now very good...?
Anyways, I must have lead ears. I used to rip my MP3s at 160kbps, now I do 160kbit AACs, and cannot really tell the difference. AAC seems a tiny bit better maybe but could be a placebo effect.
If Jesus wants me it knows where to find me.
From Apple's AAC page
Because of its exceptional performance and quality, Advanced Audio Coding (AAC) is at the core of the MPEG-4 and 3GPP specifications and is the new audio codec of choice for Internet, wireless, and digital broadcast arenas. AAC provides audio encoding that compresses much more efficiently than older formats such as MP3, yet delivers quality rivaling that of uncompressed CD audio.
AAC was developed by the MPEG group that includes Dolby, Fraunhofer (FhG), AT&T, Sony, and Nokia--companies that have also been involved in the development of audio codecs such as MP3 and AC3 (also known as Dolby Digital). The AAC codec in QuickTime 6 builds upon new, state-of-the art signal processing technology from Dolby Laboratories and brings true variable bit rate (VBR) audio encoding to QuickTime.
From Via Licensing
MPEG-4 AAC has been specified as the high-quality general audio coder for 3G wireless terminals. Apple Computer has incorporated MPEG-4 AAC into QuickTime 6 and iTunes 4, as well as the latest version of its award-winning iPod portable music player. The Digital Radio Mondiale system (the next-generation digital replacement for radio broadcasting under 30 MHZ) builds on the audio coding of MPEG-4 AAC. These exciting platforms represent the state of the art in audio coding--and Via Licensing is pleased to offer the MPEG-4 AAC Patent License Agreement.
The MPEG-4 AAC standard incorporates MPEG-2 AAC, forming the basis of the MPEG-4 audio compression technology for data rates above 32 kbps per channel. Additional tools increase the effectiveness of MPEG-2 AAC at lower bit rates, and add scalability or error resilience characteristics. These additional tools extend AAC into its MPEG-4 incarnation (ISO/IEC 14496-3, Subpart 4).
A copy of the MPEG-4 Audio standard can be purchased from the ISO online store (search for "14496-3").
It is Dolby's encoder.
Happiness is like peeing yourself. Everybody can see it but only you can feel its warmth.
Its so fucking true! Everytime an audio format gets mentioned all the simpering open sores twats come out squealing 'what about OGG? pleeeeeeeeeeeeeeaaaaaaasee mummy pleeasssee dont ignore me'
SHUT THE FUCK UP ABOUT OGG YOU PASTY FACED FAT HIPPY CUNTS
" Its pretty widely known that WMA offers superior quality"
Actually, the tests that show this were at the 64kbs range which is not useful except for voice. The break-even point is 128, and above that sampling rate, virtually everything (including MP3) is superior to WMA.
So I guess if you want a good voice-streaming codec, WMA is your codec. But for music, it isn't very good.
But perhaps you're a person who primarily listens to books on tape or something like that?
AAC is not necessarily copy protected. For instance, if you encode your own music with iTunes, the files are not protected in any way.
Obviously, it would be difficult to conduct a listening test if the files in question wouldn't play on everyone's computers because of digital rights management, right?
Because not every QuickTime movie uses AAC from a good source recording.
I could ask the same question about the majority of WMP files I find out on teh Intarweb, and I'd get the same answer.
Mikey-San
Karma: +Eleventy billion (mostly affected by watching Celebrity Jeopardy)
...ask a stupid question, then reply with the obvious answer.
however, all of those quotations you've 'collected' are found at http://home.cfl.rr.com/happysurfer/audio_bs.htm
"mostly audiophile gear is a jerk-off session of wannabee music expert wealthy bast^H^H^H^H guys who can afford to spend large anounts of money on equipment"
;-)
And this differs from computer hardware discussions how?
Computer hardware discussion usually discuss measurable quantities such as Mhz, fps, Mbps, etc. The more subjective stuff (CISC vs. RISC) is usually backed up by benchmarks (with all sides accepting that ALL benchmarks are bullshit).
It is rare to hear an audiophile even mention the word "frequency", let alone relate this to any numbers ("high" frequencies? wotsat?).
Now, if you're talking about software, that's when geeks get religious!
SCO employee? Check out the bounty
It is much more fun to cat files to a MIDI device, but you should not use ASCII, you need bytes with the high bit set. Try an XEmacs binary for example.
Whilst the listening test is interesting, look at the styles of music tested:
1) "Rock"
2) Solo Harpsichord
3) Quiet intro with acoustic and electric guitars followed by loud metal riffs
4) IDM [??]
5) Electronic mix
6) Metal, complete with screeching vocals
7) drums and bass in the far left, guitar in the far right. Female vocal in the center.
8) rock/metal riffs
9) Drums and ride cymbals intro, followed by bass and female vocals.
10) Intro consists of guitar in far left with male vocal in center.
Hardly a broad range of music! This test tells me essentially nothing about which encoder would be best for piano music, orchestral music, opera, jazz, speech, etc.
The article claims the QuickTime audio format as a clear winner. Yet in most graphs the 95% confidence markers overlapped with other formats. Most statisticians would then say "Not Enough Data!!"
OK The results suggest that Quicktime was better but its not a clear winner until the 99% confidence intervals don't overlap, let alone the 95% ones. As one other poster said. You need a bigger sample size.
As for the noise being louder in the balancing amps than from the RF, that's not true necessarily - I work at a radio station, in a high-RF environment. If we don't balance, we get audio on all of our long runs of wire... including our network cables.
-T
For Mac users the simple solution would be to use AACelerator, AAChoo or makeminempeg4. iTunes actually uses the "good" not "best" settings. Also in Quicktime there is an export/movie to mpeg-4/options/audio setting for doing it file by file. Browse the AAC forum over at Hydrogen Audio.
There are three speed/quality settings in QuickTime. The first is fast and cheap, and really only meant for real-time broadcasting. For this, we're interested in "Better" and "Best" modes. The only real difference between then is when working with more than 16-bit source. Better uses every quality optimization technique that works when the source is only 16-bit. Best uses additional techniques that improve quality with higher bit sources (like 20 or 24 bit, common in audio mastering).
iTunes is tuned for CD ripping, so using "Better" mode by default is just fine.
AAC-LC can also decode at more than 16-bit in some implementations. This means it's possible to make a AAC-LC encode that is better than CD quality, if the source is more than 16-bit. I gather Apple does this with the iTunes music store, using better than CD quality masters for the encode when available.
My video compression blog
Just to make it clear why you can't do this: There is a certain incremental difference in subjective quality, that will cause listener A to rank something 4 instead of 3, for example. Will that same incremental difference in subjective quality case listener B to also rank something 4 instead of 3? We don't even know if the scale is linear, much less whether the different increments are even the same for different listeners.
Example: on the Kuro5hin blog site, if I really like a comment I will rate it 5. If I hate it, I will rate it 1. I never use the ratings in between. Thus, sometimes a 1 is bad, and sometimes a 1 is really bad. The same could happen here. Even if different listeners perceive similar subjective changes in quality, they might assign different changes in rank to those changes in quality.
God, this entire thing is bullshit, now that I think about it.
Studio technicians and musicians aren't generally known for having 'golden ears'. In fact long hours in front of loud monitors and guitar amps tends to make for poor hearing of very high frequencies.
Most people agree that Vorbis (often referred to as Ogg, but that's the container) is superior at low bitrates as its artifacts are usually less offensive than those of low bitrate MP3s etc. Vorbis is certainly NOT the best lossy codec at high bitrates however. I would be curious to know when this test was done, and what MP3, AAC and MPC encoders were used.
The statement that at above 128 kilobits/second none of the codecs were clearly distinguishable from CD is laughable and leads me to believe the testers either have 'tin ears' or are untrained in spotting encoder artifacts. Training really matters here! It makes a big difference when you know how an encoder screws up a signal, and how to spot it.
The general consensus among those 'in the know' is that in order to reach transparency or 'near CD quality' with MP3 you'll need a good encoder like LAME and a VBR bitrate in the neighborhood of 220+ kbps. (Use the standard preset.)
I wonder if these tests were conducted using loudspeakers. Most codec testing is done with headphones which tend to be better for spotting tiny differences in encoded material.
Yes, a ranking method could have been used to evaluate the codecs instead of a rating method. The rating method is typically more powerful for smaller sample sizes, though.
BTW, there is nothing wrong with using either method. Again refer to the MPEG group's own evaluation of AAC. They used the rating method.