Slashdot Mirror


2nd Multi-Format 128kbps Public Listening Test

technology is sexy writes "Roberto Amorim has launched his latest public listening test evaluating the performance of different audio codecs at 128kbps, among them Apple's AAC implementation (used in iTunes), LAME, Ogg Vorbis fork auTuV, WMA, Musepack and even Sony's Atrac3 format, which is soon to be used in their own music store. Read more on Hydrogenaudio and check out the results of prior tests. As opposed to most evaluations of audio codecs, this is a scientific test adhering to ITU-R BS.1116-1 as much as possible while still allowing everybody to participate."

11 of 316 comments (clear)

  1. Re:Honesty of responders by Per+Wigren · · Score: 5, Insightful

    Great, now all the ____ fanboys are going to forge results to make their codec look good. Talk about useless tests.

    Not possible. All you will get is a bunch of WAV-files, you have no way to tell which file belong to which codec.

    That said, I don't care which codec wins the test because Vorbis is still the only one free from patents and the margins are so incredibly small.
    Vorbis will win for me even in the unlikely scenario that it comes out last.

    --
    My other account has a 3-digit UID.
  2. Performance is only one more factor by rnbc · · Score: 4, Insightful

    Yes... certainly this kind of listening test is important to access the capabilities of each codec.

    But in the real world other factors may be more important to chose a coded, like for example general acceptance, freely available code and specs, and a large content base available.

    You see: performance will increase allways in all codecs with time... so this kind of testing is only a minute factor amongst others.

    --
    You cannot proceed from the informal to formal by formal means
  3. Re:Ogg! by Anonymous Coward · · Score: 5, Insightful

    I wish there was a filter that scored any post with the words "You're new here, aren't you?" -5 stupid joke.

  4. Re:Objective audio analysis by The+Clockwork+Troll · · Score: 5, Insightful
    That is a great idea in theory, however there is much debate on how psychoacoustics work, i.e. what information really "needs" to be there in music in order to be perceived.

    For example, conventional wisdom says that the human ear cannot detect sounds above roughly 20kHz, yet there is at least some anecdotal evidence that higher order harmonics shape what we hear.

    If "normal" human auditory capacity was a completely decoded topic, there wouldn't be nearly as much a need for different approaches to music compression (it would be a much simpler problem with fewer possible solutions)

    --

    There are no karma whores, only moderation johns
  5. Re:Objective audio analysis by j3ll0 · · Score: 4, Insightful


    Well I could be wrong, and forgive me if I've misinterpreted your post...but

    Don't all of these compression algorithms rely on psychacoustic modeling to remove 'extraneous' information from the bitstream?

    If that is correct, and the algorithms are implemented correctly, then really what we are looking for is the best perceived result.

    Just because the output meets the algorithm input->output specs, justn't mean it's the best output as perceived by humans.

    Maybe think of it as optimizing sort routines? Yep, bubble-sort or b-tree still output a sorted list, but the perceived value is that the b-tree is better because it performs it's function more quickly.

    This isn't an exercise in getting the frequencies algorithmically correct - the end result has to be listenable.

    Humans are analog devices...

  6. Re:No matter *what* by mrgreen4242 · · Score: 4, Insightful
    128kbps doesn't cut it. It's an absolute lossy, disgusting bitrate, no matter what it's in. They should test similar file sizes instead of by bitrate, to determine whether something is good or not- this gives a better impression of quality vs size, instead of a purely comparison based test.

    Uh, if the sample is the same length, and the but rate is the same, won't the file size be the same as well? A 10 second sample at 128 Kb Per Second should be 1280Kb regardless of the format, no?

    And, just FYI, MOST people, something like 95% of listeners cannot tell the difference between 128kbps sample and the original. I generally can't, even with decent headphones on.

    I think that all you compression elitist snobs work for HD manufacturers, trying to get me to buy a 250GB drive to store the same amount of music as my 60GB will hold!

  7. Uh, file size *is* bitrate... by rsidd · · Score: 4, Insightful
    a given audio stream, at a given bitrate, for a given length of time, always has the same filesize. What else do you think bitrate measures?

    BTW, I think the difference between MP3 and Vorbis at 128 kb/s is perfectly noticeable. MP3 sounds rather bad, vorbis sounds pretty good. And the point is precisely to tell which format sounds best, so you don't want to do 512 kb/s bitrate where all formats sound close to CD quality.

  8. Re:No matter *what* by Jugalator · · Score: 4, Insightful

    No matter *what*?

    Not even if it's about average quality speakers?
    Not even if it's about some rather cheap speakers?

    I can't say I hear much of a difference with modern codecs, and I own some average speakers. Maybe 128 kbps mp3 can sound bad (although that depends a lot on the kind of music), but that's an aging codec anyway. I think encoded files in the 192 - 256 kbps range is the best, and 128 kbps ogg's often acceptable, especially with the DFX plugin (or similar) for Winamp to compensate for shortcomings in compressed formats.

    I'd definitely not call 128 kbps in modern codecs "disgusting". In ogg's I've found it to be roughly as 160-192 kbps mp3's and that's perfectfly fine for my ears.

    --
    Beware: In C++, your friends can see your privates!
  9. Sound quality is in the speakers by Anonymous Coward · · Score: 5, Insightful

    When you listen to compressed audio over inexpensive speakers / headphones, you can't hear the difference. With my Sony Studio Monitor headphones, I lost the difference at about 250k with mp3, so I started using 320K as that was the best at the time. Then I bought $2000 Martin Logan Mosaic Speakers, and the original CD was clearly better than even the 320K bitrate. So now I only do lossless compression. That's fine at home, but in any other environment, there's usually so much noise and distractions that even if you had excellent headphones or speakers, you wouldn't appreciate that little difference lossless brings over 256K or even 128K.

  10. Re:No matter *what* by Gumber · · Score: 4, Insightful

    And how do you know what you are asserting? Have you done properly controlled listening tests with 128kbps encoding using a variety of codecs?

    The fact is that for a lot of people, knowing the best codec at 128kbps is worth knowing because:

    1) They are using portable devices where they are space constrained
    2) They are using portable devices that may not have the perfect fidelity of a high-end sound system, but can go anywhere with them.
    3) They are using their portable device in a somewhat noisy environment that overshadows any sound quality issues caused by a lower bitrate.

  11. Re:What ever happened to r3mix.net? Any replacemen by DeeKayWon · · Score: 4, Insightful
    r3mix.net died because people actually did objective analysis of his recommended LAME settings and found they were crap. IIRC, the main guy behind it wasn't very accepting of criticism. Plus, he was a message board spammer.

    The best replacement for r3mix.net in my opinion is HydrogenAudio . The forums are frequented by a lot of professionals, as well as developers of LAME, FLAC, Nero AAC, Musepack, Wavpack, and other codecs.