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AAC vs. OGG vs. MP3
asv108 writes "Yesterday, Apple unveiled their new music service claiming that the AAC format "combines sound quality that rivals CD." Here is a little comparison of lossy music codecs, comparing an Apple ripped AAC file with the commonly used MP3 codec and the increasingly popular OGG codec. Spectrum analysis was used to see which format did the best job of maintaining the shape of the original waveform." Wish they had WMAs in there too. And for the spoilage, it looks like OGG comes out on top.
I've got a nice pair of Bose headphones, and I listened to an Apple Store AAC file and an OGG version of the same song. I don't consider myself a real audiophile, but it's damn near impossible to tell the difference between the two; though I can definitely hear the improvement from MP3 to AAC or OGG.
Don't forget that Apple's AAC's aren't ripped from 48.8 16-bit AIFF's, but re-mastered directly to AAC.
I hate Grammar Nazi's
And it's more efficient than MP3.
Their encoder is not particularly good, and AAC is covered by a ton of patents, so there probably are other reasons why they chose it.
For anyone else but Apple I see no reason to use AAC when you can have Ogg Vorbis.
PS: Shameless plug: I wrote a vorbis patch to add SSE support for enhanced encoder and decoder speed. It also contains some 3dnow! optimization for you K6 users, decoder only.
Tubes and transistors are different though. With Ogg vs whatever, it may be more subjective, who knows. But at least with tubes there is a known difference between how they amplify and how transistors amplify. Tubes produce more even order distortion, which to our ears sounds warm and pleasing. Transistors produce more odd order distortion, which tends to sound harsh and stressing.
Subtle difference? Perhaps, but it's there.
Ogg is a container format. I could in theory put an ACC audio file into an Ogg container.
.ogg because it is inside an Ogg container.
The audio format you're babbling about is Vorbis. Usually
Hell, it's not just a silly name problem, it's an entire naming convention issue.
According to this blind listening test conducted by c't magazine, AAC at 128kbps was ranked the lowest of all codecs sampled at that bitrate (WAV, OGG, WMA, RA, MP3Pro and MP3)... One can always hope that the claims of Apple making their AACs directly from the record masters are true, as this would help the situation some.
Slashdot's first reaction to VMware
Regarding the AAC->CD->MP3, I burned a couple of Music Store tracks to CD, then re-ripped them (using iTunes, no less) using VBR High, and they sounded indistinguishable from the original Music Store files (albeit being significantly higher average bitrates).
Regarding DRM, it appears that your Music Store file is locked to your Apple ID, and you have to Register up to three computers that you want to be able to play songs associated with your Apple ID. If you sell a computer, you have to unregister it before you can register a replacement computer. This appears to be the only restriction on usage -- you can still burn the songs to as many CDs as you want, copy them to as many iPods as you want, and streamthem to as many other Macs (and TiVo) as you want using Rendezvous.
Arguably the best resource for audio compression information can be found at Hydrogen Audio. Visit the various forums, check out the excellent Foobar2000 win32 multiformat audio player, and learn.
I have also written a guide on ripping high-quality MP3s using CDex, aimed towards beginners. If you know people who use Musicmatch, help them switch to a decent, easy-to-use CD ripper.
Cheers,
CD
Use ISO 8601 dates [YYYY-MM-DD]
The Xiph folks have signed up to add Ogg support on the Neuros audio handheld. Its a firmware upgradable handheld which currently supports mp3, but will probably have Ogg support by mid-late summer.
Check out the highlights.
http://www.neurosaudio.com/
I burned a couple of Music Store tracks to CD, then re-ripped them
.WAV file. I mean, you're paying for the track, you should get the exact same data as you can when you purchase the CD outright. But as a "best of evils," this is very good. And, truthfully, I'm not convinced that other similar services (like Listen.com's Rhapsody) don't do essentially the same thing.
.wav, and as you decrease the bitrate listen for the flutes at 0:35 to start sounding weird" or somesuch. Just a thought.
A coworker recorded a few songs to CD last night. This morning, I ripped them to q7 Ogg Vorbis, and downconverted those Ogg files to MP3 (VBR, 160 to 256 kbps).
Listening to them (on decent speakers, but still computer speakers nonetheless, and also through headphones), they all sound pretty good. I'm listening mostly for "bad artifacts" -- pumping, popping, clicking, phasing/flanging, stereo movement, etc. I can't hear anything of the sort, even on the MP3.
So, we've got WAV -> 128 AAC -> q7 Ogg -> 160+ MP3, and it's still quite listenable. Certainly, it's not studio quality, but for listening at home, on a typical system with typical speakers, it's pretty good, to my ears.
I'm still sort of annoyed, philosophically, at not being able to get a full-bandwidth
Can anyone suggest a good 'test pattern' file? Something with lots of dynamic range, easy-to-identify instruments (especially with lots of layers of detail), variations in note types / waveforms, etc.? Basically, an Indian Head for audio. Because it'd be great to be able to say "download this
Anyway, I'm satisfied with the quality, at least on the minimal sample set I've heard.
A few years back, Consumer Reports did an interesting set of listening tests. The usual blinds, of course. But the interesting part was that in addition to random staffers, they had two extra groups: sound engineers and musicians. They reported that these two groups differed radically in their rankings of sound quality. The difference was fairly straightforward: The sound engineers gave a high rank to equipment that produced the sound accurately. The musicians gave a high rank to equipment that made the music clear. These are not at all the same thing. In particular, musicians generally liked "distortions" that removed non-musical information, strengthened the fundamentals, and so on.
From a musician's viewpoint, one of the real frustrations with just about anything published about sound quality is that it's always written from the engineer's viewpoint. But what I want to know is which gadgets do a good job of reproducing the music. They never seem to tell you that.
Those who do study history are doomed to stand helplessly by while everyone else repeats it.
musicians are legendary for listening on poor equipment and filling in the rest of the music mentally
;-)
Yes, of course, but there's a different interpretation of this. It's not unusual for musicians to intentionally use low-quality equipment in order to make the music clearer. They aren't overcoming the limitations of the poor equipment; they are using it as a tool.
As an extreme example, I've known a number of musicians who have recordings of harpsichord music, but don't like the instrument itself. The reason is simple: They have good high-frequency hearing, and a live harpsichord is just a loud high-pitched buzz with barely-audible music in the background. But with a recording, especially on low-quality playback equipment, you can wipe out the high frequencies. This makes the music audible.
There are a fair number of people who have a similar reaction to violins. Although it's not as bad as a harpsichord, a violin has strong high-frequency harmonics that are often badly out of tune. If you clip off everything above 15 kHz or so, you eliminate this distracting noise and the music comes through.
I've made a lot of "very live" recordings of dance bands with a room full of dancers. One of the tricks that I've learned is to use fairly cheap mikes that don't hear the low or high frequencies. Then I don't have to do as much processing to get a good sound.
An interesting thing about this: I've occasionally made two recordings, one with good mikes and one with poor mikes that fall off around 12 or 14 kHz. When I play them for listeners who were there, they inevitably say that the "poor" recording sounds more live than the "good" one. What seems to be going on is that the human brain is fairly good at compensating for the low- and high-frequency noise in such situations. Participants don't hear all the background noise. But in a quiet room with the noise coming from a speaker, people do hear it.
This is similar to the phenomenon that photographers will tell you about: The human eye/brain system is very good at correcting for color cast. Cameras record the true color (within the bounds of the film type and latitude), so the cast is visible in the photo when it wasn't in the original scene. But photographers learn to see the full color and can't ignore a color cast, just a musicians learn to hear all the sound and can't easily ignore background noise.
(Similarly, after playing around with a polarizing filter for a few months, I found that I could "see" polarization. And now I can't turn it off.
It's all very complicted.
Those who do study history are doomed to stand helplessly by while everyone else repeats it.