SOUND SIGNATURES OF LOSSY FORMATS
PRIORITYS, and then my opinions of each one seperately= It seems the there are 3 major aspects to never lose sight of>>>
1------Since a lossy format is by it's very nature one of lower resolution than the original, there is no one right answer to achieve a "Mirror" of the original, since theoretically at least, no "mirror" is possible. THUS= there is no other option than to listen closely for a long time to all of them, and make up you own mind which is best for your uses. Opinions vary wildly ! Yah gotta put the time in and listen.
2------If the source audio is from CD's, etc, and you are creating fair use encodes for yourself, anybody who has worked with Codecs a lot will tell you= create a LOSSLESS clone of your CD or DVD, etc audio first, if you can spare the disc space.(or can back it all up to DVD, etc) This will reduce the file size almost in half, but also keep you from putting each cd in the drive, and babysitting the encode process each time. Then 5 years from now if you suddenly decide that X codec sucks, you can more easily reencode. Or perhaps your favorite software or hardware lossy player isn't supported anymore. But also, now you have an archival backup of your music, and you can lose or scratch your CD's. You probably know this already, but I see lots of people ignore this advice, and really regret it later....
3-------One of the fun things about Codecs is that even thou detail and resolution is being thrown away, the encode can easily be more euphonic to your ear than the original ! It has attitude !! If you are one of those types that love vinyl, and hates CD's, then Codecs are perfect for you, maybe for listening 24/7. The tone and flavor of compression can put some human feeling and emotion back into the clinical and more linear digital medium.
Just don't kid yourself= The compressed copy, ain't never gonna be the original any more. So plan accordingly, and don't sell off all your CD's after only doing codec rips, thinking you just created an ARCHIVE. My favorite playback format is 2" 60 ips stereo analog tape. I want it ALL. ///^ > ^ \\
====That said, here are my opinions, which may help you identify artifacts and pleasures in the transformation of the sound. Everybody fixates on the artifact of their choice. IMHO, Codecs are the most sensible fetish in all of audio. All sizes sound different with each tool, but I will address them generally, unless a particular compression ratio needs comment.
***MP3= Be sure not to miss the <LAME> or other recent builds, and don't just use the original Fraunhoffer version stuffed into some older piece of software without comparing it to a newer tuned version. LAME ain't the least bit lame. This one still wins the universal playback award. Nothing doesn't play MP3's that I know off. But different versions do sound different= with all codecs, check which version you are running in your tool.
---MP3 sounds thick and beefy to me in all versions and sizes. The upper octaves are gently tipped back. Basically, it sounds like a good analog cassette. For Rock and roll, it's awesome. It's a little wholly and blurry, but I love it dearly nonetheless for it's raw emotion. It never spits, and rings above 128 kps, so you can encode, and not have to check your works so closely. I like how it maintains the upper and lower octaves in correct proportion to the FEEL of the original mix. The treble can be like sandpaper on some music, but it seems that's the price you pay for the BEEF. Picking a higher kps might make you happier. 128 kps in MP3 is not enough for me with this one. The bigger the better,
---AAC= This one is being tuned and improved by developers intensely right now, for obvious reasons, and I haven't heard a recent build closely for about a year. But I have been very disappointed with the lower octaves. They sound missing in action, and mixes are transformed a bit, to sound bass "lean" in terms of overall EQ proportion. It doesn't get any better for me all the way out to 356 kps, so I think it's in the tuning right to the core. EG, I think they are ditching bottom (which takes a lot of bits) in exchange for that compelling top, and other benefits. To me, this just isn't what I prioritize. The upper octaves have a FOCUS and clear and clean quality that is quite remarkable, and it's just perfect for Headphones. I assume Apple picked it (helped built it) for iTunes with this in mind. It's a magnificent piece of engineering ! Almost surreal.....how did they do it ? But it's just not for me. As an AES standard container, it's not going anywhere soon, if you want to think longer term.
---WMA= There is a sweet spot for me at 128 kps (or close to this, with VBR) that really stands out as the best size. WMA, v--7, 8, 9 , it doesn't matter;; when I go UP in resolution, it just always gets worse on some level....although I',m using 192 kps fixxed a lot right now. 64 kps is a joke in any codec, and here, the artifacts are truly comical with WMA. A lot of spitting and ringing on the upper frequencys that many of the HA members have identified whenever cymbals or odd ordered harmonics in music are encoded with it. Their claims of "CD quality" are pathetic, further losing quite a few serious listeners from this posture.
However, WMA has a silver lining. It does two things, I have never heard ANY other codec do, that I value for pro audio. A--- It has punchy, solid and firm dynamics at EVERY size, and B---, if I put a mix I have created in it, even if it's got all those swurly spitty insane highs, and a rather cold general charactor, WMA is the closest thing to being a MIRROR of the original in the ways of deepest importance. The dynamics, and the EQ preportional balance perfectly from top to bottom. The EQ is really FLAT to my ear !! And uniformly so, at different sizes. When I used REAL audio, I felt compelled to have to "remaster" every encode to bring it back to the originals feel in presentation. But this is like chasing your tale....it rarely works. I always feel like EQing AAC as well. What I mean by this, is that unlike with REAL audio, or AAC, etc, if I take a mix I've created, and encoded it will WMA, I feel no need to add additional EQ or compression to make it resemble the original. It fells like a grear mirror, even as it stands out as not "transparent" simply by being a codec compressed copy. .
I suspect WM isn't actually listening to the codec with their ears very much when they tune it. Maybe once a week (tee hee..) Instead, they are looking at their test equipment, and pushing the absolute envelope of what possible technically. In many ways, this is the high road of neutrality. It ends up being far less editorial in charactor. Unfortunately, many musicians and listeners reject WMA because it's been created by that "very large cooperation", and it's not been universally accepted.
MPC Musepack= This is by far the most "musical" codec I've ever heard. It doesn't work at all at below 220 kps, but it doesn't really try to. Instead, it's tuned by real ears, and the harmonic content is always well preserved, and remains natural. The highs have an actual "Bloom" to them, an even ordered quality. Other codecs have a "disheveled" sounding treble to me, although AAC is less loose. If you like classical music like violins, I doubt MPC can be topped. It sounds like a CLASS A descreet mic pre to me !! In many ways, the antithesis of the WMA approach, the human touch is all over this one;; a labor of love. This is really my favorite, but I must go way up to a large size to make it work for me. And I can't use it, in situations where I can't ask the user to go get a new player to open it.
REALaudio= I really enjoy this whenever I must listen to an Internet STREAM, at insane sizes, like 32 kps, and 64 kps for voices. It doesn't sound flat, it just sounds smooth and forgiving. The encoding tools and player both ask me to go thru too many ridiculous hoops, so I rarely use it for encoding . But it's not a "toy", Be sure to test it. REAL has also partnered in developing OGG VORBIS in streaming situations, etc, so they almost resemble a completely open source community. And REAL has incorperated many other codec platforms as a playback plug in for their player, and did this very quickly, so this is goodf evidence they are listening to their users needs.
OGG VORBIS= This just came out on top in a recent listening test at 180 kps. - be sure to check out all the listening test reports out on HA, and not just this one. The previous builds did not impress me. It just sounded "disembodied" and lifeless, although the lack of sandpaper treble was nice. There is no HEFT, no fullness. Just sort of plain;; I was pining to hear the original all the time. Since it's totally open source, it should probably be near the top of everybodies list to try. And it is in constant developement and improvement.
THE REST= I have been self pre-empted, because this post is TOO LONG!! Go listen to them all yourself.
