MotleyCat on 29/5/2006 at 12:22
I am a big music fan and I would like to ask you about which formats do you like? I also want to ask that WHAT IS FLAC and which players will play it and is it convertible to wav or mp3?
Fingernail on 29/5/2006 at 12:42
FLAC is Free Lossless Audio Codec.
(
http://flac.sourceforge.net/)
it's rather nice, but obviously mp3 is preferable for filesize.
FLAC tends to be the preserve of PC-based audiophiles or enthusiasts.
It's also used a lot to make high-ish definition copies of LPs, CDs etc. which are burnt to new media, preserving the quality.
OrbWeaver on 29/5/2006 at 12:57
Any format is convertible to any other format, but there may be a loss of quality involved.
CBR MP3 is more or less deprecated, and should only be used if a player device doesn't support anything else. VBR (with a quality parameter) or ABR (with an average bitrate >= 192kbps) is better.
Ogg Vorbis is probably the best freely-available lossy format, but most hardware players don't support it.
Schattentänzer on 29/5/2006 at 13:03
Ogg Vorbis can also claim a better compression/sound quality ratio than mp3. I was rather sceptical on this first, but after trying it out myself I was pleasently surprised.
OrbWeaver on 29/5/2006 at 13:07
Quote Posted by Schattentänzer
I was rather sceptical on this first, but after trying it out myself I was pleasently surprised.
Why were you sceptical?
MP3 is around 15 years old, surely it is no surprise that there have been improvements in audio compression since then?
Schattentänzer on 29/5/2006 at 13:13
My scepticism was mainly because both formats employ the same maths to gain compression. Fourier is Fourier is Fourier, if you know what I mean. I should have known though that the geeks would find a way to squeeze some extra bytes of information in there.
OrbWeaver on 29/5/2006 at 13:23
It's not the Fourier transform that provides the compression, it's what you do before and after it that counts - how you split up the frequency bands, how you handle stereo information, how you eliminate undetectable sounds with a psychoacoustic model, and so on.
I think also that Ogg Vorbis allows more parameters to be dynamically adjusted as the source material changes, while MP3 is more static.
Para?noid on 29/5/2006 at 15:26
Schatt, but still, the window size and type of the Fourier transform is important? Spectral leakage can contribute to incorrect analysis, and compression can end up where it's unwanted. I don't know how dramatic the effects of this are, but resolution is important. Just consider the different types of algorithm (DFT, FFT, SFT) for a start.
Schattentänzer on 29/5/2006 at 15:38
Well, maybe it also was unwarranted prejudice towards geek formats. The file-type was rather young when I tested that.
And I really should brush up my knowledge about the mp3 compression.. somehow I thought it would use FFT exclusively...
Hmm, are there different ogg encoders? Not frontends, I mean algorithms.
Edit: Nevermind, (
http://en.wikipedia.org/wiki/Vorbis) wiki'd.
doctorfrog on 1/6/2006 at 01:34
Also from the same Wiki-p article: (
http://en.wikipedia.org/wiki/Vorbis#Listening_tests)
Quote:
2005-2006 Public group test of Lame MP3, Vorbis AoTuV, iTunes AAC, Nero AAC, and WMA Pro at ~135 kbit/s nominal. Results suggest that further group testing at this bitrate is unnecessary because all codecs are statistically tied near transparency.
I'm stuck with mp3 because I've got an iPod, but it's still good to know that LAME can hold its own with the other favorites. Best thing to do of course is to fire up your own ABX tests, let your lobes tell you what's up.