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Re: Audio Artifacts: WAV vs. WMA

Started by Curious June 1, 2004
Rob Vermeulen wrote:
> WMA is part of Microsoft's .ASF family. The encoding/decoding
algoritms are
> concidered "secret" and are known to Microsoft employees only. > > I bet you'll find more information about MPEG encoding. This
information is
> considered free for non-commercial use. > > What do you want to achieve with WMA encoding, anyway? You better
take a
> look at AACplus. That rocks your socks of when it comes to
compression on
> lower bitrates. > > Best regards, > Rob
I like the artifacts of WMA. I haven't tried AACplus.
Curious,

> I like the artifacts of WMA. I haven't tried AACplus.
You're one of few people who like artifacts, I make a living removing them. :-) Cheers, Rob
"Curious" <curious11112001@yahoo.com> wrote in message news:<c9ibvg$e4n@odak26.prod.google.com>...
> Rob Vermeulen wrote: > > WMA is part of Microsoft's .ASF family. The encoding/decoding > algoritms are > > concidered "secret" and are known to Microsoft employees only. > > > > I bet you'll find more information about MPEG encoding. This > information is > > considered free for non-commercial use. > > > > What do you want to achieve with WMA encoding, anyway? You better > take a > > look at AACplus. That rocks your socks of when it comes to > compression on > > lower bitrates. > > > > Best regards, > > Rob > > > I like the artifacts of WMA. I haven't tried AACplus.
I am looking for a WMA software that will allow a sample-rate of 44.1 KHz or higher with a bit-rate less than 32kbps. IOW the file's sample rate can be 44.1 or higher with a bit-rate less than 32k. Anything like this available?
On 2004-06-01, Curious <curious11112001@yahoo.com> wrote:
>> I like the artifacts of WMA. I haven't tried AACplus. > > I am looking for a WMA software that will allow a sample-rate of 44.1 > KHz or higher with a bit-rate less than 32kbps. IOW the file's sample > rate can be 44.1 or higher with a bit-rate less than 32k. Anything > like this available?
Heck, you should learn some dsp and write some of your own purposefully-artifacty codecs! All it takes is a little inspiration! Although a good deal of knowledge will prevent you from coming up with lots of redundant ideas. Personally, I'm really into the idea of encoding a signal using 1/3 the bandwidth as the cube root of itself. Then, to get the full signal, you just cube it! -- different MP3 every day! http://gweep.net/~shifty/snackmaster . . . . . . . . ... . . . . . . "Maybe if you ever picked up a goddamn keyboard | Niente and compiler, you'd know yourself." -Matthew 7:1 | shifty@gweep.net
Taking the cube root of the signal will not narrow its BW.

--smb

Tachyon <shifty@sidehack.sat.gweep.net> wrote:
> > Personally, I'm really into the idea of encoding a signal using > 1/3 the bandwidth as the cube root of itself. Then, to get the > full signal, you just cube it!
Curious wrote:
> > Rob Vermeulen wrote: > > WMA is part of Microsoft's .ASF family. The encoding/decoding > > algoritms are concidered "secret" and are known to Microsoft > > employees only.
Actually, that is not the case. I believe that this: http://www1.mplayerhq.hu/cgi-bin/cvsweb.cgi/ffmpeg/libavcodec/wmadec.c?rev=1.20&content-type=text/x-cvsweb-markup&cvsroot=FFMpeg is a source code WMA decoder. So no, WMA is not a secret, but Microsoft states that it does have patents over the technique. Erik -- +-----------------------------------------------------------+ Erik de Castro Lopo nospam@mega-nerd.com (Yes it's valid) +-----------------------------------------------------------+ A good debugger is no substitute for a good test suite.
Erik,

Thanks for showing me this. Do you happen to know if there's an original
spec available for the WMA codec behaviour?

Best regards,

Rob Vermeulen
Arbor AudioCommunications BV
The Netherlands

"Erik de Castro Lopo" <nospam@mega-nerd.com> wrote in message
news:40BDA455.26141F74@mega-nerd.com...
> Curious wrote: > > > > Rob Vermeulen wrote: > > > WMA is part of Microsoft's .ASF family. The encoding/decoding > > > algoritms are concidered "secret" and are known to Microsoft > > > employees only. > > Actually, that is not the case. I believe that this: > >
http://www1.mplayerhq.hu/cgi-bin/cvsweb.cgi/ffmpeg/libavcodec/wmadec.c?rev=1.20&content-type=text/x-cvsweb-markup&cvsroot=FFMpeg
> > is a source code WMA decoder. > > So no, WMA is not a secret, but Microsoft states that it does have > patents over the technique. > > > Erik > -- > +-----------------------------------------------------------+ > Erik de Castro Lopo nospam@mega-nerd.com (Yes it's valid) > +-----------------------------------------------------------+ > A good debugger is no substitute for a good test suite.
Stephan M. Bernsee wrote:

> Taking the cube root of the signal will not narrow its BW. > > --smb > > Tachyon <shifty@sidehack.sat.gweep.net> wrote: > >>Personally, I'm really into the idea of encoding a signal using >>1/3 the bandwidth as the cube root of itself. Then, to get the >>full signal, you just cube it!
Oh? You mean you don't need a left-handed wrench to turn nuts with left-handed threads? Jerry -- Engineering is the art of making what you want from things you can get. &#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;&#2013266095;
Jerry Avins <jya@ieee.org> wrote:
> Oh? You mean you don't need a left-handed wrench to turn nuts with > left-handed threads?
No Jerry, I believe taking the nuts off doesn't make the machine any smaller... --smb
Jerry Avins <jya@ieee.org> wrote:
> Oh? You mean you don't need a left-handed wrench to turn nuts with > left-handed threads?
No Jerry, I believe taking the nuts off doesn't make the machine any smaller... --smb