G.722 ADPCM Help

Started by Al Clark June 30, 2004
We have an application that uses a sub band ADPCM (G.722) coder and 
decoder. Our goal is data reduction with good quality, minimal computation 
overhead and extended speech bandwidth. We chose G.722 because we didn't 
want to reinvent the wheel and it appeared to be a good candidate.

We have several examples in C (Embree) and asm (ADI 21xx) and none of them 
give answers that make sense (at least to us). 
For example, if we input a 4K sequence (.5,0,-.5,0), we get nothing similar 
out.

I understand that there is some kind of test sequence available that we 
could use as a sanity check. I don't have a copy of the standard. Does 
anyone have this sequence?

Any suggestions?

-- 
Al Clark
Danville Signal Processing, Inc.
--------------------------------------------------------------------
comp.dsp conference July 28 - Aug 1, 2004

details at http://www.danvillesignal.com/index.php?id=compdsp
email: compdsp@danvillesignal.com

Who says you can't teach an old dog a new DSP trick?
Al Clark wrote:

> We have an application that uses a sub band ADPCM (G.722) coder and > decoder. Our goal is data reduction with good quality, minimal computation > overhead and extended speech bandwidth. We chose G.722 because we didn't > want to reinvent the wheel and it appeared to be a good candidate. > > We have several examples in C (Embree) and asm (ADI 21xx) and none of them > give answers that make sense (at least to us). > For example, if we input a 4K sequence (.5,0,-.5,0), we get nothing > similar out. > > I understand that there is some kind of test sequence available that we > could use as a sanity check. I don't have a copy of the standard. Does > anyone have this sequence? > > Any suggestions?
You can get the test documentation and sequences from www.itu.int for a small fee of 52 CHF. You want to look for G.722 Appendix II. Regards -- Adrian Hey
Adrian Hey <ahey@NoSpicedHam.iee.org> wrote in news:arqdnSKd-
aMY237dRVn_iw@nildram.net:

> www.itu.int
Thanks Adrian, Actually, I found out that you can download three publications for free. -- Al Clark Danville Signal Processing, Inc. -------------------------------------------------------------------- comp.dsp conference July 28 - Aug 1, 2004 details at http://www.danvillesignal.com/index.php?id=compdsp email: compdsp@danvillesignal.com Who says you can't teach an old dog a new DSP trick?