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FS-1016 CELP

Started by Ray Mc Carthy August 11, 2003
Hi All,
I am working with the FS-1016 4.8kb/s CELP coder but I cant understand why the
LSP's are interpolated for every subframe.Can someone tell me is there a
specific advantage for doing this?
Regards,
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Fo smoothing purpose since your LSP is computed every frame instead of
every subframe for saving quantization bits purpose, in order to get LPC
coef. for each subframe, you do linear interpolation for simplicity.
-Chunyan
>
> Hi All,
> I am working with the FS-1016 4.8kb/s CELP coder but I cant understand
> why the LSP's are interpolated for every subframe.Can someone tell me is
> there a specific advantage for doing this? Regards,
> Ray. > -------------------Legal 
> Disclaimer---
>
> The above electronic mail transmission is confidential and intended only
> for the person to whom it is addressed. Its contents may be protected by
> legal and/or professional privilege. Should it be received by you in
> error please contact the sender at the above quoted email address. Any
> unauthorised form of reproduction of this message is strictly
> prohibited. The Institute does not guarantee the security of any
> information electronically transmitted and is not liable if the
> information contained in this communication is not a proper and complete
> record of the message as transmitted by the sender nor for any delay in
> its receipt.
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Hi All

I will be releasing the ceptral based speech
enhancement technique code to the speech group once
its fine tuned.

If there are any queries relating to this do let me
know. Wrapping up my thesis at present and will
release the code as soon as my thesis presentation is
over.

Tracy Liu,

I remeber you asked about this, sorry kind of lost
your email address down the way. I will post it on the
speech group soon.

thanks and regards

In God We Trust

=====
Shree Jaisimha


hello Ray

i am not familiar with FS-1016 CELP coder, but let me answer this in context
of G.723.1.. here each frame consists of 4 subframes. the LPC to LSP
converson is done only for the last subframe. For the remaining subframes,
the LSPs are obtained using interpolation between LSPs of current and
previous frame.

The standard ofcourse doesnt tell why it does this.. but one reason for the
use of interpolation could be the fact that LSPs of adjecent frames exhibit
strong correlation and do not change much from one frame to the next. So
instead of doing the LSP search (LPC to LSP conversion) for all subframes,
just do it once in each frame. Use interpolation to obtain LSPs for the
other subframes and thus 'save some computations'.

Smoothing could be another objective of LSP interpolation, as Chunyan
suggests, but i can't comment much on this.

btw, does the FS-1016 coder follow similar sequence of operations as
G.723.1?
regards
Sameer
-----Original Message-----
From: [mailto:]
Sent: Monday, August 11, 2003 10:31 PM
To:
Cc:
Subject: Re: [speechcoding] FS-1016 CELP Fo smoothing purpose since your LSP is computed every frame instead of
every subframe for saving quantization bits purpose, in order to get LPC
coef. for each subframe, you do linear interpolation for simplicity.
-Chunyan
>
> Hi All,
> I am working with the FS-1016 4.8kb/s CELP coder but I cant understand
> why the LSP's are interpolated for every subframe.Can someone tell me is
> there a specific advantage for doing this? Regards,
> Ray.


Dear All,

Please check out the above link for an online paper on speech
enhancement of narrowband speech. This is the work on my thesis here
and I hope it serves its purpose of benefiting others in this area.

http://www.embeddedstar.com/articles/2004/1/article20040119-2.html

cheers

In God We Trust. Om Sakti Saranam, Om Nama Shiva Ya
cheers