[Speex-dev] Speex Command line, Changing the LPC order and modifying the codebook

Jean-Marc Valin Jean-Marc.Valin at USherbrooke.ca
Thu Feb 9 00:22:50 PST 2006

Le mercredi 08 février 2006 à 19:44 -0800, devilal sharma a écrit :
> Hi,
> can someone help me understand and experiment with Speex in a better
> way than my knowledge. I want to change the LPC filter order of the
> Speex algorithm.  I think I need to change the LPC order( or lpcSize)
> in modes.c file. 


> but to make it work I need to modify the codebook also


> , can someone tell me how to go about changing the codebook entries to
> support the changed order of prediction.

You also need to change the lsp quantization functions. They are the
ones using the codebooks.

That being said, I don't see much interest in playing with the LPC
order. There's plenty of areas for improvements that don't require
incompatible changes like this one.


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