[Speex-dev] lpcSize

Shridhar, Vasant vasant.shridhar at harman.com
Mon Apr 11 15:48:34 PDT 2011


Not exactly the answer I was looking for.  This sounds like a big change.  I don't mind re-writing the LSP quantizer but re-training code books and breaking compatibility is not what I want to do.  I am working on an optimization for an ARM cortex-A8.  It is desirable to process things in 4 element blocks.  Is there a simpler approach you could recommend?

Vasant Shridhar
From: Jean-Marc Valin [jmvalin at jmvalin.ca]
Sent: Monday, April 11, 2011 5:29 PM
To: Shridhar, Vasant
Cc: speex-dev at xiph.org
Subject: Re: [Speex-dev] lpcSize

On 11-04-11 11:05 AM, Shridhar, Vasant wrote:
> I would like to make lpcSize a multiple of 4. In the current library for
> narrow band mode lpcSize is currently set to 10. I would like to
> increase this 12 for optimization reasons. Is it a simple matter of just
> changing lpcSize in the structures in mode.c or are there other
> implications to doing this?

Nothing major except you'd need to rewrite the LSP quantizer, retrain
half the codebooks, change the bit-allocation and break compatibility
with the format.



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