[Flac-dev] Using line spectral pairs for LPC quantization

[Stefan Westerfeld]

   Hi!

I've recently read the flac sources, and it appears to me that you're quatizing
the LPC coefficients directly. However, this might be not as efficient, because
LPC coefficients are very sensitive to quantization error. I don't know how
much space the LPC coefficients occupy in the resulting FLAC file - if its not
much, it probably doesn't matter.

But if its a significant amount of data, it might be better to convert the LPC
coefficients to LSF/LSP coefficients, and store those quantized. This should
provide the same quality at a lower bit count, if I'm right. Here is a link
that describes LSF/LPC coefficients:

http://en.wikipedia.org/wiki/Line_spectral_pairs

   Cu... Stefan
-- 
Stefan Westerfeld, Hamburg/Germany, http://space.twc.de/~stefan