[FFmpeg-devel] [PATCH] TwinVQ decoder

Loren Merritt lorenm
Fri Aug 21 15:25:09 CEST 2009


I'm not entirely convinced it's a good idea to merge two window sizes into 
one wtype variable, but I haven't seen the alternative code so I'm not 
sure.

> * Evaluates the LPC amplitude spectrum envelope from the line spectrum pairs.
> * Probably for speed reasons, the coefficients are evaluated as
> * siiiibiiiiisiiiibiiiiisiiiibiiiiisiiiibiiiiis ...
> * where s is an evaluated value, i is a value interpolated from the others
> * and b might be either calculated or interpolated, depending on an
> * unexplained condition.
> *
> * @param step the size of a block "siiiibiiii"

Are there supposed to be 4 or 5 "i"s there?

> int sizes[4];

You only use 3 elements, and 1 of those is a duplicate.

> if (!j || j == mtab->fmode[ftype].sub-1) {
>     if (!j && wtype == 4) sub_wtype = 4;
>     if ( j && wtype == 7) sub_wtype = 7;
> }

Can you simplify that to
  if (!j && wtype == 4)
      sub_wtype = 4;
  else if (j == mtab->fmode[ftype].sub-1 && wtype == 7)
      sub_wtype = 7;
or does that break when mtab->fmode[ftype].sub == 1 ?

--Loren Merritt



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