[FFmpeg-devel] [PATCH] Common ACELP code & G.729 [2/7] - pitch lag decoding

[Vladimir Voroshilov]

2008/5/12 Michael Niedermayer <michaelni at gmx.at>:
>
> On Sun, May 11, 2008 at 09:42:26PM +0700, Vladimir Voroshilov wrote:
>  > 2008/5/10 Michael Niedermayer <michaelni at gmx.at>:

[...]

>  >
>  > >> +    energy =  MULL(ff_log2(energy),       -24660);
>  > >
>  > >> +    energy += MULL(ff_log2(subframe_size), 24660);
>  > >> +    energy += 0x9c888; // 24660 * 26
>  > >> +    energy += mean_energy;
>  > >> +
>  > >> +#ifdef G729_BITEXACT
>  > >> +    /*
>  > >> +       Reference code uses a constant instead of the two previous lines.
>  > >> +       That value (due to 2^6 rounding) differs by 2 from code above.
>  > >> +       Subtracting 2 from energy makes the result be bit-equal with
>  > >> +       the reference code.
>  > >> +    */
>  > >> +    energy -= 2;
>  > >> +#endif
>  > >
>  > > wouldnt it be easier to just pass the sum of these as argument?
>  >
>  > ok. moved to g729dec.c with comment.
>
>  its still there:
>
>
>  > +    energy += MULL(ff_log2(subframe_size), 24660);
>  > +    energy += 0x9c888; // 24660 * 26
>  > +    energy += mean_energy;
>

I misunderstood you.
I thought you speak about correction only.
Moved as constant into formats structure.
But now i'm not sure about parameter's name.

> > +    // shift prediction energy vector
>  > +    for(i=ma_pred_order-1; i>0; i--)
>  > +        quant_energy[i] = quant_energy[i-1];
>
>  the comment is redundant, its more than obvious from the code

Removed.

>  > +
>  > +    /* 3.9.1, Equation 72 */
>
>  of what? g729?

Fixed.



-- 
Regards,
Vladimir Voroshilov mailto:voroshil at gmail.com
JID: voroshil at gmail.com, voroshil at jabber.ru
ICQ: 95587719
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