[FFmpeg-devel] [PATCH] Common ACELP code & G.729 [2/7] - pitch lag decoding
Vladimir Voroshilov
voroshil
Sat May 17 19:13:53 CEST 2008
2008/5/14 Vladimir Voroshilov <voroshil at gmail.com>:
> 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.
>
>
Just ping (v51 is the same as v50)
--
Regards,
Vladimir Voroshilov mailto:voroshil at gmail.com
JID: voroshil at gmail.com, voroshil at jabber.ru
ICQ: 95587719
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