[FFmpeg-devel] [PATCH] Long-term prediction for ALS

[Ronald S. Bultje]

Hi,

On Thu, Nov 12, 2009 at 11:30 AM, Thilo Borgmann
<thilo.borgmann at googlemail.com> wrote:
> Ronald S. Bultje schrieb:
>> ltp_lag_length = 8 + samplerate >= 96000 + samplerate >= 192000;
>> (might need brackets).
>
> I like that one, too. Revision 1 attached.
[..]

One more:

> + ? ? ? ? ? ?ltp_gain[2] ? = get_unary(gb, 0, 4);
> + ? ? ? ? ? ?ltp_gain[2] <<= 2;
> + ? ? ? ? ? ?ltp_gain[2] ?+= get_bits(gb, 2);
> + ? ? ? ? ? ?ltp_gain[2] ? = ltp_gain_values[ltp_gain[2]];

No need to store the temp. variable in ltp_gain[2]. Might confuse the
compiler into doing something silly.

int idx = get_unary(gb, 0, 4) << 2 + get_bits(gb, 2);
ltp_gain[2] = ltp_gain_values[idx];

Or even:

int a = get_unary(gb, 0, 4), b = get_bits(gb, 2);
ltp_gain[2] = ltp_gain_values[a][b];

(The compiler will handle these two equivalent if it's not completely
retarded.) I also think that (if the order / behaviour is defined, I'm
not sure if it is) you could get rid of the temporary variables then,
so it fits on a single line:

ltp_gainp[2] = ltp_gain_values[get_unary(gb, 0, 4)][get_bits(gb, 2)];

Ronald