On Sun, Jul 8, 2012 at 9:42 PM, Kostya Shishkov
<kostya.shish...@gmail.com> wrote:
> On Sun, Jul 08, 2012 at 08:17:10PM -0700, Jason Garrett-Glaser wrote:
>> > +#define UNQUANT(val, q) ((q * val + 0x80) >> 8)
>>
>> I'd call this DEQUANT, but that's just me.
>
> I don't have preferences here, so why not.
>
>> > + for (i = 0; i < 4; i++) {
>> > + if (i & 1) {
>> > + t0 = UNQUANT(q[1], in[0 * 4 + i]);
>> > + t1 = UNQUANT(q[2], in[1 * 4 + i]);
>> > + t2 = UNQUANT(q[1], in[2 * 4 + i]);
>> > + t3 = UNQUANT(q[2], in[3 * 4 + i]);
>> > + } else {
>> > + t0 = UNQUANT(q[0], in[0 * 4 + i]);
>> > + t1 = UNQUANT(q[1], in[1 * 4 + i]);
>> > + t2 = UNQUANT(q[0], in[2 * 4 + i]);
>> > + t3 = UNQUANT(q[1], in[3 * 4 + i]);
>> > + }
>>
>> Branchless please? Maybe q[0+(i&1)] or such?
>
> Done.
>
>> > +static const uint8_t tscc2_zigzag[16] = {
>> > + 0, 1, 4, 8,
>> > + 5, 2, 3, 6,
>> > + 9, 12, 13, 10,
>> > + 7, 11, 14, 15
>> > +// 0, 4, 1, 2,
>> > +// 5, 8, 12, 9,
>> > +// 6, 3, 7, 10,
>> > +// 13, 14, 11, 15
>> > +};
>>
>> Use an existing one if possible?
>
> We have several standard ones but they are all 8x8.
H.264's is 4x4 and I think it matches that?
Jason
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