vpx/vp8/encoder/quantize.c
Timothy B. Terriberry e04e293522 Make the quantizer exact.
This replaces the approximate division-by-multiplication in the
 quantizer with an exact one that costs just one add and one
 shift extra.
The asm versions have not been updated in this patch, and thus
 have been disabled, since the new method requires different
 multipliers which are not compatible with the old method.

Change-Id: I53ac887af0f969d906e464c88b1f4be69c6b1206
2010-07-23 08:48:01 -07:00

166 lines
4.7 KiB
C

/*
* Copyright (c) 2010 The VP8 project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include <math.h>
#include "vpx_mem/vpx_mem.h"
#include "quantize.h"
#include "entropy.h"
#include "predictdc.h"
void vp8_fast_quantize_b_c(BLOCK *b, BLOCKD *d)
{
int i, rc, eob;
int zbin;
int x, y, z, sz;
short *coeff_ptr = &b->coeff[0];
short *zbin_ptr = &b->zbin[0][0];
short *round_ptr = &b->round[0][0];
short *quant_ptr = &b->quant[0][0];
short *quant_shift_ptr = &b->quant_shift[0][0];
short *qcoeff_ptr = d->qcoeff;
short *dqcoeff_ptr = d->dqcoeff;
short *dequant_ptr = &d->dequant[0][0];
vpx_memset(qcoeff_ptr, 0, 32);
vpx_memset(dqcoeff_ptr, 0, 32);
eob = -1;
for (i = 0; i < 16; i++)
{
rc = vp8_default_zig_zag1d[i];
z = coeff_ptr[rc];
zbin = zbin_ptr[rc] ;
sz = (z >> 31); // sign of z
x = (z ^ sz) - sz; // x = abs(z)
if (x >= zbin)
{
x += round_ptr[rc];
y = (((x * quant_ptr[rc]) >> 16) + x)
>> quant_shift_ptr[rc]; // quantize (x)
x = (y ^ sz) - sz; // get the sign back
qcoeff_ptr[rc] = x; // write to destination
dqcoeff_ptr[rc] = x * dequant_ptr[rc]; // dequantized value
if (y)
{
eob = i; // last nonzero coeffs
}
}
}
d->eob = eob + 1;
}
void vp8_regular_quantize_b(BLOCK *b, BLOCKD *d)
{
int i, rc, eob;
int zbin;
int x, y, z, sz;
short *zbin_boost_ptr = &b->zrun_zbin_boost[0];
short *coeff_ptr = &b->coeff[0];
short *zbin_ptr = &b->zbin[0][0];
short *round_ptr = &b->round[0][0];
short *quant_ptr = &b->quant[0][0];
short *quant_shift_ptr = &b->quant_shift[0][0];
short *qcoeff_ptr = d->qcoeff;
short *dqcoeff_ptr = d->dqcoeff;
short *dequant_ptr = &d->dequant[0][0];
short zbin_oq_value = b->zbin_extra;
vpx_memset(qcoeff_ptr, 0, 32);
vpx_memset(dqcoeff_ptr, 0, 32);
eob = -1;
for (i = 0; i < 16; i++)
{
rc = vp8_default_zig_zag1d[i];
z = coeff_ptr[rc];
//if ( i == 0 )
// zbin = zbin_ptr[rc] + *zbin_boost_ptr + zbin_oq_value/2;
//else
zbin = zbin_ptr[rc] + *zbin_boost_ptr + zbin_oq_value;
zbin_boost_ptr ++;
sz = (z >> 31); // sign of z
x = (z ^ sz) - sz; // x = abs(z)
if (x >= zbin)
{
x += round_ptr[rc];
y = (((x * quant_ptr[rc]) >> 16) + x)
>> quant_shift_ptr[rc]; // quantize (x)
x = (y ^ sz) - sz; // get the sign back
qcoeff_ptr[rc] = x; // write to destination
dqcoeff_ptr[rc] = x * dequant_ptr[rc]; // dequantized value
if (y)
{
eob = i; // last nonzero coeffs
zbin_boost_ptr = &b->zrun_zbin_boost[0]; // reset zero runlength
}
}
}
d->eob = eob + 1;
}
void vp8_quantize_mby(MACROBLOCK *x)
{
int i;
int has_2nd_order = (x->e_mbd.mbmi.mode != B_PRED
&& x->e_mbd.mbmi.mode != SPLITMV);
for (i = 0; i < 16; i++)
{
x->quantize_b(&x->block[i], &x->e_mbd.block[i]);
x->e_mbd.mbmi.mb_skip_coeff &=
(x->e_mbd.block[i].eob <= has_2nd_order);
}
if(has_2nd_order)
{
x->quantize_b(&x->block[24], &x->e_mbd.block[24]);
x->e_mbd.mbmi.mb_skip_coeff &= (!x->e_mbd.block[24].eob);
}
}
void vp8_quantize_mb(MACROBLOCK *x)
{
int i;
int has_2nd_order=(x->e_mbd.mbmi.mode != B_PRED
&& x->e_mbd.mbmi.mode != SPLITMV);
x->e_mbd.mbmi.mb_skip_coeff = 1;
for (i = 0; i < 24+has_2nd_order; i++)
{
x->quantize_b(&x->block[i], &x->e_mbd.block[i]);
x->e_mbd.mbmi.mb_skip_coeff &=
(x->e_mbd.block[i].eob <= (has_2nd_order && i<16));
}
}
void vp8_quantize_mbuv(MACROBLOCK *x)
{
int i;
for (i = 16; i < 24; i++)
{
x->quantize_b(&x->block[i], &x->e_mbd.block[i]);
x->e_mbd.mbmi.mb_skip_coeff &= (!x->e_mbd.block[i].eob);
}
}