ref: 7731e53839be5e6e3a21d4efd25b9a8522b28bb5
dir: /vp9/encoder/vp9_quantize.c/
/*
* Copyright (c) 2010 The WebM 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 "vp9/encoder/vp9_onyx_int.h"
#include "vp9/encoder/vp9_quantize.h"
#include "vp9/common/vp9_quant_common.h"
#include "vp9/common/vp9_seg_common.h"
#ifdef ENC_DEBUG
extern int enc_debug;
#endif
static void quantize(int16_t *coeff_ptr, int n_coeffs, int skip_block,
int16_t *zbin_ptr, int16_t *round_ptr, int16_t *quant_ptr,
uint8_t *quant_shift_ptr,
int16_t *qcoeff_ptr, int16_t *dqcoeff_ptr,
int16_t *dequant_ptr, int zbin_oq_value,
uint16_t *eob_ptr, const int *scan) {
int i, rc, eob;
int zbins[2], nzbins[2], zbin;
int x, y, z, sz;
int zero_flag = n_coeffs;
vpx_memset(qcoeff_ptr, 0, n_coeffs*sizeof(int16_t));
vpx_memset(dqcoeff_ptr, 0, n_coeffs*sizeof(int16_t));
eob = -1;
// Base ZBIN
zbins[0] = zbin_ptr[0] + zbin_oq_value;
zbins[1] = zbin_ptr[1] + zbin_oq_value;
nzbins[0] = zbins[0] * -1;
nzbins[1] = zbins[1] * -1;
if (!skip_block) {
// Pre-scan pass
for (i = n_coeffs - 1; i >= 0; i--) {
rc = scan[i];
z = coeff_ptr[rc];
if (z < zbins[rc != 0] && z > nzbins[rc != 0]) {
zero_flag--;
} else {
break;
}
}
// Quantization pass: All coefficients with index >= zero_flag are
// skippable. Note: zero_flag can be zero.
for (i = 0; i < zero_flag; i++) {
rc = scan[i];
z = coeff_ptr[rc];
zbin = (zbins[rc != 0]);
sz = (z >> 31); // sign of z
x = (z ^ sz) - sz;
if (x >= zbin) {
x += (round_ptr[rc != 0]);
y = ((int)(((int)(x * quant_ptr[rc != 0]) >> 16) + x))
>> quant_shift_ptr[rc != 0]; // quantize (x)
x = (y ^ sz) - sz; // get the sign back
qcoeff_ptr[rc] = x; // write to destination
dqcoeff_ptr[rc] = x * dequant_ptr[rc != 0]; // dequantized value
if (y) {
eob = i; // last nonzero coeffs
}
}
}
}
*eob_ptr = eob + 1;
}
// This function works well for large transform size.
static void quantize_sparse(int16_t *coeff_ptr, int n_coeffs, int skip_block,
int16_t *zbin_ptr, int16_t *round_ptr,
int16_t *quant_ptr, uint8_t *quant_shift_ptr,
int16_t *qcoeff_ptr, int16_t *dqcoeff_ptr,
int16_t *dequant_ptr, int zbin_oq_value,
uint16_t *eob_ptr, const int *scan,
int *idx_arr) {
int i, rc, eob;
int zbins[2], nzbins[2], zbin;
int x, y, z, sz;
int idx = 0;
vpx_memset(qcoeff_ptr, 0, n_coeffs*sizeof(int16_t));
vpx_memset(dqcoeff_ptr, 0, n_coeffs*sizeof(int16_t));
eob = -1;
// Base ZBIN
zbins[0] = zbin_ptr[0] + zbin_oq_value;
zbins[1] = zbin_ptr[1] + zbin_oq_value;
nzbins[0] = zbins[0] * -1;
nzbins[1] = zbins[1] * -1;
if (!skip_block) {
// Pre-scan pass
for (i = 0; i < n_coeffs; i++) {
rc = scan[i];
z = coeff_ptr[rc] * 2;
// If the coefficient is out of the base ZBIN range, keep it for
// quantization.
if (z >= zbins[rc != 0] || z <= nzbins[rc != 0])
idx_arr[idx++] = i;
}
// Quantization pass: only process the coefficients selected in
// pre-scan pass. Note: idx can be zero.
for (i = 0; i < idx; i++) {
rc = scan[idx_arr[i]];
// Calculate ZBIN
zbin = (zbins[rc != 0]);
z = coeff_ptr[rc] * 2;
sz = (z >> 31); // sign of z
x = (z ^ sz) - sz; // x = abs(z)
if (x >= zbin) {
x += (round_ptr[rc != 0]);
y = ((int)(((int)(x * quant_ptr[rc != 0]) >> 16) + x))
>> quant_shift_ptr[rc != 0]; // quantize (x)
x = (y ^ sz) - sz; // get the sign back
qcoeff_ptr[rc] = x; // write to destination
dqcoeff_ptr[rc] = x * dequant_ptr[rc != 0] / 2; // dequantized value
if (y) {
eob = idx_arr[i]; // last nonzero coeffs
}
}
}
}
*eob_ptr = eob + 1;
}
void vp9_quantize(MACROBLOCK *mb, int plane, int block, int n_coeffs,
TX_TYPE tx_type) {
MACROBLOCKD *const xd = &mb->e_mbd;
const int *scan;
// These contexts may be available in the caller
switch (n_coeffs) {
case 4 * 4:
scan = get_scan_4x4(tx_type);
break;
case 8 * 8:
scan = get_scan_8x8(tx_type);
break;
case 16 * 16:
scan = get_scan_16x16(tx_type);
break;
default:
scan = vp9_default_scan_32x32;
break;
}
// Call different quantization for different transform size.
if (n_coeffs >= 1024) {
// Save index of picked coefficient in pre-scan pass.
int idx_arr[1024];
quantize_sparse(BLOCK_OFFSET(mb->plane[plane].coeff, block, 16),
n_coeffs, mb->skip_block,
mb->plane[plane].zbin,
mb->plane[plane].round,
mb->plane[plane].quant,
mb->plane[plane].quant_shift,
BLOCK_OFFSET(xd->plane[plane].qcoeff, block, 16),
BLOCK_OFFSET(xd->plane[plane].dqcoeff, block, 16),
xd->plane[plane].dequant,
mb->plane[plane].zbin_extra,
&xd->plane[plane].eobs[block],
scan, idx_arr);
}
else {
quantize(BLOCK_OFFSET(mb->plane[plane].coeff, block, 16),
n_coeffs, mb->skip_block,
mb->plane[plane].zbin,
mb->plane[plane].round,
mb->plane[plane].quant,
mb->plane[plane].quant_shift,
BLOCK_OFFSET(xd->plane[plane].qcoeff, block, 16),
BLOCK_OFFSET(xd->plane[plane].dqcoeff, block, 16),
xd->plane[plane].dequant,
mb->plane[plane].zbin_extra,
&xd->plane[plane].eobs[block],
scan);
}
}
void vp9_regular_quantize_b_4x4(MACROBLOCK *mb, int b_idx, TX_TYPE tx_type,
int y_blocks) {
MACROBLOCKD *const xd = &mb->e_mbd;
const struct plane_block_idx pb_idx = plane_block_idx(y_blocks, b_idx);
const int *pt_scan = get_scan_4x4(tx_type);
quantize(BLOCK_OFFSET(mb->plane[pb_idx.plane].coeff, pb_idx.block, 16),
16, mb->skip_block,
mb->plane[pb_idx.plane].zbin,
mb->plane[pb_idx.plane].round,
mb->plane[pb_idx.plane].quant,
mb->plane[pb_idx.plane].quant_shift,
BLOCK_OFFSET(xd->plane[pb_idx.plane].qcoeff, pb_idx.block, 16),
BLOCK_OFFSET(xd->plane[pb_idx.plane].dqcoeff, pb_idx.block, 16),
xd->plane[pb_idx.plane].dequant,
mb->plane[pb_idx.plane].zbin_extra,
&xd->plane[pb_idx.plane].eobs[pb_idx.block],
pt_scan);
}
static void invert_quant(int16_t *quant, uint8_t *shift, int d) {
unsigned t;
int l;
t = d;
for (l = 0; t > 1; l++)
t >>= 1;
t = 1 + (1 << (16 + l)) / d;
*quant = (int16_t)(t - (1 << 16));
*shift = l;
}
void vp9_init_quantizer(VP9_COMP *cpi) {
int i;
int quant_val;
int quant_uv_val;
#if CONFIG_ALPHA
int quant_alpha_val;
#endif
int q;
for (q = 0; q < QINDEX_RANGE; q++) {
int qzbin_factor = (vp9_dc_quant(q, 0) < 148) ? 84 : 80;
int qrounding_factor = 48;
if (q == 0) {
qzbin_factor = 64;
qrounding_factor = 64;
}
// dc values
quant_val = vp9_dc_quant(q, cpi->common.y_dc_delta_q);
invert_quant(cpi->y_quant[q] + 0, cpi->y_quant_shift[q] + 0, quant_val);
cpi->y_zbin[q][0] = ROUND_POWER_OF_TWO(qzbin_factor * quant_val, 7);
cpi->y_round[q][0] = (qrounding_factor * quant_val) >> 7;
cpi->common.y_dequant[q][0] = quant_val;
quant_val = vp9_dc_quant(q, cpi->common.uv_dc_delta_q);
invert_quant(cpi->uv_quant[q] + 0, cpi->uv_quant_shift[q] + 0, quant_val);
cpi->uv_zbin[q][0] = ROUND_POWER_OF_TWO(qzbin_factor * quant_val, 7);
cpi->uv_round[q][0] = (qrounding_factor * quant_val) >> 7;
cpi->common.uv_dequant[q][0] = quant_val;
#if CONFIG_ALPHA
quant_val = vp9_dc_quant(q, cpi->common.a_dc_delta_q);
invert_quant(cpi->a_quant[q] + 0, cpi->a_quant_shift[q] + 0, quant_val);
cpi->a_zbin[q][0] = ROUND_POWER_OF_TWO(qzbin_factor * quant_val, 7);
cpi->a_round[q][0] = (qrounding_factor * quant_val) >> 7;
cpi->common.a_dequant[q][0] = quant_val;
#endif
quant_val = vp9_ac_quant(q, 0);
cpi->common.y_dequant[q][1] = quant_val;
quant_uv_val = vp9_ac_quant(q, cpi->common.uv_ac_delta_q);
cpi->common.uv_dequant[q][1] = quant_uv_val;
#if CONFIG_ALPHA
quant_alpha_val = vp9_ac_quant(q, cpi->common.a_ac_delta_q);
cpi->common.a_dequant[q][1] = quant_alpha_val;
#endif
// all the 4x4 ac values =;
for (i = 1; i < 16; i++) {
int rc = vp9_default_scan_4x4[i];
invert_quant(cpi->y_quant[q] + rc, cpi->y_quant_shift[q] + rc, quant_val);
cpi->y_zbin[q][rc] = ROUND_POWER_OF_TWO(qzbin_factor * quant_val, 7);
cpi->y_round[q][rc] = (qrounding_factor * quant_val) >> 7;
invert_quant(cpi->uv_quant[q] + rc, cpi->uv_quant_shift[q] + rc,
quant_uv_val);
cpi->uv_zbin[q][rc] = ROUND_POWER_OF_TWO(qzbin_factor * quant_uv_val, 7);
cpi->uv_round[q][rc] = (qrounding_factor * quant_uv_val) >> 7;
#if CONFIG_ALPHA
invert_quant(cpi->a_quant[q] + rc, cpi->a_quant_shift[q] + rc,
quant_alpha_val);
cpi->a_zbin[q][rc] =
ROUND_POWER_OF_TWO(qzbin_factor * quant_alpha_val, 7);
cpi->a_round[q][rc] = (qrounding_factor * quant_alpha_val) >> 7;
#endif
}
}
}
void vp9_mb_init_quantizer(VP9_COMP *cpi, MACROBLOCK *x) {
int i;
MACROBLOCKD *xd = &x->e_mbd;
int zbin_extra;
int segment_id = xd->mode_info_context->mbmi.segment_id;
const int qindex = vp9_get_qindex(xd, segment_id, cpi->common.base_qindex);
// Y
zbin_extra = (cpi->common.y_dequant[qindex][1] *
(cpi->zbin_mode_boost + x->act_zbin_adj)) >> 7;
x->plane[0].quant = cpi->y_quant[qindex];
x->plane[0].quant_shift = cpi->y_quant_shift[qindex];
x->plane[0].zbin = cpi->y_zbin[qindex];
x->plane[0].round = cpi->y_round[qindex];
x->plane[0].zbin_extra = (int16_t)zbin_extra;
x->e_mbd.plane[0].dequant = cpi->common.y_dequant[qindex];
// UV
zbin_extra = (cpi->common.uv_dequant[qindex][1] *
(cpi->zbin_mode_boost + x->act_zbin_adj)) >> 7;
for (i = 1; i < 3; i++) {
x->plane[i].quant = cpi->uv_quant[qindex];
x->plane[i].quant_shift = cpi->uv_quant_shift[qindex];
x->plane[i].zbin = cpi->uv_zbin[qindex];
x->plane[i].round = cpi->uv_round[qindex];
x->plane[i].zbin_extra = (int16_t)zbin_extra;
x->e_mbd.plane[i].dequant = cpi->common.uv_dequant[qindex];
}
#if CONFIG_ALPHA
x->plane[3].quant = cpi->a_quant[qindex];
x->plane[3].quant_shift = cpi->a_quant_shift[qindex];
x->plane[3].zbin = cpi->a_zbin[qindex];
x->plane[3].round = cpi->a_round[qindex];
x->plane[3].zbin_extra = (int16_t)zbin_extra;
x->e_mbd.plane[3].dequant = cpi->common.a_dequant[qindex];
#endif
x->skip_block = vp9_segfeature_active(xd, segment_id, SEG_LVL_SKIP);
/* save this macroblock QIndex for vp9_update_zbin_extra() */
x->e_mbd.q_index = qindex;
}
void vp9_update_zbin_extra(VP9_COMP *cpi, MACROBLOCK *x) {
const int qindex = x->e_mbd.q_index;
const int y_zbin_extra = (cpi->common.y_dequant[qindex][1] *
(cpi->zbin_mode_boost + x->act_zbin_adj)) >> 7;
const int uv_zbin_extra = (cpi->common.uv_dequant[qindex][1] *
(cpi->zbin_mode_boost + x->act_zbin_adj)) >> 7;
x->plane[0].zbin_extra = (int16_t)y_zbin_extra;
x->plane[1].zbin_extra = (int16_t)uv_zbin_extra;
x->plane[2].zbin_extra = (int16_t)uv_zbin_extra;
}
void vp9_frame_init_quantizer(VP9_COMP *cpi) {
// Clear Zbin mode boost for default case
cpi->zbin_mode_boost = 0;
// MB level quantizer setup
vp9_mb_init_quantizer(cpi, &cpi->mb);
}
void vp9_set_quantizer(struct VP9_COMP *cpi, int Q) {
VP9_COMMON *cm = &cpi->common;
cm->base_qindex = Q;
// if any of the delta_q values are changing update flag will
// have to be set.
cm->y_dc_delta_q = 0;
cm->uv_dc_delta_q = 0;
cm->uv_ac_delta_q = 0;
// quantizer has to be reinitialized if any delta_q changes.
// As there are not any here for now this is inactive code.
// if(update)
// vp9_init_quantizer(cpi);
}