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Cleaning up vp9_quantize_b_c() function.

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Change-Id: I42c75530a8c9cff68480657f074131e6b60d9fca
This commit is contained in:
Dmitry Kovalev
2013-11-05 17:41:56 -08:00
parent 648e30bca6
commit d54ff9dc3d
1 changed files with 27 additions and 41 deletions
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68
vp9/encoder/vp9_quantize.c
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@@ -22,7 +22,7 @@
extern int enc_debug;
#endif
void vp9_quantize_b_c(const int16_t *coeff_ptr, intptr_t n_coeffs,
void vp9_quantize_b_c(const int16_t *coeff_ptr, intptr_t count,
int skip_block,
const int16_t *zbin_ptr, const int16_t *round_ptr,
const int16_t *quant_ptr, const int16_t *quant_shift_ptr,
@@ -30,58 +30,44 @@ void vp9_quantize_b_c(const int16_t *coeff_ptr, intptr_t n_coeffs,
const int16_t *dequant_ptr,
int zbin_oq_value, uint16_t *eob_ptr,
const int16_t *scan, const int16_t *iscan) {
int i, rc, eob;
int zbins[2], nzbins[2], zbin;
int x, y, z, sz;
int zero_flag = n_coeffs;
int i, non_zero_count = count, eob = -1;
const int zbins[2] = { zbin_ptr[0] + zbin_oq_value,
zbin_ptr[1] + zbin_oq_value };
const int nzbins[2] = { zbins[0] * -1,
zbins[1] * -1 };
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;
vpx_memset(qcoeff_ptr, 0, count * sizeof(int16_t));
vpx_memset(dqcoeff_ptr, 0, count * sizeof(int16_t));
if (!skip_block) {
// Pre-scan pass
for (i = n_coeffs - 1; i >= 0; i--) {
rc = scan[i];
z = coeff_ptr[rc];
for (i = count - 1; i >= 0; i--) {
const int rc = scan[i];
const int coeff = coeff_ptr[rc];
if (z < zbins[rc != 0] && z > nzbins[rc != 0]) {
zero_flag--;
} else {
if (coeff < zbins[rc != 0] && coeff > nzbins[rc != 0])
non_zero_count--;
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];
for (i = 0; i < non_zero_count; i++) {
const int rc = scan[i];
const int coeff = coeff_ptr[rc];
const int coeff_sign = (coeff >> 31);
const int abs_coeff = (coeff ^ coeff_sign) - coeff_sign;
zbin = (zbins[rc != 0]);
if (abs_coeff >= zbins[rc != 0]) {
int tmp = clamp(abs_coeff + round_ptr[rc != 0], INT16_MIN, INT16_MAX);
tmp = ((((tmp * quant_ptr[rc != 0]) >> 16) + tmp) *
quant_shift_ptr[rc != 0]) >> 16; // quantization
qcoeff_ptr[rc] = (tmp ^ coeff_sign) - coeff_sign;
dqcoeff_ptr[rc] = qcoeff_ptr[rc] * dequant_ptr[rc != 0];
sz = (z >> 31); // sign of z
x = (z ^ sz) - sz;
if (x >= zbin) {
x += (round_ptr[rc != 0]);
x = clamp(x, INT16_MIN, INT16_MAX);
y = (((int)(((int)(x * quant_ptr[rc != 0]) >> 16) + x)) *
quant_shift_ptr[rc != 0]) >> 16; // 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
}
if (tmp)
eob = i;
}
}
}