Modify adaptive b quant to prefer skips
Adds a check to prefer skip blocks if there is a single
non-zero coefficient and its magnitude is 1.
Change-Id: Icafd588ec5f88ffd61fb8824410f24dedbe58117
diff --git a/aom_dsp/quantize.c b/aom_dsp/quantize.c
index 4acbf20..1c29de8 100644
--- a/aom_dsp/quantize.c
+++ b/aom_dsp/quantize.c
@@ -12,6 +12,9 @@
#include "aom_dsp/quantize.h"
#include "aom_mem/aom_mem.h"
+#define EOB_FACTOR 325
+#define SKIP_EOB_FACTOR_ADJUST 200
+
void quantize_b_adaptive_helper_c(
const tran_low_t *coeff_ptr, intptr_t n_coeffs, const int16_t *zbin_ptr,
const int16_t *round_ptr, const int16_t *quant_ptr,
@@ -28,15 +31,18 @@
memset(qcoeff_ptr, 0, n_coeffs * sizeof(*qcoeff_ptr));
memset(dqcoeff_ptr, 0, n_coeffs * sizeof(*dqcoeff_ptr));
+ int prescan_add[2];
+ for (i = 0; i < 2; ++i)
+ prescan_add[i] = ROUND_POWER_OF_TWO(dequant_ptr[i] * EOB_FACTOR, 7);
+
// Pre-scan pass
for (i = (int)n_coeffs - 1; i >= 0; i--) {
const int rc = scan[i];
const qm_val_t wt = qm_ptr != NULL ? qm_ptr[rc] : (1 << AOM_QM_BITS);
const int coeff = coeff_ptr[rc] * wt;
-
- int prescan_add = ROUND_POWER_OF_TWO(dequant_ptr[rc != 0] * 325, 7);
- if (coeff < (zbins[rc != 0] * (1 << AOM_QM_BITS) + prescan_add) &&
- coeff > (nzbins[rc != 0] * (1 << AOM_QM_BITS) - prescan_add))
+ const int prescan_add_val = prescan_add[rc != 0];
+ if (coeff < (zbins[rc != 0] * (1 << AOM_QM_BITS) + prescan_add_val) &&
+ coeff > (nzbins[rc != 0] * (1 << AOM_QM_BITS) - prescan_add_val))
non_zero_count--;
else
break;
@@ -44,6 +50,9 @@
// Quantization pass: All coefficients with index >= zero_flag are
// skippable. Note: zero_flag can be zero.
+#if SKIP_EOB_FACTOR_ADJUST
+ int first = -1;
+#endif // SKIP_EOB_FACTOR_ADJUST
for (i = 0; i < non_zero_count; i++) {
const int rc = scan[i];
const int coeff = coeff_ptr[rc];
@@ -68,9 +77,32 @@
const tran_low_t abs_dqcoeff = (tmp32 * dequant) >> log_scale;
dqcoeff_ptr[rc] = (tran_low_t)((abs_dqcoeff ^ coeff_sign) - coeff_sign);
- if (tmp32) eob = i;
+ if (tmp32) {
+ eob = i;
+#if SKIP_EOB_FACTOR_ADJUST
+ if (first == -1) first = i;
+#endif // SKIP_EOB_FACTOR_ADJUST
+ }
}
}
+#if SKIP_EOB_FACTOR_ADJUST
+ if (eob >= 0 && first == eob) {
+ const int rc = scan[eob];
+ if (qcoeff_ptr[rc] == 1 || qcoeff_ptr[rc] == -1) {
+ const qm_val_t wt = qm_ptr != NULL ? qm_ptr[rc] : (1 << AOM_QM_BITS);
+ const int coeff = coeff_ptr[rc] * wt;
+ const int factor = EOB_FACTOR + SKIP_EOB_FACTOR_ADJUST;
+ const int prescan_add_val =
+ ROUND_POWER_OF_TWO(dequant_ptr[rc != 0] * factor, 7);
+ if (coeff < (zbins[rc != 0] * (1 << AOM_QM_BITS) + prescan_add_val) &&
+ coeff > (nzbins[rc != 0] * (1 << AOM_QM_BITS) - prescan_add_val)) {
+ qcoeff_ptr[rc] = 0;
+ dqcoeff_ptr[rc] = 0;
+ eob = -1;
+ }
+ }
+ }
+#endif // SKIP_EOB_FACTOR_ADJUST
*eob_ptr = eob + 1;
}
@@ -155,6 +187,10 @@
memset(qcoeff_ptr, 0, n_coeffs * sizeof(*qcoeff_ptr));
memset(dqcoeff_ptr, 0, n_coeffs * sizeof(*dqcoeff_ptr));
+ int prescan_add[2];
+ for (i = 0; i < 2; ++i)
+ prescan_add[i] = ROUND_POWER_OF_TWO(dequant_ptr[i] * EOB_FACTOR, 7);
+
// Pre-scan pass
for (i = 0; i < n_coeffs; i++) {
const int rc = scan[i];
@@ -163,14 +199,17 @@
// If the coefficient is out of the base ZBIN range, keep it for
// quantization.
- int prescan_add = ROUND_POWER_OF_TWO(dequant_ptr[rc != 0] * 325, 7);
- if (coeff >= (zbins[rc != 0] * (1 << AOM_QM_BITS) + prescan_add) &&
- coeff <= (nzbins[rc != 0] * (1 << AOM_QM_BITS) - prescan_add))
+ const int prescan_add_val = prescan_add[rc != 0];
+ if (coeff >= (zbins[rc != 0] * (1 << AOM_QM_BITS) + prescan_add_val) &&
+ coeff <= (nzbins[rc != 0] * (1 << AOM_QM_BITS) - prescan_add_val))
idx_arr[idx++] = i;
}
// Quantization pass: only process the coefficients selected in
// pre-scan pass. Note: idx can be zero.
+#if SKIP_EOB_FACTOR_ADJUST
+ int first = -1;
+#endif // SKIP_EOB_FACTOR_ADJUST
for (i = 0; i < idx; i++) {
const int rc = scan[idx_arr[i]];
const int coeff = coeff_ptr[rc];
@@ -189,8 +228,31 @@
(dequant_ptr[rc != 0] * iwt + (1 << (AOM_QM_BITS - 1))) >> AOM_QM_BITS;
const tran_low_t abs_dqcoeff = (abs_qcoeff * dequant) >> log_scale;
dqcoeff_ptr[rc] = (tran_low_t)((abs_dqcoeff ^ coeff_sign) - coeff_sign);
- if (abs_qcoeff) eob = idx_arr[i];
+ if (abs_qcoeff) {
+ eob = idx_arr[i];
+#if SKIP_EOB_FACTOR_ADJUST
+ if (first == -1) first = eob;
+#endif // SKIP_EOB_FACTOR_ADJUST
+ }
}
+#if SKIP_EOB_FACTOR_ADJUST
+ if (eob >= 0 && first == eob) {
+ const int rc = scan[eob];
+ if (qcoeff_ptr[rc] == 1 || qcoeff_ptr[rc] == -1) {
+ const qm_val_t wt = qm_ptr != NULL ? qm_ptr[rc] : (1 << AOM_QM_BITS);
+ const int coeff = coeff_ptr[rc] * wt;
+ const int factor = EOB_FACTOR + SKIP_EOB_FACTOR_ADJUST;
+ const int prescan_add_val =
+ ROUND_POWER_OF_TWO(dequant_ptr[rc != 0] * factor, 7);
+ if (coeff < (zbins[rc != 0] * (1 << AOM_QM_BITS) + prescan_add_val) &&
+ coeff > (nzbins[rc != 0] * (1 << AOM_QM_BITS) - prescan_add_val)) {
+ qcoeff_ptr[rc] = 0;
+ dqcoeff_ptr[rc] = 0;
+ eob = -1;
+ }
+ }
+ }
+#endif // SKIP_EOB_FACTOR_ADJUST
*eob_ptr = eob + 1;
}
