ref: 59a200f1ea73d2327746fff3d35a05aec10e436f
parent: 915f13bd5972c7e004b48533a455c9c7b7bc6d2d
author: Paul Wilkins <paulwilkins@google.com>
date: Wed Feb 8 10:52:07 EST 2012
Changes to coding of dual_pred flag. Further use of common prediction functions and experiments with alternate contexts based on mode and reference frame. For the Derf set using reference frame as basis of context gives +0.18% Overall Psnr and +0.08 SSIM Change-Id: Ie7eb76f329f74c9c698614f01ece31de0b6bfc9e
--- a/vp8/common/pred_common.c
+++ b/vp8/common/pred_common.c
@@ -39,10 +39,27 @@
break;
case PRED_DUAL:
- // Second ref not INTRA indicates use of dual pred in neighbour
- pred_context =
- ((m - 1)->mbmi.second_ref_frame != INTRA_FRAME) +
- ((m - cm->mode_info_stride)->mbmi.second_ref_frame != INTRA_FRAME);
+ // Context based on use of dual pred flag by neighbours
+ //pred_context =
+ // ((m - 1)->mbmi.second_ref_frame != INTRA_FRAME) +
+ // ((m - cm->mode_info_stride)->mbmi.second_ref_frame != INTRA_FRAME);
+
+ // Context based on mode
+ //if ( m->mbmi.mode == ZEROMV )
+ // pred_context = 0;
+ //else if ( (m->mbmi.mode == NEARESTMV) || (m->mbmi.mode == NEARMV) )
+ // pred_context = 1;
+ //else
+ // pred_context = 2;
+
+ // Context based on reference frame
+ if ( m->mbmi.ref_frame == LAST_FRAME )
+ pred_context = 0;
+ else if ( m->mbmi.ref_frame == GOLDEN_FRAME )
+ pred_context = 1;
+ else
+ pred_context = 2;
+
break;
#endif
@@ -79,7 +96,9 @@
break;
case PRED_DUAL:
- // Second ref non zero indicates use of dual pred in neighbour
+ // In keeping with convention elsewhre the probability returned is
+ // the probability of a "0" outcome which in this case means the
+ // probability of dual pred off.
pred_probability = cm->prob_dualpred[pred_context];
break;
#endif
--- a/vp8/encoder/bitstream.c
+++ b/vp8/encoder/bitstream.c
@@ -1057,8 +1057,11 @@
int row, col;
int prob_skip_false = 0;
+
#if CONFIG_DUALPRED
+#if !CONFIG_COMPRED
int prob_dual_pred[3];
+#endif
#endif /* CONFIG_DUALPRED */
// Values used in prediction model coding
@@ -1111,8 +1114,20 @@
{if (cpi->single_pred_count[i] + cpi->dual_pred_count[i])
{+#if CONFIG_COMPRED
+ pc->prob_dualpred[i] = cpi->single_pred_count[i] * 255 /
+ (cpi->single_pred_count[i] + cpi->dual_pred_count[i]);
+ if (pc->prob_dualpred[i] < 1)
+ pc->prob_dualpred[i] = 1;
+ }
+ else
+ {+ pc->prob_dualpred[i] = 128;
+ }
+ vp8_write_literal(w, pc->prob_dualpred[i], 8);
+#else
prob_dual_pred[i] = cpi->single_pred_count[i] * 256 /
- (cpi->single_pred_count[i] + cpi->dual_pred_count[i]);
+ (cpi->single_pred_count[i] + cpi->dual_pred_count[i]);
if (prob_dual_pred[i] < 1)
prob_dual_pred[i] = 1;
else if (prob_dual_pred[i] > 255)
@@ -1123,9 +1138,6 @@
prob_dual_pred[i] = 128;
}
vp8_write_literal(w, prob_dual_pred[i], 8);
-
-#if CONFIG_COMPRED
- pc->prob_dualpred[i] = prob_dual_pred[i];
#endif
}
}
@@ -1457,7 +1469,9 @@
int prob_skip_false = 0;
#if CONFIG_DUALPRED
+#if !CONFIG_COMPRED
int prob_dual_pred[3];
+#endif
#endif /* CONFIG_DUALPRED */
// Values used in prediction model coding
@@ -1507,8 +1521,20 @@
{if (cpi->single_pred_count[i] + cpi->dual_pred_count[i])
{+#if CONFIG_COMPRED
+ pc->prob_dualpred[i] = cpi->single_pred_count[i] * 255 /
+ (cpi->single_pred_count[i] + cpi->dual_pred_count[i]);
+ if (pc->prob_dualpred[i] < 1)
+ pc->prob_dualpred[i] = 1;
+ }
+ else
+ {+ pc->prob_dualpred[i] = 128;
+ }
+ vp8_write_literal(w, pc->prob_dualpred[i], 8);
+#else
prob_dual_pred[i] = cpi->single_pred_count[i] * 256 /
- (cpi->single_pred_count[i] + cpi->dual_pred_count[i]);
+ (cpi->single_pred_count[i] + cpi->dual_pred_count[i]);
if (prob_dual_pred[i] < 1)
prob_dual_pred[i] = 1;
else if (prob_dual_pred[i] > 255)
@@ -1519,9 +1545,6 @@
prob_dual_pred[i] = 128;
}
vp8_write_literal(w, prob_dual_pred[i], 8);
-
-#if CONFIG_COMPRED
- pc->prob_dualpred[i] = prob_dual_pred[i];
#endif
}
}
--- a/vp8/encoder/encodeframe.c
+++ b/vp8/encoder/encodeframe.c
@@ -1811,13 +1811,21 @@
if (x->e_mbd.mode_info_context->mbmi.ref_frame &&
x->e_mbd.mode_info_context->mbmi.mode != SPLITMV)
{- MB_MODE_INFO *t = &x->e_mbd.mode_info_context[-cpi->common.mode_info_stride].mbmi;
+ unsigned char pred_context;
+
+#if CONFIG_COMPRED
+ pred_context = get_pred_context( cm, xd, PRED_DUAL );
+#else
+ MB_MODE_INFO *t = &x->e_mbd.mode_info_context
+ [-cpi->common.mode_info_stride].mbmi;
MB_MODE_INFO *l = &x->e_mbd.mode_info_context[-1].mbmi;
- int cnt = (t->second_ref_frame != INTRA_FRAME) + (l->second_ref_frame != INTRA_FRAME);
- if (x->e_mbd.mode_info_context->mbmi.second_ref_frame == INTRA_FRAME)
- cpi->single_pred_count[cnt]++;
+ pred_context = (t->second_ref_frame != INTRA_FRAME) +
+ (l->second_ref_frame != INTRA_FRAME);
+#endif
+ if (xd->mode_info_context->mbmi.second_ref_frame == INTRA_FRAME)
+ cpi->single_pred_count[pred_context]++;
else
- cpi->dual_pred_count[cnt]++;
+ cpi->dual_pred_count[pred_context]++;
}
#endif /* CONFIG_DUALPRED */
--
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