ref: 91dc8ce70d8071b114c907bf760d65bad83fe072
parent: 6e364a57c0bf7477b35284e7acbcf776e1d5ec3e
author: John Koleszar <jkoleszar@google.com>
date: Thu Oct 18 12:27:30 EDT 2012
calculate probs consistently There were several different methods for calculating bitstream probabilities in use. Consolodate these into a pair of functions, get_prob() and get_binary_prob(). Change-Id: I5534f517f74027fee16d89c9baefaafea8156b2f
--- a/vp8/encoder/bitstream.c
+++ b/vp8/encoder/bitstream.c
@@ -238,7 +238,7 @@
}
}
-static __inline int get_prob(int num, int den) {+static int get_prob(int num, int den) {int p;
if (den <= 0)
return 128;
@@ -250,6 +250,10 @@
return p;
}
+static int get_binary_prob(int n0, int n1) {+ return get_prob(n0, n0 + n1);
+}
+
void update_skip_probs(VP8_COMP *cpi) {VP8_COMMON *const pc = &cpi->common;
int prob_skip_false[3] = {0, 0, 0};@@ -256,20 +260,8 @@
int k;
for (k = 0; k < MBSKIP_CONTEXTS; ++k) {- if ((cpi->skip_false_count[k] + cpi->skip_true_count[k])) {- prob_skip_false[k] =
- cpi->skip_false_count[k] * 256 /
- (cpi->skip_false_count[k] + cpi->skip_true_count[k]);
-
- if (prob_skip_false[k] <= 1)
- prob_skip_false[k] = 1;
-
- if (prob_skip_false[k] > 255)
- prob_skip_false[k] = 255;
- } else
- prob_skip_false[k] = 128;
-
- pc->mbskip_pred_probs[k] = prob_skip_false[k];
+ pc->mbskip_pred_probs[k] = get_binary_prob(cpi->skip_false_count[k],
+ cpi->skip_true_count[k]);
}
}
@@ -345,16 +337,9 @@
} else {// From the prediction counts set the probabilities for each context
for (i = 0; i < PREDICTION_PROBS; i++) {- tot_count = cpi->ref_pred_count[i][0] + cpi->ref_pred_count[i][1];
- if (tot_count) {- new_pred_probs[i] =
- (cpi->ref_pred_count[i][0] * 255 + (tot_count >> 1)) / tot_count;
+ new_pred_probs[i] = get_binary_prob(cpi->ref_pred_count[i][0],
+ cpi->ref_pred_count[i][1]);
- // Clamp to minimum allowed value
- new_pred_probs[i] += !new_pred_probs[i];
- } else
- new_pred_probs[i] = 128;
-
// Decide whether or not to update the reference frame probs.
// Returned costs are in 1/256 bit units.
old_cost =
@@ -824,24 +809,10 @@
const int rf_inter = rfct[LAST_FRAME] +
rfct[GOLDEN_FRAME] + rfct[ALTREF_FRAME];
- cm->prob_intra_coded = (rf_intra + rf_inter)
- ? rf_intra * 255 / (rf_intra + rf_inter) : 1;
+ cm->prob_intra_coded = get_binary_prob(rf_intra, rf_inter);
+ cm->prob_last_coded = get_prob(rfct[LAST_FRAME], rf_inter);
+ cm->prob_gf_coded = get_binary_prob(rfct[GOLDEN_FRAME], rfct[ALTREF_FRAME]);
- if (!cm->prob_intra_coded)
- cm->prob_intra_coded = 1;
-
- cm->prob_last_coded = rf_inter ? (rfct[LAST_FRAME] * 255) / rf_inter : 128;
-
- if (!cm->prob_last_coded)
- cm->prob_last_coded = 1;
-
- cm->prob_gf_coded = (rfct[GOLDEN_FRAME] + rfct[ALTREF_FRAME])
- ? (rfct[GOLDEN_FRAME] * 255) /
- (rfct[GOLDEN_FRAME] + rfct[ALTREF_FRAME]) : 128;
-
- if (!cm->prob_gf_coded)
- cm->prob_gf_coded = 1;
-
// Compute a modified set of probabilities to use when prediction of the
// reference frame fails
compute_mod_refprobs(cm);
@@ -2588,12 +2559,9 @@
#if CONFIG_SUPERBLOCKS
{/* sb mode probability */
- int sb_coded = 256 - (cpi->sb_count << 8) / (((pc->mb_rows + 1) >> 1) * ((pc->mb_cols + 1) >> 1));
- if (sb_coded <= 0)
- sb_coded = 1;
- else if (sb_coded >= 256)
- sb_coded = 255;
- pc->sb_coded = sb_coded;
+ const int sb_max = (((pc->mb_rows + 1) >> 1) * ((pc->mb_cols + 1) >> 1));
+
+ pc->sb_coded = get_prob(cpi->sb_count, sb_max);
vp8_write_literal(&header_bc, pc->sb_coded, 8);
}
#endif
@@ -2847,15 +2815,8 @@
vp8_write(&header_bc, use_hybrid_pred, 128);
if (use_hybrid_pred) { for (i = 0; i < COMP_PRED_CONTEXTS; i++) {- if (cpi->single_pred_count[i] + cpi->comp_pred_count[i]) {- pc->prob_comppred[i] = cpi->single_pred_count[i] * 255 /
- (cpi->single_pred_count[i]
- + cpi->comp_pred_count[i]);
- if (pc->prob_comppred[i] < 1)
- pc->prob_comppred[i] = 1;
- } else {- pc->prob_comppred[i] = 128;
- }
+ pc->prob_comppred[i] = get_binary_prob(cpi->single_pred_count[i],
+ cpi->comp_pred_count[i]);
vp8_write_literal(&header_bc, pc->prob_comppred[i], 8);
}
}
@@ -2928,14 +2889,9 @@
for (k = 0; k < PREV_COEF_CONTEXTS; k++) { fprintf(f, " {"); for (l = 0; l < ENTROPY_NODES; l++) {- Sum = tree_update_hist[i][j][k][l][0] + tree_update_hist[i][j][k][l][1];
- if (Sum > 0) {- if (((tree_update_hist[i][j][k][l][0] * 255) / Sum) > 0)
- fprintf(f, "%3ld, ", (tree_update_hist[i][j][k][l][0] * 255) / Sum);
- else
- fprintf(f, "%3ld, ", 1);
- } else
- fprintf(f, "%3ld, ", 128);
+ fprintf(f, "%3ld, ",
+ get_binary_prob(tree_update_hist[i][j][k][l][0],
+ tree_update_hist[i][j][k][l][1]));
}
fprintf(f, "},\n");
}
@@ -2957,14 +2913,9 @@
for (k = 0; k < PREV_COEF_CONTEXTS; k++) { fprintf(f, " {"); for (l = 0; l < MAX_ENTROPY_TOKENS - 1; l++) {- Sum = tree_update_hist_8x8[i][j][k][l][0] + tree_update_hist_8x8[i][j][k][l][1];
- if (Sum > 0) {- if (((tree_update_hist_8x8[i][j][k][l][0] * 255) / Sum) > 0)
- fprintf(f, "%3ld, ", (tree_update_hist_8x8[i][j][k][l][0] * 255) / Sum);
- else
- fprintf(f, "%3ld, ", 1);
- } else
- fprintf(f, "%3ld, ", 128);
+ fprintf(f, "%3ld, ",
+ get_binary_prob(tree_update_hist_8x8[i][j][k][l][0],
+ tree_update_hist_8x8[i][j][k][l][1]));
}
fprintf(f, "},\n");
}
@@ -2985,14 +2936,9 @@
for (k = 0; k < PREV_COEF_CONTEXTS; k++) { fprintf(f, " {"); for (l = 0; l < MAX_ENTROPY_TOKENS - 1; l++) {- Sum = tree_update_hist_16x16[i][j][k][l][0] + tree_update_hist_16x16[i][j][k][l][1];
- if (Sum > 0) {- if (((tree_update_hist_16x16[i][j][k][l][0] * 255) / Sum) > 0)
- fprintf(f, "%3ld, ", (tree_update_hist_16x16[i][j][k][l][0] * 255) / Sum);
- else
- fprintf(f, "%3ld, ", 1);
- } else
- fprintf(f, "%3ld, ", 128);
+ fprintf(f, "%3ld, ",
+ get_binary_prob(tree_update_hist_16x16[i][j][k][l][0],
+ tree_update_hist_16x16[i][j][k][l][1]));
}
fprintf(f, "},\n");
}
--
⑨