static void count_segs(VP9_COMP *cpi,
MODE_INFO *mi,
int *no_pred_segcounts,
int (*temporal_predictor_count)[2],
int *t_unpred_seg_counts,
int bw, int bh, int mi_row, int mi_col) {
VP9_COMMON *const cm = &cpi->common;
MACROBLOCKD *const xd = &cpi->mb.e_mbd;
int segment_id;
if (mi_row >= cm->mi_rows || mi_col >= cm->mi_cols)
return;
segment_id = mi->mbmi.segment_id;
xd->mode_info_context = mi;
set_mi_row_col(cm, xd, mi_row, bh, mi_col, bw);
// Count the number of hits on each segment with no prediction
no_pred_segcounts[segment_id]++;
// Temporal prediction not allowed on key frames
if (cm->frame_type != KEY_FRAME) {
// Test to see if the segment id matches the predicted value.
const int pred_seg_id = vp9_get_pred_mi_segid(cm, mi->mbmi.sb_type,
mi_row, mi_col);
const int seg_predicted = (segment_id == pred_seg_id);
// Get the segment id prediction context
const int pred_context = vp9_get_pred_context(cm, xd, PRED_SEG_ID);
// Store the prediction status for this mb and update counts
// as appropriate
vp9_set_pred_flag(xd, PRED_SEG_ID, seg_predicted);
temporal_predictor_count[pred_context][seg_predicted]++;
if (!seg_predicted)
// Update the "unpredicted" segment count
t_unpred_seg_counts[segment_id]++;
}
}
void vp9_choose_segmap_coding_method(VP9_COMP *cpi) {
VP9_COMMON *const cm = &cpi->common;
MACROBLOCKD *const xd = &cpi->mb.e_mbd;
int i;
int tot_count;
int no_pred_cost;
int t_pred_cost = INT_MAX;
int pred_context;
int mb_row, mb_col;
int segmap_index = 0;
unsigned char segment_id;
int temporal_predictor_count[PREDICTION_PROBS][2];
int no_pred_segcounts[MAX_MB_SEGMENTS];
int t_unpred_seg_counts[MAX_MB_SEGMENTS];
vp9_prob no_pred_tree[MB_FEATURE_TREE_PROBS];
vp9_prob t_pred_tree[MB_FEATURE_TREE_PROBS];
vp9_prob t_nopred_prob[PREDICTION_PROBS];
#if CONFIG_SUPERBLOCKS
const int mis = cm->mode_info_stride;
#endif
// Set default state for the segment tree probabilities and the
// temporal coding probabilities
vpx_memset(xd->mb_segment_tree_probs, 255,
sizeof(xd->mb_segment_tree_probs));
vpx_memset(cm->segment_pred_probs, 255,
sizeof(cm->segment_pred_probs));
vpx_memset(no_pred_segcounts, 0, sizeof(no_pred_segcounts));
vpx_memset(t_unpred_seg_counts, 0, sizeof(t_unpred_seg_counts));
vpx_memset(temporal_predictor_count, 0, sizeof(temporal_predictor_count));
// First of all generate stats regarding how well the last segment map
// predicts this one
// Initialize macroblock decoder mode info context for the first mb
// in the frame
xd->mode_info_context = cm->mi;
for (mb_row = 0; mb_row < cm->mb_rows; mb_row += 2) {
for (mb_col = 0; mb_col < cm->mb_cols; mb_col += 2) {
for (i = 0; i < 4; i++) {
static const int dx[4] = { +1, -1, +1, +1 };
static const int dy[4] = { 0, +1, 0, -1 };
int x_idx = i & 1, y_idx = i >> 1;
if (mb_col + x_idx >= cm->mb_cols ||
mb_row + y_idx >= cm->mb_rows) {
goto end;
}
xd->mb_to_top_edge = -((mb_row * 16) << 3);
xd->mb_to_left_edge = -((mb_col * 16) << 3);
segmap_index = (mb_row + y_idx) * cm->mb_cols + mb_col + x_idx;
segment_id = xd->mode_info_context->mbmi.segment_id;
#if CONFIG_SUPERBLOCKS
if (xd->mode_info_context->mbmi.encoded_as_sb) {
if (mb_col + 1 < cm->mb_cols)
segment_id = segment_id &&
xd->mode_info_context[1].mbmi.segment_id;
if (mb_row + 1 < cm->mb_rows) {
segment_id = segment_id &&
xd->mode_info_context[mis].mbmi.segment_id;
if (mb_col + 1 < cm->mb_cols)
segment_id = segment_id &&
xd->mode_info_context[mis + 1].mbmi.segment_id;
}
xd->mb_to_bottom_edge = ((cm->mb_rows - 2 - mb_row) * 16) << 3;
xd->mb_to_right_edge = ((cm->mb_cols - 2 - mb_col) * 16) << 3;
} else {
#endif
xd->mb_to_bottom_edge = ((cm->mb_rows - 1 - mb_row) * 16) << 3;
xd->mb_to_right_edge = ((cm->mb_cols - 1 - mb_col) * 16) << 3;
#if CONFIG_SUPERBLOCKS
}
#endif
// Count the number of hits on each segment with no prediction
no_pred_segcounts[segment_id]++;
// Temporal prediction not allowed on key frames
if (cm->frame_type != KEY_FRAME) {
// Test to see if the segment id matches the predicted value.
int seg_predicted =
(segment_id == vp9_get_pred_mb_segid(cm, xd, segmap_index));
// Get the segment id prediction context
pred_context =
vp9_get_pred_context(cm, xd, PRED_SEG_ID);
// Store the prediction status for this mb and update counts
// as appropriate
vp9_set_pred_flag(xd, PRED_SEG_ID, seg_predicted);
temporal_predictor_count[pred_context][seg_predicted]++;
if (!seg_predicted)
// Update the "unpredicted" segment count
t_unpred_seg_counts[segment_id]++;
}
#if CONFIG_SUPERBLOCKS
if (xd->mode_info_context->mbmi.encoded_as_sb) {
assert(!i);
xd->mode_info_context += 2;
break;
}
#endif
end:
xd->mode_info_context += dx[i] + dy[i] * cm->mode_info_stride;
}
}
// this is to account for the border in mode_info_context
xd->mode_info_context -= mb_col;
xd->mode_info_context += cm->mode_info_stride * 2;
}
// Work out probability tree for coding segments without prediction
// and the cost.
calc_segtree_probs(xd, no_pred_segcounts, no_pred_tree);
no_pred_cost = cost_segmap(xd, no_pred_segcounts, no_pred_tree);
// Key frames cannot use temporal prediction
if (cm->frame_type != KEY_FRAME) {
// Work out probability tree for coding those segments not
// predicted using the temporal method and the cost.
calc_segtree_probs(xd, t_unpred_seg_counts, t_pred_tree);
t_pred_cost = cost_segmap(xd, t_unpred_seg_counts, t_pred_tree);
// Add in the cost of the signalling for each prediction context
for (i = 0; i < PREDICTION_PROBS; i++) {
tot_count = temporal_predictor_count[i][0] +
temporal_predictor_count[i][1];
// Work out the context probabilities for the segment
// prediction flag
if (tot_count) {
t_nopred_prob[i] = (temporal_predictor_count[i][0] * 255) /
tot_count;
// Clamp to minimum allowed value
if (t_nopred_prob[i] < 1)
t_nopred_prob[i] = 1;
} else
t_nopred_prob[i] = 1;
// Add in the predictor signaling cost
t_pred_cost += (temporal_predictor_count[i][0] *
vp9_cost_zero(t_nopred_prob[i])) +
(temporal_predictor_count[i][1] *
vp9_cost_one(t_nopred_prob[i]));
}
}
// Now choose which coding method to use.
if (t_pred_cost < no_pred_cost) {
cm->temporal_update = 1;
vpx_memcpy(xd->mb_segment_tree_probs,
t_pred_tree, sizeof(t_pred_tree));
vpx_memcpy(&cm->segment_pred_probs,
t_nopred_prob, sizeof(t_nopred_prob));
} else {
cm->temporal_update = 0;
vpx_memcpy(xd->mb_segment_tree_probs,
no_pred_tree, sizeof(no_pred_tree));
}
}
