New way of updating last frame segmentation map.

Implementing more natural (and faster) way of updating last frame
segmentation map.

Change-Id: I9fefa8f78e77bd7948133b04173da45edc15a17e

vp9/decoder/vp9_decodemv.c

@@ -75,28 +75,9 @@ static TX_SIZE read_tx_size(VP9D_COMP *pbi, TX_MODE tx_mode,
     return TX_4X4;
 }
 
-static void set_segment_id(VP9_COMMON *cm, BLOCK_SIZE bsize,
-                           int mi_row, int mi_col, int segment_id) {
-  const int mi_offset = mi_row * cm->mi_cols + mi_col;
-  const int bw = 1 << mi_width_log2(bsize);
-  const int bh = 1 << mi_height_log2(bsize);
-  const int xmis = MIN(cm->mi_cols - mi_col, bw);
-  const int ymis = MIN(cm->mi_rows - mi_row, bh);
-  int x, y;
-
-  assert(segment_id >= 0 && segment_id < MAX_SEGMENTS);
-
-  for (y = 0; y < ymis; y++)
-    for (x = 0; x < xmis; x++)
-      cm->last_frame_seg_map[mi_offset + y * cm->mi_cols + x] = segment_id;
-}
-
 static int read_intra_segment_id(VP9D_COMP *pbi, int mi_row, int mi_col,
                                  vp9_reader *r) {
-  MACROBLOCKD *const xd = &pbi->mb;
   struct segmentation *const seg = &pbi->common.seg;
-  const BLOCK_SIZE bsize = xd->this_mi->mbmi.sb_type;
-  int segment_id;
 
   if (!seg->enabled)
     return 0;  // Default for disabled segmentation
@@ -104,9 +85,7 @@ static int read_intra_segment_id(VP9D_COMP *pbi, int mi_row, int mi_col,
   if (!seg->update_map)
     return 0;
 
-  segment_id = read_segment_id(r, seg);
-  set_segment_id(&pbi->common, bsize, mi_row, mi_col, segment_id);
-  return segment_id;
+  return read_segment_id(r, seg);
 }
 
 static int read_inter_segment_id(VP9D_COMP *pbi, int mi_row, int mi_col,
@@ -115,7 +94,7 @@ static int read_inter_segment_id(VP9D_COMP *pbi, int mi_row, int mi_col,
   MACROBLOCKD *const xd = &pbi->mb;
   struct segmentation *const seg = &cm->seg;
   const BLOCK_SIZE bsize = xd->this_mi->mbmi.sb_type;
-  int pred_segment_id, segment_id;
+  int pred_segment_id;;
 
   if (!seg->enabled)
     return 0;  // Default for disabled segmentation
@@ -129,13 +108,10 @@ static int read_inter_segment_id(VP9D_COMP *pbi, int mi_row, int mi_col,
     const vp9_prob pred_prob = vp9_get_pred_prob_seg_id(seg, xd);
     const int pred_flag = vp9_read(r, pred_prob);
     vp9_set_pred_flag_seg_id(xd, pred_flag);
-    segment_id = pred_flag ? pred_segment_id
-                           : read_segment_id(r, seg);
+    return pred_flag ? pred_segment_id : read_segment_id(r, seg);
   } else {
-    segment_id = read_segment_id(r, seg);
+    return read_segment_id(r, seg);
   }
-  set_segment_id(cm, bsize, mi_row, mi_col, segment_id);
-  return segment_id;
 }
 
 static uint8_t read_skip_coeff(VP9D_COMP *pbi, int segment_id, vp9_reader *r) {

vp9/decoder/vp9_decodframe.c

@@ -935,6 +935,15 @@ void vp9_init_dequantizer(VP9_COMMON *cm) {
   }
 }
 
+static void update_segmentation_map(VP9_COMMON *cm) {
+  int i, j;
+
+  for (i = 0; i < cm->mi_rows; ++i)
+    for (j = 0; j < cm->mi_cols; ++j)
+      cm->last_frame_seg_map[i * cm->mi_cols + j] =
+          cm->mi_grid_visible[i * cm->mode_info_stride + j]->mbmi.segment_id;
+}
+
 int vp9_decode_frame(VP9D_COMP *pbi, const uint8_t **p_data_end) {
   int i;
   VP9_COMMON *const cm = &pbi->common;
@@ -1014,5 +1023,7 @@ int vp9_decode_frame(VP9D_COMP *pbi, const uint8_t **p_data_end) {
   if (cm->refresh_frame_context)
     cm->frame_contexts[cm->frame_context_idx] = cm->fc;
 
+  update_segmentation_map(cm);
+
   return 0;
 }