1 /*
2  *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 #include "vp9/common/vp9_tile_common.h"
12 
13 #include "vp9/common/vp9_onyxc_int.h"
14 
15 #define MIN_TILE_WIDTH_B64 4
16 #define MAX_TILE_WIDTH_B64 64
17 
get_tile_offset(int idx,int mis,int log2)18 static int get_tile_offset(int idx, int mis, int log2) {
19   const int sb_cols = mi_cols_aligned_to_sb(mis) >> MI_BLOCK_SIZE_LOG2;
20   const int offset = ((idx * sb_cols) >> log2) << MI_BLOCK_SIZE_LOG2;
21   return MIN(offset, mis);
22 }
23 
vp9_tile_init(TileInfo * tile,const VP9_COMMON * cm,int row,int col)24 void vp9_tile_init(TileInfo *tile, const VP9_COMMON *cm, int row, int col) {
25   tile->mi_row_start = get_tile_offset(row, cm->mi_rows, cm->log2_tile_rows);
26   tile->mi_row_end = get_tile_offset(row + 1, cm->mi_rows, cm->log2_tile_rows);
27   tile->mi_col_start = get_tile_offset(col, cm->mi_cols, cm->log2_tile_cols);
28   tile->mi_col_end = get_tile_offset(col + 1, cm->mi_cols, cm->log2_tile_cols);
29 }
30 
vp9_get_tile_n_bits(int mi_cols,int * min_log2_tile_cols,int * max_log2_tile_cols)31 void vp9_get_tile_n_bits(int mi_cols,
32                          int *min_log2_tile_cols, int *max_log2_tile_cols) {
33   const int sb_cols = mi_cols_aligned_to_sb(mi_cols) >> MI_BLOCK_SIZE_LOG2;
34   int min_log2 = 0, max_log2 = 0;
35 
36   // max
37   while ((sb_cols >> max_log2) >= MIN_TILE_WIDTH_B64)
38     ++max_log2;
39   --max_log2;
40   if (max_log2 < 0)
41     max_log2 = 0;
42 
43   // min
44   while ((MAX_TILE_WIDTH_B64 << min_log2) < sb_cols)
45     ++min_log2;
46 
47   assert(min_log2 <= max_log2);
48 
49   *min_log2_tile_cols = min_log2;
50   *max_log2_tile_cols = max_log2;
51 }
52