1 /* 2 * Copyright (c) 2014 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 <limits.h> 12 #include <math.h> 13 14 #include "vp9/common/vp9_seg_common.h" 15 16 #include "vp9/encoder/vp9_segmentation.h" 17 18 static const double in_frame_q_adj_ratio[MAX_SEGMENTS] = 19 {1.0, 2.0, 1.0, 1.0, 1.0, 1.0, 1.0, 1.0}; 20 21 void vp9_setup_in_frame_q_adj(VP9_COMP *cpi) { 22 VP9_COMMON *const cm = &cpi->common; 23 struct segmentation *const seg = &cm->seg; 24 25 // Make SURE use of floating point in this function is safe. 26 vp9_clear_system_state(); 27 28 if (cm->frame_type == KEY_FRAME || 29 cpi->refresh_alt_ref_frame || 30 (cpi->refresh_golden_frame && !cpi->rc.is_src_frame_alt_ref)) { 31 int segment; 32 33 // Clear down the segment map. 34 vpx_memset(cpi->segmentation_map, 0, cm->mi_rows * cm->mi_cols); 35 36 // Clear down the complexity map used for rd. 37 vpx_memset(cpi->complexity_map, 0, cm->mi_rows * cm->mi_cols); 38 39 vp9_enable_segmentation(seg); 40 vp9_clearall_segfeatures(seg); 41 42 // Select delta coding method. 43 seg->abs_delta = SEGMENT_DELTADATA; 44 45 // Segment 0 "Q" feature is disabled so it defaults to the baseline Q. 46 vp9_disable_segfeature(seg, 0, SEG_LVL_ALT_Q); 47 48 // Use some of the segments for in frame Q adjustment. 49 for (segment = 1; segment < 2; segment++) { 50 const int qindex_delta = 51 vp9_compute_qdelta_by_rate(cpi, 52 cm->base_qindex, 53 in_frame_q_adj_ratio[segment]); 54 vp9_enable_segfeature(seg, segment, SEG_LVL_ALT_Q); 55 vp9_set_segdata(seg, segment, SEG_LVL_ALT_Q, qindex_delta); 56 } 57 } 58 } 59 60 // Select a segment for the current SB64 61 void vp9_select_in_frame_q_segment(VP9_COMP *cpi, 62 int mi_row, int mi_col, 63 int output_enabled, int projected_rate) { 64 VP9_COMMON *const cm = &cpi->common; 65 66 const int mi_offset = mi_row * cm->mi_cols + mi_col; 67 const int bw = num_8x8_blocks_wide_lookup[BLOCK_64X64]; 68 const int bh = num_8x8_blocks_high_lookup[BLOCK_64X64]; 69 const int xmis = MIN(cm->mi_cols - mi_col, bw); 70 const int ymis = MIN(cm->mi_rows - mi_row, bh); 71 int complexity_metric = 64; 72 int x, y; 73 74 unsigned char segment; 75 76 if (!output_enabled) { 77 segment = 0; 78 } else { 79 // Rate depends on fraction of a SB64 in frame (xmis * ymis / bw * bh). 80 // It is converted to bits * 256 units. 81 const int target_rate = (cpi->rc.sb64_target_rate * xmis * ymis * 256) / 82 (bw * bh); 83 84 if (projected_rate < (target_rate / 4)) { 85 segment = 1; 86 } else { 87 segment = 0; 88 } 89 90 if (target_rate > 0) { 91 complexity_metric = 92 clamp((int)((projected_rate * 64) / target_rate), 16, 255); 93 } 94 } 95 96 // Fill in the entires in the segment map corresponding to this SB64. 97 for (y = 0; y < ymis; y++) { 98 for (x = 0; x < xmis; x++) { 99 cpi->segmentation_map[mi_offset + y * cm->mi_cols + x] = segment; 100 cpi->complexity_map[mi_offset + y * cm->mi_cols + x] = 101 (unsigned char)complexity_metric; 102 } 103 } 104 } 105
