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 <assert.h>
12 #include <limits.h>
13
14 #include "./vpx_scale_rtcd.h"
15 #include "vpx_dsp/psnr.h"
16 #include "vpx_mem/vpx_mem.h"
17 #include "vpx_ports/mem.h"
18
19 #include "vp9/common/vp9_loopfilter.h"
20 #include "vp9/common/vp9_onyxc_int.h"
21 #include "vp9/common/vp9_quant_common.h"
22
23 #include "vp9/encoder/vp9_encoder.h"
24 #include "vp9/encoder/vp9_picklpf.h"
25 #include "vp9/encoder/vp9_quantize.h"
26
get_max_filter_level(const VP9_COMP * cpi)27 static int get_max_filter_level(const VP9_COMP *cpi) {
28 if (cpi->oxcf.pass == 2) {
29 return cpi->twopass.section_intra_rating > 8 ? MAX_LOOP_FILTER * 3 / 4
30 : MAX_LOOP_FILTER;
31 } else {
32 return MAX_LOOP_FILTER;
33 }
34 }
35
try_filter_frame(const YV12_BUFFER_CONFIG * sd,VP9_COMP * const cpi,int filt_level,int partial_frame)36 static int64_t try_filter_frame(const YV12_BUFFER_CONFIG *sd,
37 VP9_COMP *const cpi, int filt_level,
38 int partial_frame) {
39 VP9_COMMON *const cm = &cpi->common;
40 int64_t filt_err;
41
42 vp9_build_mask_frame(cm, filt_level, partial_frame);
43
44 if (cpi->num_workers > 1)
45 vp9_loop_filter_frame_mt(cm->frame_to_show, cm, cpi->td.mb.e_mbd.plane,
46 filt_level, 1, partial_frame, cpi->workers,
47 cpi->num_workers, &cpi->lf_row_sync);
48 else
49 vp9_loop_filter_frame(cm->frame_to_show, cm, &cpi->td.mb.e_mbd, filt_level,
50 1, partial_frame);
51
52 #if CONFIG_VP9_HIGHBITDEPTH
53 if (cm->use_highbitdepth) {
54 filt_err = vpx_highbd_get_y_sse(sd, cm->frame_to_show);
55 } else {
56 filt_err = vpx_get_y_sse(sd, cm->frame_to_show);
57 }
58 #else
59 filt_err = vpx_get_y_sse(sd, cm->frame_to_show);
60 #endif // CONFIG_VP9_HIGHBITDEPTH
61
62 // Re-instate the unfiltered frame
63 vpx_yv12_copy_y(&cpi->last_frame_uf, cm->frame_to_show);
64
65 return filt_err;
66 }
67
search_filter_level(const YV12_BUFFER_CONFIG * sd,VP9_COMP * cpi,int partial_frame)68 static int search_filter_level(const YV12_BUFFER_CONFIG *sd, VP9_COMP *cpi,
69 int partial_frame) {
70 const VP9_COMMON *const cm = &cpi->common;
71 const struct loopfilter *const lf = &cm->lf;
72 const int min_filter_level = 0;
73 const int max_filter_level = get_max_filter_level(cpi);
74 int filt_direction = 0;
75 int64_t best_err;
76 int filt_best;
77
78 // Start the search at the previous frame filter level unless it is now out of
79 // range.
80 int filt_mid = clamp(lf->last_filt_level, min_filter_level, max_filter_level);
81 int filter_step = filt_mid < 16 ? 4 : filt_mid / 4;
82 // Sum squared error at each filter level
83 int64_t ss_err[MAX_LOOP_FILTER + 1];
84
85 // Set each entry to -1
86 memset(ss_err, 0xFF, sizeof(ss_err));
87
88 // Make a copy of the unfiltered / processed recon buffer
89 vpx_yv12_copy_y(cm->frame_to_show, &cpi->last_frame_uf);
90
91 best_err = try_filter_frame(sd, cpi, filt_mid, partial_frame);
92 filt_best = filt_mid;
93 ss_err[filt_mid] = best_err;
94
95 while (filter_step > 0) {
96 const int filt_high = VPXMIN(filt_mid + filter_step, max_filter_level);
97 const int filt_low = VPXMAX(filt_mid - filter_step, min_filter_level);
98
99 // Bias against raising loop filter in favor of lowering it.
100 int64_t bias = (best_err >> (15 - (filt_mid / 8))) * filter_step;
101
102 if ((cpi->oxcf.pass == 2) && (cpi->twopass.section_intra_rating < 20))
103 bias = (bias * cpi->twopass.section_intra_rating) / 20;
104
105 // yx, bias less for large block size
106 if (cm->tx_mode != ONLY_4X4) bias >>= 1;
107
108 if (filt_direction <= 0 && filt_low != filt_mid) {
109 // Get Low filter error score
110 if (ss_err[filt_low] < 0) {
111 ss_err[filt_low] = try_filter_frame(sd, cpi, filt_low, partial_frame);
112 }
113 // If value is close to the best so far then bias towards a lower loop
114 // filter value.
115 if ((ss_err[filt_low] - bias) < best_err) {
116 // Was it actually better than the previous best?
117 if (ss_err[filt_low] < best_err) best_err = ss_err[filt_low];
118
119 filt_best = filt_low;
120 }
121 }
122
123 // Now look at filt_high
124 if (filt_direction >= 0 && filt_high != filt_mid) {
125 if (ss_err[filt_high] < 0) {
126 ss_err[filt_high] = try_filter_frame(sd, cpi, filt_high, partial_frame);
127 }
128 // Was it better than the previous best?
129 if (ss_err[filt_high] < (best_err - bias)) {
130 best_err = ss_err[filt_high];
131 filt_best = filt_high;
132 }
133 }
134
135 // Half the step distance if the best filter value was the same as last time
136 if (filt_best == filt_mid) {
137 filter_step /= 2;
138 filt_direction = 0;
139 } else {
140 filt_direction = (filt_best < filt_mid) ? -1 : 1;
141 filt_mid = filt_best;
142 }
143 }
144
145 return filt_best;
146 }
147
vp9_pick_filter_level(const YV12_BUFFER_CONFIG * sd,VP9_COMP * cpi,LPF_PICK_METHOD method)148 void vp9_pick_filter_level(const YV12_BUFFER_CONFIG *sd, VP9_COMP *cpi,
149 LPF_PICK_METHOD method) {
150 VP9_COMMON *const cm = &cpi->common;
151 struct loopfilter *const lf = &cm->lf;
152
153 lf->sharpness_level = cm->frame_type == KEY_FRAME ? 0 : cpi->oxcf.sharpness;
154
155 if (method == LPF_PICK_MINIMAL_LPF && lf->filter_level) {
156 lf->filter_level = 0;
157 } else if (method >= LPF_PICK_FROM_Q) {
158 const int min_filter_level = 0;
159 const int max_filter_level = get_max_filter_level(cpi);
160 const int q = vp9_ac_quant(cm->base_qindex, 0, cm->bit_depth);
161 // These values were determined by linear fitting the result of the
162 // searched level, filt_guess = q * 0.316206 + 3.87252
163 #if CONFIG_VP9_HIGHBITDEPTH
164 int filt_guess;
165 switch (cm->bit_depth) {
166 case VPX_BITS_8:
167 filt_guess = ROUND_POWER_OF_TWO(q * 20723 + 1015158, 18);
168 break;
169 case VPX_BITS_10:
170 filt_guess = ROUND_POWER_OF_TWO(q * 20723 + 4060632, 20);
171 break;
172 case VPX_BITS_12:
173 filt_guess = ROUND_POWER_OF_TWO(q * 20723 + 16242526, 22);
174 break;
175 default:
176 assert(0 &&
177 "bit_depth should be VPX_BITS_8, VPX_BITS_10 "
178 "or VPX_BITS_12");
179 return;
180 }
181 #else
182 int filt_guess = ROUND_POWER_OF_TWO(q * 20723 + 1015158, 18);
183 #endif // CONFIG_VP9_HIGHBITDEPTH
184 if (cpi->oxcf.pass == 0 && cpi->oxcf.rc_mode == VPX_CBR &&
185 cpi->oxcf.aq_mode == CYCLIC_REFRESH_AQ && cm->seg.enabled &&
186 cpi->oxcf.content != VP9E_CONTENT_SCREEN && cm->frame_type != KEY_FRAME)
187 filt_guess = 5 * filt_guess >> 3;
188
189 if (cm->frame_type == KEY_FRAME) filt_guess -= 4;
190 lf->filter_level = clamp(filt_guess, min_filter_level, max_filter_level);
191 } else {
192 lf->filter_level =
193 search_filter_level(sd, cpi, method == LPF_PICK_FROM_SUBIMAGE);
194 }
195 }
196