1 /*
2 * Copyright (c) 2016, Alliance for Open Media. All rights reserved
3 *
4 * This source code is subject to the terms of the BSD 2 Clause License and
5 * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
6 * was not distributed with this source code in the LICENSE file, you can
7 * obtain it at www.aomedia.org/license/software. If the Alliance for Open
8 * Media Patent License 1.0 was not distributed with this source code in the
9 * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
10 */
11
12 #ifndef AOM_AV1_COMMON_MV_H_
13 #define AOM_AV1_COMMON_MV_H_
14
15 #include "av1/common/common.h"
16 #include "av1/common/common_data.h"
17 #include "aom_dsp/aom_filter.h"
18
19 #ifdef __cplusplus
20 extern "C" {
21 #endif
22
23 #define INVALID_MV 0x80008000
24
25 typedef struct mv {
26 int16_t row;
27 int16_t col;
28 } MV;
29
30 static const MV kZeroMv = { 0, 0 };
31
32 typedef union int_mv {
33 uint32_t as_int;
34 MV as_mv;
35 } int_mv; /* facilitates faster equality tests and copies */
36
37 typedef struct mv32 {
38 int32_t row;
39 int32_t col;
40 } MV32;
41
42 // Bits of precision used for the model
43 #define WARPEDMODEL_PREC_BITS 16
44 #define WARPEDMODEL_ROW3HOMO_PREC_BITS 16
45
46 #define WARPEDMODEL_TRANS_CLAMP (128 << WARPEDMODEL_PREC_BITS)
47 #define WARPEDMODEL_NONDIAGAFFINE_CLAMP (1 << (WARPEDMODEL_PREC_BITS - 3))
48 #define WARPEDMODEL_ROW3HOMO_CLAMP (1 << (WARPEDMODEL_PREC_BITS - 2))
49
50 // Bits of subpel precision for warped interpolation
51 #define WARPEDPIXEL_PREC_BITS 6
52 #define WARPEDPIXEL_PREC_SHIFTS (1 << WARPEDPIXEL_PREC_BITS)
53
54 #define WARP_PARAM_REDUCE_BITS 6
55
56 #define WARPEDDIFF_PREC_BITS (WARPEDMODEL_PREC_BITS - WARPEDPIXEL_PREC_BITS)
57
58 /* clang-format off */
59 enum {
60 IDENTITY = 0, // identity transformation, 0-parameter
61 TRANSLATION = 1, // translational motion 2-parameter
62 ROTZOOM = 2, // simplified affine with rotation + zoom only, 4-parameter
63 AFFINE = 3, // affine, 6-parameter
64 TRANS_TYPES,
65 } UENUM1BYTE(TransformationType);
66 /* clang-format on */
67
68 // Number of types used for global motion (must be >= 3 and <= TRANS_TYPES)
69 // The following can be useful:
70 // GLOBAL_TRANS_TYPES 3 - up to rotation-zoom
71 // GLOBAL_TRANS_TYPES 4 - up to affine
72 // GLOBAL_TRANS_TYPES 6 - up to hor/ver trapezoids
73 // GLOBAL_TRANS_TYPES 7 - up to full homography
74 #define GLOBAL_TRANS_TYPES 4
75
76 typedef struct {
77 int global_warp_allowed;
78 int local_warp_allowed;
79 } WarpTypesAllowed;
80
81 // number of parameters used by each transformation in TransformationTypes
82 static const int trans_model_params[TRANS_TYPES] = { 0, 2, 4, 6 };
83
84 // The order of values in the wmmat matrix below is best described
85 // by the homography:
86 // [x' (m2 m3 m0 [x
87 // z . y' = m4 m5 m1 * y
88 // 1] m6 m7 1) 1]
89 typedef struct {
90 int32_t wmmat[8];
91 int16_t alpha, beta, gamma, delta;
92 TransformationType wmtype;
93 int8_t invalid;
94 } WarpedMotionParams;
95
96 /* clang-format off */
97 static const WarpedMotionParams default_warp_params = {
98 { 0, 0, (1 << WARPEDMODEL_PREC_BITS), 0, 0, (1 << WARPEDMODEL_PREC_BITS), 0,
99 0 },
100 0, 0, 0, 0,
101 IDENTITY,
102 0,
103 };
104 /* clang-format on */
105
106 // The following constants describe the various precisions
107 // of different parameters in the global motion experiment.
108 //
109 // Given the general homography:
110 // [x' (a b c [x
111 // z . y' = d e f * y
112 // 1] g h i) 1]
113 //
114 // Constants using the name ALPHA here are related to parameters
115 // a, b, d, e. Constants using the name TRANS are related
116 // to parameters c and f.
117 //
118 // Anything ending in PREC_BITS is the number of bits of precision
119 // to maintain when converting from double to integer.
120 //
121 // The ABS parameters are used to create an upper and lower bound
122 // for each parameter. In other words, after a parameter is integerized
123 // it is clamped between -(1 << ABS_XXX_BITS) and (1 << ABS_XXX_BITS).
124 //
125 // XXX_PREC_DIFF and XXX_DECODE_FACTOR
126 // are computed once here to prevent repetitive
127 // computation on the decoder side. These are
128 // to allow the global motion parameters to be encoded in a lower
129 // precision than the warped model precision. This means that they
130 // need to be changed to warped precision when they are decoded.
131 //
132 // XX_MIN, XX_MAX are also computed to avoid repeated computation
133
134 #define SUBEXPFIN_K 3
135 #define GM_TRANS_PREC_BITS 6
136 #define GM_ABS_TRANS_BITS 12
137 #define GM_ABS_TRANS_ONLY_BITS (GM_ABS_TRANS_BITS - GM_TRANS_PREC_BITS + 3)
138 #define GM_TRANS_PREC_DIFF (WARPEDMODEL_PREC_BITS - GM_TRANS_PREC_BITS)
139 #define GM_TRANS_ONLY_PREC_DIFF (WARPEDMODEL_PREC_BITS - 3)
140 #define GM_TRANS_DECODE_FACTOR (1 << GM_TRANS_PREC_DIFF)
141 #define GM_TRANS_ONLY_DECODE_FACTOR (1 << GM_TRANS_ONLY_PREC_DIFF)
142
143 #define GM_ALPHA_PREC_BITS 15
144 #define GM_ABS_ALPHA_BITS 12
145 #define GM_ALPHA_PREC_DIFF (WARPEDMODEL_PREC_BITS - GM_ALPHA_PREC_BITS)
146 #define GM_ALPHA_DECODE_FACTOR (1 << GM_ALPHA_PREC_DIFF)
147
148 #define GM_ROW3HOMO_PREC_BITS 16
149 #define GM_ABS_ROW3HOMO_BITS 11
150 #define GM_ROW3HOMO_PREC_DIFF \
151 (WARPEDMODEL_ROW3HOMO_PREC_BITS - GM_ROW3HOMO_PREC_BITS)
152 #define GM_ROW3HOMO_DECODE_FACTOR (1 << GM_ROW3HOMO_PREC_DIFF)
153
154 #define GM_TRANS_MAX (1 << GM_ABS_TRANS_BITS)
155 #define GM_ALPHA_MAX (1 << GM_ABS_ALPHA_BITS)
156 #define GM_ROW3HOMO_MAX (1 << GM_ABS_ROW3HOMO_BITS)
157
158 #define GM_TRANS_MIN -GM_TRANS_MAX
159 #define GM_ALPHA_MIN -GM_ALPHA_MAX
160 #define GM_ROW3HOMO_MIN -GM_ROW3HOMO_MAX
161
block_center_x(int mi_col,BLOCK_SIZE bs)162 static INLINE int block_center_x(int mi_col, BLOCK_SIZE bs) {
163 const int bw = block_size_wide[bs];
164 return mi_col * MI_SIZE + bw / 2 - 1;
165 }
166
block_center_y(int mi_row,BLOCK_SIZE bs)167 static INLINE int block_center_y(int mi_row, BLOCK_SIZE bs) {
168 const int bh = block_size_high[bs];
169 return mi_row * MI_SIZE + bh / 2 - 1;
170 }
171
convert_to_trans_prec(int allow_hp,int coor)172 static INLINE int convert_to_trans_prec(int allow_hp, int coor) {
173 if (allow_hp)
174 return ROUND_POWER_OF_TWO_SIGNED(coor, WARPEDMODEL_PREC_BITS - 3);
175 else
176 return ROUND_POWER_OF_TWO_SIGNED(coor, WARPEDMODEL_PREC_BITS - 2) * 2;
177 }
integer_mv_precision(MV * mv)178 static INLINE void integer_mv_precision(MV *mv) {
179 int mod = (mv->row % 8);
180 if (mod != 0) {
181 mv->row -= mod;
182 if (abs(mod) > 4) {
183 if (mod > 0) {
184 mv->row += 8;
185 } else {
186 mv->row -= 8;
187 }
188 }
189 }
190
191 mod = (mv->col % 8);
192 if (mod != 0) {
193 mv->col -= mod;
194 if (abs(mod) > 4) {
195 if (mod > 0) {
196 mv->col += 8;
197 } else {
198 mv->col -= 8;
199 }
200 }
201 }
202 }
203 // Convert a global motion vector into a motion vector at the centre of the
204 // given block.
205 //
206 // The resulting motion vector will have three fractional bits of precision. If
207 // allow_hp is zero, the bottom bit will always be zero. If CONFIG_AMVR and
208 // is_integer is true, the bottom three bits will be zero (so the motion vector
209 // represents an integer)
gm_get_motion_vector(const WarpedMotionParams * gm,int allow_hp,BLOCK_SIZE bsize,int mi_col,int mi_row,int is_integer)210 static INLINE int_mv gm_get_motion_vector(const WarpedMotionParams *gm,
211 int allow_hp, BLOCK_SIZE bsize,
212 int mi_col, int mi_row,
213 int is_integer) {
214 int_mv res;
215
216 if (gm->wmtype == IDENTITY) {
217 res.as_int = 0;
218 return res;
219 }
220
221 const int32_t *mat = gm->wmmat;
222 int x, y, tx, ty;
223
224 if (gm->wmtype == TRANSLATION) {
225 // All global motion vectors are stored with WARPEDMODEL_PREC_BITS (16)
226 // bits of fractional precision. The offset for a translation is stored in
227 // entries 0 and 1. For translations, all but the top three (two if
228 // cm->allow_high_precision_mv is false) fractional bits are always zero.
229 //
230 // After the right shifts, there are 3 fractional bits of precision. If
231 // allow_hp is false, the bottom bit is always zero (so we don't need a
232 // call to convert_to_trans_prec here)
233 res.as_mv.row = gm->wmmat[0] >> GM_TRANS_ONLY_PREC_DIFF;
234 res.as_mv.col = gm->wmmat[1] >> GM_TRANS_ONLY_PREC_DIFF;
235 assert(IMPLIES(1 & (res.as_mv.row | res.as_mv.col), allow_hp));
236 if (is_integer) {
237 integer_mv_precision(&res.as_mv);
238 }
239 return res;
240 }
241
242 x = block_center_x(mi_col, bsize);
243 y = block_center_y(mi_row, bsize);
244
245 if (gm->wmtype == ROTZOOM) {
246 assert(gm->wmmat[5] == gm->wmmat[2]);
247 assert(gm->wmmat[4] == -gm->wmmat[3]);
248 }
249
250 const int xc =
251 (mat[2] - (1 << WARPEDMODEL_PREC_BITS)) * x + mat[3] * y + mat[0];
252 const int yc =
253 mat[4] * x + (mat[5] - (1 << WARPEDMODEL_PREC_BITS)) * y + mat[1];
254 tx = convert_to_trans_prec(allow_hp, xc);
255 ty = convert_to_trans_prec(allow_hp, yc);
256
257 res.as_mv.row = ty;
258 res.as_mv.col = tx;
259
260 if (is_integer) {
261 integer_mv_precision(&res.as_mv);
262 }
263 return res;
264 }
265
get_wmtype(const WarpedMotionParams * gm)266 static INLINE TransformationType get_wmtype(const WarpedMotionParams *gm) {
267 if (gm->wmmat[5] == (1 << WARPEDMODEL_PREC_BITS) && !gm->wmmat[4] &&
268 gm->wmmat[2] == (1 << WARPEDMODEL_PREC_BITS) && !gm->wmmat[3]) {
269 return ((!gm->wmmat[1] && !gm->wmmat[0]) ? IDENTITY : TRANSLATION);
270 }
271 if (gm->wmmat[2] == gm->wmmat[5] && gm->wmmat[3] == -gm->wmmat[4])
272 return ROTZOOM;
273 else
274 return AFFINE;
275 }
276
277 typedef struct candidate_mv {
278 int_mv this_mv;
279 int_mv comp_mv;
280 int weight;
281 } CANDIDATE_MV;
282
is_zero_mv(const MV * mv)283 static INLINE int is_zero_mv(const MV *mv) {
284 return *((const uint32_t *)mv) == 0;
285 }
286
is_equal_mv(const MV * a,const MV * b)287 static INLINE int is_equal_mv(const MV *a, const MV *b) {
288 return *((const uint32_t *)a) == *((const uint32_t *)b);
289 }
290
clamp_mv(MV * mv,int min_col,int max_col,int min_row,int max_row)291 static INLINE void clamp_mv(MV *mv, int min_col, int max_col, int min_row,
292 int max_row) {
293 mv->col = clamp(mv->col, min_col, max_col);
294 mv->row = clamp(mv->row, min_row, max_row);
295 }
296
297 #ifdef __cplusplus
298 } // extern "C"
299 #endif
300
301 #endif // AOM_AV1_COMMON_MV_H_
302