1 /*****************************************************************************
2 * This file is part of Kvazaar HEVC encoder.
3 *
4 * Copyright (c) 2021, Tampere University, ITU/ISO/IEC, project contributors
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without modification,
8 * are permitted provided that the following conditions are met:
9 *
10 * * Redistributions of source code must retain the above copyright notice, this
11 * list of conditions and the following disclaimer.
12 *
13 * * Redistributions in binary form must reproduce the above copyright notice, this
14 * list of conditions and the following disclaimer in the documentation and/or
15 * other materials provided with the distribution.
16 *
17 * * Neither the name of the Tampere University or ITU/ISO/IEC nor the names of its
18 * contributors may be used to endorse or promote products derived from
19 * this software without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
23 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
24 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
25 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
26 * INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
27 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION HOWEVER CAUSED AND ON
28 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 * INCLUDING NEGLIGENCE OR OTHERWISE ARISING IN ANY WAY OUT OF THE USE OF THIS
31 ****************************************************************************/
32
33 #include "context.h"
34
35 #include "tables.h"
36
37
38 static const uint8_t INIT_SAO_MERGE_FLAG[3] = { 153, 153, 153 };
39 static const uint8_t INIT_SAO_TYPE_IDX[3] = { 160, 185, 200 };
40
41 static const uint8_t INIT_QT_ROOT_CBF[3][1] = {
42 { 79, },
43 { 79, },
44 { CNU, },
45 };
46
47 static const uint8_t INIT_MVP_IDX[3][2] = {
48 { 168, CNU, },
49 { 168, CNU, },
50 { CNU, CNU, },
51 };
52
53 static const uint8_t INIT_REF_PIC[3][2] = {
54 { 153, 153 },
55 { 153, 153 },
56 { CNU, CNU },
57 };
58
59 static const uint8_t INIT_MVD[3][2] = {
60 { 169, 198, },
61 { 140, 198, },
62 { CNU, CNU, },
63 };
64
65 static const uint8_t INIT_MERGE_FLAG_EXT[3][1] = {
66 { 154, },
67 { 110, },
68 { CNU, },
69 };
70
71 static const uint8_t INIT_MERGE_IDX_EXT[3][1] = {
72 { 137, },
73 { 122, },
74 { CNU, },
75 };
76
77 static const uint8_t INIT_CU_TRANSQUANT_BYPASS[3][1] = {
78 { 154, },
79 { 154, },
80 { 154, },
81 };
82
83 static const uint8_t INIT_SKIP_FLAG[3][3] = {
84 { 197, 185, 201, },
85 { 197, 185, 201, },
86 { CNU, CNU, CNU, },
87 };
88
89 static const uint8_t INIT_PRED_MODE[3][1] = {
90 { 134, },
91 { 149, },
92 { CNU, },
93 };
94
95
96 static const uint8_t INIT_PART_SIZE[3][4] = {
97 { 154, 139, CNU, CNU, },
98 { 154, 139, CNU, CNU, },
99 { 184, CNU, CNU, CNU, },
100 };
101
102 static const uint8_t INIT_SPLIT_FLAG[3][3] = {
103 { 107, 139, 126 },
104 { 107, 139, 126 },
105 { 139, 141, 157 },
106 };
107
108 static const uint8_t INIT_INTRA_PRED_MODE[3] = {
109 183, 154, 184
110 };
111
112 static const uint8_t INIT_CHROMA_PRED_MODE[3][2] = {
113 { 152, 139 },
114 { 152, 139 },
115 { 63, 139 },
116 };
117
118 static const uint8_t INIT_INTER_DIR[3][5] = {
119 { 95, 79, 63, 31, 31, },
120 { 95, 79, 63, 31, 31, },
121 { CNU, CNU, CNU, CNU, CNU, },
122 };
123
124 static const uint8_t INIT_TRANS_SUBDIV_FLAG[3][3] = {
125 { 224, 167, 122 },
126 { 124, 138, 94 },
127 { 153, 138, 138 },
128 };
129
130 static const uint8_t INIT_QT_CBF[3][8] = {
131 { 153, 111, CNU, CNU, 149, 92, 167, 154 },
132 { 153, 111, CNU, CNU, 149, 107, 167, 154 },
133 { 111, 141, CNU, CNU, 94, 138, 182, 154 },
134 };
135
136 static const uint8_t INIT_CU_QP_DELTA_ABS[3][2] = {
137 { 154, 154 },
138 { 154, 154 },
139 { 154, 154 },
140 };
141
142 static const uint8_t INIT_SIG_CG_FLAG[3][4] = {
143 { 121, 140, 61, 154 },
144 { 121, 140, 61, 154 },
145 { 91, 171, 134, 141 },
146 };
147
148 static const uint8_t INIT_SIG_FLAG[3][42] = {
149 {170,154,139,153,139,123,123, 63,124,166,
150 183,140,136,153,154,166,183,140,136,153,
151 154,166,183,140,136,153,154,170,153,138,
152 138,122,121,122,121,167,151,183,140,151,
153 183,140},
154 {155,154,139,153,139,123,123,63,153,166,
155 183,140,136,153,154,166,183,140,136,153,
156 154,166,183,140,136,153,154,170,153,123,
157 123,107,121,107,121,167,151,183,140,151,
158 183,140},
159 {111,111,125,110,110,94,124,108,124,107,
160 125,141,179,153,125,107,125,141,179,153,
161 125,107,125,141,179,153,125,140,139,182,
162 182,152,136,152,136,153,136,139,111,136,
163 139,111},
164 };
165
166 static const uint8_t INIT_LAST[3][30] = {
167 { 125, 110, 124, 110, 95, 94, 125, 111, 111, 79, 125, 126, 111, 111, 79,
168 108, 123, 93, CNU, CNU, CNU, CNU, CNU, CNU, CNU, CNU, CNU, CNU, CNU, CNU },
169 { 125, 110, 94, 110, 95, 79, 125, 111, 110, 78, 110, 111, 111, 95, 94,
170 108, 123, 108, CNU, CNU, CNU, CNU, CNU, CNU, CNU, CNU, CNU, CNU, CNU, CNU },
171 { 110, 110, 124, 125, 140, 153, 125, 127, 140, 109, 111, 143, 127, 111, 79,
172 108, 123, 63, CNU, CNU, CNU, CNU, CNU, CNU, CNU, CNU, CNU, CNU, CNU, CNU },
173 };
174
175 static const uint8_t INIT_ONE_FLAG[3][24] =
176 {
177 {154,196,167,167,154,152,167,182,182,134,149,136,153,121,136,122,169,208,166,167,154,152,167,182},
178 {154,196,196,167,154,152,167,182,182,134,149,136,153,121,136,137,169,194,166,167,154,167,137,182},
179 {140, 92,137,138,140,152,138,139,153, 74,149, 92,139,107,122,152,140,179,166,182,140,227,122,197},
180 };
181
182 static const uint8_t INIT_ABS_FLAG[3][6] =
183 {
184 { 107,167, 91,107,107,167},
185 { 107,167, 91,122,107,167},
186 { 138,153,136,167,152,152},
187 };
188
189 static const uint8_t INIT_TRANSFORMSKIP_FLAG[3][2] =
190 {
191 { 139, 139},
192 { 139, 139},
193 { 139, 139},
194 };
195
196
197
198
199 /**
200 * \brief Initialize struct cabac_ctx.
201 */
kvz_ctx_init(cabac_ctx_t * ctx,uint32_t qp,uint32_t init_value)202 void kvz_ctx_init(cabac_ctx_t *ctx, uint32_t qp, uint32_t init_value)
203 {
204 int slope = (init_value >> 4) * 5 - 45;
205 int offset = ((init_value & 15) << 3) - 16;
206 int init_state = MIN(MAX(1, ((slope * (int)qp) >> 4) + offset), 126);
207
208 if (init_state >= 64) {
209 ctx->uc_state = ((init_state - 64) << 1) + 1;
210 } else {
211 ctx->uc_state = (63 - init_state) << 1;
212 }
213 }
214
215 /**
216 * \brief Initialize cabac context to be used for coding
217 * \param encoder encoder control struct
218 * \param slice type of slice we are coding (P/B/I)
219 */
220
kvz_init_contexts(encoder_state_t * state,int8_t QP,int8_t slice)221 void kvz_init_contexts(encoder_state_t *state, int8_t QP, int8_t slice)
222 {
223 cabac_data_t * const cabac = &state->cabac;
224 uint16_t i;
225
226 // Initialize contexts
227 kvz_ctx_init(&cabac->ctx.transform_skip_model_luma, QP, INIT_TRANSFORMSKIP_FLAG[slice][0]);
228 kvz_ctx_init(&cabac->ctx.transform_skip_model_chroma, QP, INIT_TRANSFORMSKIP_FLAG[slice][1]);
229
230 kvz_ctx_init(&cabac->ctx.sao_merge_flag_model, QP, INIT_SAO_MERGE_FLAG[slice]);
231 kvz_ctx_init(&cabac->ctx.sao_type_idx_model, QP, INIT_SAO_TYPE_IDX[slice]);
232
233 kvz_ctx_init(&cabac->ctx.cu_merge_flag_ext_model, QP, INIT_MERGE_FLAG_EXT[slice][0]);
234 kvz_ctx_init(&cabac->ctx.cu_merge_idx_ext_model, QP, INIT_MERGE_IDX_EXT[slice][0]);
235 kvz_ctx_init(&cabac->ctx.cu_pred_mode_model, QP, INIT_PRED_MODE[slice][0]);
236 kvz_ctx_init(&cabac->ctx.cu_transquant_bypass, QP, INIT_CU_TRANSQUANT_BYPASS[slice][0]);
237
238 kvz_ctx_init(&cabac->ctx.cu_skip_flag_model[0], QP, INIT_SKIP_FLAG[slice][0]);
239 kvz_ctx_init(&cabac->ctx.cu_skip_flag_model[1], QP, INIT_SKIP_FLAG[slice][1]);
240 kvz_ctx_init(&cabac->ctx.cu_skip_flag_model[2], QP, INIT_SKIP_FLAG[slice][2]);
241
242 kvz_ctx_init(&cabac->ctx.split_flag_model[0], QP, INIT_SPLIT_FLAG[slice][0]);
243 kvz_ctx_init(&cabac->ctx.split_flag_model[1], QP, INIT_SPLIT_FLAG[slice][1]);
244 kvz_ctx_init(&cabac->ctx.split_flag_model[2], QP, INIT_SPLIT_FLAG[slice][2]);
245
246 kvz_ctx_init(&cabac->ctx.intra_mode_model, QP, INIT_INTRA_PRED_MODE[slice]);
247
248 kvz_ctx_init(&cabac->ctx.chroma_pred_model[0], QP, INIT_CHROMA_PRED_MODE[slice][0]);
249 kvz_ctx_init(&cabac->ctx.chroma_pred_model[1], QP, INIT_CHROMA_PRED_MODE[slice][1]);
250
251 kvz_ctx_init(&cabac->ctx.cu_abs_model_chroma[0], QP, INIT_ABS_FLAG[slice][4]);
252 kvz_ctx_init(&cabac->ctx.cu_abs_model_chroma[1], QP, INIT_ABS_FLAG[slice][5]);
253
254 //TODO: ignore P/B contexts on intra frame
255 kvz_ctx_init(&cabac->ctx.cu_qt_root_cbf_model, QP, INIT_QT_ROOT_CBF[slice][0]);
256
257 kvz_ctx_init(&cabac->ctx.cu_mvd_model[0], QP, INIT_MVD[slice][0]);
258 kvz_ctx_init(&cabac->ctx.cu_mvd_model[1], QP, INIT_MVD[slice][1]);
259 kvz_ctx_init(&cabac->ctx.cu_ref_pic_model[0], QP, INIT_REF_PIC[slice][0]);
260 kvz_ctx_init(&cabac->ctx.cu_ref_pic_model[1], QP, INIT_REF_PIC[slice][1]);
261 kvz_ctx_init(&cabac->ctx.mvp_idx_model[0], QP, INIT_MVP_IDX[slice][0]);
262 kvz_ctx_init(&cabac->ctx.mvp_idx_model[1], QP, INIT_MVP_IDX[slice][1]);
263
264 kvz_ctx_init(&cabac->ctx.cu_qp_delta_abs[0], QP, INIT_CU_QP_DELTA_ABS[slice][0]);
265 kvz_ctx_init(&cabac->ctx.cu_qp_delta_abs[1], QP, INIT_CU_QP_DELTA_ABS[slice][1]);
266
267 for (i = 0; i < 4; i++) {
268 kvz_ctx_init(&cabac->ctx.cu_sig_coeff_group_model[i], QP, INIT_SIG_CG_FLAG[slice][i]);
269 kvz_ctx_init(&cabac->ctx.cu_abs_model_luma[i], QP, INIT_ABS_FLAG[slice][i]);
270 kvz_ctx_init(&cabac->ctx.part_size_model[i], QP, INIT_PART_SIZE[slice][i]);
271 }
272 for (i = 0; i < 3; i++) {
273 kvz_ctx_init(&cabac->ctx.trans_subdiv_model[i], QP, INIT_TRANS_SUBDIV_FLAG[slice][i]);
274 }
275 for (i = 0; i < 4; i++) {
276 kvz_ctx_init(&cabac->ctx.qt_cbf_model_luma[i], QP, INIT_QT_CBF[slice][i]);
277 kvz_ctx_init(&cabac->ctx.qt_cbf_model_chroma[i], QP, INIT_QT_CBF[slice][i + 4]);
278 }
279
280 for (i = 0; i < 5; i++) {
281 kvz_ctx_init(&cabac->ctx.inter_dir[i], QP, INIT_INTER_DIR[slice][i]);
282 }
283
284 for (i = 0; i < 8; i++) {
285 kvz_ctx_init(&cabac->ctx.cu_one_model_chroma[i], QP, INIT_ONE_FLAG[slice][i+16]);
286 }
287
288 for (i = 0; i < 15; i++) {
289 kvz_ctx_init(&cabac->ctx.cu_ctx_last_y_luma[i], QP, INIT_LAST[slice][i] );
290 kvz_ctx_init(&cabac->ctx.cu_ctx_last_x_luma[i], QP, INIT_LAST[slice][i] );
291
292 kvz_ctx_init(&cabac->ctx.cu_ctx_last_y_chroma[i], QP, INIT_LAST[slice][i+15] );
293 kvz_ctx_init(&cabac->ctx.cu_ctx_last_x_chroma[i], QP, INIT_LAST[slice][i+15] );
294
295 kvz_ctx_init(&cabac->ctx.cu_one_model_luma[i], QP, INIT_ONE_FLAG[slice][i]);
296 }
297 kvz_ctx_init(&cabac->ctx.cu_one_model_luma[15], QP, INIT_ONE_FLAG[slice][15]);
298
299 for (i = 0; i < 27; i++) {
300 kvz_ctx_init(&cabac->ctx.cu_sig_model_luma[i], QP, INIT_SIG_FLAG[slice][i]);
301 if(i < 15) kvz_ctx_init(&cabac->ctx.cu_sig_model_chroma[i], QP, INIT_SIG_FLAG[slice][i+27]);
302 }
303 }
304
kvz_context_copy(encoder_state_t * const target_state,const encoder_state_t * const source_state)305 void kvz_context_copy(encoder_state_t * const target_state, const encoder_state_t * const source_state) {
306 cabac_data_t * const target_cabac = &target_state->cabac;
307 const cabac_data_t * const source_cabac = &source_state->cabac;
308
309 if (target_cabac == source_cabac) return;
310
311 target_cabac->ctx = source_cabac->ctx;
312 }
313
314
kvz_context_get_sig_coeff_group(uint32_t * sig_coeff_group_flag,uint32_t pos_x,uint32_t pos_y,int32_t width)315 uint32_t kvz_context_get_sig_coeff_group( uint32_t *sig_coeff_group_flag,
316 uint32_t pos_x,
317 uint32_t pos_y,
318 int32_t width)
319 {
320 uint32_t uiRight = 0;
321 uint32_t uiLower = 0;
322 width >>= 2;
323 if (pos_x < (uint32_t)width - 1) uiRight = (sig_coeff_group_flag[pos_y * width + pos_x + 1] != 0);
324 if (pos_y < (uint32_t)width - 1) uiLower = (sig_coeff_group_flag[(pos_y + 1 ) * width + pos_x] != 0);
325
326 return uiRight || uiLower;
327 }
328
329
330 /**
331 * \brief Pattern decision for context derivation process of significant_coeff_flag
332 * \param sig_coeff_group_flag pointer to prior coded significant coeff group
333 * \param pos_x column of current coefficient group
334 * \param pos_y row of current coefficient group
335 * \param width width of the block
336 * \returns pattern for current coefficient group
337 */
338
kvz_context_calc_pattern_sig_ctx(const uint32_t * sig_coeff_group_flag,uint32_t pos_x,uint32_t pos_y,int32_t width)339 int32_t kvz_context_calc_pattern_sig_ctx(const uint32_t *sig_coeff_group_flag, uint32_t pos_x, uint32_t pos_y, int32_t width)
340 {
341 uint32_t sigRight = 0;
342 uint32_t sigLower = 0;
343
344 if (width == 4) return -1;
345
346 width >>= 2;
347 if (pos_x < (uint32_t)width - 1) sigRight = (sig_coeff_group_flag[pos_y * width + pos_x + 1] != 0);
348 if (pos_y < (uint32_t)width - 1) sigLower = (sig_coeff_group_flag[(pos_y + 1 ) * width + pos_x] != 0);
349
350 return sigRight + (sigLower<<1);
351 }
352
353
354 /**
355 * \brief Context derivation process of coeff_abs_significant_flag
356 * \param pattern_sig_ctx pattern for current coefficient group
357 * \param scan_idx pixel scan type in use
358 * \param pos_x column of current scan position
359 * \param pos_y row of current scan position
360 * \param block_type log2 value of block size if square block, or 4 otherwise
361 * \param width width of the block
362 * \param texture_type texture type (TEXT_LUMA...)
363 * \returns ctx_inc for current scan position
364 */
365
kvz_context_get_sig_ctx_inc(int32_t pattern_sig_ctx,uint32_t scan_idx,int32_t pos_x,int32_t pos_y,int32_t block_type,int8_t texture_type)366 int32_t kvz_context_get_sig_ctx_inc(int32_t pattern_sig_ctx, uint32_t scan_idx, int32_t pos_x,
367 int32_t pos_y, int32_t block_type, int8_t texture_type)
368 {
369 const int32_t ctx_ind_map[16] =
370 {
371 0, 1, 4, 5,
372 2, 3, 4, 5,
373 6, 6, 8, 8,
374 7, 7, 8, 8
375 };
376
377 int32_t cnt,offset,pos_x_in_subset,pos_y_in_subset;
378
379 if (pos_x + pos_y == 0) return 0;
380
381 if (block_type == 2) return ctx_ind_map[4 * pos_y + pos_x];
382
383 offset = (block_type == 3) ? ((scan_idx == SCAN_DIAG) ? 9 : 15) : ((texture_type == 0) ? 21 : 12);
384 pos_x_in_subset = pos_x - ((pos_x>>2)<<2);
385 pos_y_in_subset = pos_y - ((pos_y>>2)<<2);
386
387 if (pattern_sig_ctx == 0) {
388 cnt = (pos_x_in_subset + pos_y_in_subset <= 2) ? ((pos_x_in_subset + pos_y_in_subset==0) ? 2 : 1) : 0;
389 } else if (pattern_sig_ctx==1) {
390 cnt = (pos_y_in_subset <= 1) ? ((pos_y_in_subset == 0) ? 2 : 1) : 0;
391 } else if (pattern_sig_ctx==2) {
392 cnt = (pos_x_in_subset <= 1) ? ((pos_x_in_subset == 0) ? 2 : 1) : 0;
393 } else {
394 cnt = 2;
395 }
396 return (( texture_type == 0 && ((pos_x>>2) + (pos_y>>2)) > 0 ) ? 3 : 0) + offset + cnt;
397 }
398