1 /*
2 * Copyright (c) 2020, 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 /*!\file
13 * \brief Declares high level functions to search through intra modes.
14 */
15 #ifndef AOM_AV1_ENCODER_INTRA_MODE_SEARCH_H_
16 #define AOM_AV1_ENCODER_INTRA_MODE_SEARCH_H_
17
18 #include "av1/encoder/encoder.h"
19
20 #ifdef __cplusplus
21 extern "C" {
22 #endif
23
24 /*! \brief Variables related to intra-mode search during inter frame coding.
25 *
26 * \ingroup intra_mode_search
27 * This is a set of variables used during intra-mode search for inter frames.
28 * This includes an histogram of gradient speed features and a cache of uv
29 * prediction to avoid repeated search of chroma prediction.
30 */
31 typedef struct IntraModeSearchState {
32 /*!
33 * \brief The best luma intra-mode found so far
34 */
35 PREDICTION_MODE best_intra_mode;
36
37 /** \name Speed feature variables
38 * Variables to help with pruning some luma intra-modes during inter frame
39 * coding process.
40 */
41 /**@{*/
42 /*!
43 * \brief Whether to terminate all intra mode search.
44 */
45 int skip_intra_modes;
46 /*!
47 * \brief Whether a directional mode is pruned.
48 */
49 uint8_t directional_mode_skip_mask[INTRA_MODES];
50 /*!
51 * \brief Whether \ref directional_mode_skip_mask is valid for pruning.
52 */
53 int dir_mode_skip_mask_ready;
54 /**@}*/
55
56 /** \name Chroma mode search cache
57 * A cache of the best chroma prediction mode to avoid having to search for
58 * chroma predictions repeatedly in \ref
59 * av1_search_intra_uv_modes_in_interframe()
60 */
61 /**@{*/
62 int rate_uv_intra; /*!< \brief Total rate to transmit uv_mode */
63 int rate_uv_tokenonly; /*!< \brief Rate transmit txfm tokens */
64 int64_t dist_uvs; /*!< \brief Distortion of the uv_mode's recon */
65 int skip_uvs; /*!< \brief Whether the uv txfm is skippable */
66 UV_PREDICTION_MODE mode_uv; /*!< \brief The best uv mode */
67 PALETTE_MODE_INFO pmi_uv; /*!< \brief Color map if mode_uv is palette */
68 int8_t uv_angle_delta; /*!< \brief Angle delta if mode_uv directional */
69 /**@}*/
70 } IntraModeSearchState;
71
72 /*!\brief Evaluate a given luma intra-mode for inter frames.
73 *
74 * \ingroup intra_mode_search
75 * \callgraph
76 * \callergraph
77 * This function handles an intra-mode luma prediction when the current frame
78 * is an inter frame. This is the intra-mode counterpart of handle_inter_mode.
79 * This function performs an intra luma prediction using the mode specified by
80 * x->e_mbd.mi[0]->mode. This function does *not* support palette mode
81 * prediction in the luma channel.
82 *
83 * \param[in,out] intra_search_state Structure to intra search state.
84 * \param[in] cpi Top-level encoder structure.
85 * \param[in,out] x Pointer to structure holding all the
86 * data for the current macroblock.
87 * \param[in] bsize Current partition block size.
88 * \param[in] ref_frame_cost The entropy cost for signaling that the
89 * current ref frame is an intra frame.
90 * \param[in] ctx Structure to hold the number of 4x4 blks
91 * to copy tx_type and txfm_skip arrays.
92 * \param[out] rd_stats_y Struct to keep track of the current
93 * intra-mode's rd_stats (luma only).
94 * \param[in] best_rd Best RD seen for this block so far.
95 * \param[out] mode_cost_y The cost needed to signal the current
96 * intra mode.
97 * \param[out] rd_y The rdcost of the chosen mode.
98 * \param[in] best_model_rd Best model RD seen for this block so far
99 * \param[in] top_intra_model_rd Top intra model RD seen for this
100 * block so far.
101 *
102 * \return Returns 1 if a valid intra mode is found, 0 otherwise.
103 * The corresponding values in x->e_mbd.mi[0], rd_stats_y, mode_cost_y, and
104 * rd_y are also updated. Moreover, in the first evaluation with directional
105 * mode, a prune_mask computed with histogram of gradient is also stored in
106 * intra_search_state.
107 */
108 int av1_handle_intra_y_mode(IntraModeSearchState *intra_search_state,
109 const AV1_COMP *cpi, MACROBLOCK *x,
110 BLOCK_SIZE bsize, unsigned int ref_frame_cost,
111 const PICK_MODE_CONTEXT *ctx, RD_STATS *rd_stats_y,
112 int64_t best_rd, int *mode_cost_y, int64_t *rd_y,
113 int64_t *best_model_rd,
114 int64_t top_intra_model_rd[]);
115
116 /*!\brief Search through all chroma intra-modes for inter frames.
117 *
118 * \ingroup intra_mode_search
119 * \callgraph
120 * \callergraph
121 * This function handles intra-mode chroma prediction when the current frame
122 * is an inter frame. This is done by calling \ref av1_rd_pick_intra_sbuv_mode
123 * with some additional book-keeping.
124 *
125 * \param[in,out] intra_search_state Structure to intra search state.
126 * \param[in] cpi Top-level encoder structure.
127 * \param[in,out] x Pointer to structure holding all the
128 * data for the current macroblock.
129 * \param[in] bsize Current partition block size.
130 * \param[out] rd_stats Struct to keep track of the current
131 * intra-mode's rd_stats (all planes).
132 * \param[out] rd_stats_y Struct to keep track of the current
133 * intra-mode's rd_stats (luma only).
134 * \param[out] rd_stats_uv Struct to keep track of the current
135 * intra-mode's rd_stats (chroma only).
136 * \param[in] best_rd Best RD seen for this block so far.
137 *
138 * \return Returns 1 if a valid intra mode is found, 0 otherwise.
139 * The corresponding values in x->e_mbd.mi[0], rd_stats(_y|_uv) are also
140 * updated. Moreover, in the first evocation of the function, the chroma intra
141 * mode result is cached in intra_search_state to be used in subsequent calls.
142 */
143 int av1_search_intra_uv_modes_in_interframe(
144 IntraModeSearchState *intra_search_state, const AV1_COMP *cpi,
145 MACROBLOCK *x, BLOCK_SIZE bsize, RD_STATS *rd_stats,
146 const RD_STATS *rd_stats_y, RD_STATS *rd_stats_uv, int64_t best_rd);
147
148 /*!\brief Evaluate luma palette mode for inter frames.
149 *
150 * \ingroup intra_mode_search
151 * \callergraph
152 * \callgraph
153 * This function handles luma palette mode when the current frame is an
154 * inter frame.
155 *
156 * \param[in] intra_search_state Structure to hold the best luma intra mode
157 * and cache chroma prediction for speed up.
158 * \param[in] cpi Top-level encoder structure.
159 * \param[in] x Pointer to structure holding all the data
160 * for the current macroblock.
161 * \param[in] bsize Current partition block size.
162 * \param[in] ref_frame_cost The entropy cost for signaling that the
163 * current ref frame is an intra frame.
164 * \param[in] ctx Structure to hold the number of 4x4 blks to
165 * copy the tx_type and txfm_skip arrays.
166 * \param[in] this_rd_cost Struct to keep track of palette mode's
167 * rd_stats.
168 * \param[in] best_rd Best RD seen for this block so far.
169 *
170 * \return Returns whether luma palette mode can skip the txfm. The
171 * corresponding mbmi, this_rd_costs, intra_search_state, and tx_type arrays in
172 * ctx are also updated.
173 */
174 int av1_search_palette_mode(IntraModeSearchState *intra_search_state,
175 const AV1_COMP *cpi, MACROBLOCK *x,
176 BLOCK_SIZE bsize, unsigned int ref_frame_cost,
177 PICK_MODE_CONTEXT *ctx, RD_STATS *this_rd_cost,
178 int64_t best_rd);
179
180 /*!\brief Perform intra-mode search on luma channels for intra frames.
181 *
182 * \ingroup intra_mode_search
183 * \callgraph
184 * \callergraph
185 * This function performs intra-mode search on the luma channel when the
186 * current frame is intra-only. This function does not search intrabc mode,
187 * but it does search palette and filter_intra.
188 *
189 * \param[in] cpi Top-level encoder structure.
190 * \param[in] x Pointer to structure holding all the data
191 * for the current macroblock.
192 * \param[in] rate The total rate needed to predict the current
193 * chroma block.
194 * \param[in] rate_tokenonly The rate without the cost of sending the
195 * prediction modes.
196 * chroma block.
197 * after the reconstruction.
198 * \param[in] distortion The chroma distortion of the best prediction
199 * after the reconstruction.
200 * \param[in] skippable Whether we can skip txfm process.
201 * \param[in] bsize Current partition block size.
202 * \param[in] best_rd Best RD seen for this block so far.
203 * \param[in] ctx Structure to hold the number of 4x4 blks to
204 * copy the tx_type and txfm_skip arrays.
205 *
206 * \return Returns the rd_cost if this function finds a mode better than
207 * best_rd, otherwise returns INT64_MAX. This also updates the mbmi, the rate
208 * and distortion, and the tx_type arrays in ctx.
209 */
210 int64_t av1_rd_pick_intra_sby_mode(const AV1_COMP *const cpi, MACROBLOCK *x,
211 int *rate, int *rate_tokenonly,
212 int64_t *distortion, int *skippable,
213 BLOCK_SIZE bsize, int64_t best_rd,
214 PICK_MODE_CONTEXT *ctx);
215
216 /*!\brief Perform intra-mode search on chroma channels.
217 *
218 * \ingroup intra_mode_search
219 * \callergraph
220 * \callgraph
221 * This function performs intra-mode search on the chroma channels. Just like
222 * \ref av1_rd_pick_intra_sby_mode(), this function searches over palette mode
223 * (filter_intra is not available on chroma planes). Unlike \ref
224 * av1_rd_pick_intra_sby_mode() this function is used by both inter and intra
225 * frames.
226 *
227 * \param[in] cpi Top-level encoder structure.
228 * \param[in] x Pointer to structure holding all the data
229 * for the current macroblock.
230 * \param[in] rate The total rate needed to predict the current
231 * chroma block.
232 * \param[in] rate_tokenonly The rate without the cost of sending the
233 * prediction modes.
234 * chroma block.
235 * after the reconstruction.
236 * \param[in] distortion The chroma distortion of the best prediction
237 * after the reconstruction.
238 * \param[in] skippable Whether we can skip txfm process.
239 * \param[in] bsize Current partition block size.
240 * \param[in] max_tx_size The maximum tx_size available
241 *
242 * \return Returns the rd_cost of the best uv mode found. This also updates the
243 * mbmi, the rate and distortion, distortion.
244 */
245 int64_t av1_rd_pick_intra_sbuv_mode(const AV1_COMP *const cpi, MACROBLOCK *x,
246 int *rate, int *rate_tokenonly,
247 int64_t *distortion, int *skippable,
248 BLOCK_SIZE bsize, TX_SIZE max_tx_size);
249
250 /*! \brief Return the number of colors in src. Used by palette mode.
251 */
252 void av1_count_colors(const uint8_t *src, int stride, int rows, int cols,
253 int *val_count, int *num_colors);
254
255 /*! \brief See \ref av1_count_colors(), but for highbd.
256 */
257 void av1_count_colors_highbd(const uint8_t *src8, int stride, int rows,
258 int cols, int bit_depth, int *val_count,
259 int *val_count_8bit, int *num_color_bins,
260 int *num_colors);
261
262 /*! \brief Initializes the \ref IntraModeSearchState struct.
263 */
init_intra_mode_search_state(IntraModeSearchState * intra_search_state)264 static AOM_INLINE void init_intra_mode_search_state(
265 IntraModeSearchState *intra_search_state) {
266 memset(intra_search_state, 0, sizeof(*intra_search_state));
267 intra_search_state->rate_uv_intra = INT_MAX;
268 }
269
270 /*! \brief set the luma intra mode and delta angles for a given mode index.
271 * The total number of luma intra mode is LUMA_MODE_COUNT = 61.
272 * The first 13 modes are from DC_PRED to PAETH_PRED, followed by directional
273 * modes. Each of the main 8 directional modes have 6 = MAX_ANGLE_DELTA * 2
274 * delta angles.
275 * \param[in] mode_idx mode index in intra mode decision
276 * process.
277 * \param[in] mbmi Pointer to structure holding
278 * the mode info for the current macroblock.
279 */
280 void set_y_mode_and_delta_angle(const int mode_idx, MB_MODE_INFO *const mbmi);
281
282 /*! \brief prune luma intra mode based on the model rd.
283 * \param[in] this_model_rd model rd for current mode.
284 * \param[in] best_model_rd Best model RD seen for this block so
285 * far.
286 * \param[in] top_intra_model_rd Top intra model RD seen for this
287 * block so far.
288 * \param[in] model_cnt_allowed The number of top intra model RD allowed.
289 */
290 int prune_intra_y_mode(int64_t this_model_rd, int64_t *best_model_rd,
291 int64_t top_intra_model_rd[], int model_cnt_allowed);
292
293 #ifdef __cplusplus
294 } // extern "C"
295 #endif
296
297 #endif // AOM_AV1_ENCODER_INTRA_MODE_SEARCH_H_
298