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1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
6  * License as published by the Free Software Foundation; either
7  * version 2.1 of the License, or (at your option) any later version.
8  *
9  * FFmpeg is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12  * Lesser General Public License for more details.
13  *
14  * You should have received a copy of the GNU Lesser General Public
15  * License along with FFmpeg; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 
19 #ifndef AVUTIL_FILM_GRAIN_PARAMS_H
20 #define AVUTIL_FILM_GRAIN_PARAMS_H
21 
22 #include "frame.h"
23 
24 enum AVFilmGrainParamsType {
25     AV_FILM_GRAIN_PARAMS_NONE = 0,
26 
27     /**
28      * The union is valid when interpreted as AVFilmGrainAOMParams (codec.aom)
29      */
30     AV_FILM_GRAIN_PARAMS_AV1,
31 
32     /**
33      * The union is valid when interpreted as AVFilmGrainH274Params (codec.h274)
34      */
35     AV_FILM_GRAIN_PARAMS_H274,
36 };
37 
38 /**
39  * This structure describes how to handle film grain synthesis for AOM codecs.
40  *
41  * @note The struct must be allocated as part of AVFilmGrainParams using
42  *       av_film_grain_params_alloc(). Its size is not a part of the public ABI.
43  */
44 typedef struct AVFilmGrainAOMParams {
45     /**
46      * Number of points, and the scale and value for each point of the
47      * piecewise linear scaling function for the uma plane.
48      */
49     int num_y_points;
50     uint8_t y_points[14][2 /* value, scaling */];
51 
52     /**
53      * Signals whether to derive the chroma scaling function from the luma.
54      * Not equivalent to copying the luma values and scales.
55      */
56     int chroma_scaling_from_luma;
57 
58     /**
59      * If chroma_scaling_from_luma is set to 0, signals the chroma scaling
60      * function parameters.
61      */
62     int num_uv_points[2 /* cb, cr */];
63     uint8_t uv_points[2 /* cb, cr */][10][2 /* value, scaling */];
64 
65     /**
66      * Specifies the shift applied to the chroma components. For AV1, its within
67      * [8; 11] and determines the range and quantization of the film grain.
68      */
69     int scaling_shift;
70 
71     /**
72      * Specifies the auto-regression lag.
73      */
74     int ar_coeff_lag;
75 
76     /**
77      * Luma auto-regression coefficients. The number of coefficients is given by
78      * 2 * ar_coeff_lag * (ar_coeff_lag + 1).
79      */
80     int8_t ar_coeffs_y[24];
81 
82     /**
83      * Chroma auto-regression coefficients. The number of coefficients is given by
84      * 2 * ar_coeff_lag * (ar_coeff_lag + 1) + !!num_y_points.
85      */
86     int8_t ar_coeffs_uv[2 /* cb, cr */][25];
87 
88     /**
89      * Specifies the range of the auto-regressive coefficients. Values of 6,
90      * 7, 8 and so on represent a range of [-2, 2), [-1, 1), [-0.5, 0.5) and
91      * so on. For AV1 must be between 6 and 9.
92      */
93     int ar_coeff_shift;
94 
95     /**
96      * Signals the down shift applied to the generated gaussian numbers during
97      * synthesis.
98      */
99     int grain_scale_shift;
100 
101     /**
102      * Specifies the luma/chroma multipliers for the index to the component
103      * scaling function.
104      */
105     int uv_mult[2 /* cb, cr */];
106     int uv_mult_luma[2 /* cb, cr */];
107 
108     /**
109      * Offset used for component scaling function. For AV1 its a 9-bit value
110      * with a range [-256, 255]
111      */
112     int uv_offset[2 /* cb, cr */];
113 
114     /**
115      * Signals whether to overlap film grain blocks.
116      */
117     int overlap_flag;
118 
119     /**
120      * Signals to clip to limited color levels after film grain application.
121      */
122     int limit_output_range;
123 } AVFilmGrainAOMParams;
124 
125 /**
126  * This structure describes how to handle film grain synthesis for codecs using
127  * the ITU-T H.274 Versatile suplemental enhancement information message.
128  *
129  * @note The struct must be allocated as part of AVFilmGrainParams using
130  *       av_film_grain_params_alloc(). Its size is not a part of the public ABI.
131  */
132 typedef struct AVFilmGrainH274Params {
133     /**
134      * Specifies the film grain simulation mode.
135      * 0 = Frequency filtering, 1 = Auto-regression
136      */
137     int model_id;
138 
139     /**
140      * Specifies the bit depth used for the luma component.
141      */
142     int bit_depth_luma;
143 
144     /**
145      * Specifies the bit depth used for the chroma components.
146      */
147     int bit_depth_chroma;
148 
149     enum AVColorRange                  color_range;
150     enum AVColorPrimaries              color_primaries;
151     enum AVColorTransferCharacteristic color_trc;
152     enum AVColorSpace                  color_space;
153 
154     /**
155      * Specifies the blending mode used to blend the simulated film grain
156      * with the decoded images.
157      *
158      * 0 = Additive, 1 = Multiplicative
159      */
160     int blending_mode_id;
161 
162     /**
163      * Specifies a scale factor used in the film grain characterization equations.
164      */
165     int log2_scale_factor;
166 
167     /**
168      * Indicates if the modelling of film grain for a given component is present.
169      */
170     int component_model_present[3 /* y, cb, cr */];
171 
172     /**
173      * Specifies the number of intensity intervals for which a specific set of
174      * model values has been estimated, with a range of [1, 256].
175      */
176     uint16_t num_intensity_intervals[3 /* y, cb, cr */];
177 
178     /**
179      * Specifies the number of model values present for each intensity interval
180      * in which the film grain has been modelled, with a range of [1, 6].
181      */
182     uint8_t num_model_values[3 /* y, cb, cr */];
183 
184     /**
185      * Specifies the lower ounds of each intensity interval for whichthe set of
186      * model values applies for the component.
187      */
188     uint8_t intensity_interval_lower_bound[3 /* y, cb, cr */][256 /* intensity interval */];
189 
190     /**
191      * Specifies the upper bound of each intensity interval for which the set of
192      * model values applies for the component.
193      */
194     uint8_t intensity_interval_upper_bound[3 /* y, cb, cr */][256 /* intensity interval */];
195 
196     /**
197      * Specifies the model values for the component for each intensity interval.
198      * - When model_id == 0, the following applies:
199      *     For comp_model_value[y], the range of values is [0, 2^bit_depth_luma - 1]
200      *     For comp_model_value[cb..cr], the range of values is [0, 2^bit_depth_chroma - 1]
201      * - Otherwise, the following applies:
202      *     For comp_model_value[y], the range of values is [-2^(bit_depth_luma - 1), 2^(bit_depth_luma - 1) - 1]
203      *     For comp_model_value[cb..cr], the range of values is [-2^(bit_depth_chroma - 1), 2^(bit_depth_chroma - 1) - 1]
204      */
205     int16_t comp_model_value[3 /* y, cb, cr */][256 /* intensity interval */][6 /* model value */];
206 } AVFilmGrainH274Params;
207 
208 /**
209  * This structure describes how to handle film grain synthesis in video
210  * for specific codecs. Must be present on every frame where film grain is
211  * meant to be synthesised for correct presentation.
212  *
213  * @note The struct must be allocated with av_film_grain_params_alloc() and
214  *       its size is not a part of the public ABI.
215  */
216 typedef struct AVFilmGrainParams {
217     /**
218      * Specifies the codec for which this structure is valid.
219      */
220     enum AVFilmGrainParamsType type;
221 
222     /**
223      * Seed to use for the synthesis process, if the codec allows for it.
224      *
225      * @note For H.264, this refers to `pic_offset` as defined in
226      *       SMPTE RDD 5-2006.
227      */
228     uint64_t seed;
229 
230     /**
231      * Additional fields may be added both here and in any structure included.
232      * If a codec's film grain structure differs slightly over another
233      * codec's, fields within may change meaning depending on the type.
234      */
235     union {
236         AVFilmGrainAOMParams aom;
237         AVFilmGrainH274Params h274;
238     } codec;
239 } AVFilmGrainParams;
240 
241 /**
242  * Allocate an AVFilmGrainParams structure and set its fields to
243  * default values. The resulting struct can be freed using av_freep().
244  * If size is not NULL it will be set to the number of bytes allocated.
245  *
246  * @return An AVFilmGrainParams filled with default values or NULL
247  *         on failure.
248  */
249 AVFilmGrainParams *av_film_grain_params_alloc(size_t *size);
250 
251 /**
252  * Allocate a complete AVFilmGrainParams and add it to the frame.
253  *
254  * @param frame The frame which side data is added to.
255  *
256  * @return The AVFilmGrainParams structure to be filled by caller.
257  */
258 AVFilmGrainParams *av_film_grain_params_create_side_data(AVFrame *frame);
259 
260 #endif /* AVUTIL_FILM_GRAIN_PARAMS_H */
261