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_ENCODER_RATECTRL_H_
13 #define AOM_AV1_ENCODER_RATECTRL_H_
14 
15 #include "aom/aom_codec.h"
16 #include "aom/aom_integer.h"
17 
18 #include "av1/common/blockd.h"
19 
20 #ifdef __cplusplus
21 extern "C" {
22 #endif
23 
24 // Bits Per MB at different Q (Multiplied by 512)
25 #define BPER_MB_NORMBITS 9
26 
27 #define CUSTOMIZED_GF 1
28 
29 #if CONFIG_FIX_GF_LENGTH
30 #define FIXED_GF_LENGTH 16
31 #define MAX_PYRAMID_LVL 4
32 // We allow a frame to have at most two left/right descendants before changing
33 // them into to a subtree, i.e., we allow the following structure:
34 /*                    OUT_OF_ORDER_FRAME
35                      / /              \ \
36 (two left children) F F                F F (two right children) */
37 // Therefore the max gf size supported by 4 layer structure is
38 // 1 (KEY/OVERLAY) + 1 + 2 + 4 + 16 (two children on both side of their parent)
39 #define MAX_PYRAMID_SIZE 24
40 #define USE_SYMM_MULTI_LAYER 1
41 #define REDUCE_LAST_ALT_BOOST 1
42 #define REDUCE_LAST_GF_LENGTH 1
43 #define MULTI_LVL_BOOST_VBR_CQ 1
44 #else
45 #define USE_SYMM_MULTI_LAYER 0
46 #define REDUCE_LAST_ALT_BOOST 0
47 #define REDUCE_LAST_GF_LENGTH 0
48 #define MULTI_LVL_BOOST_VBR_CQ 0
49 #endif
50 
51 #if USE_SYMM_MULTI_LAYER
52 #define USE_MANUAL_GF4_STRUCT 0
53 #endif
54 
55 #define MIN_GF_INTERVAL 4
56 #define MAX_GF_INTERVAL 16
57 #define FIXED_GF_INTERVAL 8  // Used in some testing modes only
58 
59 typedef enum {
60   INTER_NORMAL = 0,
61   INTER_LOW = 1,
62   INTER_HIGH = 2,
63   GF_ARF_LOW = 3,
64   GF_ARF_STD = 4,
65   KF_STD = 5,
66   RATE_FACTOR_LEVELS = 6
67 } RATE_FACTOR_LEVEL;
68 
69 static const double rate_factor_deltas[RATE_FACTOR_LEVELS] = {
70   1.00,  // INTER_NORMAL
71   0.80,  // INTER_LOW
72   1.50,  // INTER_HIGH
73   1.25,  // GF_ARF_LOW
74   2.00,  // GF_ARF_STD
75   2.00,  // KF_STD
76 };
77 
78 typedef struct {
79   int resize_width;
80   int resize_height;
81   uint8_t superres_denom;
82 } size_params_type;
83 
84 typedef struct {
85   // Rate targetting variables
86   int base_frame_target;  // A baseline frame target before adjustment
87                           // for previous under or over shoot.
88   int this_frame_target;  // Actual frame target after rc adjustment.
89   int projected_frame_size;
90   int sb64_target_rate;
91   int last_q[FRAME_TYPES];  // Separate values for Intra/Inter
92   int last_boosted_qindex;  // Last boosted GF/KF/ARF q
93   int last_kf_qindex;       // Q index of the last key frame coded.
94 
95   int gfu_boost;
96   int last_boost;
97   int kf_boost;
98 
99   double rate_correction_factors[RATE_FACTOR_LEVELS];
100 
101   int frames_since_golden;
102   int frames_till_gf_update_due;
103   int min_gf_interval;
104   int max_gf_interval;
105   int static_scene_max_gf_interval;
106   int baseline_gf_interval;
107   int constrained_gf_group;
108   int frames_to_key;
109   int frames_since_key;
110   int this_key_frame_forced;
111   int next_key_frame_forced;
112   int source_alt_ref_pending;
113   int source_alt_ref_active;
114   int is_src_frame_alt_ref;
115   int sframe_due;
116 
117   // Length of the bi-predictive frame group interval
118   int bipred_group_interval;
119 
120   // NOTE: Different types of frames may have different bits allocated
121   //       accordingly, aiming to achieve the overall optimal RD performance.
122   int is_bwd_ref_frame;
123   int is_last_bipred_frame;
124   int is_bipred_frame;
125   int is_src_frame_ext_arf;
126 
127   int avg_frame_bandwidth;  // Average frame size target for clip
128   int min_frame_bandwidth;  // Minimum allocation used for any frame
129   int max_frame_bandwidth;  // Maximum burst rate allowed for a frame.
130 
131   int ni_av_qi;
132   int ni_tot_qi;
133   int ni_frames;
134   int avg_frame_qindex[FRAME_TYPES];
135   double tot_q;
136   double avg_q;
137 
138   int64_t buffer_level;
139   int64_t bits_off_target;
140   int64_t vbr_bits_off_target;
141   int64_t vbr_bits_off_target_fast;
142 
143   int decimation_factor;
144   int decimation_count;
145 
146   int rolling_target_bits;
147   int rolling_actual_bits;
148 
149   int long_rolling_target_bits;
150   int long_rolling_actual_bits;
151 
152   int rate_error_estimate;
153 
154   int64_t total_actual_bits;
155   int64_t total_target_bits;
156   int64_t total_target_vs_actual;
157 
158   int worst_quality;
159   int best_quality;
160 
161   int64_t starting_buffer_level;
162   int64_t optimal_buffer_level;
163   int64_t maximum_buffer_size;
164 
165   // rate control history for last frame(1) and the frame before(2).
166   // -1: undershot
167   //  1: overshoot
168   //  0: not initialized.
169   int rc_1_frame;
170   int rc_2_frame;
171   int q_1_frame;
172   int q_2_frame;
173 
174   // Auto frame-scaling variables.
175   int rf_level_maxq[RATE_FACTOR_LEVELS];
176   float arf_boost_factor;
177   // Q index used for ALT frame
178   int arf_q;
179 } RATE_CONTROL;
180 
181 struct AV1_COMP;
182 struct AV1EncoderConfig;
183 
184 void av1_rc_init(const struct AV1EncoderConfig *oxcf, int pass,
185                  RATE_CONTROL *rc);
186 
187 int av1_estimate_bits_at_q(FRAME_TYPE frame_kind, int q, int mbs,
188                            double correction_factor, aom_bit_depth_t bit_depth);
189 
190 double av1_convert_qindex_to_q(int qindex, aom_bit_depth_t bit_depth);
191 
192 void av1_rc_init_minq_luts(void);
193 
194 int av1_rc_get_default_min_gf_interval(int width, int height, double framerate);
195 // Note av1_rc_get_default_max_gf_interval() requires the min_gf_interval to
196 // be passed in to ensure that the max_gf_interval returned is at least as bis
197 // as that.
198 int av1_rc_get_default_max_gf_interval(double framerate, int min_frame_rate);
199 
200 // Generally at the high level, the following flow is expected
201 // to be enforced for rate control:
202 // First call per frame, one of:
203 //   av1_rc_get_one_pass_vbr_params()
204 //   av1_rc_get_one_pass_cbr_params()
205 //   av1_rc_get_first_pass_params()
206 //   av1_rc_get_second_pass_params()
207 // depending on the usage to set the rate control encode parameters desired.
208 //
209 // Then, call encode_frame_to_data_rate() to perform the
210 // actual encode. This function will in turn call encode_frame()
211 // one or more times, followed by one of:
212 //   av1_rc_postencode_update()
213 //   av1_rc_postencode_update_drop_frame()
214 //
215 // The majority of rate control parameters are only expected
216 // to be set in the av1_rc_get_..._params() functions and
217 // updated during the av1_rc_postencode_update...() functions.
218 // The only exceptions are av1_rc_drop_frame() and
219 // av1_rc_update_rate_correction_factors() functions.
220 
221 // Functions to set parameters for encoding before the actual
222 // encode_frame_to_data_rate() function.
223 void av1_rc_get_one_pass_vbr_params(struct AV1_COMP *cpi);
224 void av1_rc_get_one_pass_cbr_params(struct AV1_COMP *cpi);
225 
226 // Post encode update of the rate control parameters based
227 // on bytes used
228 void av1_rc_postencode_update(struct AV1_COMP *cpi, uint64_t bytes_used);
229 // Post encode update of the rate control parameters for dropped frames
230 void av1_rc_postencode_update_drop_frame(struct AV1_COMP *cpi);
231 
232 // Updates rate correction factors
233 // Changes only the rate correction factors in the rate control structure.
234 void av1_rc_update_rate_correction_factors(struct AV1_COMP *cpi, int width,
235                                            int height);
236 
237 // Decide if we should drop this frame: For 1-pass CBR.
238 // Changes only the decimation count in the rate control structure
239 int av1_rc_drop_frame(struct AV1_COMP *cpi);
240 
241 // Computes frame size bounds.
242 void av1_rc_compute_frame_size_bounds(const struct AV1_COMP *cpi,
243                                       int this_frame_target,
244                                       int *frame_under_shoot_limit,
245                                       int *frame_over_shoot_limit);
246 
247 // Picks q and q bounds given the target for bits
248 int av1_rc_pick_q_and_bounds(struct AV1_COMP *cpi, int width, int height,
249                              int *bottom_index, int *top_index);
250 
251 // Estimates q to achieve a target bits per frame
252 int av1_rc_regulate_q(const struct AV1_COMP *cpi, int target_bits_per_frame,
253                       int active_best_quality, int active_worst_quality,
254                       int width, int height);
255 
256 // Estimates bits per mb for a given qindex and correction factor.
257 int av1_rc_bits_per_mb(FRAME_TYPE frame_type, int qindex,
258                        double correction_factor, aom_bit_depth_t bit_depth);
259 
260 // Clamping utilities for bitrate targets for iframes and pframes.
261 int av1_rc_clamp_iframe_target_size(const struct AV1_COMP *const cpi,
262                                     int target);
263 int av1_rc_clamp_pframe_target_size(const struct AV1_COMP *const cpi,
264                                     int target);
265 // Utility to set frame_target into the RATE_CONTROL structure
266 // This function is called only from the av1_rc_get_..._params() functions.
267 void av1_rc_set_frame_target(struct AV1_COMP *cpi, int target);
268 
269 // Computes a q delta (in "q index" terms) to get from a starting q value
270 // to a target q value
271 int av1_compute_qdelta(const RATE_CONTROL *rc, double qstart, double qtarget,
272                        aom_bit_depth_t bit_depth);
273 
274 // Computes a q delta (in "q index" terms) to get from a starting q value
275 // to a value that should equate to the given rate ratio.
276 int av1_compute_qdelta_by_rate(const RATE_CONTROL *rc, FRAME_TYPE frame_type,
277                                int qindex, double rate_target_ratio,
278                                aom_bit_depth_t bit_depth);
279 
280 int av1_frame_type_qdelta(const struct AV1_COMP *cpi, int rf_level, int q);
281 
282 void av1_rc_update_framerate(struct AV1_COMP *cpi, int width, int height);
283 
284 void av1_rc_set_gf_interval_range(const struct AV1_COMP *const cpi,
285                                   RATE_CONTROL *const rc);
286 
287 void av1_set_target_rate(struct AV1_COMP *cpi, int width, int height);
288 
289 int av1_resize_one_pass_cbr(struct AV1_COMP *cpi);
290 
291 #ifdef __cplusplus
292 }  // extern "C"
293 #endif
294 
295 #endif  // AOM_AV1_ENCODER_RATECTRL_H_
296