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      1 /*
      2  *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
      3  *
      4  *  Use of this source code is governed by a BSD-style license
      5  *  that can be found in the LICENSE file in the root of the source
      6  *  tree. An additional intellectual property rights grant can be found
      7  *  in the file PATENTS.  All contributing project authors may
      8  *  be found in the AUTHORS file in the root of the source tree.
      9  */
     10 
     11 #ifndef VP9_ENCODER_VP9_RATECTRL_H_
     12 #define VP9_ENCODER_VP9_RATECTRL_H_
     13 
     14 #include "vpx/vpx_codec.h"
     15 #include "vpx/vpx_integer.h"
     16 
     17 #include "vp9/common/vp9_blockd.h"
     18 #include "vp9/encoder/vp9_lookahead.h"
     19 
     20 #ifdef __cplusplus
     21 extern "C" {
     22 #endif
     23 
     24 // Used to control aggressive VBR mode.
     25 // #define AGGRESSIVE_VBR 1
     26 
     27 // Bits Per MB at different Q (Multiplied by 512)
     28 #define BPER_MB_NORMBITS 9
     29 
     30 #define MIN_GF_INTERVAL 4
     31 #define MAX_GF_INTERVAL 16
     32 #define FIXED_GF_INTERVAL 8  // Used in some testing modes only
     33 #define ONEHALFONLY_RESIZE 0
     34 
     35 typedef enum {
     36   INTER_NORMAL = 0,
     37   INTER_HIGH = 1,
     38   GF_ARF_LOW = 2,
     39   GF_ARF_STD = 3,
     40   KF_STD = 4,
     41   RATE_FACTOR_LEVELS = 5
     42 } RATE_FACTOR_LEVEL;
     43 
     44 // Internal frame scaling level.
     45 typedef enum {
     46   UNSCALED = 0,     // Frame is unscaled.
     47   SCALE_STEP1 = 1,  // First-level down-scaling.
     48   FRAME_SCALE_STEPS
     49 } FRAME_SCALE_LEVEL;
     50 
     51 typedef enum {
     52   NO_RESIZE = 0,
     53   DOWN_THREEFOUR = 1,  // From orig to 3/4.
     54   DOWN_ONEHALF = 2,    // From orig or 3/4 to 1/2.
     55   UP_THREEFOUR = -1,   // From 1/2 to 3/4.
     56   UP_ORIG = -2,        // From 1/2 or 3/4 to orig.
     57 } RESIZE_ACTION;
     58 
     59 typedef enum { ORIG = 0, THREE_QUARTER = 1, ONE_HALF = 2 } RESIZE_STATE;
     60 
     61 // Frame dimensions multiplier wrt the native frame size, in 1/16ths,
     62 // specified for the scale-up case.
     63 // e.g. 24 => 16/24 = 2/3 of native size. The restriction to 1/16th is
     64 // intended to match the capabilities of the normative scaling filters,
     65 // giving precedence to the up-scaling accuracy.
     66 static const int frame_scale_factor[FRAME_SCALE_STEPS] = { 16, 24 };
     67 
     68 // Multiplier of the target rate to be used as threshold for triggering scaling.
     69 static const double rate_thresh_mult[FRAME_SCALE_STEPS] = { 1.0, 2.0 };
     70 
     71 // Scale dependent Rate Correction Factor multipliers. Compensates for the
     72 // greater number of bits per pixel generated in down-scaled frames.
     73 static const double rcf_mult[FRAME_SCALE_STEPS] = { 1.0, 2.0 };
     74 
     75 typedef struct {
     76   // Rate targetting variables
     77   int base_frame_target;  // A baseline frame target before adjustment
     78                           // for previous under or over shoot.
     79   int this_frame_target;  // Actual frame target after rc adjustment.
     80   int projected_frame_size;
     81   int sb64_target_rate;
     82   int last_q[FRAME_TYPES];  // Separate values for Intra/Inter
     83   int last_boosted_qindex;  // Last boosted GF/KF/ARF q
     84   int last_kf_qindex;       // Q index of the last key frame coded.
     85 
     86   int gfu_boost;
     87   int last_boost;
     88   int kf_boost;
     89 
     90   double rate_correction_factors[RATE_FACTOR_LEVELS];
     91 
     92   int frames_since_golden;
     93   int frames_till_gf_update_due;
     94   int min_gf_interval;
     95   int max_gf_interval;
     96   int static_scene_max_gf_interval;
     97   int baseline_gf_interval;
     98   int constrained_gf_group;
     99   int frames_to_key;
    100   int frames_since_key;
    101   int this_key_frame_forced;
    102   int next_key_frame_forced;
    103   int source_alt_ref_pending;
    104   int source_alt_ref_active;
    105   int is_src_frame_alt_ref;
    106 
    107   int avg_frame_bandwidth;  // Average frame size target for clip
    108   int min_frame_bandwidth;  // Minimum allocation used for any frame
    109   int max_frame_bandwidth;  // Maximum burst rate allowed for a frame.
    110 
    111   int ni_av_qi;
    112   int ni_tot_qi;
    113   int ni_frames;
    114   int avg_frame_qindex[FRAME_TYPES];
    115   double tot_q;
    116   double avg_q;
    117 
    118   int64_t buffer_level;
    119   int64_t bits_off_target;
    120   int64_t vbr_bits_off_target;
    121   int64_t vbr_bits_off_target_fast;
    122 
    123   int decimation_factor;
    124   int decimation_count;
    125 
    126   int rolling_target_bits;
    127   int rolling_actual_bits;
    128 
    129   int long_rolling_target_bits;
    130   int long_rolling_actual_bits;
    131 
    132   int rate_error_estimate;
    133 
    134   int64_t total_actual_bits;
    135   int64_t total_target_bits;
    136   int64_t total_target_vs_actual;
    137 
    138   int worst_quality;
    139   int best_quality;
    140 
    141   int64_t starting_buffer_level;
    142   int64_t optimal_buffer_level;
    143   int64_t maximum_buffer_size;
    144 
    145   // rate control history for last frame(1) and the frame before(2).
    146   // -1: undershot
    147   //  1: overshoot
    148   //  0: not initialized.
    149   int rc_1_frame;
    150   int rc_2_frame;
    151   int q_1_frame;
    152   int q_2_frame;
    153 
    154   // Auto frame-scaling variables.
    155   FRAME_SCALE_LEVEL frame_size_selector;
    156   FRAME_SCALE_LEVEL next_frame_size_selector;
    157   int frame_width[FRAME_SCALE_STEPS];
    158   int frame_height[FRAME_SCALE_STEPS];
    159   int rf_level_maxq[RATE_FACTOR_LEVELS];
    160 
    161   int fac_active_worst_inter;
    162   int fac_active_worst_gf;
    163   uint64_t avg_source_sad[MAX_LAG_BUFFERS];
    164   uint64_t prev_avg_source_sad_lag;
    165   int high_source_sad_lagindex;
    166   int alt_ref_gf_group;
    167   int high_source_sad;
    168   int count_last_scene_change;
    169   int avg_frame_low_motion;
    170   int af_ratio_onepass_vbr;
    171   int force_qpmin;
    172 } RATE_CONTROL;
    173 
    174 struct VP9_COMP;
    175 struct VP9EncoderConfig;
    176 
    177 void vp9_rc_init(const struct VP9EncoderConfig *oxcf, int pass,
    178                  RATE_CONTROL *rc);
    179 
    180 int vp9_estimate_bits_at_q(FRAME_TYPE frame_kind, int q, int mbs,
    181                            double correction_factor, vpx_bit_depth_t bit_depth);
    182 
    183 double vp9_convert_qindex_to_q(int qindex, vpx_bit_depth_t bit_depth);
    184 
    185 int vp9_convert_q_to_qindex(double q_val, vpx_bit_depth_t bit_depth);
    186 
    187 void vp9_rc_init_minq_luts(void);
    188 
    189 int vp9_rc_get_default_min_gf_interval(int width, int height, double framerate);
    190 // Note vp9_rc_get_default_max_gf_interval() requires the min_gf_interval to
    191 // be passed in to ensure that the max_gf_interval returned is at least as bis
    192 // as that.
    193 int vp9_rc_get_default_max_gf_interval(double framerate, int min_frame_rate);
    194 
    195 // Generally at the high level, the following flow is expected
    196 // to be enforced for rate control:
    197 // First call per frame, one of:
    198 //   vp9_rc_get_one_pass_vbr_params()
    199 //   vp9_rc_get_one_pass_cbr_params()
    200 //   vp9_rc_get_svc_params()
    201 //   vp9_rc_get_first_pass_params()
    202 //   vp9_rc_get_second_pass_params()
    203 // depending on the usage to set the rate control encode parameters desired.
    204 //
    205 // Then, call encode_frame_to_data_rate() to perform the
    206 // actual encode. This function will in turn call encode_frame()
    207 // one or more times, followed by one of:
    208 //   vp9_rc_postencode_update()
    209 //   vp9_rc_postencode_update_drop_frame()
    210 //
    211 // The majority of rate control parameters are only expected
    212 // to be set in the vp9_rc_get_..._params() functions and
    213 // updated during the vp9_rc_postencode_update...() functions.
    214 // The only exceptions are vp9_rc_drop_frame() and
    215 // vp9_rc_update_rate_correction_factors() functions.
    216 
    217 // Functions to set parameters for encoding before the actual
    218 // encode_frame_to_data_rate() function.
    219 void vp9_rc_get_one_pass_vbr_params(struct VP9_COMP *cpi);
    220 void vp9_rc_get_one_pass_cbr_params(struct VP9_COMP *cpi);
    221 void vp9_rc_get_svc_params(struct VP9_COMP *cpi);
    222 
    223 // Post encode update of the rate control parameters based
    224 // on bytes used
    225 void vp9_rc_postencode_update(struct VP9_COMP *cpi, uint64_t bytes_used);
    226 // Post encode update of the rate control parameters for dropped frames
    227 void vp9_rc_postencode_update_drop_frame(struct VP9_COMP *cpi);
    228 
    229 // Updates rate correction factors
    230 // Changes only the rate correction factors in the rate control structure.
    231 void vp9_rc_update_rate_correction_factors(struct VP9_COMP *cpi);
    232 
    233 // Decide if we should drop this frame: For 1-pass CBR.
    234 // Changes only the decimation count in the rate control structure
    235 int vp9_rc_drop_frame(struct VP9_COMP *cpi);
    236 
    237 // Computes frame size bounds.
    238 void vp9_rc_compute_frame_size_bounds(const struct VP9_COMP *cpi,
    239                                       int this_frame_target,
    240                                       int *frame_under_shoot_limit,
    241                                       int *frame_over_shoot_limit);
    242 
    243 // Picks q and q bounds given the target for bits
    244 int vp9_rc_pick_q_and_bounds(const struct VP9_COMP *cpi, int *bottom_index,
    245                              int *top_index);
    246 
    247 // Estimates q to achieve a target bits per frame
    248 int vp9_rc_regulate_q(const struct VP9_COMP *cpi, int target_bits_per_frame,
    249                       int active_best_quality, int active_worst_quality);
    250 
    251 // Estimates bits per mb for a given qindex and correction factor.
    252 int vp9_rc_bits_per_mb(FRAME_TYPE frame_type, int qindex,
    253                        double correction_factor, vpx_bit_depth_t bit_depth);
    254 
    255 // Clamping utilities for bitrate targets for iframes and pframes.
    256 int vp9_rc_clamp_iframe_target_size(const struct VP9_COMP *const cpi,
    257                                     int target);
    258 int vp9_rc_clamp_pframe_target_size(const struct VP9_COMP *const cpi,
    259                                     int target);
    260 // Utility to set frame_target into the RATE_CONTROL structure
    261 // This function is called only from the vp9_rc_get_..._params() functions.
    262 void vp9_rc_set_frame_target(struct VP9_COMP *cpi, int target);
    263 
    264 // Computes a q delta (in "q index" terms) to get from a starting q value
    265 // to a target q value
    266 int vp9_compute_qdelta(const RATE_CONTROL *rc, double qstart, double qtarget,
    267                        vpx_bit_depth_t bit_depth);
    268 
    269 // Computes a q delta (in "q index" terms) to get from a starting q value
    270 // to a value that should equate to the given rate ratio.
    271 int vp9_compute_qdelta_by_rate(const RATE_CONTROL *rc, FRAME_TYPE frame_type,
    272                                int qindex, double rate_target_ratio,
    273                                vpx_bit_depth_t bit_depth);
    274 
    275 int vp9_frame_type_qdelta(const struct VP9_COMP *cpi, int rf_level, int q);
    276 
    277 void vp9_rc_update_framerate(struct VP9_COMP *cpi);
    278 
    279 void vp9_rc_set_gf_interval_range(const struct VP9_COMP *const cpi,
    280                                   RATE_CONTROL *const rc);
    281 
    282 void vp9_set_target_rate(struct VP9_COMP *cpi);
    283 
    284 int vp9_resize_one_pass_cbr(struct VP9_COMP *cpi);
    285 
    286 void vp9_scene_detection_onepass(struct VP9_COMP *cpi);
    287 
    288 int vp9_encodedframe_overshoot(struct VP9_COMP *cpi, int frame_size, int *q);
    289 
    290 #ifdef __cplusplus
    291 }  // extern "C"
    292 #endif
    293 
    294 #endif  // VP9_ENCODER_VP9_RATECTRL_H_
    295