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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 
     12 #ifndef VP9_ENCODER_VP9_RATECTRL_H_
     13 #define VP9_ENCODER_VP9_RATECTRL_H_
     14 
     15 #include "vpx/vpx_codec.h"
     16 #include "vpx/vpx_integer.h"
     17 
     18 #include "vp9/common/vp9_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 MIN_GF_INTERVAL     4
     28 #define MAX_GF_INTERVAL     16
     29 #define ONEHALFONLY_RESIZE  0
     30 
     31 typedef enum {
     32   INTER_NORMAL = 0,
     33   INTER_HIGH = 1,
     34   GF_ARF_LOW = 2,
     35   GF_ARF_STD = 3,
     36   KF_STD = 4,
     37   RATE_FACTOR_LEVELS = 5
     38 } RATE_FACTOR_LEVEL;
     39 
     40 // Internal frame scaling level.
     41 typedef enum {
     42   UNSCALED = 0,     // Frame is unscaled.
     43   SCALE_STEP1 = 1,  // First-level down-scaling.
     44   FRAME_SCALE_STEPS
     45 } FRAME_SCALE_LEVEL;
     46 
     47 typedef enum {
     48   NO_RESIZE = 0,
     49   DOWN_THREEFOUR = 1,  // From orig to 3/4.
     50   DOWN_ONEHALF = 2,    // From orig or 3/4 to 1/2.
     51   UP_THREEFOUR = -1,   // From 1/2 to 3/4.
     52   UP_ORIG = -2,        // From 1/2 or 3/4 to orig.
     53 } RESIZE_ACTION;
     54 
     55 typedef enum {
     56   ORIG = 0,
     57   THREE_QUARTER = 1,
     58   ONE_HALF = 2
     59 } 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   uint64_t avg_source_sad;
    162   int high_source_sad;
    163 } RATE_CONTROL;
    164 
    165 struct VP9_COMP;
    166 struct VP9EncoderConfig;
    167 
    168 void vp9_rc_init(const struct VP9EncoderConfig *oxcf, int pass,
    169                  RATE_CONTROL *rc);
    170 
    171 int vp9_estimate_bits_at_q(FRAME_TYPE frame_kind, int q, int mbs,
    172                            double correction_factor,
    173                            vpx_bit_depth_t bit_depth);
    174 
    175 double vp9_convert_qindex_to_q(int qindex, vpx_bit_depth_t bit_depth);
    176 
    177 void vp9_rc_init_minq_luts(void);
    178 
    179 int vp9_rc_get_default_min_gf_interval(int width, int height, double framerate);
    180 // Note vp9_rc_get_default_max_gf_interval() requires the min_gf_interval to
    181 // be passed in to ensure that the max_gf_interval returned is at least as bis
    182 // as that.
    183 int vp9_rc_get_default_max_gf_interval(double framerate, int min_frame_rate);
    184 
    185 // Generally at the high level, the following flow is expected
    186 // to be enforced for rate control:
    187 // First call per frame, one of:
    188 //   vp9_rc_get_one_pass_vbr_params()
    189 //   vp9_rc_get_one_pass_cbr_params()
    190 //   vp9_rc_get_svc_params()
    191 //   vp9_rc_get_first_pass_params()
    192 //   vp9_rc_get_second_pass_params()
    193 // depending on the usage to set the rate control encode parameters desired.
    194 //
    195 // Then, call encode_frame_to_data_rate() to perform the
    196 // actual encode. This function will in turn call encode_frame()
    197 // one or more times, followed by one of:
    198 //   vp9_rc_postencode_update()
    199 //   vp9_rc_postencode_update_drop_frame()
    200 //
    201 // The majority of rate control parameters are only expected
    202 // to be set in the vp9_rc_get_..._params() functions and
    203 // updated during the vp9_rc_postencode_update...() functions.
    204 // The only exceptions are vp9_rc_drop_frame() and
    205 // vp9_rc_update_rate_correction_factors() functions.
    206 
    207 // Functions to set parameters for encoding before the actual
    208 // encode_frame_to_data_rate() function.
    209 void vp9_rc_get_one_pass_vbr_params(struct VP9_COMP *cpi);
    210 void vp9_rc_get_one_pass_cbr_params(struct VP9_COMP *cpi);
    211 void vp9_rc_get_svc_params(struct VP9_COMP *cpi);
    212 
    213 // Post encode update of the rate control parameters based
    214 // on bytes used
    215 void vp9_rc_postencode_update(struct VP9_COMP *cpi, uint64_t bytes_used);
    216 // Post encode update of the rate control parameters for dropped frames
    217 void vp9_rc_postencode_update_drop_frame(struct VP9_COMP *cpi);
    218 
    219 // Updates rate correction factors
    220 // Changes only the rate correction factors in the rate control structure.
    221 void vp9_rc_update_rate_correction_factors(struct VP9_COMP *cpi);
    222 
    223 // Decide if we should drop this frame: For 1-pass CBR.
    224 // Changes only the decimation count in the rate control structure
    225 int vp9_rc_drop_frame(struct VP9_COMP *cpi);
    226 
    227 // Computes frame size bounds.
    228 void vp9_rc_compute_frame_size_bounds(const struct VP9_COMP *cpi,
    229                                       int this_frame_target,
    230                                       int *frame_under_shoot_limit,
    231                                       int *frame_over_shoot_limit);
    232 
    233 // Picks q and q bounds given the target for bits
    234 int vp9_rc_pick_q_and_bounds(const struct VP9_COMP *cpi,
    235                              int *bottom_index,
    236                              int *top_index);
    237 
    238 // Estimates q to achieve a target bits per frame
    239 int vp9_rc_regulate_q(const struct VP9_COMP *cpi, int target_bits_per_frame,
    240                       int active_best_quality, int active_worst_quality);
    241 
    242 // Estimates bits per mb for a given qindex and correction factor.
    243 int vp9_rc_bits_per_mb(FRAME_TYPE frame_type, int qindex,
    244                        double correction_factor, vpx_bit_depth_t bit_depth);
    245 
    246 // Clamping utilities for bitrate targets for iframes and pframes.
    247 int vp9_rc_clamp_iframe_target_size(const struct VP9_COMP *const cpi,
    248                                     int target);
    249 int vp9_rc_clamp_pframe_target_size(const struct VP9_COMP *const cpi,
    250                                     int target);
    251 // Utility to set frame_target into the RATE_CONTROL structure
    252 // This function is called only from the vp9_rc_get_..._params() functions.
    253 void vp9_rc_set_frame_target(struct VP9_COMP *cpi, int target);
    254 
    255 // Computes a q delta (in "q index" terms) to get from a starting q value
    256 // to a target q value
    257 int vp9_compute_qdelta(const RATE_CONTROL *rc, double qstart, double qtarget,
    258                        vpx_bit_depth_t bit_depth);
    259 
    260 // Computes a q delta (in "q index" terms) to get from a starting q value
    261 // to a value that should equate to the given rate ratio.
    262 int vp9_compute_qdelta_by_rate(const RATE_CONTROL *rc, FRAME_TYPE frame_type,
    263                                int qindex, double rate_target_ratio,
    264                                vpx_bit_depth_t bit_depth);
    265 
    266 int vp9_frame_type_qdelta(const struct VP9_COMP *cpi, int rf_level, int q);
    267 
    268 void vp9_rc_update_framerate(struct VP9_COMP *cpi);
    269 
    270 void vp9_rc_set_gf_interval_range(const struct VP9_COMP *const cpi,
    271                                   RATE_CONTROL *const rc);
    272 
    273 void vp9_set_target_rate(struct VP9_COMP *cpi);
    274 
    275 int vp9_resize_one_pass_cbr(struct VP9_COMP *cpi);
    276 
    277 void vp9_avg_source_sad(struct VP9_COMP *cpi);
    278 
    279 int vp9_encodedframe_overshoot(struct VP9_COMP *cpi, int frame_size, int *q);
    280 
    281 #ifdef __cplusplus
    282 }  // extern "C"
    283 #endif
    284 
    285 #endif  // VP9_ENCODER_VP9_RATECTRL_H_
    286