1 /*****************************************************************************
2 * ratecontrol.c: h264 encoder library (Rate Control)
3 *****************************************************************************
4 * Copyright (C) 2005-2008 x264 project
6 * Authors: Loren Merritt <lorenm@u.washington.edu>
7 * Michael Niedermayer <michaelni@gmx.at>
8 * Gabriel Bouvigne <gabriel.bouvigne@joost.com>
9 * Fiona Glaser <fiona@x264.com>
10 * Måns Rullgård <mru@mru.ath.cx>
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111, USA.
25 *****************************************************************************/
27 #define _ISOC99_SOURCE
28 #undef NDEBUG // always check asserts, the speed effect is far too small to disable them
31 #include "common/common.h"
32 #include "common/cpu.h"
33 #include "ratecontrol.h"
45 uint64_t expected_bits; /*total expected bits up to the current frame (current one excluded)*/
52 float blurred_complexity;
55 int16_t i_weight_denom;
60 } ratecontrol_entry_t;
70 struct x264_ratecontrol_t
79 double rate_tolerance;
81 int nmb; /* number of macroblocks in a frame */
85 ratecontrol_entry_t *rce;
86 int qp; /* qp for current frame */
87 int qpm; /* qp for current macroblock */
88 float f_qpm; /* qp for current macroblock: precise float for AQ */
89 float qpa_rc; /* average of macroblocks' qp before aq */
90 float qpa_aq; /* average of macroblocks' qp after aq */
91 float qp_novbv; /* QP for the current frame if 1-pass VBV was disabled. */
96 double buffer_fill_final; /* real buffer as of the last finished frame */
97 double buffer_fill; /* planned buffer, if all in-progress frames hit their bit budget */
98 double buffer_rate; /* # of bits added to buffer_fill after each frame */
99 double vbv_max_rate; /* # of bits added to buffer_fill per second */
100 predictor_t *pred; /* predict frame size from satd */
101 int single_frame_vbv;
102 double rate_factor_max_increment; /* Don't allow RF above (CRF + this value). */
107 double cplxr_sum; /* sum of bits*qscale/rceq */
108 double expected_bits_sum; /* sum of qscale2bits after rceq, ratefactor, and overflow, only includes finished frames */
109 double wanted_bits_window; /* target bitrate * window */
111 double short_term_cplxsum;
112 double short_term_cplxcount;
113 double rate_factor_constant;
118 FILE *p_stat_file_out;
119 char *psz_stat_file_tmpname;
120 FILE *p_mbtree_stat_file_out;
121 char *psz_mbtree_stat_file_tmpname;
122 char *psz_mbtree_stat_file_name;
123 FILE *p_mbtree_stat_file_in;
125 int num_entries; /* number of ratecontrol_entry_ts */
126 ratecontrol_entry_t *entry; /* FIXME: copy needed data and free this once init is done */
128 double last_qscale_for[5]; /* last qscale for a specific pict type, used for max_diff & ipb factor stuff */
129 int last_non_b_pict_type;
130 double accum_p_qp; /* for determining I-frame quant */
132 double last_accum_p_norm;
133 double lmin[5]; /* min qscale by frame type */
135 double lstep; /* max change (multiply) in qscale per frame */
136 uint16_t *qp_buffer[2]; /* Global buffers for converting MB-tree quantizer data. */
137 int qpbuf_pos; /* In order to handle pyramid reordering, QP buffer acts as a stack.
138 * This value is the current position (0 or 1). */
141 float frame_size_estimated; /* Access to this variable must be atomic: double is
142 * not atomic on all arches we care about */
143 double frame_size_maximum; /* Maximum frame size due to MinCR */
144 double frame_size_planned;
145 double slice_size_planned;
146 double max_frame_error;
147 predictor_t (*row_pred)[2];
148 predictor_t row_preds[5][2];
149 predictor_t *pred_b_from_p; /* predict B-frame size from P-frame satd */
150 int bframes; /* # consecutive B-frames before this P-frame */
151 int bframe_bits; /* total cost of those frames */
155 x264_zone_t *prev_zone;
158 int initial_cpb_removal_delay;
159 int initial_cpb_removal_delay_offset;
160 double nrt_first_access_unit; /* nominal removal time */
161 double previous_cpb_final_arrival_time;
165 static int parse_zones( x264_t *h );
166 static int init_pass2(x264_t *);
167 static float rate_estimate_qscale( x264_t *h );
168 static int update_vbv( x264_t *h, int bits );
169 static void update_vbv_plan( x264_t *h, int overhead );
170 static double predict_size( predictor_t *p, double q, double var );
171 static void update_predictor( predictor_t *p, double q, double var, double bits );
173 #define CMP_OPT_FIRST_PASS( opt, param_val )\
175 if( ( p = strstr( opts, opt "=" ) ) && sscanf( p, opt "=%d" , &i ) && param_val != i )\
177 x264_log( h, X264_LOG_ERROR, "different " opt " setting than first pass (%d vs %d)\n", param_val, i );\
183 * qp = h.264's quantizer
184 * qscale = linearized quantizer = Lagrange multiplier
186 static inline double qp2qscale( double qp )
188 return 0.85 * pow( 2.0, ( qp - 12.0 ) / 6.0 );
190 static inline double qscale2qp( double qscale )
192 return 12.0 + 6.0 * log2( qscale/0.85 );
195 /* Texture bitrate is not quite inversely proportional to qscale,
196 * probably due the the changing number of SKIP blocks.
197 * MV bits level off at about qp<=12, because the lambda used
198 * for motion estimation is constant there. */
199 static inline double qscale2bits( ratecontrol_entry_t *rce, double qscale )
203 return (rce->tex_bits + .1) * pow( rce->qscale / qscale, 1.1 )
204 + rce->mv_bits * pow( X264_MAX(rce->qscale, 1) / X264_MAX(qscale, 1), 0.5 )
208 static ALWAYS_INLINE uint32_t ac_energy_plane( x264_t *h, int mb_x, int mb_y, x264_frame_t *frame, int i )
211 int shift = i ? 6 : 8;
212 int stride = frame->i_stride[i];
213 int offset = h->mb.b_interlaced
214 ? w * (mb_x + (mb_y&~1) * stride) + (mb_y&1) * stride
215 : w * (mb_x + mb_y * stride);
216 int pix = i ? PIXEL_8x8 : PIXEL_16x16;
217 stride <<= h->mb.b_interlaced;
218 uint64_t res = h->pixf.var[pix]( frame->plane[i] + offset, stride );
219 uint32_t sum = (uint32_t)res;
220 uint32_t sqr = res >> 32;
221 return sqr - (sum * sum >> shift);
224 // Find the total AC energy of the block in all planes.
225 static NOINLINE uint32_t ac_energy_mb( x264_t *h, int mb_x, int mb_y, x264_frame_t *frame )
227 /* This function contains annoying hacks because GCC has a habit of reordering emms
228 * and putting it after floating point ops. As a result, we put the emms at the end of the
229 * function and make sure that its always called before the float math. Noinline makes
230 * sure no reordering goes on. */
231 uint32_t var = ac_energy_plane( h, mb_x, mb_y, frame, 0 );
232 var += ac_energy_plane( h, mb_x, mb_y, frame, 1 );
233 var += ac_energy_plane( h, mb_x, mb_y, frame, 2 );
238 void x264_adaptive_quant_frame( x264_t *h, x264_frame_t *frame )
240 /* constants chosen to result in approximately the same overall bitrate as without AQ.
241 * FIXME: while they're written in 5 significant digits, they're only tuned to 2. */
244 /* Need to init it anyways for MB tree. */
245 if( h->param.rc.f_aq_strength == 0 )
247 memset( frame->f_qp_offset, 0, h->mb.i_mb_count * sizeof(float) );
248 memset( frame->f_qp_offset_aq, 0, h->mb.i_mb_count * sizeof(float) );
249 if( h->frames.b_have_lowres )
250 for( int mb_xy = 0; mb_xy < h->mb.i_mb_count; mb_xy++ )
251 frame->i_inv_qscale_factor[mb_xy] = 256;
255 if( h->param.rc.i_aq_mode == X264_AQ_AUTOVARIANCE )
257 float avg_adj_pow2 = 0.f;
258 for( int mb_y = 0; mb_y < h->sps->i_mb_height; mb_y++ )
259 for( int mb_x = 0; mb_x < h->sps->i_mb_width; mb_x++ )
261 uint32_t energy = ac_energy_mb( h, mb_x, mb_y, frame );
262 float qp_adj = powf( energy + 1, 0.125f );
263 frame->f_qp_offset[mb_x + mb_y*h->mb.i_mb_stride] = qp_adj;
265 avg_adj_pow2 += qp_adj * qp_adj;
267 avg_adj /= h->mb.i_mb_count;
268 avg_adj_pow2 /= h->mb.i_mb_count;
269 strength = h->param.rc.f_aq_strength * avg_adj;
270 avg_adj = avg_adj - 0.5f * (avg_adj_pow2 - 14.f) / avg_adj;
273 strength = h->param.rc.f_aq_strength * 1.0397f;
275 for( int mb_y = 0; mb_y < h->sps->i_mb_height; mb_y++ )
276 for( int mb_x = 0; mb_x < h->sps->i_mb_width; mb_x++ )
279 if( h->param.rc.i_aq_mode == X264_AQ_AUTOVARIANCE )
281 qp_adj = frame->f_qp_offset[mb_x + mb_y*h->mb.i_mb_stride];
282 qp_adj = strength * (qp_adj - avg_adj);
286 uint32_t energy = ac_energy_mb( h, mb_x, mb_y, frame );
287 qp_adj = strength * (x264_log2( X264_MAX(energy, 1) ) - 14.427f);
289 frame->f_qp_offset[mb_x + mb_y*h->mb.i_mb_stride] =
290 frame->f_qp_offset_aq[mb_x + mb_y*h->mb.i_mb_stride] = qp_adj;
291 if( h->frames.b_have_lowres )
292 frame->i_inv_qscale_factor[mb_x + mb_y*h->mb.i_mb_stride] = x264_exp2fix8(qp_adj);
297 /*****************************************************************************
298 * x264_adaptive_quant:
299 * adjust macroblock QP based on variance (AC energy) of the MB.
300 * high variance = higher QP
301 * low variance = lower QP
302 * This generally increases SSIM and lowers PSNR.
303 *****************************************************************************/
304 void x264_adaptive_quant( x264_t *h )
307 /* MB-tree currently doesn't adjust quantizers in unreferenced frames. */
308 float qp_offset = h->fdec->b_kept_as_ref ? h->fenc->f_qp_offset[h->mb.i_mb_xy] : h->fenc->f_qp_offset_aq[h->mb.i_mb_xy];
309 h->mb.i_qp = x264_clip3( h->rc->f_qpm + qp_offset + .5, h->param.rc.i_qp_min, h->param.rc.i_qp_max );
312 int x264_macroblock_tree_read( x264_t *h, x264_frame_t *frame )
314 x264_ratecontrol_t *rc = h->rc;
315 uint8_t i_type_actual = rc->entry[frame->i_frame].pict_type;
317 if( rc->entry[frame->i_frame].kept_as_ref )
320 if( rc->qpbuf_pos < 0 )
326 if( !fread( &i_type, 1, 1, rc->p_mbtree_stat_file_in ) )
328 if( fread( rc->qp_buffer[rc->qpbuf_pos], sizeof(uint16_t), h->mb.i_mb_count, rc->p_mbtree_stat_file_in ) != h->mb.i_mb_count )
331 if( i_type != i_type_actual && rc->qpbuf_pos == 1 )
333 x264_log(h, X264_LOG_ERROR, "MB-tree frametype %d doesn't match actual frametype %d.\n", i_type, i_type_actual);
336 } while( i_type != i_type_actual );
339 for( int i = 0; i < h->mb.i_mb_count; i++ )
341 frame->f_qp_offset[i] = ((float)(int16_t)endian_fix16( rc->qp_buffer[rc->qpbuf_pos][i] )) * (1/256.0);
342 if( h->frames.b_have_lowres )
343 frame->i_inv_qscale_factor[i] = x264_exp2fix8(frame->f_qp_offset[i]);
348 x264_adaptive_quant_frame( h, frame );
351 x264_log(h, X264_LOG_ERROR, "Incomplete MB-tree stats file.\n");
355 int x264_reference_build_list_optimal( x264_t *h )
357 ratecontrol_entry_t *rce = h->rc->rce;
358 x264_frame_t *frames[16];
359 x264_weight_t weights[16][3];
362 if( rce->refs != h->i_ref0 )
365 memcpy( frames, h->fref0, sizeof(frames) );
366 memcpy( refcount, rce->refcount, sizeof(refcount) );
367 memcpy( weights, h->fenc->weight, sizeof(weights) );
368 memset( &h->fenc->weight[1][0], 0, sizeof(x264_weight_t[15][3]) );
370 /* For now don't reorder ref 0; it seems to lower quality
371 in most cases due to skips. */
372 for( int ref = 1; ref < h->i_ref0; ref++ )
377 for( int i = 1; i < h->i_ref0; i++ )
378 if( !frames[i]->b_duplicate || frames[i]->i_frame != h->fref0[ref-1]->i_frame )
379 /* Favor lower POC as a tiebreaker. */
380 COPY2_IF_GT( max, refcount[i], bestref, i );
382 /* FIXME: If there are duplicates from frames other than ref0 then it is possible
383 * that the optimal ordering doesnt place every duplicate. */
385 refcount[bestref] = -1;
386 h->fref0[ref] = frames[bestref];
387 memcpy( h->fenc->weight[ref], weights[bestref], sizeof(weights[bestref]) );
393 static char *x264_strcat_filename( char *input, char *suffix )
395 char *output = x264_malloc( strlen( input ) + strlen( suffix ) + 1 );
398 strcpy( output, input );
399 strcat( output, suffix );
403 void x264_ratecontrol_init_reconfigurable( x264_t *h, int b_init )
405 x264_ratecontrol_t *rc = h->rc;
406 if( !b_init && rc->b_2pass )
409 if( h->param.rc.i_rc_method == X264_RC_CRF )
411 /* Arbitrary rescaling to make CRF somewhat similar to QP.
412 * Try to compensate for MB-tree's effects as well. */
413 double base_cplx = h->mb.i_mb_count * (h->param.i_bframe ? 120 : 80);
414 double mbtree_offset = h->param.rc.b_mb_tree ? (1.0-h->param.rc.f_qcompress)*13.5 : 0;
415 rc->rate_factor_constant = pow( base_cplx, 1 - rc->qcompress )
416 / qp2qscale( h->param.rc.f_rf_constant + mbtree_offset );
419 if( h->param.rc.i_vbv_max_bitrate > 0 && h->param.rc.i_vbv_buffer_size > 0 )
421 if( h->param.rc.i_vbv_buffer_size < (int)(h->param.rc.i_vbv_max_bitrate / rc->fps) )
423 h->param.rc.i_vbv_buffer_size = h->param.rc.i_vbv_max_bitrate / rc->fps;
424 x264_log( h, X264_LOG_WARNING, "VBV buffer size cannot be smaller than one frame, using %d kbit\n",
425 h->param.rc.i_vbv_buffer_size );
428 /* We don't support changing the ABR bitrate right now,
429 so if the stream starts as CBR, keep it CBR. */
430 if( rc->b_vbv_min_rate )
431 h->param.rc.i_vbv_max_bitrate = h->param.rc.i_bitrate;
433 int vbv_buffer_size = h->param.rc.i_vbv_buffer_size * 1000;
434 int vbv_max_bitrate = h->param.rc.i_vbv_max_bitrate * 1000;
437 if( h->param.i_nal_hrd && b_init )
439 h->sps->vui.hrd.i_cpb_cnt = 1;
440 h->sps->vui.hrd.b_cbr_hrd = h->param.i_nal_hrd == X264_NAL_HRD_CBR;
441 h->sps->vui.hrd.i_time_offset_length = 0;
446 int bitrate = 1000*h->param.rc.i_vbv_max_bitrate;
447 int bufsize = 1000*h->param.rc.i_vbv_buffer_size;
449 // normalize HRD size and rate to the value / scale notation
450 h->sps->vui.hrd.i_bit_rate_scale = x264_clip3( x264_ctz( bitrate ) - BR_SHIFT, 0, 15 );
451 h->sps->vui.hrd.i_bit_rate_value = bitrate >> ( h->sps->vui.hrd.i_bit_rate_scale + BR_SHIFT );
452 h->sps->vui.hrd.i_bit_rate_unscaled = h->sps->vui.hrd.i_bit_rate_value << ( h->sps->vui.hrd.i_bit_rate_scale + BR_SHIFT );
453 h->sps->vui.hrd.i_cpb_size_scale = x264_clip3( x264_ctz( bufsize ) - CPB_SHIFT, 0, 15 );
454 h->sps->vui.hrd.i_cpb_size_value = bufsize >> ( h->sps->vui.hrd.i_cpb_size_scale + CPB_SHIFT );
455 h->sps->vui.hrd.i_cpb_size_unscaled = h->sps->vui.hrd.i_cpb_size_value << ( h->sps->vui.hrd.i_cpb_size_scale + CPB_SHIFT );
461 #define MAX_DURATION 0.5
463 int max_cpb_output_delay = h->param.i_keyint_max * MAX_DURATION * h->sps->vui.i_time_scale / h->sps->vui.i_num_units_in_tick;
464 int max_dpb_output_delay = h->sps->vui.i_max_dec_frame_buffering * MAX_DURATION * h->sps->vui.i_time_scale / h->sps->vui.i_num_units_in_tick;
465 int max_delay = (int)(90000.0 * (double)h->sps->vui.hrd.i_cpb_size_unscaled / h->sps->vui.hrd.i_bit_rate_unscaled + 0.5);
467 h->sps->vui.hrd.i_initial_cpb_removal_delay_length = 2 + x264_clip3( 32 - x264_clz( max_delay ), 4, 22 );
468 h->sps->vui.hrd.i_cpb_removal_delay_length = x264_clip3( 32 - x264_clz( max_cpb_output_delay ), 4, 32 );
469 h->sps->vui.hrd.i_dpb_output_delay_length = x264_clip3( 32 - x264_clz( max_dpb_output_delay ), 4, 32 );
473 vbv_buffer_size = X264_MIN( vbv_buffer_size, h->sps->vui.hrd.i_cpb_size_unscaled );
474 vbv_max_bitrate = X264_MIN( vbv_max_bitrate, h->sps->vui.hrd.i_bit_rate_unscaled );
476 else if( h->param.i_nal_hrd && !b_init )
478 x264_log( h, X264_LOG_WARNING, "VBV parameters cannot be changed when NAL HRD is in use\n" );
482 rc->buffer_rate = vbv_max_bitrate / rc->fps;
483 rc->vbv_max_rate = vbv_max_bitrate;
484 rc->buffer_size = vbv_buffer_size;
485 rc->single_frame_vbv = rc->buffer_rate * 1.1 > rc->buffer_size;
486 rc->cbr_decay = 1.0 - rc->buffer_rate / rc->buffer_size
487 * 0.5 * X264_MAX(0, 1.5 - rc->buffer_rate * rc->fps / rc->bitrate);
488 if( h->param.rc.i_rc_method == X264_RC_CRF && h->param.rc.f_rf_constant_max )
490 rc->rate_factor_max_increment = h->param.rc.f_rf_constant_max - h->param.rc.f_rf_constant;
491 if( rc->rate_factor_max_increment <= 0 )
493 x264_log( h, X264_LOG_WARNING, "CRF max must be greater than CRF\n" );
494 rc->rate_factor_max_increment = 0;
499 if( h->param.rc.f_vbv_buffer_init > 1. )
500 h->param.rc.f_vbv_buffer_init = x264_clip3f( h->param.rc.f_vbv_buffer_init / h->param.rc.i_vbv_buffer_size, 0, 1 );
501 h->param.rc.f_vbv_buffer_init = x264_clip3f( X264_MAX( h->param.rc.f_vbv_buffer_init, rc->buffer_rate / rc->buffer_size ), 0, 1);
502 rc->buffer_fill_final = rc->buffer_size * h->param.rc.f_vbv_buffer_init;
504 rc->b_vbv_min_rate = !rc->b_2pass
505 && h->param.rc.i_rc_method == X264_RC_ABR
506 && h->param.rc.i_vbv_max_bitrate <= h->param.rc.i_bitrate;
511 int x264_ratecontrol_new( x264_t *h )
513 x264_ratecontrol_t *rc;
517 CHECKED_MALLOCZERO( h->rc, h->param.i_threads * sizeof(x264_ratecontrol_t) );
520 rc->b_abr = h->param.rc.i_rc_method != X264_RC_CQP && !h->param.rc.b_stat_read;
521 rc->b_2pass = h->param.rc.i_rc_method == X264_RC_ABR && h->param.rc.b_stat_read;
523 /* FIXME: use integers */
524 if( h->param.i_fps_num > 0 && h->param.i_fps_den > 0 )
525 rc->fps = (float) h->param.i_fps_num / h->param.i_fps_den;
529 if( h->param.rc.b_mb_tree )
531 h->param.rc.f_pb_factor = 1;
535 rc->qcompress = h->param.rc.f_qcompress;
537 rc->bitrate = h->param.rc.i_bitrate * 1000.;
538 rc->rate_tolerance = h->param.rc.f_rate_tolerance;
539 rc->nmb = h->mb.i_mb_count;
540 rc->last_non_b_pict_type = -1;
543 if( h->param.rc.i_rc_method == X264_RC_CRF && h->param.rc.b_stat_read )
545 x264_log(h, X264_LOG_ERROR, "constant rate-factor is incompatible with 2pass.\n");
549 x264_ratecontrol_init_reconfigurable( h, 1 );
551 if( rc->rate_tolerance < 0.01 )
553 x264_log(h, X264_LOG_WARNING, "bitrate tolerance too small, using .01\n");
554 rc->rate_tolerance = 0.01;
557 h->mb.b_variable_qp = rc->b_vbv || h->param.rc.i_aq_mode;
561 /* FIXME ABR_INIT_QP is actually used only in CRF */
562 #define ABR_INIT_QP ( h->param.rc.i_rc_method == X264_RC_CRF ? h->param.rc.f_rf_constant : 24 )
563 rc->accum_p_norm = .01;
564 rc->accum_p_qp = ABR_INIT_QP * rc->accum_p_norm;
565 /* estimated ratio that produces a reasonable QP for the first I-frame */
566 rc->cplxr_sum = .01 * pow( 7.0e5, rc->qcompress ) * pow( h->mb.i_mb_count, 0.5 );
567 rc->wanted_bits_window = 1.0 * rc->bitrate / rc->fps;
568 rc->last_non_b_pict_type = SLICE_TYPE_I;
571 rc->ip_offset = 6.0 * log2f( h->param.rc.f_ip_factor );
572 rc->pb_offset = 6.0 * log2f( h->param.rc.f_pb_factor );
573 rc->qp_constant[SLICE_TYPE_P] = h->param.rc.i_qp_constant;
574 rc->qp_constant[SLICE_TYPE_I] = x264_clip3( h->param.rc.i_qp_constant - rc->ip_offset + 0.5, 0, 51 );
575 rc->qp_constant[SLICE_TYPE_B] = x264_clip3( h->param.rc.i_qp_constant + rc->pb_offset + 0.5, 0, 51 );
576 h->mb.ip_offset = rc->ip_offset + 0.5;
578 rc->lstep = pow( 2, h->param.rc.i_qp_step / 6.0 );
579 rc->last_qscale = qp2qscale( 26 );
580 int num_preds = h->param.b_sliced_threads * h->param.i_threads + 1;
581 CHECKED_MALLOC( rc->pred, 5 * sizeof(predictor_t) * num_preds );
582 CHECKED_MALLOC( rc->pred_b_from_p, sizeof(predictor_t) );
583 for( int i = 0; i < 5; i++ )
585 rc->last_qscale_for[i] = qp2qscale( ABR_INIT_QP );
586 rc->lmin[i] = qp2qscale( h->param.rc.i_qp_min );
587 rc->lmax[i] = qp2qscale( h->param.rc.i_qp_max );
588 for( int j = 0; j < num_preds; j++ )
590 rc->pred[i+j*5].coeff= 2.0;
591 rc->pred[i+j*5].count= 1.0;
592 rc->pred[i+j*5].decay= 0.5;
593 rc->pred[i+j*5].offset= 0.0;
595 for( int j = 0; j < 2; j++ )
597 rc->row_preds[i][j].coeff= .25;
598 rc->row_preds[i][j].count= 1.0;
599 rc->row_preds[i][j].decay= 0.5;
600 rc->row_preds[i][j].offset= 0.0;
603 *rc->pred_b_from_p = rc->pred[0];
605 if( parse_zones( h ) < 0 )
607 x264_log( h, X264_LOG_ERROR, "failed to parse zones\n" );
611 /* Load stat file and init 2pass algo */
612 if( h->param.rc.b_stat_read )
614 char *p, *stats_in, *stats_buf;
616 /* read 1st pass stats */
617 assert( h->param.rc.psz_stat_in );
618 stats_buf = stats_in = x264_slurp_file( h->param.rc.psz_stat_in );
621 x264_log(h, X264_LOG_ERROR, "ratecontrol_init: can't open stats file\n");
624 if( h->param.rc.b_mb_tree )
626 char *mbtree_stats_in = x264_strcat_filename( h->param.rc.psz_stat_in, ".mbtree" );
627 if( !mbtree_stats_in )
629 rc->p_mbtree_stat_file_in = fopen( mbtree_stats_in, "rb" );
630 x264_free( mbtree_stats_in );
631 if( !rc->p_mbtree_stat_file_in )
633 x264_log(h, X264_LOG_ERROR, "ratecontrol_init: can't open mbtree stats file\n");
638 /* check whether 1st pass options were compatible with current options */
639 if( !strncmp( stats_buf, "#options:", 9 ) )
642 char *opts = stats_buf;
643 stats_in = strchr( stats_buf, '\n' );
648 if( sscanf( opts, "#options: %dx%d", &i, &j ) != 2 )
650 x264_log( h, X264_LOG_ERROR, "resolution specified in stats file not valid\n" );
653 else if( h->param.rc.b_mb_tree && (i != h->param.i_width || j != h->param.i_height) )
655 x264_log( h, X264_LOG_ERROR, "MB-tree doesn't support different resolution than 1st pass (%dx%d vs %dx%d)\n",
656 h->param.i_width, h->param.i_height, i, j );
660 if( ( p = strstr( opts, "timebase=" ) ) && sscanf( p, "timebase=%d/%d", &i, &j ) != 2 )
662 x264_log( h, X264_LOG_ERROR, "timebase specified in stats file not valid\n" );
665 if( i != h->param.i_timebase_num || j != h->param.i_timebase_den )
667 x264_log( h, X264_LOG_ERROR, "timebase mismatch with 1st pass (%d/%d vs %d/%d)\n",
668 h->param.i_timebase_num, h->param.i_timebase_den, i, j );
672 CMP_OPT_FIRST_PASS( "wpredp", X264_MAX( 0, h->param.analyse.i_weighted_pred ) );
673 CMP_OPT_FIRST_PASS( "bframes", h->param.i_bframe );
674 CMP_OPT_FIRST_PASS( "b_pyramid", h->param.i_bframe_pyramid );
675 CMP_OPT_FIRST_PASS( "intra_refresh", h->param.b_intra_refresh );
676 CMP_OPT_FIRST_PASS( "keyint", h->param.i_keyint_max );
678 if( strstr( opts, "qp=0" ) && h->param.rc.i_rc_method == X264_RC_ABR )
679 x264_log( h, X264_LOG_WARNING, "1st pass was lossless, bitrate prediction will be inaccurate\n" );
681 if( !strstr( opts, "direct=3" ) && h->param.analyse.i_direct_mv_pred == X264_DIRECT_PRED_AUTO )
683 x264_log( h, X264_LOG_WARNING, "direct=auto not used on the first pass\n" );
684 h->mb.b_direct_auto_write = 1;
687 if( ( p = strstr( opts, "b_adapt=" ) ) && sscanf( p, "b_adapt=%d", &i ) && i >= X264_B_ADAPT_NONE && i <= X264_B_ADAPT_TRELLIS )
688 h->param.i_bframe_adaptive = i;
689 else if( h->param.i_bframe )
691 x264_log( h, X264_LOG_ERROR, "b_adapt method specified in stats file not valid\n" );
695 if( h->param.rc.b_mb_tree && ( p = strstr( opts, "rc_lookahead=" ) ) && sscanf( p, "rc_lookahead=%d", &i ) )
696 h->param.rc.i_lookahead = i;
699 /* find number of pics */
702 for( num_entries = -1; p; num_entries++ )
703 p = strchr( p + 1, ';' );
706 x264_log(h, X264_LOG_ERROR, "empty stats file\n");
709 rc->num_entries = num_entries;
711 if( h->param.i_frame_total < rc->num_entries && h->param.i_frame_total > 0 )
713 x264_log( h, X264_LOG_WARNING, "2nd pass has fewer frames than 1st pass (%d vs %d)\n",
714 h->param.i_frame_total, rc->num_entries );
716 if( h->param.i_frame_total > rc->num_entries )
718 x264_log( h, X264_LOG_ERROR, "2nd pass has more frames than 1st pass (%d vs %d)\n",
719 h->param.i_frame_total, rc->num_entries );
723 CHECKED_MALLOCZERO( rc->entry, rc->num_entries * sizeof(ratecontrol_entry_t) );
725 /* init all to skipped p frames */
726 for( int i = 0; i < rc->num_entries; i++ )
728 ratecontrol_entry_t *rce = &rc->entry[i];
729 rce->pict_type = SLICE_TYPE_P;
730 rce->qscale = rce->new_qscale = qp2qscale( 20 );
731 rce->misc_bits = rc->nmb + 10;
737 for( int i = 0; i < rc->num_entries; i++ )
739 ratecontrol_entry_t *rce;
747 next= strchr(p, ';');
749 *next++ = 0; //sscanf is unbelievably slow on long strings
750 e = sscanf( p, " in:%d ", &frame_number );
752 if( frame_number < 0 || frame_number >= rc->num_entries )
754 x264_log( h, X264_LOG_ERROR, "bad frame number (%d) at stats line %d\n", frame_number, i );
757 rce = &rc->entry[frame_number];
758 rce->direct_mode = 0;
760 e += sscanf( p, " in:%*d out:%*d type:%c dur:%d cpbdur:%d q:%f tex:%d mv:%d misc:%d imb:%d pmb:%d smb:%d d:%c",
761 &pict_type, &rce->i_duration, &rce->i_cpb_duration, &qp, &rce->tex_bits,
762 &rce->mv_bits, &rce->misc_bits, &rce->i_count, &rce->p_count,
763 &rce->s_count, &rce->direct_mode );
765 p = strstr( p, "ref:" );
769 for( ref = 0; ref < 16; ref++ )
771 if( sscanf( p, " %d", &rce->refcount[ref] ) != 1 )
773 p = strchr( p+1, ' ' );
780 rce->i_weight_denom = -1;
781 char *w = strchr( p, 'w' );
783 if( sscanf( w, "w:%hd,%hd,%hd", &rce->i_weight_denom, &rce->weight[0], &rce->weight[1] ) != 3 )
784 rce->i_weight_denom = -1;
786 if( pict_type != 'b' )
787 rce->kept_as_ref = 1;
791 rce->frame_type = X264_TYPE_IDR;
792 rce->pict_type = SLICE_TYPE_I;
795 rce->frame_type = X264_TYPE_I;
796 rce->pict_type = SLICE_TYPE_I;
799 rce->frame_type = X264_TYPE_P;
800 rce->pict_type = SLICE_TYPE_P;
803 rce->frame_type = X264_TYPE_BREF;
804 rce->pict_type = SLICE_TYPE_B;
807 rce->frame_type = X264_TYPE_B;
808 rce->pict_type = SLICE_TYPE_B;
810 default: e = -1; break;
815 x264_log( h, X264_LOG_ERROR, "statistics are damaged at line %d, parser out=%d\n", i, e );
818 rce->qscale = qp2qscale( qp );
822 x264_free( stats_buf );
824 if( h->param.rc.i_rc_method == X264_RC_ABR )
826 if( init_pass2( h ) < 0 )
828 } /* else we're using constant quant, so no need to run the bitrate allocation */
831 /* Open output file */
832 /* If input and output files are the same, output to a temp file
833 * and move it to the real name only when it's complete */
834 if( h->param.rc.b_stat_write )
837 rc->psz_stat_file_tmpname = x264_strcat_filename( h->param.rc.psz_stat_out, ".temp" );
838 if( !rc->psz_stat_file_tmpname )
841 rc->p_stat_file_out = fopen( rc->psz_stat_file_tmpname, "wb" );
842 if( rc->p_stat_file_out == NULL )
844 x264_log(h, X264_LOG_ERROR, "ratecontrol_init: can't open stats file\n");
848 p = x264_param2string( &h->param, 1 );
850 fprintf( rc->p_stat_file_out, "#options: %s\n", p );
852 if( h->param.rc.b_mb_tree && !h->param.rc.b_stat_read )
854 rc->psz_mbtree_stat_file_tmpname = x264_strcat_filename( h->param.rc.psz_stat_out, ".mbtree.temp" );
855 rc->psz_mbtree_stat_file_name = x264_strcat_filename( h->param.rc.psz_stat_out, ".mbtree" );
856 if( !rc->psz_mbtree_stat_file_tmpname || !rc->psz_mbtree_stat_file_name )
859 rc->p_mbtree_stat_file_out = fopen( rc->psz_mbtree_stat_file_tmpname, "wb" );
860 if( rc->p_mbtree_stat_file_out == NULL )
862 x264_log(h, X264_LOG_ERROR, "ratecontrol_init: can't open mbtree stats file\n");
868 if( h->param.rc.b_mb_tree && (h->param.rc.b_stat_read || h->param.rc.b_stat_write) )
870 CHECKED_MALLOC( rc->qp_buffer[0], h->mb.i_mb_count * sizeof(uint16_t) );
871 if( h->param.i_bframe_pyramid && h->param.rc.b_stat_read )
872 CHECKED_MALLOC( rc->qp_buffer[1], h->mb.i_mb_count * sizeof(uint16_t) );
876 for( int i = 0; i<h->param.i_threads; i++ )
878 h->thread[i]->rc = rc+i;
882 h->thread[i]->param = h->param;
883 h->thread[i]->mb.b_variable_qp = h->mb.b_variable_qp;
892 static int parse_zone( x264_t *h, x264_zone_t *z, char *p )
895 char *tok, UNUSED *saveptr=NULL;
897 z->f_bitrate_factor = 1;
898 if( 3 <= sscanf(p, "%u,%u,q=%u%n", &z->i_start, &z->i_end, &z->i_qp, &len) )
900 else if( 3 <= sscanf(p, "%u,%u,b=%f%n", &z->i_start, &z->i_end, &z->f_bitrate_factor, &len) )
902 else if( 2 <= sscanf(p, "%u,%u%n", &z->i_start, &z->i_end, &len) )
906 x264_log( h, X264_LOG_ERROR, "invalid zone: \"%s\"\n", p );
912 CHECKED_MALLOC( z->param, sizeof(x264_param_t) );
913 memcpy( z->param, &h->param, sizeof(x264_param_t) );
914 z->param->param_free = x264_free;
915 while( (tok = strtok_r( p, ",", &saveptr )) )
917 char *val = strchr( tok, '=' );
923 if( x264_param_parse( z->param, tok, val ) )
925 x264_log( h, X264_LOG_ERROR, "invalid zone param: %s = %s\n", tok, val );
935 static int parse_zones( x264_t *h )
937 x264_ratecontrol_t *rc = h->rc;
938 if( h->param.rc.psz_zones && !h->param.rc.i_zones )
941 CHECKED_MALLOC( psz_zones, strlen( h->param.rc.psz_zones )+1 );
942 strcpy( psz_zones, h->param.rc.psz_zones );
943 h->param.rc.i_zones = 1;
944 for( p = psz_zones; *p; p++ )
945 h->param.rc.i_zones += (*p == '/');
946 CHECKED_MALLOC( h->param.rc.zones, h->param.rc.i_zones * sizeof(x264_zone_t) );
948 for( int i = 0; i < h->param.rc.i_zones; i++ )
950 int i_tok = strcspn( p, "/" );
952 if( parse_zone( h, &h->param.rc.zones[i], p ) )
956 x264_free( psz_zones );
959 if( h->param.rc.i_zones > 0 )
961 for( int i = 0; i < h->param.rc.i_zones; i++ )
963 x264_zone_t z = h->param.rc.zones[i];
964 if( z.i_start < 0 || z.i_start > z.i_end )
966 x264_log( h, X264_LOG_ERROR, "invalid zone: start=%d end=%d\n",
967 z.i_start, z.i_end );
970 else if( !z.b_force_qp && z.f_bitrate_factor <= 0 )
972 x264_log( h, X264_LOG_ERROR, "invalid zone: bitrate_factor=%f\n",
973 z.f_bitrate_factor );
978 rc->i_zones = h->param.rc.i_zones + 1;
979 CHECKED_MALLOC( rc->zones, rc->i_zones * sizeof(x264_zone_t) );
980 memcpy( rc->zones+1, h->param.rc.zones, (rc->i_zones-1) * sizeof(x264_zone_t) );
982 // default zone to fall back to if none of the others match
983 rc->zones[0].i_start = 0;
984 rc->zones[0].i_end = INT_MAX;
985 rc->zones[0].b_force_qp = 0;
986 rc->zones[0].f_bitrate_factor = 1;
987 CHECKED_MALLOC( rc->zones[0].param, sizeof(x264_param_t) );
988 memcpy( rc->zones[0].param, &h->param, sizeof(x264_param_t) );
989 for( int i = 1; i < rc->i_zones; i++ )
991 if( !rc->zones[i].param )
992 rc->zones[i].param = rc->zones[0].param;
1001 static x264_zone_t *get_zone( x264_t *h, int frame_num )
1003 for( int i = h->rc->i_zones - 1; i >= 0; i-- )
1005 x264_zone_t *z = &h->rc->zones[i];
1006 if( frame_num >= z->i_start && frame_num <= z->i_end )
1012 void x264_ratecontrol_summary( x264_t *h )
1014 x264_ratecontrol_t *rc = h->rc;
1015 if( rc->b_abr && h->param.rc.i_rc_method == X264_RC_ABR && rc->cbr_decay > .9999 )
1017 double base_cplx = h->mb.i_mb_count * (h->param.i_bframe ? 120 : 80);
1018 double mbtree_offset = h->param.rc.b_mb_tree ? (1.0-h->param.rc.f_qcompress)*13.5 : 0;
1019 x264_log( h, X264_LOG_INFO, "final ratefactor: %.2f\n",
1020 qscale2qp( pow( base_cplx, 1 - rc->qcompress )
1021 * rc->cplxr_sum / rc->wanted_bits_window ) - mbtree_offset );
1025 void x264_ratecontrol_delete( x264_t *h )
1027 x264_ratecontrol_t *rc = h->rc;
1030 if( rc->p_stat_file_out )
1032 b_regular_file = x264_is_regular_file( rc->p_stat_file_out );
1033 fclose( rc->p_stat_file_out );
1034 if( h->i_frame >= rc->num_entries && b_regular_file )
1035 if( rename( rc->psz_stat_file_tmpname, h->param.rc.psz_stat_out ) != 0 )
1037 x264_log( h, X264_LOG_ERROR, "failed to rename \"%s\" to \"%s\"\n",
1038 rc->psz_stat_file_tmpname, h->param.rc.psz_stat_out );
1040 x264_free( rc->psz_stat_file_tmpname );
1042 if( rc->p_mbtree_stat_file_out )
1044 b_regular_file = x264_is_regular_file( rc->p_mbtree_stat_file_out );
1045 fclose( rc->p_mbtree_stat_file_out );
1046 if( h->i_frame >= rc->num_entries && b_regular_file )
1047 if( rename( rc->psz_mbtree_stat_file_tmpname, rc->psz_mbtree_stat_file_name ) != 0 )
1049 x264_log( h, X264_LOG_ERROR, "failed to rename \"%s\" to \"%s\"\n",
1050 rc->psz_mbtree_stat_file_tmpname, rc->psz_mbtree_stat_file_name );
1052 x264_free( rc->psz_mbtree_stat_file_tmpname );
1053 x264_free( rc->psz_mbtree_stat_file_name );
1055 if( rc->p_mbtree_stat_file_in )
1056 fclose( rc->p_mbtree_stat_file_in );
1057 x264_free( rc->pred );
1058 x264_free( rc->pred_b_from_p );
1059 x264_free( rc->entry );
1060 x264_free( rc->qp_buffer[0] );
1061 x264_free( rc->qp_buffer[1] );
1064 x264_free( rc->zones[0].param );
1065 for( int i = 1; i < rc->i_zones; i++ )
1066 if( rc->zones[i].param != rc->zones[0].param && rc->zones[i].param->param_free )
1067 rc->zones[i].param->param_free( rc->zones[i].param );
1068 x264_free( rc->zones );
1073 static void accum_p_qp_update( x264_t *h, float qp )
1075 x264_ratecontrol_t *rc = h->rc;
1076 rc->accum_p_qp *= .95;
1077 rc->accum_p_norm *= .95;
1078 rc->accum_p_norm += 1;
1079 if( h->sh.i_type == SLICE_TYPE_I )
1080 rc->accum_p_qp += qp + rc->ip_offset;
1082 rc->accum_p_qp += qp;
1085 /* Before encoding a frame, choose a QP for it */
1086 void x264_ratecontrol_start( x264_t *h, int i_force_qp, int overhead )
1088 x264_ratecontrol_t *rc = h->rc;
1089 ratecontrol_entry_t *rce = NULL;
1090 x264_zone_t *zone = get_zone( h, h->fenc->i_frame );
1095 if( zone && (!rc->prev_zone || zone->param != rc->prev_zone->param) )
1096 x264_encoder_reconfig( h, zone->param );
1097 rc->prev_zone = zone;
1099 rc->qp_force = i_force_qp;
1101 if( h->param.rc.b_stat_read )
1103 int frame = h->fenc->i_frame;
1104 assert( frame >= 0 && frame < rc->num_entries );
1105 rce = h->rc->rce = &h->rc->entry[frame];
1107 if( h->sh.i_type == SLICE_TYPE_B
1108 && h->param.analyse.i_direct_mv_pred == X264_DIRECT_PRED_AUTO )
1110 h->sh.b_direct_spatial_mv_pred = ( rce->direct_mode == 's' );
1111 h->mb.b_direct_auto_read = ( rce->direct_mode == 's' || rce->direct_mode == 't' );
1117 memset( h->fdec->i_row_bits, 0, h->sps->i_mb_height * sizeof(int) );
1118 rc->row_pred = &rc->row_preds[h->sh.i_type];
1119 rc->buffer_rate = h->fenc->i_cpb_duration * rc->vbv_max_rate * h->sps->vui.i_num_units_in_tick / h->sps->vui.i_time_scale;
1120 update_vbv_plan( h, overhead );
1122 const x264_level_t *l = x264_levels;
1123 while( l->level_idc != 0 && l->level_idc != h->param.i_level_idc )
1126 int mincr = l->mincr;
1128 /* Blu-ray requires this */
1129 if( l->level_idc == 41 && h->param.i_nal_hrd )
1132 /* The spec has a bizarre special case for the first frame. */
1133 if( h->i_frame == 0 )
1135 //384 * ( Max( PicSizeInMbs, fR * MaxMBPS ) + MaxMBPS * ( tr( 0 ) - tr,n( 0 ) ) ) / MinCR
1136 double fr = 1. / 172;
1137 int pic_size_in_mbs = h->sps->i_mb_width * h->sps->i_mb_height;
1138 rc->frame_size_maximum = 384 * 8 * X264_MAX( pic_size_in_mbs, fr*l->mbps ) / mincr;
1142 //384 * MaxMBPS * ( tr( n ) - tr( n - 1 ) ) / MinCR
1143 rc->frame_size_maximum = 384 * 8 * ((double)h->fenc->i_cpb_duration * h->sps->vui.i_num_units_in_tick / h->sps->vui.i_time_scale) * l->mbps / mincr;
1147 if( h->sh.i_type != SLICE_TYPE_B )
1148 rc->bframes = h->fenc->i_bframes;
1154 else if( rc->b_abr )
1156 q = qscale2qp( rate_estimate_qscale( h ) );
1158 else if( rc->b_2pass )
1160 rce->new_qscale = rate_estimate_qscale( h );
1161 q = qscale2qp( rce->new_qscale );
1165 if( h->sh.i_type == SLICE_TYPE_B && h->fdec->b_kept_as_ref )
1166 q = ( rc->qp_constant[ SLICE_TYPE_B ] + rc->qp_constant[ SLICE_TYPE_P ] ) / 2;
1168 q = rc->qp_constant[ h->sh.i_type ];
1172 if( zone->b_force_qp )
1173 q += zone->i_qp - rc->qp_constant[SLICE_TYPE_P];
1175 q -= 6*log2f( zone->f_bitrate_factor );
1179 q = x264_clip3f( q, h->param.rc.i_qp_min, h->param.rc.i_qp_max );
1184 rc->qp = x264_clip3( (int)(q + 0.5), 0, 51 );
1185 h->fdec->f_qp_avg_rc =
1186 h->fdec->f_qp_avg_aq =
1189 rce->new_qp = rc->qp;
1191 accum_p_qp_update( h, rc->f_qpm );
1193 if( h->sh.i_type != SLICE_TYPE_B )
1194 rc->last_non_b_pict_type = h->sh.i_type;
1197 static double predict_row_size( x264_t *h, int y, int qp )
1199 /* average between two predictors:
1200 * absolute SATD, and scaled bit cost of the colocated row in the previous frame */
1201 x264_ratecontrol_t *rc = h->rc;
1202 double pred_s = predict_size( rc->row_pred[0], qp2qscale( qp ), h->fdec->i_row_satd[y] );
1204 if( h->sh.i_type == SLICE_TYPE_I || qp >= h->fref0[0]->i_row_qp[y] )
1206 if( h->sh.i_type == SLICE_TYPE_P
1207 && h->fref0[0]->i_type == h->fdec->i_type
1208 && h->fref0[0]->i_row_satd[y] > 0
1209 && (abs(h->fref0[0]->i_row_satd[y] - h->fdec->i_row_satd[y]) < h->fdec->i_row_satd[y]/2))
1211 pred_t = h->fref0[0]->i_row_bits[y] * h->fdec->i_row_satd[y] / h->fref0[0]->i_row_satd[y]
1212 * qp2qscale( h->fref0[0]->i_row_qp[y] ) / qp2qscale( qp );
1216 return (pred_s + pred_t) / 2;
1218 /* Our QP is lower than the reference! */
1221 double pred_intra = predict_size( rc->row_pred[1], qp2qscale( qp ), h->fdec->i_row_satds[0][0][y] );
1222 /* Sum: better to overestimate than underestimate by using only one of the two predictors. */
1223 return pred_intra + pred_s;
1227 static double row_bits_so_far( x264_t *h, int y )
1230 for( int i = h->i_threadslice_start; i <= y; i++ )
1231 bits += h->fdec->i_row_bits[i];
1235 static double predict_row_size_sum( x264_t *h, int y, int qp )
1237 double bits = row_bits_so_far(h, y);
1238 for( int i = y+1; i < h->i_threadslice_end; i++ )
1239 bits += predict_row_size( h, i, qp );
1244 void x264_ratecontrol_mb( x264_t *h, int bits )
1246 x264_ratecontrol_t *rc = h->rc;
1247 const int y = h->mb.i_mb_y;
1251 h->fdec->i_row_bits[y] += bits;
1252 rc->qpa_rc += rc->f_qpm;
1253 rc->qpa_aq += h->mb.i_qp;
1255 if( h->mb.i_mb_x != h->sps->i_mb_width - 1 || !rc->b_vbv )
1258 h->fdec->i_row_qp[y] = rc->qpm;
1260 update_predictor( rc->row_pred[0], qp2qscale( rc->qpm ), h->fdec->i_row_satd[y], h->fdec->i_row_bits[y] );
1261 if( h->sh.i_type == SLICE_TYPE_P && rc->qpm < h->fref0[0]->i_row_qp[y] )
1262 update_predictor( rc->row_pred[1], qp2qscale( rc->qpm ), h->fdec->i_row_satds[0][0][y], h->fdec->i_row_bits[y] );
1264 /* tweak quality based on difference from predicted size */
1265 if( y < h->i_threadslice_end-1 )
1267 int prev_row_qp = h->fdec->i_row_qp[y];
1268 int i_qp_min = X264_MAX( prev_row_qp - h->param.rc.i_qp_step, h->param.rc.i_qp_min );
1269 int i_qp_absolute_max = h->param.rc.i_qp_max;
1270 if( rc->rate_factor_max_increment )
1271 i_qp_absolute_max = X264_MIN( i_qp_absolute_max, rc->qp_novbv + rc->rate_factor_max_increment );
1272 int i_qp_max = X264_MIN( prev_row_qp + h->param.rc.i_qp_step, i_qp_absolute_max );
1274 /* B-frames shouldn't use lower QP than their reference frames. */
1275 if( h->sh.i_type == SLICE_TYPE_B )
1277 i_qp_min = X264_MAX( i_qp_min, X264_MAX( h->fref0[0]->i_row_qp[y+1], h->fref1[0]->i_row_qp[y+1] ) );
1278 rc->qpm = X264_MAX( rc->qpm, i_qp_min );
1281 float buffer_left_planned = rc->buffer_fill - rc->frame_size_planned;
1282 float slice_size_planned = h->param.b_sliced_threads ? rc->slice_size_planned : rc->frame_size_planned;
1283 float size_of_other_slices = 0;
1284 if( h->param.b_sliced_threads )
1286 for( int i = 0; i < h->param.i_threads; i++ )
1287 if( h != h->thread[i] )
1288 size_of_other_slices += h->thread[i]->rc->frame_size_estimated;
1291 rc->max_frame_error = X264_MAX( 0.05, 1.0 / (h->sps->i_mb_width) );
1293 /* More threads means we have to be more cautious in letting ratecontrol use up extra bits. */
1294 float rc_tol = buffer_left_planned / h->param.i_threads * rc->rate_tolerance;
1295 int b1 = predict_row_size_sum( h, y, rc->qpm ) + size_of_other_slices;
1297 /* Don't modify the row QPs until a sufficent amount of the bits of the frame have been processed, in case a flat */
1298 /* area at the top of the frame was measured inaccurately. */
1299 if( row_bits_so_far( h, y ) < 0.05 * slice_size_planned )
1302 if( h->sh.i_type != SLICE_TYPE_I )
1305 if( !rc->b_vbv_min_rate )
1306 i_qp_min = X264_MAX( i_qp_min, h->sh.i_qp );
1308 while( rc->qpm < i_qp_max
1309 && ((b1 > rc->frame_size_planned + rc_tol) ||
1310 (rc->buffer_fill - b1 < buffer_left_planned * 0.5) ||
1311 (b1 > rc->frame_size_planned && rc->qpm < rc->qp_novbv)) )
1314 b1 = predict_row_size_sum( h, y, rc->qpm ) + size_of_other_slices;
1317 while( rc->qpm > i_qp_min
1318 && (rc->qpm > h->fdec->i_row_qp[0] || rc->single_frame_vbv)
1319 && ((b1 < rc->frame_size_planned * 0.8 && rc->qpm <= prev_row_qp)
1320 || b1 < (rc->buffer_fill - rc->buffer_size + rc->buffer_rate) * 1.1) )
1323 b1 = predict_row_size_sum( h, y, rc->qpm ) + size_of_other_slices;
1326 /* avoid VBV underflow or MinCR violation */
1327 while( (rc->qpm < i_qp_absolute_max)
1328 && ((rc->buffer_fill - b1 < rc->buffer_rate * rc->max_frame_error) ||
1329 (rc->frame_size_maximum - b1 < rc->frame_size_maximum * rc->max_frame_error)))
1332 b1 = predict_row_size_sum( h, y, rc->qpm ) + size_of_other_slices;
1335 h->rc->frame_size_estimated = predict_row_size_sum( h, y, rc->qpm );
1338 /* loses the fractional part of the frame-wise qp */
1339 rc->f_qpm = rc->qpm;
1342 int x264_ratecontrol_qp( x264_t *h )
1347 /* In 2pass, force the same frame types as in the 1st pass */
1348 int x264_ratecontrol_slice_type( x264_t *h, int frame_num )
1350 x264_ratecontrol_t *rc = h->rc;
1351 if( h->param.rc.b_stat_read )
1353 if( frame_num >= rc->num_entries )
1355 /* We could try to initialize everything required for ABR and
1356 * adaptive B-frames, but that would be complicated.
1357 * So just calculate the average QP used so far. */
1358 h->param.rc.i_qp_constant = (h->stat.i_frame_count[SLICE_TYPE_P] == 0) ? 24
1359 : 1 + h->stat.f_frame_qp[SLICE_TYPE_P] / h->stat.i_frame_count[SLICE_TYPE_P];
1360 rc->qp_constant[SLICE_TYPE_P] = x264_clip3( h->param.rc.i_qp_constant, 0, 51 );
1361 rc->qp_constant[SLICE_TYPE_I] = x264_clip3( (int)( qscale2qp( qp2qscale( h->param.rc.i_qp_constant ) / fabs( h->param.rc.f_ip_factor )) + 0.5 ), 0, 51 );
1362 rc->qp_constant[SLICE_TYPE_B] = x264_clip3( (int)( qscale2qp( qp2qscale( h->param.rc.i_qp_constant ) * fabs( h->param.rc.f_pb_factor )) + 0.5 ), 0, 51 );
1364 x264_log(h, X264_LOG_ERROR, "2nd pass has more frames than 1st pass (%d)\n", rc->num_entries);
1365 x264_log(h, X264_LOG_ERROR, "continuing anyway, at constant QP=%d\n", h->param.rc.i_qp_constant);
1366 if( h->param.i_bframe_adaptive )
1367 x264_log(h, X264_LOG_ERROR, "disabling adaptive B-frames\n");
1369 for( int i = 0; i < h->param.i_threads; i++ )
1371 h->thread[i]->rc->b_abr = 0;
1372 h->thread[i]->rc->b_2pass = 0;
1373 h->thread[i]->param.rc.i_rc_method = X264_RC_CQP;
1374 h->thread[i]->param.rc.b_stat_read = 0;
1375 h->thread[i]->param.i_bframe_adaptive = 0;
1376 h->thread[i]->param.i_scenecut_threshold = 0;
1377 h->thread[i]->param.rc.b_mb_tree = 0;
1378 if( h->thread[i]->param.i_bframe > 1 )
1379 h->thread[i]->param.i_bframe = 1;
1381 return X264_TYPE_AUTO;
1383 return rc->entry[frame_num].frame_type;
1386 return X264_TYPE_AUTO;
1389 void x264_ratecontrol_set_weights( x264_t *h, x264_frame_t *frm )
1391 ratecontrol_entry_t *rce = &h->rc->entry[frm->i_frame];
1392 if( h->param.analyse.i_weighted_pred <= 0 )
1394 if( rce->i_weight_denom >= 0 )
1395 SET_WEIGHT( frm->weight[0][0], 1, rce->weight[0], rce->i_weight_denom, rce->weight[1] );
1398 /* After encoding one frame, save stats and update ratecontrol state */
1399 int x264_ratecontrol_end( x264_t *h, int bits, int *filler )
1401 x264_ratecontrol_t *rc = h->rc;
1402 const int *mbs = h->stat.frame.i_mb_count;
1406 h->stat.frame.i_mb_count_skip = mbs[P_SKIP] + mbs[B_SKIP];
1407 h->stat.frame.i_mb_count_i = mbs[I_16x16] + mbs[I_8x8] + mbs[I_4x4];
1408 h->stat.frame.i_mb_count_p = mbs[P_L0] + mbs[P_8x8];
1409 for( int i = B_DIRECT; i < B_8x8; i++ )
1410 h->stat.frame.i_mb_count_p += mbs[i];
1412 h->fdec->f_qp_avg_rc = rc->qpa_rc /= h->mb.i_mb_count;
1413 h->fdec->f_qp_avg_aq = rc->qpa_aq /= h->mb.i_mb_count;
1415 if( h->param.rc.b_stat_write )
1417 char c_type = h->sh.i_type==SLICE_TYPE_I ? (h->fenc->i_poc==0 ? 'I' : 'i')
1418 : h->sh.i_type==SLICE_TYPE_P ? 'P'
1419 : h->fenc->b_kept_as_ref ? 'B' : 'b';
1420 int dir_frame = h->stat.frame.i_direct_score[1] - h->stat.frame.i_direct_score[0];
1421 int dir_avg = h->stat.i_direct_score[1] - h->stat.i_direct_score[0];
1422 char c_direct = h->mb.b_direct_auto_write ?
1423 ( dir_frame>0 ? 's' : dir_frame<0 ? 't' :
1424 dir_avg>0 ? 's' : dir_avg<0 ? 't' : '-' )
1426 if( fprintf( rc->p_stat_file_out,
1427 "in:%d out:%d type:%c dur:%d cpbdur:%d q:%.2f tex:%d mv:%d misc:%d imb:%d pmb:%d smb:%d d:%c ref:",
1428 h->fenc->i_frame, h->i_frame,
1429 c_type, h->fenc->i_duration,
1430 h->fenc->i_cpb_duration, rc->qpa_rc,
1431 h->stat.frame.i_tex_bits,
1432 h->stat.frame.i_mv_bits,
1433 h->stat.frame.i_misc_bits,
1434 h->stat.frame.i_mb_count_i,
1435 h->stat.frame.i_mb_count_p,
1436 h->stat.frame.i_mb_count_skip,
1440 /* Only write information for reference reordering once. */
1441 int use_old_stats = h->param.rc.b_stat_read && rc->rce->refs > 1;
1442 for( int i = 0; i < (use_old_stats ? rc->rce->refs : h->i_ref0); i++ )
1444 int refcount = use_old_stats ? rc->rce->refcount[i]
1445 : h->param.b_interlaced ? h->stat.frame.i_mb_count_ref[0][i*2]
1446 + h->stat.frame.i_mb_count_ref[0][i*2+1]
1447 : h->stat.frame.i_mb_count_ref[0][i];
1448 if( fprintf( rc->p_stat_file_out, "%d ", refcount ) < 0 )
1452 if( h->sh.weight[0][0].weightfn )
1454 if( fprintf( rc->p_stat_file_out, "w:%"PRId32",%"PRId32",%"PRId32, h->sh.weight[0][0].i_denom, h->sh.weight[0][0].i_scale, h->sh.weight[0][0].i_offset ) < 0 )
1458 if( fprintf( rc->p_stat_file_out, ";\n") < 0 )
1461 /* Don't re-write the data in multi-pass mode. */
1462 if( h->param.rc.b_mb_tree && h->fenc->b_kept_as_ref && !h->param.rc.b_stat_read )
1464 uint8_t i_type = h->sh.i_type;
1465 /* Values are stored as big-endian FIX8.8 */
1466 for( int i = 0; i < h->mb.i_mb_count; i++ )
1467 rc->qp_buffer[0][i] = endian_fix16( h->fenc->f_qp_offset[i]*256.0 );
1468 if( fwrite( &i_type, 1, 1, rc->p_mbtree_stat_file_out ) < 1 )
1470 if( fwrite( rc->qp_buffer[0], sizeof(uint16_t), h->mb.i_mb_count, rc->p_mbtree_stat_file_out ) < h->mb.i_mb_count )
1477 if( h->sh.i_type != SLICE_TYPE_B )
1478 rc->cplxr_sum += bits * qp2qscale( rc->qpa_rc ) / rc->last_rceq;
1481 /* Depends on the fact that B-frame's QP is an offset from the following P-frame's.
1482 * Not perfectly accurate with B-refs, but good enough. */
1483 rc->cplxr_sum += bits * qp2qscale( rc->qpa_rc ) / (rc->last_rceq * fabs( h->param.rc.f_pb_factor ));
1485 rc->cplxr_sum *= rc->cbr_decay;
1486 double frame_duration = (double)h->fenc->i_duration * h->sps->vui.i_num_units_in_tick / h->sps->vui.i_time_scale;
1488 rc->wanted_bits_window += frame_duration * rc->bitrate;
1489 rc->wanted_bits_window *= rc->cbr_decay;
1493 rc->expected_bits_sum += qscale2bits( rc->rce, qp2qscale( rc->rce->new_qp ) );
1495 if( h->mb.b_variable_qp )
1497 if( h->sh.i_type == SLICE_TYPE_B )
1499 rc->bframe_bits += bits;
1500 if( h->fenc->b_last_minigop_bframe )
1502 update_predictor( rc->pred_b_from_p, qp2qscale( rc->qpa_rc ),
1503 h->fref1[h->i_ref1-1]->i_satd, rc->bframe_bits / rc->bframes );
1504 rc->bframe_bits = 0;
1509 *filler = update_vbv( h, bits );
1511 if( h->sps->vui.b_nal_hrd_parameters_present )
1513 if( h->fenc->i_frame == 0 )
1515 // access unit initialises the HRD
1516 h->fenc->hrd_timing.cpb_initial_arrival_time = 0;
1517 rc->initial_cpb_removal_delay = h->initial_cpb_removal_delay;
1518 rc->initial_cpb_removal_delay_offset = h->initial_cpb_removal_delay_offset;
1519 h->fenc->hrd_timing.cpb_removal_time = rc->nrt_first_access_unit = (double)rc->initial_cpb_removal_delay / 90000;
1523 h->fenc->hrd_timing.cpb_removal_time = rc->nrt_first_access_unit + (double)h->fenc->i_cpb_delay *
1524 h->sps->vui.i_num_units_in_tick / h->sps->vui.i_time_scale;
1526 double cpb_earliest_arrival_time = h->fenc->hrd_timing.cpb_removal_time - (double)rc->initial_cpb_removal_delay / 90000;
1527 if( h->fenc->b_keyframe )
1529 rc->nrt_first_access_unit = h->fenc->hrd_timing.cpb_removal_time;
1530 rc->initial_cpb_removal_delay = h->initial_cpb_removal_delay;
1531 rc->initial_cpb_removal_delay_offset = h->initial_cpb_removal_delay_offset;
1534 cpb_earliest_arrival_time -= (double)rc->initial_cpb_removal_delay_offset / 90000;
1536 if( h->sps->vui.hrd.b_cbr_hrd )
1537 h->fenc->hrd_timing.cpb_initial_arrival_time = rc->previous_cpb_final_arrival_time;
1539 h->fenc->hrd_timing.cpb_initial_arrival_time = X264_MAX( rc->previous_cpb_final_arrival_time, cpb_earliest_arrival_time );
1541 int filler_bits = *filler ? X264_MAX( (FILLER_OVERHEAD - h->param.b_annexb), *filler )*8 : 0;
1543 h->fenc->hrd_timing.cpb_final_arrival_time = rc->previous_cpb_final_arrival_time = h->fenc->hrd_timing.cpb_initial_arrival_time +
1544 (double)(bits + filler_bits) / h->sps->vui.hrd.i_bit_rate_unscaled;
1546 h->fenc->hrd_timing.dpb_output_time = (double)h->fenc->i_dpb_output_delay * h->sps->vui.i_num_units_in_tick / h->sps->vui.i_time_scale +
1547 h->fenc->hrd_timing.cpb_removal_time;
1552 x264_log(h, X264_LOG_ERROR, "ratecontrol_end: stats file could not be written to\n");
1556 /****************************************************************************
1558 ***************************************************************************/
1561 * modify the bitrate curve from pass1 for one frame
1563 static double get_qscale(x264_t *h, ratecontrol_entry_t *rce, double rate_factor, int frame_num)
1565 x264_ratecontrol_t *rcc= h->rc;
1566 x264_zone_t *zone = get_zone( h, frame_num );
1567 double q = pow( rce->blurred_complexity, 1 - rcc->qcompress );
1569 // avoid NaN's in the rc_eq
1570 if( !isfinite(q) || rce->tex_bits + rce->mv_bits == 0 )
1571 q = rcc->last_qscale_for[rce->pict_type];
1576 rcc->last_qscale = q;
1581 if( zone->b_force_qp )
1582 q = qp2qscale( zone->i_qp );
1584 q /= zone->f_bitrate_factor;
1590 static double get_diff_limited_q(x264_t *h, ratecontrol_entry_t *rce, double q)
1592 x264_ratecontrol_t *rcc = h->rc;
1593 const int pict_type = rce->pict_type;
1595 // force I/B quants as a function of P quants
1596 const double last_p_q = rcc->last_qscale_for[SLICE_TYPE_P];
1597 const double last_non_b_q= rcc->last_qscale_for[rcc->last_non_b_pict_type];
1598 if( pict_type == SLICE_TYPE_I )
1601 double pq = qp2qscale( rcc->accum_p_qp / rcc->accum_p_norm );
1602 double ip_factor = fabs( h->param.rc.f_ip_factor );
1603 /* don't apply ip_factor if the following frame is also I */
1604 if( rcc->accum_p_norm <= 0 )
1606 else if( h->param.rc.f_ip_factor < 0 )
1608 else if( rcc->accum_p_norm >= 1 )
1611 q = rcc->accum_p_norm * pq / ip_factor + (1 - rcc->accum_p_norm) * iq;
1613 else if( pict_type == SLICE_TYPE_B )
1615 if( h->param.rc.f_pb_factor > 0 )
1617 if( !rce->kept_as_ref )
1618 q *= fabs( h->param.rc.f_pb_factor );
1620 else if( pict_type == SLICE_TYPE_P
1621 && rcc->last_non_b_pict_type == SLICE_TYPE_P
1622 && rce->tex_bits == 0 )
1627 /* last qscale / qdiff stuff */
1628 if( rcc->last_non_b_pict_type == pict_type &&
1629 (pict_type!=SLICE_TYPE_I || rcc->last_accum_p_norm < 1) )
1631 double last_q = rcc->last_qscale_for[pict_type];
1632 double max_qscale = last_q * rcc->lstep;
1633 double min_qscale = last_q / rcc->lstep;
1635 if ( q > max_qscale ) q = max_qscale;
1636 else if( q < min_qscale ) q = min_qscale;
1639 rcc->last_qscale_for[pict_type] = q;
1640 if( pict_type != SLICE_TYPE_B )
1641 rcc->last_non_b_pict_type = pict_type;
1642 if( pict_type == SLICE_TYPE_I )
1644 rcc->last_accum_p_norm = rcc->accum_p_norm;
1645 rcc->accum_p_norm = 0;
1646 rcc->accum_p_qp = 0;
1648 if( pict_type == SLICE_TYPE_P )
1650 float mask = 1 - pow( (float)rce->i_count / rcc->nmb, 2 );
1651 rcc->accum_p_qp = mask * (qscale2qp( q ) + rcc->accum_p_qp);
1652 rcc->accum_p_norm = mask * (1 + rcc->accum_p_norm);
1657 static double predict_size( predictor_t *p, double q, double var )
1659 return (p->coeff*var + p->offset) / (q*p->count);
1662 static void update_predictor( predictor_t *p, double q, double var, double bits )
1664 const double range = 1.5;
1667 double old_coeff = p->coeff / p->count;
1668 double new_coeff = bits*q / var;
1669 double new_coeff_clipped = x264_clip3f( new_coeff, old_coeff/range, old_coeff*range );
1670 double new_offset = bits*q - new_coeff_clipped * var;
1671 if( new_offset >= 0 )
1672 new_coeff = new_coeff_clipped;
1675 p->count *= p->decay;
1676 p->coeff *= p->decay;
1677 p->offset *= p->decay;
1679 p->coeff += new_coeff;
1680 p->offset += new_offset;
1683 // update VBV after encoding a frame
1684 static int update_vbv( x264_t *h, int bits )
1688 x264_ratecontrol_t *rcc = h->rc;
1689 x264_ratecontrol_t *rct = h->thread[0]->rc;
1691 if( rcc->last_satd >= h->mb.i_mb_count )
1692 update_predictor( &rct->pred[h->sh.i_type], qp2qscale( rcc->qpa_rc ), rcc->last_satd, bits );
1697 rct->buffer_fill_final -= bits;
1699 if( rct->buffer_fill_final < 0 )
1700 x264_log( h, X264_LOG_WARNING, "VBV underflow (frame %d, %.0f bits)\n", h->i_frame, rct->buffer_fill_final );
1701 rct->buffer_fill_final = X264_MAX( rct->buffer_fill_final, 0 );
1702 rct->buffer_fill_final += rcc->buffer_rate;
1704 if( h->sps->vui.hrd.b_cbr_hrd && rct->buffer_fill_final > rcc->buffer_size )
1706 filler = ceil( (rct->buffer_fill_final - rcc->buffer_size) / 8 );
1707 rct->buffer_fill_final -= X264_MAX( (FILLER_OVERHEAD - h->param.b_annexb), filler ) * 8;
1710 rct->buffer_fill_final = X264_MIN( rct->buffer_fill_final, rcc->buffer_size );
1715 int x264_hrd_fullness( x264_t *h )
1717 x264_ratecontrol_t *rct = h->thread[0]->rc;
1718 double cpb_bits = rct->buffer_fill_final;
1719 double bps = h->sps->vui.hrd.i_bit_rate_unscaled;
1720 double cpb_size = h->sps->vui.hrd.i_cpb_size_unscaled;
1721 double cpb_fullness = 90000.0*cpb_bits/bps;
1723 if( cpb_bits < 0 || cpb_bits > cpb_size )
1725 x264_log( h, X264_LOG_WARNING, "CPB %s: %.0lf bits in a %.0lf-bit buffer\n",
1726 cpb_bits < 0 ? "underflow" : "overflow", cpb_bits, cpb_size );
1729 h->initial_cpb_removal_delay_offset = 90000.0*(cpb_size - cpb_bits)/bps;
1731 return x264_clip3f( cpb_fullness + 0.5, 0, 90000.0*cpb_size/bps ); // just lie if we are in a weird state
1734 // provisionally update VBV according to the planned size of all frames currently in progress
1735 static void update_vbv_plan( x264_t *h, int overhead )
1737 x264_ratecontrol_t *rcc = h->rc;
1738 rcc->buffer_fill = h->thread[0]->rc->buffer_fill_final;
1739 if( h->i_thread_frames > 1 )
1741 int j = h->rc - h->thread[0]->rc;
1742 for( int i = 1; i < h->i_thread_frames; i++ )
1744 x264_t *t = h->thread[ (j+i)%h->i_thread_frames ];
1745 double bits = t->rc->frame_size_planned;
1746 if( !t->b_thread_active )
1748 bits = X264_MAX(bits, t->rc->frame_size_estimated);
1749 rcc->buffer_fill -= bits;
1750 rcc->buffer_fill = X264_MAX( rcc->buffer_fill, 0 );
1751 rcc->buffer_fill += t->rc->buffer_rate;
1752 rcc->buffer_fill = X264_MIN( rcc->buffer_fill, rcc->buffer_size );
1755 rcc->buffer_fill = X264_MIN( rcc->buffer_fill, rcc->buffer_size );
1756 rcc->buffer_fill -= overhead;
1759 // apply VBV constraints and clip qscale to between lmin and lmax
1760 static double clip_qscale( x264_t *h, int pict_type, double q )
1762 x264_ratecontrol_t *rcc = h->rc;
1763 double lmin = rcc->lmin[pict_type];
1764 double lmax = rcc->lmax[pict_type];
1765 if( rcc->rate_factor_max_increment )
1766 lmax = X264_MIN( lmax, qp2qscale( rcc->qp_novbv + rcc->rate_factor_max_increment ) );
1769 /* B-frames are not directly subject to VBV,
1770 * since they are controlled by the P-frames' QPs. */
1772 if( rcc->b_vbv && rcc->last_satd > 0 )
1774 /* Lookahead VBV: raise the quantizer as necessary such that no frames in
1775 * the lookahead overflow and such that the buffer is in a reasonable state
1776 * by the end of the lookahead. */
1777 if( h->param.rc.i_lookahead )
1781 /* Avoid an infinite loop. */
1782 for( int iterations = 0; iterations < 1000 && terminate != 3; iterations++ )
1785 double cur_bits = predict_size( &rcc->pred[h->sh.i_type], q, rcc->last_satd );
1786 double buffer_fill_cur = rcc->buffer_fill - cur_bits;
1788 double total_duration = 0;
1789 frame_q[0] = h->sh.i_type == SLICE_TYPE_I ? q * h->param.rc.f_ip_factor : q;
1790 frame_q[1] = frame_q[0] * h->param.rc.f_pb_factor;
1791 frame_q[2] = frame_q[0] / h->param.rc.f_ip_factor;
1793 /* Loop over the planned future frames. */
1794 for( int j = 0; buffer_fill_cur >= 0 && buffer_fill_cur <= rcc->buffer_size; j++ )
1796 total_duration += h->fenc->f_planned_cpb_duration[j];
1797 buffer_fill_cur += rcc->vbv_max_rate * h->fenc->f_planned_cpb_duration[j];
1798 int i_type = h->fenc->i_planned_type[j];
1799 int i_satd = h->fenc->i_planned_satd[j];
1800 if( i_type == X264_TYPE_AUTO )
1802 i_type = IS_X264_TYPE_I( i_type ) ? SLICE_TYPE_I : IS_X264_TYPE_B( i_type ) ? SLICE_TYPE_B : SLICE_TYPE_P;
1803 cur_bits = predict_size( &rcc->pred[i_type], frame_q[i_type], i_satd );
1804 buffer_fill_cur -= cur_bits;
1806 /* Try to get to get the buffer at least 50% filled, but don't set an impossible goal. */
1807 target_fill = X264_MIN( rcc->buffer_fill + total_duration * rcc->vbv_max_rate * 0.5, rcc->buffer_size * 0.5 );
1808 if( buffer_fill_cur < target_fill )
1814 /* Try to get the buffer no more than 80% filled, but don't set an impossible goal. */
1815 target_fill = x264_clip3f( rcc->buffer_fill - total_duration * rcc->vbv_max_rate * 0.5, rcc->buffer_size * 0.8, rcc->buffer_size );
1816 if( rcc->b_vbv_min_rate && buffer_fill_cur > target_fill )
1825 /* Fallback to old purely-reactive algorithm: no lookahead. */
1828 if( ( pict_type == SLICE_TYPE_P ||
1829 ( pict_type == SLICE_TYPE_I && rcc->last_non_b_pict_type == SLICE_TYPE_I ) ) &&
1830 rcc->buffer_fill/rcc->buffer_size < 0.5 )
1832 q /= x264_clip3f( 2.0*rcc->buffer_fill/rcc->buffer_size, 0.5, 1.0 );
1835 /* Now a hard threshold to make sure the frame fits in VBV.
1836 * This one is mostly for I-frames. */
1837 double bits = predict_size( &rcc->pred[h->sh.i_type], q, rcc->last_satd );
1839 /* For small VBVs, allow the frame to use up the entire VBV. */
1840 double max_fill_factor = h->param.rc.i_vbv_buffer_size >= 5*h->param.rc.i_vbv_max_bitrate / rcc->fps ? 2 : 1;
1841 /* For single-frame VBVs, request that the frame use up the entire VBV. */
1842 double min_fill_factor = rcc->single_frame_vbv ? 1 : 2;
1844 if( bits > rcc->buffer_fill/max_fill_factor )
1845 qf = x264_clip3f( rcc->buffer_fill/(max_fill_factor*bits), 0.2, 1.0 );
1848 if( bits < rcc->buffer_rate/min_fill_factor )
1849 q *= bits*min_fill_factor/rcc->buffer_rate;
1850 q = X264_MAX( q0, q );
1853 /* Apply MinCR restrictions */
1854 double bits = predict_size( &rcc->pred[h->sh.i_type], q, rcc->last_satd );
1855 if( bits > rcc->frame_size_maximum )
1856 q *= bits / rcc->frame_size_maximum;
1857 bits = predict_size( &rcc->pred[h->sh.i_type], q, rcc->last_satd );
1859 /* Check B-frame complexity, and use up any bits that would
1860 * overflow before the next P-frame. */
1861 if( h->sh.i_type == SLICE_TYPE_P && !rcc->single_frame_vbv )
1863 int nb = rcc->bframes;
1864 double pbbits = bits;
1865 double bbits = predict_size( rcc->pred_b_from_p, q * h->param.rc.f_pb_factor, rcc->last_satd );
1867 double bframe_cpb_duration = 0;
1868 double minigop_cpb_duration;
1869 for( int i = 0; i < nb; i++ )
1870 bframe_cpb_duration += h->fenc->f_planned_cpb_duration[1+i];
1872 if( bbits * nb > bframe_cpb_duration * rcc->vbv_max_rate )
1874 pbbits += nb * bbits;
1876 minigop_cpb_duration = bframe_cpb_duration + h->fenc->f_planned_cpb_duration[0];
1877 space = rcc->buffer_fill + minigop_cpb_duration*rcc->vbv_max_rate - rcc->buffer_size;
1878 if( pbbits < space )
1880 q *= X264_MAX( pbbits / space, bits / (0.5 * rcc->buffer_size) );
1882 q = X264_MAX( q0-5, q );
1885 if( !rcc->b_vbv_min_rate )
1886 q = X264_MAX( q0, q );
1891 else if( rcc->b_2pass )
1893 double min2 = log( lmin );
1894 double max2 = log( lmax );
1895 q = (log(q) - min2)/(max2-min2) - 0.5;
1896 q = 1.0/(1.0 + exp( -4*q ));
1897 q = q*(max2-min2) + min2;
1901 return x264_clip3f( q, lmin, lmax );
1904 // update qscale for 1 frame based on actual bits used so far
1905 static float rate_estimate_qscale( x264_t *h )
1908 x264_ratecontrol_t *rcc = h->rc;
1909 ratecontrol_entry_t rce;
1910 int pict_type = h->sh.i_type;
1911 int64_t total_bits = 8*(h->stat.i_frame_size[SLICE_TYPE_I]
1912 + h->stat.i_frame_size[SLICE_TYPE_P]
1913 + h->stat.i_frame_size[SLICE_TYPE_B]);
1918 if( pict_type != rce.pict_type )
1920 x264_log( h, X264_LOG_ERROR, "slice=%c but 2pass stats say %c\n",
1921 slice_type_to_char[pict_type], slice_type_to_char[rce.pict_type] );
1925 if( pict_type == SLICE_TYPE_B )
1927 /* B-frames don't have independent ratecontrol, but rather get the
1928 * average QP of the two adjacent P-frames + an offset */
1930 int i0 = IS_X264_TYPE_I(h->fref0[0]->i_type);
1931 int i1 = IS_X264_TYPE_I(h->fref1[0]->i_type);
1932 int dt0 = abs(h->fenc->i_poc - h->fref0[0]->i_poc);
1933 int dt1 = abs(h->fenc->i_poc - h->fref1[0]->i_poc);
1934 float q0 = h->fref0[0]->f_qp_avg_rc;
1935 float q1 = h->fref1[0]->f_qp_avg_rc;
1937 if( h->fref0[0]->i_type == X264_TYPE_BREF )
1938 q0 -= rcc->pb_offset/2;
1939 if( h->fref1[0]->i_type == X264_TYPE_BREF )
1940 q1 -= rcc->pb_offset/2;
1943 q = (q0 + q1) / 2 + rcc->ip_offset;
1949 q = (q0*dt1 + q1*dt0) / (dt0 + dt1);
1951 if( h->fenc->b_kept_as_ref )
1952 q += rcc->pb_offset/2;
1954 q += rcc->pb_offset;
1956 if( rcc->b_2pass && rcc->b_vbv )
1957 rcc->frame_size_planned = qscale2bits( &rce, q );
1959 rcc->frame_size_planned = predict_size( rcc->pred_b_from_p, q, h->fref1[h->i_ref1-1]->i_satd );
1960 h->rc->frame_size_estimated = rcc->frame_size_planned;
1964 rcc->last_satd = x264_rc_analyse_slice( h );
1966 return qp2qscale( q );
1970 double abr_buffer = 2 * rcc->rate_tolerance * rcc->bitrate;
1974 double lmin = rcc->lmin[pict_type];
1975 double lmax = rcc->lmax[pict_type];
1977 int64_t predicted_bits = total_bits;
1978 /* Adjust ABR buffer based on distance to the end of the video. */
1979 if( rcc->num_entries > h->fenc->i_frame )
1980 abr_buffer *= 0.5 * sqrt( rcc->num_entries - h->fenc->i_frame );
1984 if( h->i_thread_frames > 1 )
1986 int j = h->rc - h->thread[0]->rc;
1987 for( int i = 1; i < h->i_thread_frames; i++ )
1989 x264_t *t = h->thread[ (j+i)%h->i_thread_frames ];
1990 double bits = t->rc->frame_size_planned;
1991 if( !t->b_thread_active )
1993 bits = X264_MAX(bits, t->rc->frame_size_estimated);
1994 predicted_bits += (int64_t)bits;
2000 if( h->fenc->i_frame < h->i_thread_frames )
2001 predicted_bits += (int64_t)h->fenc->i_frame * rcc->bitrate / rcc->fps;
2003 predicted_bits += (int64_t)(h->i_thread_frames - 1) * rcc->bitrate / rcc->fps;
2006 diff = predicted_bits - (int64_t)rce.expected_bits;
2008 q /= x264_clip3f((double)(abr_buffer - diff) / abr_buffer, .5, 2);
2009 if( ((h->fenc->i_frame + 1 - h->i_thread_frames) >= rcc->fps) &&
2010 (rcc->expected_bits_sum > 0))
2012 /* Adjust quant based on the difference between
2013 * achieved and expected bitrate so far */
2014 double cur_time = (double)h->fenc->i_frame / rcc->num_entries;
2015 double w = x264_clip3f( cur_time*100, 0.0, 1.0 );
2016 q *= pow( (double)total_bits / rcc->expected_bits_sum, w );
2020 /* Do not overflow vbv */
2021 double expected_size = qscale2bits( &rce, q );
2022 double expected_vbv = rcc->buffer_fill + rcc->buffer_rate - expected_size;
2023 double expected_fullness = rce.expected_vbv / rcc->buffer_size;
2024 double qmax = q*(2 - expected_fullness);
2025 double size_constraint = 1 + expected_fullness;
2026 qmax = X264_MAX( qmax, rce.new_qscale );
2027 if( expected_fullness < .05 )
2029 qmax = X264_MIN(qmax, lmax);
2030 while( ((expected_vbv < rce.expected_vbv/size_constraint) && (q < qmax)) ||
2031 ((expected_vbv < 0) && (q < lmax)))
2034 expected_size = qscale2bits(&rce, q);
2035 expected_vbv = rcc->buffer_fill + rcc->buffer_rate - expected_size;
2037 rcc->last_satd = x264_rc_analyse_slice( h );
2039 q = x264_clip3f( q, lmin, lmax );
2041 else /* 1pass ABR */
2043 /* Calculate the quantizer which would have produced the desired
2044 * average bitrate if it had been applied to all frames so far.
2045 * Then modulate that quant based on the current frame's complexity
2046 * relative to the average complexity so far (using the 2pass RCEQ).
2047 * Then bias the quant up or down if total size so far was far from
2049 * Result: Depending on the value of rate_tolerance, there is a
2050 * tradeoff between quality and bitrate precision. But at large
2051 * tolerances, the bit distribution approaches that of 2pass. */
2053 double wanted_bits, overflow = 1;
2055 rcc->last_satd = x264_rc_analyse_slice( h );
2056 rcc->short_term_cplxsum *= 0.5;
2057 rcc->short_term_cplxcount *= 0.5;
2058 rcc->short_term_cplxsum += rcc->last_satd;
2059 rcc->short_term_cplxcount ++;
2061 rce.tex_bits = rcc->last_satd;
2062 rce.blurred_complexity = rcc->short_term_cplxsum / rcc->short_term_cplxcount;
2064 rce.p_count = rcc->nmb;
2068 rce.pict_type = pict_type;
2070 if( h->param.rc.i_rc_method == X264_RC_CRF )
2072 q = get_qscale( h, &rce, rcc->rate_factor_constant, h->fenc->i_frame );
2076 int i_frame_done = h->fenc->i_frame + 1 - h->i_thread_frames;
2077 double i_time_done = i_frame_done / rcc->fps;
2078 if( h->param.b_vfr_input )
2079 i_time_done = ((double)(h->fenc->i_reordered_pts - h->first_pts)) * h->param.i_timebase_num / h->param.i_timebase_den;
2081 q = get_qscale( h, &rce, rcc->wanted_bits_window / rcc->cplxr_sum, h->fenc->i_frame );
2083 /* ABR code can potentially be counterproductive in CBR, so just don't bother.
2084 * Don't run it if the frame complexity is zero either. */
2085 if( !rcc->b_vbv_min_rate && rcc->last_satd )
2087 // FIXME is it simpler to keep track of wanted_bits in ratecontrol_end?
2088 wanted_bits = i_time_done * rcc->bitrate;
2089 if( wanted_bits > 0 )
2091 abr_buffer *= X264_MAX( 1, sqrt(i_time_done) );
2092 overflow = x264_clip3f( 1.0 + (total_bits - wanted_bits) / abr_buffer, .5, 2 );
2098 if( pict_type == SLICE_TYPE_I && h->param.i_keyint_max > 1
2099 /* should test _next_ pict type, but that isn't decided yet */
2100 && rcc->last_non_b_pict_type != SLICE_TYPE_I )
2102 q = qp2qscale( rcc->accum_p_qp / rcc->accum_p_norm );
2103 q /= fabs( h->param.rc.f_ip_factor );
2105 else if( h->i_frame > 0 )
2107 /* Asymmetric clipping, because symmetric would prevent
2108 * overflow control in areas of rapidly oscillating complexity */
2109 double lmin = rcc->last_qscale_for[pict_type] / rcc->lstep;
2110 double lmax = rcc->last_qscale_for[pict_type] * rcc->lstep;
2111 if( overflow > 1.1 && h->i_frame > 3 )
2113 else if( overflow < 0.9 )
2116 q = x264_clip3f(q, lmin, lmax);
2118 else if( h->param.rc.i_rc_method == X264_RC_CRF && rcc->qcompress != 1 )
2120 q = qp2qscale( ABR_INIT_QP ) / fabs( h->param.rc.f_ip_factor );
2122 rcc->qp_novbv = qscale2qp( q );
2124 //FIXME use get_diff_limited_q() ?
2125 q = clip_qscale( h, pict_type, q );
2128 rcc->last_qscale_for[pict_type] =
2129 rcc->last_qscale = q;
2131 if( !(rcc->b_2pass && !rcc->b_vbv) && h->fenc->i_frame == 0 )
2132 rcc->last_qscale_for[SLICE_TYPE_P] = q * fabs( h->param.rc.f_ip_factor );
2134 if( rcc->b_2pass && rcc->b_vbv )
2135 rcc->frame_size_planned = qscale2bits(&rce, q);
2137 rcc->frame_size_planned = predict_size( &rcc->pred[h->sh.i_type], q, rcc->last_satd );
2139 /* Always use up the whole VBV in this case. */
2140 if( rcc->single_frame_vbv )
2141 rcc->frame_size_planned = rcc->buffer_rate;
2142 h->rc->frame_size_estimated = rcc->frame_size_planned;
2147 void x264_threads_normalize_predictors( x264_t *h )
2149 double totalsize = 0;
2150 for( int i = 0; i < h->param.i_threads; i++ )
2151 totalsize += h->thread[i]->rc->slice_size_planned;
2152 double factor = h->rc->frame_size_planned / totalsize;
2153 for( int i = 0; i < h->param.i_threads; i++ )
2154 h->thread[i]->rc->slice_size_planned *= factor;
2157 void x264_threads_distribute_ratecontrol( x264_t *h )
2160 x264_ratecontrol_t *rc = h->rc;
2162 /* Initialize row predictors */
2163 if( h->i_frame == 0 )
2164 for( int i = 0; i < h->param.i_threads; i++ )
2166 x264_ratecontrol_t *t = h->thread[i]->rc;
2167 memcpy( t->row_preds, rc->row_preds, sizeof(rc->row_preds) );
2170 for( int i = 0; i < h->param.i_threads; i++ )
2172 x264_t *t = h->thread[i];
2173 memcpy( t->rc, rc, offsetof(x264_ratecontrol_t, row_pred) );
2174 t->rc->row_pred = &t->rc->row_preds[h->sh.i_type];
2175 /* Calculate the planned slice size. */
2176 if( rc->b_vbv && rc->frame_size_planned )
2179 for( row = t->i_threadslice_start; row < t->i_threadslice_end; row++ )
2180 size += h->fdec->i_row_satd[row];
2181 t->rc->slice_size_planned = predict_size( &rc->pred[h->sh.i_type + (i+1)*5], rc->qpm, size );
2184 t->rc->slice_size_planned = 0;
2186 if( rc->b_vbv && rc->frame_size_planned )
2188 x264_threads_normalize_predictors( h );
2190 if( rc->single_frame_vbv )
2192 /* Compensate for our max frame error threshold: give more bits (proportionally) to smaller slices. */
2193 for( int i = 0; i < h->param.i_threads; i++ )
2195 x264_t *t = h->thread[i];
2196 t->rc->max_frame_error = X264_MAX( 0.05, 1.0 / (t->i_threadslice_end - t->i_threadslice_start) );
2197 t->rc->slice_size_planned += 2 * t->rc->max_frame_error * rc->frame_size_planned;
2199 x264_threads_normalize_predictors( h );
2202 for( int i = 0; i < h->param.i_threads; i++ )
2203 h->thread[i]->rc->frame_size_estimated = h->thread[i]->rc->slice_size_planned;
2207 void x264_threads_merge_ratecontrol( x264_t *h )
2209 x264_ratecontrol_t *rc = h->rc;
2212 for( int i = 0; i < h->param.i_threads; i++ )
2214 x264_t *t = h->thread[i];
2215 x264_ratecontrol_t *rct = h->thread[i]->rc;
2216 if( h->param.rc.i_vbv_buffer_size )
2219 for( int row = t->i_threadslice_start; row < t->i_threadslice_end; row++ )
2220 size += h->fdec->i_row_satd[row];
2221 int bits = t->stat.frame.i_mv_bits + t->stat.frame.i_tex_bits + t->stat.frame.i_misc_bits;
2222 int mb_count = (t->i_threadslice_end - t->i_threadslice_start) * h->sps->i_mb_width;
2223 update_predictor( &rc->pred[h->sh.i_type+5*i], qp2qscale( rct->qpa_rc/mb_count ), size, bits );
2227 rc->qpa_rc += rct->qpa_rc;
2228 rc->qpa_aq += rct->qpa_aq;
2232 void x264_thread_sync_ratecontrol( x264_t *cur, x264_t *prev, x264_t *next )
2236 #define COPY(var) memcpy(&cur->rc->var, &prev->rc->var, sizeof(cur->rc->var))
2237 /* these vars are updated in x264_ratecontrol_start()
2238 * so copy them from the context that most recently started (prev)
2239 * to the context that's about to start (cur). */
2244 COPY(last_qscale_for);
2245 COPY(last_non_b_pict_type);
2246 COPY(short_term_cplxsum);
2247 COPY(short_term_cplxcount);
2251 /* these vars can be updated by x264_ratecontrol_init_reconfigurable */
2254 COPY(single_frame_vbv);
2256 COPY(b_vbv_min_rate);
2257 COPY(rate_factor_constant);
2263 #define COPY(var) next->rc->var = cur->rc->var
2264 /* these vars are updated in x264_ratecontrol_end()
2265 * so copy them from the context that most recently ended (cur)
2266 * to the context that's about to end (next) */
2268 COPY(expected_bits_sum);
2269 COPY(wanted_bits_window);
2271 COPY(initial_cpb_removal_delay);
2272 COPY(initial_cpb_removal_delay_offset);
2273 COPY(nrt_first_access_unit);
2274 COPY(previous_cpb_final_arrival_time);
2277 //FIXME row_preds[] (not strictly necessary, but would improve prediction)
2278 /* the rest of the variables are either constant or thread-local */
2281 static int find_underflow( x264_t *h, double *fills, int *t0, int *t1, int over )
2283 /* find an interval ending on an overflow or underflow (depending on whether
2284 * we're adding or removing bits), and starting on the earliest frame that
2285 * can influence the buffer fill of that end frame. */
2286 x264_ratecontrol_t *rcc = h->rc;
2287 const double buffer_min = (over ? .1 : .1) * rcc->buffer_size;
2288 const double buffer_max = .9 * rcc->buffer_size;
2289 double fill = fills[*t0-1];
2290 double parity = over ? 1. : -1.;
2291 int start = -1, end = -1;
2292 for( int i = *t0; i < rcc->num_entries; i++ )
2294 fill += (rcc->entry[i].i_cpb_duration * rcc->vbv_max_rate * h->sps->vui.i_num_units_in_tick / h->sps->vui.i_time_scale -
2295 qscale2bits( &rcc->entry[i], rcc->entry[i].new_qscale )) * parity;
2296 fill = x264_clip3f(fill, 0, rcc->buffer_size);
2298 if( fill <= buffer_min || i == 0 )
2304 else if( fill >= buffer_max && start >= 0 )
2309 return start >= 0 && end >= 0;
2312 static int fix_underflow( x264_t *h, int t0, int t1, double adjustment, double qscale_min, double qscale_max)
2314 x264_ratecontrol_t *rcc = h->rc;
2315 double qscale_orig, qscale_new;
2319 for( int i = t0; i <= t1; i++ )
2321 qscale_orig = rcc->entry[i].new_qscale;
2322 qscale_orig = x264_clip3f( qscale_orig, qscale_min, qscale_max );
2323 qscale_new = qscale_orig * adjustment;
2324 qscale_new = x264_clip3f( qscale_new, qscale_min, qscale_max );
2325 rcc->entry[i].new_qscale = qscale_new;
2326 adjusted = adjusted || (qscale_new != qscale_orig);
2331 static double count_expected_bits( x264_t *h )
2333 x264_ratecontrol_t *rcc = h->rc;
2334 double expected_bits = 0;
2335 for( int i = 0; i < rcc->num_entries; i++ )
2337 ratecontrol_entry_t *rce = &rcc->entry[i];
2338 rce->expected_bits = expected_bits;
2339 expected_bits += qscale2bits( rce, rce->new_qscale );
2341 return expected_bits;
2344 static int vbv_pass2( x264_t *h, double all_available_bits )
2346 /* for each interval of buffer_full .. underflow, uniformly increase the qp of all
2347 * frames in the interval until either buffer is full at some intermediate frame or the
2348 * last frame in the interval no longer underflows. Recompute intervals and repeat.
2349 * Then do the converse to put bits back into overflow areas until target size is met */
2351 x264_ratecontrol_t *rcc = h->rc;
2353 double expected_bits = 0;
2355 double prev_bits = 0;
2357 double qscale_min = qp2qscale( h->param.rc.i_qp_min );
2358 double qscale_max = qp2qscale( h->param.rc.i_qp_max );
2360 int adj_min, adj_max;
2361 CHECKED_MALLOC( fills, (rcc->num_entries+1)*sizeof(double) );
2365 /* adjust overall stream size */
2369 prev_bits = expected_bits;
2372 { /* not first iteration */
2373 adjustment = X264_MAX(X264_MIN(expected_bits / all_available_bits, 0.999), 0.9);
2374 fills[-1] = rcc->buffer_size * h->param.rc.f_vbv_buffer_init;
2378 while(adj_min && find_underflow( h, fills, &t0, &t1, 1 ))
2380 adj_min = fix_underflow( h, t0, t1, adjustment, qscale_min, qscale_max );
2385 fills[-1] = rcc->buffer_size * (1. - h->param.rc.f_vbv_buffer_init);
2387 /* fix underflows -- should be done after overflow, as we'd better undersize target than underflowing VBV */
2389 while( adj_max && find_underflow( h, fills, &t0, &t1, 0 ) )
2390 adj_max = fix_underflow( h, t0, t1, 1.001, qscale_min, qscale_max );
2392 expected_bits = count_expected_bits( h );
2393 } while( (expected_bits < .995*all_available_bits) && ((int64_t)(expected_bits+.5) > (int64_t)(prev_bits+.5)) );
2396 x264_log( h, X264_LOG_WARNING, "vbv-maxrate issue, qpmax or vbv-maxrate too low\n");
2398 /* store expected vbv filling values for tracking when encoding */
2399 for( int i = 0; i < rcc->num_entries; i++ )
2400 rcc->entry[i].expected_vbv = rcc->buffer_size - fills[i];
2402 x264_free( fills-1 );
2408 static int init_pass2( x264_t *h )
2410 x264_ratecontrol_t *rcc = h->rc;
2411 uint64_t all_const_bits = 0;
2412 double duration = 0;
2413 for( int i = 0; i < rcc->num_entries; i++ )
2414 duration += rcc->entry[i].i_duration;
2415 duration *= (double)h->sps->vui.i_num_units_in_tick / h->sps->vui.i_time_scale;
2416 uint64_t all_available_bits = h->param.rc.i_bitrate * 1000. * duration;
2417 double rate_factor, step_mult;
2418 double qblur = h->param.rc.f_qblur;
2419 double cplxblur = h->param.rc.f_complexity_blur;
2420 const int filter_size = (int)(qblur*4) | 1;
2421 double expected_bits;
2422 double *qscale, *blurred_qscale;
2424 /* find total/average complexity & const_bits */
2425 for( int i = 0; i < rcc->num_entries; i++ )
2427 ratecontrol_entry_t *rce = &rcc->entry[i];
2428 all_const_bits += rce->misc_bits;
2431 if( all_available_bits < all_const_bits)
2433 x264_log( h, X264_LOG_ERROR, "requested bitrate is too low. estimated minimum is %d kbps\n",
2434 (int)(all_const_bits * rcc->fps / (rcc->num_entries * 1000.)) );
2438 /* Blur complexities, to reduce local fluctuation of QP.
2439 * We don't blur the QPs directly, because then one very simple frame
2440 * could drag down the QP of a nearby complex frame and give it more
2441 * bits than intended. */
2442 for( int i = 0; i < rcc->num_entries; i++ )
2444 ratecontrol_entry_t *rce = &rcc->entry[i];
2445 double weight_sum = 0;
2446 double cplx_sum = 0;
2447 double weight = 1.0;
2448 double gaussian_weight;
2449 /* weighted average of cplx of future frames */
2450 for( int j = 1; j < cplxblur*2 && j < rcc->num_entries-i; j++ )
2452 ratecontrol_entry_t *rcj = &rcc->entry[i+j];
2453 weight *= 1 - pow( (float)rcj->i_count / rcc->nmb, 2 );
2454 if( weight < .0001 )
2456 gaussian_weight = weight * exp( -j*j/200.0 );
2457 weight_sum += gaussian_weight;
2458 cplx_sum += gaussian_weight * (qscale2bits(rcj, 1) - rcj->misc_bits);
2460 /* weighted average of cplx of past frames */
2462 for( int j = 0; j <= cplxblur*2 && j <= i; j++ )
2464 ratecontrol_entry_t *rcj = &rcc->entry[i-j];
2465 gaussian_weight = weight * exp( -j*j/200.0 );
2466 weight_sum += gaussian_weight;
2467 cplx_sum += gaussian_weight * (qscale2bits( rcj, 1 ) - rcj->misc_bits);
2468 weight *= 1 - pow( (float)rcj->i_count / rcc->nmb, 2 );
2469 if( weight < .0001 )
2472 rce->blurred_complexity = cplx_sum / weight_sum;
2475 CHECKED_MALLOC( qscale, sizeof(double)*rcc->num_entries );
2476 if( filter_size > 1 )
2477 CHECKED_MALLOC( blurred_qscale, sizeof(double)*rcc->num_entries );
2479 blurred_qscale = qscale;
2481 /* Search for a factor which, when multiplied by the RCEQ values from
2482 * each frame, adds up to the desired total size.
2483 * There is no exact closed-form solution because of VBV constraints and
2484 * because qscale2bits is not invertible, but we can start with the simple
2485 * approximation of scaling the 1st pass by the ratio of bitrates.
2486 * The search range is probably overkill, but speed doesn't matter here. */
2489 for( int i = 0; i < rcc->num_entries; i++ )
2491 double q = get_qscale(h, &rcc->entry[i], 1.0, i);
2492 expected_bits += qscale2bits(&rcc->entry[i], q);
2493 rcc->last_qscale_for[rcc->entry[i].pict_type] = q;
2495 step_mult = all_available_bits / expected_bits;
2498 for( double step = 1E4 * step_mult; step > 1E-7 * step_mult; step *= 0.5)
2501 rate_factor += step;
2503 rcc->last_non_b_pict_type = -1;
2504 rcc->last_accum_p_norm = 1;
2505 rcc->accum_p_norm = 0;
2508 for( int i = 0; i < rcc->num_entries; i++ )
2510 qscale[i] = get_qscale( h, &rcc->entry[i], rate_factor, i );
2511 rcc->last_qscale_for[rcc->entry[i].pict_type] = qscale[i];
2514 /* fixed I/B qscale relative to P */
2515 for( int i = rcc->num_entries-1; i >= 0; i-- )
2517 qscale[i] = get_diff_limited_q( h, &rcc->entry[i], qscale[i] );
2518 assert(qscale[i] >= 0);
2522 if( filter_size > 1 )
2524 assert( filter_size%2 == 1 );
2525 for( int i = 0; i < rcc->num_entries; i++ )
2527 ratecontrol_entry_t *rce = &rcc->entry[i];
2528 double q = 0.0, sum = 0.0;
2530 for( int j = 0; j < filter_size; j++ )
2532 int index = i+j-filter_size/2;
2534 double coeff = qblur==0 ? 1.0 : exp( -d*d/(qblur*qblur) );
2535 if( index < 0 || index >= rcc->num_entries )
2537 if( rce->pict_type != rcc->entry[index].pict_type )
2539 q += qscale[index] * coeff;
2542 blurred_qscale[i] = q/sum;
2546 /* find expected bits */
2547 for( int i = 0; i < rcc->num_entries; i++ )
2549 ratecontrol_entry_t *rce = &rcc->entry[i];
2550 rce->new_qscale = clip_qscale( h, rce->pict_type, blurred_qscale[i] );
2551 assert(rce->new_qscale >= 0);
2552 expected_bits += qscale2bits( rce, rce->new_qscale );
2555 if( expected_bits > all_available_bits )
2556 rate_factor -= step;
2559 x264_free( qscale );
2560 if( filter_size > 1 )
2561 x264_free( blurred_qscale );
2564 if( vbv_pass2( h, all_available_bits ) )
2566 expected_bits = count_expected_bits( h );
2568 if( fabs( expected_bits/all_available_bits - 1.0 ) > 0.01 )
2571 for( int i = 0; i < rcc->num_entries; i++ )
2572 avgq += rcc->entry[i].new_qscale;
2573 avgq = qscale2qp( avgq / rcc->num_entries );
2575 if( expected_bits > all_available_bits || !rcc->b_vbv )
2576 x264_log( h, X264_LOG_WARNING, "Error: 2pass curve failed to converge\n" );
2577 x264_log( h, X264_LOG_WARNING, "target: %.2f kbit/s, expected: %.2f kbit/s, avg QP: %.4f\n",
2578 (float)h->param.rc.i_bitrate,
2579 expected_bits * rcc->fps / (rcc->num_entries * 1000.),
2581 if( expected_bits < all_available_bits && avgq < h->param.rc.i_qp_min + 2 )
2583 if( h->param.rc.i_qp_min > 0 )
2584 x264_log( h, X264_LOG_WARNING, "try reducing target bitrate or reducing qp_min (currently %d)\n", h->param.rc.i_qp_min );
2586 x264_log( h, X264_LOG_WARNING, "try reducing target bitrate\n" );
2588 else if( expected_bits > all_available_bits && avgq > h->param.rc.i_qp_max - 2 )
2590 if( h->param.rc.i_qp_max < 51 )
2591 x264_log( h, X264_LOG_WARNING, "try increasing target bitrate or increasing qp_max (currently %d)\n", h->param.rc.i_qp_max );
2593 x264_log( h, X264_LOG_WARNING, "try increasing target bitrate\n");
2595 else if( !(rcc->b_2pass && rcc->b_vbv) )
2596 x264_log( h, X264_LOG_WARNING, "internal error\n" );