1 /*****************************************************************************
2 * ratecontrol.c: ratecontrol
3 *****************************************************************************
4 * Copyright (C) 2005-2011 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.
26 * This program is also available under a commercial proprietary license.
27 * For more information, contact us at licensing@x264.com.
28 *****************************************************************************/
30 #define _ISOC99_SOURCE
31 #undef NDEBUG // always check asserts, the speed effect is far too small to disable them
33 #include "common/common.h"
34 #include "ratecontrol.h"
46 uint64_t expected_bits; /*total expected bits up to the current frame (current one excluded)*/
53 float blurred_complexity;
56 int16_t i_weight_denom[2];
60 int64_t i_cpb_duration;
61 } ratecontrol_entry_t;
71 struct x264_ratecontrol_t
80 double rate_tolerance;
82 int nmb; /* number of macroblocks in a frame */
86 ratecontrol_entry_t *rce;
87 int qp; /* qp for current frame */
88 float qpm; /* qp for current macroblock: precise float for AQ */
89 float qpa_rc; /* average of macroblocks' qp before aq */
90 int qpa_aq; /* average of macroblocks' qp after aq */
91 float qp_novbv; /* QP for the current frame if 1-pass VBV was disabled. */
95 int64_t buffer_fill_final;
96 double buffer_fill; /* planned buffer, if all in-progress frames hit their bit budget */
97 double buffer_rate; /* # of bits added to buffer_fill after each frame */
98 double vbv_max_rate; /* # of bits added to buffer_fill per second */
99 predictor_t *pred; /* predict frame size from satd */
100 int single_frame_vbv;
101 double rate_factor_max_increment; /* Don't allow RF above (CRF + this value). */
106 double cplxr_sum; /* sum of bits*qscale/rceq */
107 double expected_bits_sum; /* sum of qscale2bits after rceq, ratefactor, and overflow, only includes finished frames */
108 int64_t filler_bits_sum; /* sum in bits of finished frames' filler data */
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[3]; /* 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[3]; /* 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 predictor_t (*row_pred)[2];
147 predictor_t row_preds[3][2];
148 predictor_t *pred_b_from_p; /* predict B-frame size from P-frame satd */
149 int bframes; /* # consecutive B-frames before this P-frame */
150 int bframe_bits; /* total cost of those frames */
154 x264_zone_t *prev_zone;
157 int initial_cpb_removal_delay;
158 int initial_cpb_removal_delay_offset;
159 double nrt_first_access_unit; /* nominal removal time */
160 double previous_cpb_final_arrival_time;
161 uint64_t hrd_multiply_denom;
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 float predict_size( predictor_t *p, float q, float var );
171 static void update_predictor( predictor_t *p, float q, float var, float 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 float qp2qscale( float qp )
188 return 0.85f * powf( 2.0f, ( qp - 12.0f ) / 6.0f );
190 static inline float qscale2qp( float qscale )
192 return 12.0f + 6.0f * log2f( qscale/0.85f );
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_var( uint64_t sum_ssd, int shift, x264_frame_t *frame, int i, int b_store )
210 uint32_t sum = sum_ssd;
211 uint32_t ssd = sum_ssd >> 32;
214 frame->i_pixel_sum[i] += sum;
215 frame->i_pixel_ssd[i] += ssd;
217 return ssd - ((uint64_t)sum * sum >> shift);
220 static ALWAYS_INLINE uint32_t ac_energy_plane( x264_t *h, int mb_x, int mb_y, x264_frame_t *frame, int i, int field, int b_store )
223 int stride = frame->i_stride[i];
225 ? 16 * mb_x + w * (mb_y&~1) * stride + (mb_y&1) * stride
226 : 16 * mb_x + w * mb_y * stride;
230 ALIGNED_ARRAY_16( pixel, pix,[FENC_STRIDE*8] );
231 h->mc.load_deinterleave_8x8x2_fenc( pix, frame->plane[1] + offset, stride );
232 return ac_energy_var( h->pixf.var[PIXEL_8x8]( pix, FENC_STRIDE ), 6, frame, 1, b_store )
233 + ac_energy_var( h->pixf.var[PIXEL_8x8]( pix+FENC_STRIDE/2, FENC_STRIDE ), 6, frame, 2, b_store );
236 return ac_energy_var( h->pixf.var[PIXEL_16x16]( frame->plane[0] + offset, stride ), 8, frame, 0, b_store );
239 // Find the total AC energy of the block in all planes.
240 static NOINLINE uint32_t x264_ac_energy_mb( x264_t *h, int mb_x, int mb_y, x264_frame_t *frame )
242 /* This function contains annoying hacks because GCC has a habit of reordering emms
243 * and putting it after floating point ops. As a result, we put the emms at the end of the
244 * function and make sure that its always called before the float math. Noinline makes
245 * sure no reordering goes on. */
247 if( h->mb.b_adaptive_mbaff )
249 /* We don't know the super-MB mode we're going to pick yet, so
250 * simply try both and pick the lower of the two. */
251 uint32_t var_interlaced, var_progressive;
252 var_interlaced = ac_energy_plane( h, mb_x, mb_y, frame, 0, 1, 1 );
253 var_interlaced += ac_energy_plane( h, mb_x, mb_y, frame, 1, 1, 1 );
254 var_progressive = ac_energy_plane( h, mb_x, mb_y, frame, 0, 0, 0 );
255 var_progressive += ac_energy_plane( h, mb_x, mb_y, frame, 1, 0, 0 );
256 var = X264_MIN( var_interlaced, var_progressive );
260 var = ac_energy_plane( h, mb_x, mb_y, frame, 0, PARAM_INTERLACED, 1 );
261 var += ac_energy_plane( h, mb_x, mb_y, frame, 1, PARAM_INTERLACED, 1 );
267 void x264_adaptive_quant_frame( x264_t *h, x264_frame_t *frame, float *quant_offsets )
269 /* constants chosen to result in approximately the same overall bitrate as without AQ.
270 * FIXME: while they're written in 5 significant digits, they're only tuned to 2. */
273 /* Initialize frame stats */
274 for( int i = 0; i < 3; i++ )
276 frame->i_pixel_sum[i] = 0;
277 frame->i_pixel_ssd[i] = 0;
280 /* Degenerate cases */
281 if( h->param.rc.i_aq_mode == X264_AQ_NONE || h->param.rc.f_aq_strength == 0 )
283 /* Need to init it anyways for MB tree */
284 if( h->param.rc.i_aq_mode && h->param.rc.f_aq_strength == 0 )
288 for( int mb_xy = 0; mb_xy < h->mb.i_mb_count; mb_xy++ )
289 frame->f_qp_offset[mb_xy] = frame->f_qp_offset_aq[mb_xy] = quant_offsets[mb_xy];
290 if( h->frames.b_have_lowres )
291 for( int mb_xy = 0; mb_xy < h->mb.i_mb_count; mb_xy++ )
292 frame->i_inv_qscale_factor[mb_xy] = x264_exp2fix8( frame->f_qp_offset[mb_xy] );
296 memset( frame->f_qp_offset, 0, h->mb.i_mb_count * sizeof(float) );
297 memset( frame->f_qp_offset_aq, 0, h->mb.i_mb_count * sizeof(float) );
298 if( h->frames.b_have_lowres )
299 for( int mb_xy = 0; mb_xy < h->mb.i_mb_count; mb_xy++ )
300 frame->i_inv_qscale_factor[mb_xy] = 256;
303 /* Need variance data for weighted prediction */
304 if( h->param.analyse.i_weighted_pred )
306 for( int mb_y = 0; mb_y < h->mb.i_mb_height; mb_y++ )
307 for( int mb_x = 0; mb_x < h->mb.i_mb_width; mb_x++ )
308 x264_ac_energy_mb( h, mb_x, mb_y, frame );
313 /* Actual adaptive quantization */
316 if( h->param.rc.i_aq_mode == X264_AQ_AUTOVARIANCE )
318 float bit_depth_correction = powf(1 << (BIT_DEPTH-8), 0.5f);
319 float avg_adj_pow2 = 0.f;
320 for( int mb_y = 0; mb_y < h->mb.i_mb_height; mb_y++ )
321 for( int mb_x = 0; mb_x < h->mb.i_mb_width; mb_x++ )
323 uint32_t energy = x264_ac_energy_mb( h, mb_x, mb_y, frame );
324 float qp_adj = powf( energy + 1, 0.125f );
325 frame->f_qp_offset[mb_x + mb_y*h->mb.i_mb_stride] = qp_adj;
327 avg_adj_pow2 += qp_adj * qp_adj;
329 avg_adj /= h->mb.i_mb_count;
330 avg_adj_pow2 /= h->mb.i_mb_count;
331 strength = h->param.rc.f_aq_strength * avg_adj / bit_depth_correction;
332 avg_adj = avg_adj - 0.5f * (avg_adj_pow2 - (14.f * bit_depth_correction)) / avg_adj;
335 strength = h->param.rc.f_aq_strength * 1.0397f;
337 for( int mb_y = 0; mb_y < h->mb.i_mb_height; mb_y++ )
338 for( int mb_x = 0; mb_x < h->mb.i_mb_width; mb_x++ )
341 int mb_xy = mb_x + mb_y*h->mb.i_mb_stride;
342 if( h->param.rc.i_aq_mode == X264_AQ_AUTOVARIANCE )
344 qp_adj = frame->f_qp_offset[mb_xy];
345 qp_adj = strength * (qp_adj - avg_adj);
349 uint32_t energy = x264_ac_energy_mb( h, mb_x, mb_y, frame );
350 qp_adj = strength * (x264_log2( X264_MAX(energy, 1) ) - (14.427f + 2*(BIT_DEPTH-8)));
353 qp_adj += quant_offsets[mb_xy];
354 frame->f_qp_offset[mb_xy] =
355 frame->f_qp_offset_aq[mb_xy] = qp_adj;
356 if( h->frames.b_have_lowres )
357 frame->i_inv_qscale_factor[mb_xy] = x264_exp2fix8(qp_adj);
361 /* Remove mean from SSD calculation */
362 for( int i = 0; i < 3; i++ )
364 uint64_t ssd = frame->i_pixel_ssd[i];
365 uint64_t sum = frame->i_pixel_sum[i];
366 int width = h->mb.i_mb_width*16>>!!i;
367 int height = h->mb.i_mb_height*16>>!!i;
368 frame->i_pixel_ssd[i] = ssd - (sum * sum + width * height / 2) / (width * height);
372 int x264_macroblock_tree_read( x264_t *h, x264_frame_t *frame, float *quant_offsets )
374 x264_ratecontrol_t *rc = h->rc;
375 uint8_t i_type_actual = rc->entry[frame->i_frame].pict_type;
377 if( rc->entry[frame->i_frame].kept_as_ref )
380 if( rc->qpbuf_pos < 0 )
386 if( !fread( &i_type, 1, 1, rc->p_mbtree_stat_file_in ) )
388 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 )
391 if( i_type != i_type_actual && rc->qpbuf_pos == 1 )
393 x264_log(h, X264_LOG_ERROR, "MB-tree frametype %d doesn't match actual frametype %d.\n", i_type, i_type_actual);
396 } while( i_type != i_type_actual );
399 for( int i = 0; i < h->mb.i_mb_count; i++ )
401 frame->f_qp_offset[i] = ((float)(int16_t)endian_fix16( rc->qp_buffer[rc->qpbuf_pos][i] )) * (1/256.0);
402 if( h->frames.b_have_lowres )
403 frame->i_inv_qscale_factor[i] = x264_exp2fix8(frame->f_qp_offset[i]);
408 x264_stack_align( x264_adaptive_quant_frame, h, frame, quant_offsets );
411 x264_log(h, X264_LOG_ERROR, "Incomplete MB-tree stats file.\n");
415 int x264_reference_build_list_optimal( x264_t *h )
417 ratecontrol_entry_t *rce = h->rc->rce;
418 x264_frame_t *frames[16];
419 x264_weight_t weights[16][3];
422 if( rce->refs != h->i_ref[0] )
425 memcpy( frames, h->fref[0], sizeof(frames) );
426 memcpy( refcount, rce->refcount, sizeof(refcount) );
427 memcpy( weights, h->fenc->weight, sizeof(weights) );
428 memset( &h->fenc->weight[1][0], 0, sizeof(x264_weight_t[15][3]) );
430 /* For now don't reorder ref 0; it seems to lower quality
431 in most cases due to skips. */
432 for( int ref = 1; ref < h->i_ref[0]; ref++ )
437 for( int i = 1; i < h->i_ref[0]; i++ )
438 /* Favor lower POC as a tiebreaker. */
439 COPY2_IF_GT( max, refcount[i], bestref, i );
441 /* FIXME: If there are duplicates from frames other than ref0 then it is possible
442 * that the optimal ordering doesnt place every duplicate. */
444 refcount[bestref] = -1;
445 h->fref[0][ref] = frames[bestref];
446 memcpy( h->fenc->weight[ref], weights[bestref], sizeof(weights[bestref]) );
452 static char *x264_strcat_filename( char *input, char *suffix )
454 char *output = x264_malloc( strlen( input ) + strlen( suffix ) + 1 );
457 strcpy( output, input );
458 strcat( output, suffix );
462 void x264_ratecontrol_init_reconfigurable( x264_t *h, int b_init )
464 x264_ratecontrol_t *rc = h->rc;
465 if( !b_init && rc->b_2pass )
468 if( h->param.rc.i_rc_method == X264_RC_CRF )
470 /* Arbitrary rescaling to make CRF somewhat similar to QP.
471 * Try to compensate for MB-tree's effects as well. */
472 double base_cplx = h->mb.i_mb_count * (h->param.i_bframe ? 120 : 80);
473 double mbtree_offset = h->param.rc.b_mb_tree ? (1.0-h->param.rc.f_qcompress)*13.5 : 0;
474 rc->rate_factor_constant = pow( base_cplx, 1 - rc->qcompress )
475 / qp2qscale( h->param.rc.f_rf_constant + mbtree_offset + QP_BD_OFFSET );
478 if( h->param.rc.i_vbv_max_bitrate > 0 && h->param.rc.i_vbv_buffer_size > 0 )
480 /* We don't support changing the ABR bitrate right now,
481 so if the stream starts as CBR, keep it CBR. */
482 if( rc->b_vbv_min_rate )
483 h->param.rc.i_vbv_max_bitrate = h->param.rc.i_bitrate;
485 if( h->param.rc.i_vbv_buffer_size < (int)(h->param.rc.i_vbv_max_bitrate / rc->fps) )
487 h->param.rc.i_vbv_buffer_size = h->param.rc.i_vbv_max_bitrate / rc->fps;
488 x264_log( h, X264_LOG_WARNING, "VBV buffer size cannot be smaller than one frame, using %d kbit\n",
489 h->param.rc.i_vbv_buffer_size );
492 int vbv_buffer_size = h->param.rc.i_vbv_buffer_size * 1000;
493 int vbv_max_bitrate = h->param.rc.i_vbv_max_bitrate * 1000;
496 if( h->param.i_nal_hrd && b_init )
498 h->sps->vui.hrd.i_cpb_cnt = 1;
499 h->sps->vui.hrd.b_cbr_hrd = h->param.i_nal_hrd == X264_NAL_HRD_CBR;
500 h->sps->vui.hrd.i_time_offset_length = 0;
505 int bitrate = 1000*h->param.rc.i_vbv_max_bitrate;
506 int bufsize = 1000*h->param.rc.i_vbv_buffer_size;
508 // normalize HRD size and rate to the value / scale notation
509 h->sps->vui.hrd.i_bit_rate_scale = x264_clip3( x264_ctz( bitrate ) - BR_SHIFT, 0, 15 );
510 h->sps->vui.hrd.i_bit_rate_value = bitrate >> ( h->sps->vui.hrd.i_bit_rate_scale + BR_SHIFT );
511 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 );
512 h->sps->vui.hrd.i_cpb_size_scale = x264_clip3( x264_ctz( bufsize ) - CPB_SHIFT, 0, 15 );
513 h->sps->vui.hrd.i_cpb_size_value = bufsize >> ( h->sps->vui.hrd.i_cpb_size_scale + CPB_SHIFT );
514 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 );
520 #define MAX_DURATION 0.5
522 int max_cpb_output_delay = X264_MIN( h->param.i_keyint_max * MAX_DURATION * h->sps->vui.i_time_scale / h->sps->vui.i_num_units_in_tick, INT_MAX );
523 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;
524 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);
526 h->sps->vui.hrd.i_initial_cpb_removal_delay_length = 2 + x264_clip3( 32 - x264_clz( max_delay ), 4, 22 );
527 h->sps->vui.hrd.i_cpb_removal_delay_length = x264_clip3( 32 - x264_clz( max_cpb_output_delay ), 4, 31 );
528 h->sps->vui.hrd.i_dpb_output_delay_length = x264_clip3( 32 - x264_clz( max_dpb_output_delay ), 4, 31 );
532 vbv_buffer_size = h->sps->vui.hrd.i_cpb_size_unscaled;
533 vbv_max_bitrate = h->sps->vui.hrd.i_bit_rate_unscaled;
535 else if( h->param.i_nal_hrd && !b_init )
537 x264_log( h, X264_LOG_WARNING, "VBV parameters cannot be changed when NAL HRD is in use\n" );
540 h->sps->vui.hrd.i_bit_rate_unscaled = vbv_max_bitrate;
541 h->sps->vui.hrd.i_cpb_size_unscaled = vbv_buffer_size;
543 if( rc->b_vbv_min_rate )
544 rc->bitrate = h->param.rc.i_bitrate * 1000.;
545 rc->buffer_rate = vbv_max_bitrate / rc->fps;
546 rc->vbv_max_rate = vbv_max_bitrate;
547 rc->buffer_size = vbv_buffer_size;
548 rc->single_frame_vbv = rc->buffer_rate * 1.1 > rc->buffer_size;
549 rc->cbr_decay = 1.0 - rc->buffer_rate / rc->buffer_size
550 * 0.5 * X264_MAX(0, 1.5 - rc->buffer_rate * rc->fps / rc->bitrate);
551 if( h->param.rc.i_rc_method == X264_RC_CRF && h->param.rc.f_rf_constant_max )
553 rc->rate_factor_max_increment = h->param.rc.f_rf_constant_max - h->param.rc.f_rf_constant;
554 if( rc->rate_factor_max_increment <= 0 )
556 x264_log( h, X264_LOG_WARNING, "CRF max must be greater than CRF\n" );
557 rc->rate_factor_max_increment = 0;
562 if( h->param.rc.f_vbv_buffer_init > 1. )
563 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 );
564 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);
565 rc->buffer_fill_final = rc->buffer_size * h->param.rc.f_vbv_buffer_init * h->sps->vui.i_time_scale;
567 rc->b_vbv_min_rate = !rc->b_2pass
568 && h->param.rc.i_rc_method == X264_RC_ABR
569 && h->param.rc.i_vbv_max_bitrate <= h->param.rc.i_bitrate;
574 int x264_ratecontrol_new( x264_t *h )
576 x264_ratecontrol_t *rc;
580 CHECKED_MALLOCZERO( h->rc, h->param.i_threads * sizeof(x264_ratecontrol_t) );
583 rc->b_abr = h->param.rc.i_rc_method != X264_RC_CQP && !h->param.rc.b_stat_read;
584 rc->b_2pass = h->param.rc.i_rc_method == X264_RC_ABR && h->param.rc.b_stat_read;
586 /* FIXME: use integers */
587 if( h->param.i_fps_num > 0 && h->param.i_fps_den > 0 )
588 rc->fps = (float) h->param.i_fps_num / h->param.i_fps_den;
592 if( h->param.rc.b_mb_tree )
594 h->param.rc.f_pb_factor = 1;
598 rc->qcompress = h->param.rc.f_qcompress;
600 rc->bitrate = h->param.rc.i_bitrate * 1000.;
601 rc->rate_tolerance = h->param.rc.f_rate_tolerance;
602 rc->nmb = h->mb.i_mb_count;
603 rc->last_non_b_pict_type = -1;
606 if( h->param.rc.i_rc_method == X264_RC_CRF && h->param.rc.b_stat_read )
608 x264_log(h, X264_LOG_ERROR, "constant rate-factor is incompatible with 2pass.\n");
612 x264_ratecontrol_init_reconfigurable( h, 1 );
614 if( h->param.i_nal_hrd )
616 uint64_t denom = (uint64_t)h->sps->vui.hrd.i_bit_rate_unscaled * h->sps->vui.i_time_scale;
617 uint64_t num = 180000;
618 x264_reduce_fraction64( &num, &denom );
619 rc->hrd_multiply_denom = 180000 / num;
621 double bits_required = log2( 180000 / rc->hrd_multiply_denom )
622 + log2( h->sps->vui.i_time_scale )
623 + log2( h->sps->vui.hrd.i_cpb_size_unscaled );
624 if( bits_required >= 63 )
626 x264_log( h, X264_LOG_ERROR, "HRD with very large timescale and bufsize not supported\n" );
631 if( rc->rate_tolerance < 0.01 )
633 x264_log(h, X264_LOG_WARNING, "bitrate tolerance too small, using .01\n");
634 rc->rate_tolerance = 0.01;
637 h->mb.b_variable_qp = rc->b_vbv || h->param.rc.i_aq_mode;
641 /* FIXME ABR_INIT_QP is actually used only in CRF */
642 #define ABR_INIT_QP (( h->param.rc.i_rc_method == X264_RC_CRF ? h->param.rc.f_rf_constant : 24 ) + QP_BD_OFFSET)
643 rc->accum_p_norm = .01;
644 rc->accum_p_qp = ABR_INIT_QP * rc->accum_p_norm;
645 /* estimated ratio that produces a reasonable QP for the first I-frame */
646 rc->cplxr_sum = .01 * pow( 7.0e5, rc->qcompress ) * pow( h->mb.i_mb_count, 0.5 );
647 rc->wanted_bits_window = 1.0 * rc->bitrate / rc->fps;
648 rc->last_non_b_pict_type = SLICE_TYPE_I;
651 rc->ip_offset = 6.0 * log2f( h->param.rc.f_ip_factor );
652 rc->pb_offset = 6.0 * log2f( h->param.rc.f_pb_factor );
653 rc->qp_constant[SLICE_TYPE_P] = h->param.rc.i_qp_constant;
654 rc->qp_constant[SLICE_TYPE_I] = x264_clip3( h->param.rc.i_qp_constant - rc->ip_offset + 0.5, 0, QP_MAX );
655 rc->qp_constant[SLICE_TYPE_B] = x264_clip3( h->param.rc.i_qp_constant + rc->pb_offset + 0.5, 0, QP_MAX );
656 h->mb.ip_offset = rc->ip_offset + 0.5;
658 rc->lstep = pow( 2, h->param.rc.i_qp_step / 6.0 );
659 rc->last_qscale = qp2qscale( 26 );
660 int num_preds = h->param.b_sliced_threads * h->param.i_threads + 1;
661 CHECKED_MALLOC( rc->pred, 5 * sizeof(predictor_t) * num_preds );
662 CHECKED_MALLOC( rc->pred_b_from_p, sizeof(predictor_t) );
663 for( int i = 0; i < 3; i++ )
665 rc->last_qscale_for[i] = qp2qscale( ABR_INIT_QP );
666 rc->lmin[i] = qp2qscale( h->param.rc.i_qp_min );
667 rc->lmax[i] = qp2qscale( h->param.rc.i_qp_max );
668 for( int j = 0; j < num_preds; j++ )
670 rc->pred[i+j*5].coeff= 2.0;
671 rc->pred[i+j*5].count= 1.0;
672 rc->pred[i+j*5].decay= 0.5;
673 rc->pred[i+j*5].offset= 0.0;
675 for( int j = 0; j < 2; j++ )
677 rc->row_preds[i][j].coeff= .25;
678 rc->row_preds[i][j].count= 1.0;
679 rc->row_preds[i][j].decay= 0.5;
680 rc->row_preds[i][j].offset= 0.0;
683 *rc->pred_b_from_p = rc->pred[0];
685 if( parse_zones( h ) < 0 )
687 x264_log( h, X264_LOG_ERROR, "failed to parse zones\n" );
691 /* Load stat file and init 2pass algo */
692 if( h->param.rc.b_stat_read )
694 char *p, *stats_in, *stats_buf;
696 /* read 1st pass stats */
697 assert( h->param.rc.psz_stat_in );
698 stats_buf = stats_in = x264_slurp_file( h->param.rc.psz_stat_in );
701 x264_log(h, X264_LOG_ERROR, "ratecontrol_init: can't open stats file\n");
704 if( h->param.rc.b_mb_tree )
706 char *mbtree_stats_in = x264_strcat_filename( h->param.rc.psz_stat_in, ".mbtree" );
707 if( !mbtree_stats_in )
709 rc->p_mbtree_stat_file_in = fopen( mbtree_stats_in, "rb" );
710 x264_free( mbtree_stats_in );
711 if( !rc->p_mbtree_stat_file_in )
713 x264_log(h, X264_LOG_ERROR, "ratecontrol_init: can't open mbtree stats file\n");
718 /* check whether 1st pass options were compatible with current options */
719 if( !strncmp( stats_buf, "#options:", 9 ) )
723 char *opts = stats_buf;
724 stats_in = strchr( stats_buf, '\n' );
729 if( sscanf( opts, "#options: %dx%d", &i, &j ) != 2 )
731 x264_log( h, X264_LOG_ERROR, "resolution specified in stats file not valid\n" );
734 else if( h->param.rc.b_mb_tree && (i != h->param.i_width || j != h->param.i_height) )
736 x264_log( h, X264_LOG_ERROR, "MB-tree doesn't support different resolution than 1st pass (%dx%d vs %dx%d)\n",
737 h->param.i_width, h->param.i_height, i, j );
741 if( ( p = strstr( opts, "timebase=" ) ) && sscanf( p, "timebase=%u/%u", &k, &l ) != 2 )
743 x264_log( h, X264_LOG_ERROR, "timebase specified in stats file not valid\n" );
746 if( k != h->param.i_timebase_num || l != h->param.i_timebase_den )
748 x264_log( h, X264_LOG_ERROR, "timebase mismatch with 1st pass (%u/%u vs %u/%u)\n",
749 h->param.i_timebase_num, h->param.i_timebase_den, k, l );
753 CMP_OPT_FIRST_PASS( "bitdepth", BIT_DEPTH );
754 CMP_OPT_FIRST_PASS( "weightp", X264_MAX( 0, h->param.analyse.i_weighted_pred ) );
755 CMP_OPT_FIRST_PASS( "bframes", h->param.i_bframe );
756 CMP_OPT_FIRST_PASS( "b_pyramid", h->param.i_bframe_pyramid );
757 CMP_OPT_FIRST_PASS( "intra_refresh", h->param.b_intra_refresh );
758 CMP_OPT_FIRST_PASS( "open_gop", h->param.b_open_gop );
759 CMP_OPT_FIRST_PASS( "bluray_compat", h->param.b_bluray_compat );
761 if( (p = strstr( opts, "keyint=" )) )
764 char buf[13] = "infinite ";
765 if( h->param.i_keyint_max != X264_KEYINT_MAX_INFINITE )
766 sprintf( buf, "%d ", h->param.i_keyint_max );
767 if( strncmp( p, buf, strlen(buf) ) )
769 x264_log( h, X264_LOG_ERROR, "different keyint setting than first pass (%.*s vs %.*s)\n",
770 strlen(buf)-1, buf, strcspn(p, " "), p );
775 if( strstr( opts, "qp=0" ) && h->param.rc.i_rc_method == X264_RC_ABR )
776 x264_log( h, X264_LOG_WARNING, "1st pass was lossless, bitrate prediction will be inaccurate\n" );
778 if( !strstr( opts, "direct=3" ) && h->param.analyse.i_direct_mv_pred == X264_DIRECT_PRED_AUTO )
780 x264_log( h, X264_LOG_WARNING, "direct=auto not used on the first pass\n" );
781 h->mb.b_direct_auto_write = 1;
784 if( ( p = strstr( opts, "b_adapt=" ) ) && sscanf( p, "b_adapt=%d", &i ) && i >= X264_B_ADAPT_NONE && i <= X264_B_ADAPT_TRELLIS )
785 h->param.i_bframe_adaptive = i;
786 else if( h->param.i_bframe )
788 x264_log( h, X264_LOG_ERROR, "b_adapt method specified in stats file not valid\n" );
792 if( (h->param.rc.b_mb_tree || h->param.rc.i_vbv_buffer_size) && ( p = strstr( opts, "rc_lookahead=" ) ) && sscanf( p, "rc_lookahead=%d", &i ) )
793 h->param.rc.i_lookahead = i;
796 /* find number of pics */
799 for( num_entries = -1; p; num_entries++ )
800 p = strchr( p + 1, ';' );
803 x264_log(h, X264_LOG_ERROR, "empty stats file\n");
806 rc->num_entries = num_entries;
808 if( h->param.i_frame_total < rc->num_entries && h->param.i_frame_total > 0 )
810 x264_log( h, X264_LOG_WARNING, "2nd pass has fewer frames than 1st pass (%d vs %d)\n",
811 h->param.i_frame_total, rc->num_entries );
813 if( h->param.i_frame_total > rc->num_entries )
815 x264_log( h, X264_LOG_ERROR, "2nd pass has more frames than 1st pass (%d vs %d)\n",
816 h->param.i_frame_total, rc->num_entries );
820 CHECKED_MALLOCZERO( rc->entry, rc->num_entries * sizeof(ratecontrol_entry_t) );
822 /* init all to skipped p frames */
823 for( int i = 0; i < rc->num_entries; i++ )
825 ratecontrol_entry_t *rce = &rc->entry[i];
826 rce->pict_type = SLICE_TYPE_P;
827 rce->qscale = rce->new_qscale = qp2qscale( 20 );
828 rce->misc_bits = rc->nmb + 10;
834 for( int i = 0; i < rc->num_entries; i++ )
836 ratecontrol_entry_t *rce;
844 next= strchr(p, ';');
846 *next++ = 0; //sscanf is unbelievably slow on long strings
847 e = sscanf( p, " in:%d ", &frame_number );
849 if( frame_number < 0 || frame_number >= rc->num_entries )
851 x264_log( h, X264_LOG_ERROR, "bad frame number (%d) at stats line %d\n", frame_number, i );
854 rce = &rc->entry[frame_number];
855 rce->direct_mode = 0;
857 e += sscanf( p, " in:%*d out:%*d type:%c dur:%"SCNd64" cpbdur:%"SCNd64" q:%f tex:%d mv:%d misc:%d imb:%d pmb:%d smb:%d d:%c",
858 &pict_type, &rce->i_duration, &rce->i_cpb_duration, &qp, &rce->tex_bits,
859 &rce->mv_bits, &rce->misc_bits, &rce->i_count, &rce->p_count,
860 &rce->s_count, &rce->direct_mode );
862 p = strstr( p, "ref:" );
866 for( ref = 0; ref < 16; ref++ )
868 if( sscanf( p, " %d", &rce->refcount[ref] ) != 1 )
870 p = strchr( p+1, ' ' );
877 rce->i_weight_denom[0] = rce->i_weight_denom[1] = -1;
878 char *w = strchr( p, 'w' );
881 int count = sscanf( w, "w:%hd,%hd,%hd,%hd,%hd,%hd,%hd,%hd",
882 &rce->i_weight_denom[0], &rce->weight[0][0], &rce->weight[0][1],
883 &rce->i_weight_denom[1], &rce->weight[1][0], &rce->weight[1][1],
884 &rce->weight[2][0], &rce->weight[2][1] );
886 rce->i_weight_denom[1] = -1;
887 else if ( count != 8 )
888 rce->i_weight_denom[0] = rce->i_weight_denom[1] = -1;
891 if( pict_type != 'b' )
892 rce->kept_as_ref = 1;
896 rce->frame_type = X264_TYPE_IDR;
897 rce->pict_type = SLICE_TYPE_I;
900 rce->frame_type = X264_TYPE_I;
901 rce->pict_type = SLICE_TYPE_I;
904 rce->frame_type = X264_TYPE_P;
905 rce->pict_type = SLICE_TYPE_P;
908 rce->frame_type = X264_TYPE_BREF;
909 rce->pict_type = SLICE_TYPE_B;
912 rce->frame_type = X264_TYPE_B;
913 rce->pict_type = SLICE_TYPE_B;
915 default: e = -1; break;
920 x264_log( h, X264_LOG_ERROR, "statistics are damaged at line %d, parser out=%d\n", i, e );
923 rce->qscale = qp2qscale( qp );
927 x264_free( stats_buf );
929 if( h->param.rc.i_rc_method == X264_RC_ABR )
931 if( init_pass2( h ) < 0 )
933 } /* else we're using constant quant, so no need to run the bitrate allocation */
936 /* Open output file */
937 /* If input and output files are the same, output to a temp file
938 * and move it to the real name only when it's complete */
939 if( h->param.rc.b_stat_write )
942 rc->psz_stat_file_tmpname = x264_strcat_filename( h->param.rc.psz_stat_out, ".temp" );
943 if( !rc->psz_stat_file_tmpname )
946 rc->p_stat_file_out = fopen( rc->psz_stat_file_tmpname, "wb" );
947 if( rc->p_stat_file_out == NULL )
949 x264_log(h, X264_LOG_ERROR, "ratecontrol_init: can't open stats file\n");
953 p = x264_param2string( &h->param, 1 );
955 fprintf( rc->p_stat_file_out, "#options: %s\n", p );
957 if( h->param.rc.b_mb_tree && !h->param.rc.b_stat_read )
959 rc->psz_mbtree_stat_file_tmpname = x264_strcat_filename( h->param.rc.psz_stat_out, ".mbtree.temp" );
960 rc->psz_mbtree_stat_file_name = x264_strcat_filename( h->param.rc.psz_stat_out, ".mbtree" );
961 if( !rc->psz_mbtree_stat_file_tmpname || !rc->psz_mbtree_stat_file_name )
964 rc->p_mbtree_stat_file_out = fopen( rc->psz_mbtree_stat_file_tmpname, "wb" );
965 if( rc->p_mbtree_stat_file_out == NULL )
967 x264_log(h, X264_LOG_ERROR, "ratecontrol_init: can't open mbtree stats file\n");
973 if( h->param.rc.b_mb_tree && (h->param.rc.b_stat_read || h->param.rc.b_stat_write) )
975 CHECKED_MALLOC( rc->qp_buffer[0], h->mb.i_mb_count * sizeof(uint16_t) );
976 if( h->param.i_bframe_pyramid && h->param.rc.b_stat_read )
977 CHECKED_MALLOC( rc->qp_buffer[1], h->mb.i_mb_count * sizeof(uint16_t) );
981 for( int i = 0; i<h->param.i_threads; i++ )
983 h->thread[i]->rc = rc+i;
987 h->thread[i]->param = h->param;
988 h->thread[i]->mb.b_variable_qp = h->mb.b_variable_qp;
989 h->thread[i]->mb.ip_offset = h->mb.ip_offset;
998 static int parse_zone( x264_t *h, x264_zone_t *z, char *p )
1001 char *tok, UNUSED *saveptr=NULL;
1003 z->f_bitrate_factor = 1;
1004 if( 3 <= sscanf(p, "%d,%d,q=%d%n", &z->i_start, &z->i_end, &z->i_qp, &len) )
1006 else if( 3 <= sscanf(p, "%d,%d,b=%f%n", &z->i_start, &z->i_end, &z->f_bitrate_factor, &len) )
1008 else if( 2 <= sscanf(p, "%d,%d%n", &z->i_start, &z->i_end, &len) )
1012 x264_log( h, X264_LOG_ERROR, "invalid zone: \"%s\"\n", p );
1018 CHECKED_MALLOC( z->param, sizeof(x264_param_t) );
1019 memcpy( z->param, &h->param, sizeof(x264_param_t) );
1020 z->param->param_free = x264_free;
1021 while( (tok = strtok_r( p, ",", &saveptr )) )
1023 char *val = strchr( tok, '=' );
1029 if( x264_param_parse( z->param, tok, val ) )
1031 x264_log( h, X264_LOG_ERROR, "invalid zone param: %s = %s\n", tok, val );
1041 static int parse_zones( x264_t *h )
1043 x264_ratecontrol_t *rc = h->rc;
1044 if( h->param.rc.psz_zones && !h->param.rc.i_zones )
1046 char *psz_zones, *p;
1047 CHECKED_MALLOC( psz_zones, strlen( h->param.rc.psz_zones )+1 );
1048 strcpy( psz_zones, h->param.rc.psz_zones );
1049 h->param.rc.i_zones = 1;
1050 for( p = psz_zones; *p; p++ )
1051 h->param.rc.i_zones += (*p == '/');
1052 CHECKED_MALLOC( h->param.rc.zones, h->param.rc.i_zones * sizeof(x264_zone_t) );
1054 for( int i = 0; i < h->param.rc.i_zones; i++ )
1056 int i_tok = strcspn( p, "/" );
1058 if( parse_zone( h, &h->param.rc.zones[i], p ) )
1062 x264_free( psz_zones );
1065 if( h->param.rc.i_zones > 0 )
1067 for( int i = 0; i < h->param.rc.i_zones; i++ )
1069 x264_zone_t z = h->param.rc.zones[i];
1070 if( z.i_start < 0 || z.i_start > z.i_end )
1072 x264_log( h, X264_LOG_ERROR, "invalid zone: start=%d end=%d\n",
1073 z.i_start, z.i_end );
1076 else if( !z.b_force_qp && z.f_bitrate_factor <= 0 )
1078 x264_log( h, X264_LOG_ERROR, "invalid zone: bitrate_factor=%f\n",
1079 z.f_bitrate_factor );
1084 rc->i_zones = h->param.rc.i_zones + 1;
1085 CHECKED_MALLOC( rc->zones, rc->i_zones * sizeof(x264_zone_t) );
1086 memcpy( rc->zones+1, h->param.rc.zones, (rc->i_zones-1) * sizeof(x264_zone_t) );
1088 // default zone to fall back to if none of the others match
1089 rc->zones[0].i_start = 0;
1090 rc->zones[0].i_end = INT_MAX;
1091 rc->zones[0].b_force_qp = 0;
1092 rc->zones[0].f_bitrate_factor = 1;
1093 CHECKED_MALLOC( rc->zones[0].param, sizeof(x264_param_t) );
1094 memcpy( rc->zones[0].param, &h->param, sizeof(x264_param_t) );
1095 for( int i = 1; i < rc->i_zones; i++ )
1097 if( !rc->zones[i].param )
1098 rc->zones[i].param = rc->zones[0].param;
1107 static x264_zone_t *get_zone( x264_t *h, int frame_num )
1109 for( int i = h->rc->i_zones - 1; i >= 0; i-- )
1111 x264_zone_t *z = &h->rc->zones[i];
1112 if( frame_num >= z->i_start && frame_num <= z->i_end )
1118 void x264_ratecontrol_summary( x264_t *h )
1120 x264_ratecontrol_t *rc = h->rc;
1121 if( rc->b_abr && h->param.rc.i_rc_method == X264_RC_ABR && rc->cbr_decay > .9999 )
1123 double base_cplx = h->mb.i_mb_count * (h->param.i_bframe ? 120 : 80);
1124 double mbtree_offset = h->param.rc.b_mb_tree ? (1.0-h->param.rc.f_qcompress)*13.5 : 0;
1125 x264_log( h, X264_LOG_INFO, "final ratefactor: %.2f\n",
1126 qscale2qp( pow( base_cplx, 1 - rc->qcompress )
1127 * rc->cplxr_sum / rc->wanted_bits_window ) - mbtree_offset - QP_BD_OFFSET );
1131 void x264_ratecontrol_delete( x264_t *h )
1133 x264_ratecontrol_t *rc = h->rc;
1136 if( rc->p_stat_file_out )
1138 b_regular_file = x264_is_regular_file( rc->p_stat_file_out );
1139 fclose( rc->p_stat_file_out );
1140 if( h->i_frame >= rc->num_entries && b_regular_file )
1141 if( rename( rc->psz_stat_file_tmpname, h->param.rc.psz_stat_out ) != 0 )
1143 x264_log( h, X264_LOG_ERROR, "failed to rename \"%s\" to \"%s\"\n",
1144 rc->psz_stat_file_tmpname, h->param.rc.psz_stat_out );
1146 x264_free( rc->psz_stat_file_tmpname );
1148 if( rc->p_mbtree_stat_file_out )
1150 b_regular_file = x264_is_regular_file( rc->p_mbtree_stat_file_out );
1151 fclose( rc->p_mbtree_stat_file_out );
1152 if( h->i_frame >= rc->num_entries && b_regular_file )
1153 if( rename( rc->psz_mbtree_stat_file_tmpname, rc->psz_mbtree_stat_file_name ) != 0 )
1155 x264_log( h, X264_LOG_ERROR, "failed to rename \"%s\" to \"%s\"\n",
1156 rc->psz_mbtree_stat_file_tmpname, rc->psz_mbtree_stat_file_name );
1158 x264_free( rc->psz_mbtree_stat_file_tmpname );
1159 x264_free( rc->psz_mbtree_stat_file_name );
1161 if( rc->p_mbtree_stat_file_in )
1162 fclose( rc->p_mbtree_stat_file_in );
1163 x264_free( rc->pred );
1164 x264_free( rc->pred_b_from_p );
1165 x264_free( rc->entry );
1166 x264_free( rc->qp_buffer[0] );
1167 x264_free( rc->qp_buffer[1] );
1170 x264_free( rc->zones[0].param );
1171 for( int i = 1; i < rc->i_zones; i++ )
1172 if( rc->zones[i].param != rc->zones[0].param && rc->zones[i].param->param_free )
1173 rc->zones[i].param->param_free( rc->zones[i].param );
1174 x264_free( rc->zones );
1179 static void accum_p_qp_update( x264_t *h, float qp )
1181 x264_ratecontrol_t *rc = h->rc;
1182 rc->accum_p_qp *= .95;
1183 rc->accum_p_norm *= .95;
1184 rc->accum_p_norm += 1;
1185 if( h->sh.i_type == SLICE_TYPE_I )
1186 rc->accum_p_qp += qp + rc->ip_offset;
1188 rc->accum_p_qp += qp;
1191 /* Before encoding a frame, choose a QP for it */
1192 void x264_ratecontrol_start( x264_t *h, int i_force_qp, int overhead )
1194 x264_ratecontrol_t *rc = h->rc;
1195 ratecontrol_entry_t *rce = NULL;
1196 x264_zone_t *zone = get_zone( h, h->fenc->i_frame );
1201 if( zone && (!rc->prev_zone || zone->param != rc->prev_zone->param) )
1202 x264_encoder_reconfig( h, zone->param );
1203 rc->prev_zone = zone;
1205 if( h->param.rc.b_stat_read )
1207 int frame = h->fenc->i_frame;
1208 assert( frame >= 0 && frame < rc->num_entries );
1209 rce = h->rc->rce = &h->rc->entry[frame];
1211 if( h->sh.i_type == SLICE_TYPE_B
1212 && h->param.analyse.i_direct_mv_pred == X264_DIRECT_PRED_AUTO )
1214 h->sh.b_direct_spatial_mv_pred = ( rce->direct_mode == 's' );
1215 h->mb.b_direct_auto_read = ( rce->direct_mode == 's' || rce->direct_mode == 't' );
1221 memset( h->fdec->i_row_bits, 0, h->mb.i_mb_height * sizeof(int) );
1222 rc->row_pred = &rc->row_preds[h->sh.i_type];
1223 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;
1224 update_vbv_plan( h, overhead );
1226 const x264_level_t *l = x264_levels;
1227 while( l->level_idc != 0 && l->level_idc != h->param.i_level_idc )
1230 int mincr = l->mincr;
1232 if( h->param.b_bluray_compat )
1235 /* High 10 doesn't require minCR, so just set the maximum to a large value. */
1236 if( h->sps->i_profile_idc == PROFILE_HIGH10 )
1237 rc->frame_size_maximum = 1e9;
1240 /* The spec has a bizarre special case for the first frame. */
1241 if( h->i_frame == 0 )
1243 //384 * ( Max( PicSizeInMbs, fR * MaxMBPS ) + MaxMBPS * ( tr( 0 ) - tr,n( 0 ) ) ) / MinCR
1244 double fr = 1. / 172;
1245 int pic_size_in_mbs = h->mb.i_mb_width * h->mb.i_mb_height;
1246 rc->frame_size_maximum = 384 * BIT_DEPTH * X264_MAX( pic_size_in_mbs, fr*l->mbps ) / mincr;
1250 //384 * MaxMBPS * ( tr( n ) - tr( n - 1 ) ) / MinCR
1251 rc->frame_size_maximum = 384 * BIT_DEPTH * ((double)h->fenc->i_cpb_duration * h->sps->vui.i_num_units_in_tick / h->sps->vui.i_time_scale) * l->mbps / mincr;
1256 if( h->sh.i_type != SLICE_TYPE_B )
1257 rc->bframes = h->fenc->i_bframes;
1261 q = qscale2qp( rate_estimate_qscale( h ) );
1263 else if( rc->b_2pass )
1265 rce->new_qscale = rate_estimate_qscale( h );
1266 q = qscale2qp( rce->new_qscale );
1270 if( h->sh.i_type == SLICE_TYPE_B && h->fdec->b_kept_as_ref )
1271 q = ( rc->qp_constant[ SLICE_TYPE_B ] + rc->qp_constant[ SLICE_TYPE_P ] ) / 2;
1273 q = rc->qp_constant[ h->sh.i_type ];
1277 if( zone->b_force_qp )
1278 q += zone->i_qp - rc->qp_constant[SLICE_TYPE_P];
1280 q -= 6*log2f( zone->f_bitrate_factor );
1283 if( i_force_qp != X264_QP_AUTO )
1286 q = x264_clip3f( q, h->param.rc.i_qp_min, h->param.rc.i_qp_max );
1290 rc->qp = x264_clip3( q + 0.5f, 0, QP_MAX );
1291 h->fdec->f_qp_avg_rc =
1292 h->fdec->f_qp_avg_aq =
1295 rce->new_qp = rc->qp;
1297 accum_p_qp_update( h, rc->qpm );
1299 if( h->sh.i_type != SLICE_TYPE_B )
1300 rc->last_non_b_pict_type = h->sh.i_type;
1303 static float predict_row_size( x264_t *h, int y, float qscale )
1305 /* average between two predictors:
1306 * absolute SATD, and scaled bit cost of the colocated row in the previous frame */
1307 x264_ratecontrol_t *rc = h->rc;
1308 float pred_s = predict_size( rc->row_pred[0], qscale, h->fdec->i_row_satd[y] );
1309 if( h->sh.i_type == SLICE_TYPE_I || qscale >= h->fref[0][0]->f_row_qscale[y] )
1311 if( h->sh.i_type == SLICE_TYPE_P
1312 && h->fref[0][0]->i_type == h->fdec->i_type
1313 && h->fref[0][0]->i_row_satd[y] > 0
1314 && (abs(h->fref[0][0]->i_row_satd[y] - h->fdec->i_row_satd[y]) < h->fdec->i_row_satd[y]/2))
1316 float pred_t = h->fref[0][0]->i_row_bits[y] * h->fdec->i_row_satd[y] / h->fref[0][0]->i_row_satd[y]
1317 * h->fref[0][0]->f_row_qscale[y] / qscale;
1318 return (pred_s + pred_t) * 0.5f;
1322 /* Our QP is lower than the reference! */
1325 float pred_intra = predict_size( rc->row_pred[1], qscale, h->fdec->i_row_satds[0][0][y] );
1326 /* Sum: better to overestimate than underestimate by using only one of the two predictors. */
1327 return pred_intra + pred_s;
1331 static int row_bits_so_far( x264_t *h, int y )
1334 for( int i = h->i_threadslice_start+SLICE_MBAFF; i <= y; i+=(SLICE_MBAFF+1) )
1335 bits += h->fdec->i_row_bits[i];
1339 static float predict_row_size_sum( x264_t *h, int y, float qp )
1341 float qscale = qp2qscale( qp );
1342 float bits = row_bits_so_far( h, y );
1343 for( int i = y+1+SLICE_MBAFF; i < h->i_threadslice_end; i+=(1+SLICE_MBAFF) )
1344 bits += predict_row_size( h, i, qscale );
1349 * eliminate all use of qp in row ratecontrol: make it entirely qscale-based.
1350 * make this function stop being needlessly O(N^2)
1351 * update more often than once per row? */
1352 void x264_ratecontrol_mb( x264_t *h, int bits )
1354 x264_ratecontrol_t *rc = h->rc;
1355 const int y = h->mb.i_mb_y;
1357 h->fdec->i_row_bits[y] += bits;
1358 rc->qpa_aq += h->mb.i_qp;
1360 rc->qpa_aq += h->mb.i_last_qp;
1362 if( h->mb.i_mb_x != h->mb.i_mb_width - 1 )
1366 rc->qpa_rc += rc->qpm * (h->mb.i_mb_width << SLICE_MBAFF);
1371 float qscale = qp2qscale( rc->qpm );
1372 h->fdec->f_row_qp[y] = rc->qpm;
1373 h->fdec->f_row_qscale[y] = qscale;
1375 update_predictor( rc->row_pred[0], qscale, h->fdec->i_row_satd[y], h->fdec->i_row_bits[y] );
1376 if( h->sh.i_type == SLICE_TYPE_P && rc->qpm < h->fref[0][0]->f_row_qp[y] )
1377 update_predictor( rc->row_pred[1], qscale, h->fdec->i_row_satds[0][0][y], h->fdec->i_row_bits[y] );
1379 /* tweak quality based on difference from predicted size */
1380 if( y < h->i_threadslice_end-1 )
1382 float prev_row_qp = h->fdec->f_row_qp[y];
1383 float qp_min = X264_MAX( prev_row_qp - h->param.rc.i_qp_step, h->param.rc.i_qp_min );
1384 float qp_absolute_max = h->param.rc.i_qp_max;
1385 if( rc->rate_factor_max_increment )
1386 qp_absolute_max = X264_MIN( qp_absolute_max, rc->qp_novbv + rc->rate_factor_max_increment );
1387 float qp_max = X264_MIN( prev_row_qp + h->param.rc.i_qp_step, qp_absolute_max );
1388 float step_size = 0.5f;
1390 /* B-frames shouldn't use lower QP than their reference frames. */
1391 if( h->sh.i_type == SLICE_TYPE_B )
1393 qp_min = X264_MAX( qp_min, X264_MAX( h->fref[0][0]->f_row_qp[y+1+SLICE_MBAFF], h->fref[1][0]->f_row_qp[y+1+SLICE_MBAFF] ) );
1394 rc->qpm = X264_MAX( rc->qpm, qp_min );
1397 float buffer_left_planned = rc->buffer_fill - rc->frame_size_planned;
1398 float slice_size_planned = h->param.b_sliced_threads ? rc->slice_size_planned : rc->frame_size_planned;
1399 float max_frame_error = X264_MAX( 0.05f, 1.0f / h->mb.i_mb_height );
1400 float size_of_other_slices = 0;
1401 if( h->param.b_sliced_threads )
1403 float size_of_other_slices_planned = 0;
1404 for( int i = 0; i < h->param.i_threads; i++ )
1405 if( h != h->thread[i] )
1407 size_of_other_slices += h->thread[i]->rc->frame_size_estimated;
1408 size_of_other_slices_planned += h->thread[i]->rc->slice_size_planned;
1410 float weight = rc->slice_size_planned / rc->frame_size_planned;
1411 size_of_other_slices = (size_of_other_slices - size_of_other_slices_planned) * weight + size_of_other_slices_planned;
1414 /* More threads means we have to be more cautious in letting ratecontrol use up extra bits. */
1415 float rc_tol = buffer_left_planned / h->param.i_threads * rc->rate_tolerance;
1416 float b1 = predict_row_size_sum( h, y, rc->qpm ) + size_of_other_slices;
1418 /* Don't modify the row QPs until a sufficent amount of the bits of the frame have been processed, in case a flat */
1419 /* area at the top of the frame was measured inaccurately. */
1420 if( row_bits_so_far( h, y ) < 0.05f * slice_size_planned )
1423 if( h->sh.i_type != SLICE_TYPE_I )
1426 if( !rc->b_vbv_min_rate )
1427 qp_min = X264_MAX( qp_min, rc->qp_novbv );
1429 while( rc->qpm < qp_max
1430 && ((b1 > rc->frame_size_planned + rc_tol) ||
1431 (rc->buffer_fill - b1 < buffer_left_planned * 0.5f) ||
1432 (b1 > rc->frame_size_planned && rc->qpm < rc->qp_novbv)) )
1434 rc->qpm += step_size;
1435 b1 = predict_row_size_sum( h, y, rc->qpm ) + size_of_other_slices;
1438 while( rc->qpm > qp_min
1439 && (rc->qpm > h->fdec->f_row_qp[0] || rc->single_frame_vbv)
1440 && ((b1 < rc->frame_size_planned * 0.8f && rc->qpm <= prev_row_qp)
1441 || b1 < (rc->buffer_fill - rc->buffer_size + rc->buffer_rate) * 1.1f) )
1443 rc->qpm -= step_size;
1444 b1 = predict_row_size_sum( h, y, rc->qpm ) + size_of_other_slices;
1447 /* avoid VBV underflow or MinCR violation */
1448 while( (rc->qpm < qp_absolute_max)
1449 && ((rc->buffer_fill - b1 < rc->buffer_rate * max_frame_error) ||
1450 (rc->frame_size_maximum - b1 < rc->frame_size_maximum * max_frame_error)))
1452 rc->qpm += step_size;
1453 b1 = predict_row_size_sum( h, y, rc->qpm ) + size_of_other_slices;
1456 h->rc->frame_size_estimated = b1 - size_of_other_slices;
1460 int x264_ratecontrol_qp( x264_t *h )
1463 return x264_clip3( h->rc->qpm + 0.5f, h->param.rc.i_qp_min, h->param.rc.i_qp_max );
1466 int x264_ratecontrol_mb_qp( x264_t *h )
1469 float qp = h->rc->qpm;
1470 if( h->param.rc.i_aq_mode )
1472 /* MB-tree currently doesn't adjust quantizers in unreferenced frames. */
1473 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];
1474 /* Scale AQ's effect towards zero in emergency mode. */
1475 if( qp > QP_MAX_SPEC )
1476 qp_offset *= (QP_MAX - qp) / (QP_MAX - QP_MAX_SPEC);
1479 return x264_clip3( qp + 0.5f, h->param.rc.i_qp_min, h->param.rc.i_qp_max );
1482 /* In 2pass, force the same frame types as in the 1st pass */
1483 int x264_ratecontrol_slice_type( x264_t *h, int frame_num )
1485 x264_ratecontrol_t *rc = h->rc;
1486 if( h->param.rc.b_stat_read )
1488 if( frame_num >= rc->num_entries )
1490 /* We could try to initialize everything required for ABR and
1491 * adaptive B-frames, but that would be complicated.
1492 * So just calculate the average QP used so far. */
1493 h->param.rc.i_qp_constant = (h->stat.i_frame_count[SLICE_TYPE_P] == 0) ? 24 + QP_BD_OFFSET
1494 : 1 + h->stat.f_frame_qp[SLICE_TYPE_P] / h->stat.i_frame_count[SLICE_TYPE_P];
1495 rc->qp_constant[SLICE_TYPE_P] = x264_clip3( h->param.rc.i_qp_constant, 0, QP_MAX );
1496 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, QP_MAX );
1497 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, QP_MAX );
1499 x264_log(h, X264_LOG_ERROR, "2nd pass has more frames than 1st pass (%d)\n", rc->num_entries);
1500 x264_log(h, X264_LOG_ERROR, "continuing anyway, at constant QP=%d\n", h->param.rc.i_qp_constant);
1501 if( h->param.i_bframe_adaptive )
1502 x264_log(h, X264_LOG_ERROR, "disabling adaptive B-frames\n");
1504 for( int i = 0; i < h->param.i_threads; i++ )
1506 h->thread[i]->rc->b_abr = 0;
1507 h->thread[i]->rc->b_2pass = 0;
1508 h->thread[i]->param.rc.i_rc_method = X264_RC_CQP;
1509 h->thread[i]->param.rc.b_stat_read = 0;
1510 h->thread[i]->param.i_bframe_adaptive = 0;
1511 h->thread[i]->param.i_scenecut_threshold = 0;
1512 h->thread[i]->param.rc.b_mb_tree = 0;
1513 if( h->thread[i]->param.i_bframe > 1 )
1514 h->thread[i]->param.i_bframe = 1;
1516 return X264_TYPE_AUTO;
1518 return rc->entry[frame_num].frame_type;
1521 return X264_TYPE_AUTO;
1524 void x264_ratecontrol_set_weights( x264_t *h, x264_frame_t *frm )
1526 ratecontrol_entry_t *rce = &h->rc->entry[frm->i_frame];
1527 if( h->param.analyse.i_weighted_pred <= 0 )
1530 if( rce->i_weight_denom[0] >= 0 )
1531 SET_WEIGHT( frm->weight[0][0], 1, rce->weight[0][0], rce->i_weight_denom[0], rce->weight[0][1] );
1533 if( rce->i_weight_denom[1] >= 0 )
1535 SET_WEIGHT( frm->weight[0][1], 1, rce->weight[1][0], rce->i_weight_denom[1], rce->weight[1][1] );
1536 SET_WEIGHT( frm->weight[0][2], 1, rce->weight[2][0], rce->i_weight_denom[1], rce->weight[2][1] );
1540 /* After encoding one frame, save stats and update ratecontrol state */
1541 int x264_ratecontrol_end( x264_t *h, int bits, int *filler )
1543 x264_ratecontrol_t *rc = h->rc;
1544 const int *mbs = h->stat.frame.i_mb_count;
1548 h->stat.frame.i_mb_count_skip = mbs[P_SKIP] + mbs[B_SKIP];
1549 h->stat.frame.i_mb_count_i = mbs[I_16x16] + mbs[I_8x8] + mbs[I_4x4];
1550 h->stat.frame.i_mb_count_p = mbs[P_L0] + mbs[P_8x8];
1551 for( int i = B_DIRECT; i < B_8x8; i++ )
1552 h->stat.frame.i_mb_count_p += mbs[i];
1554 h->fdec->f_qp_avg_rc = rc->qpa_rc /= h->mb.i_mb_count;
1555 h->fdec->f_qp_avg_aq = (float)rc->qpa_aq / h->mb.i_mb_count;
1557 if( h->param.rc.b_stat_write )
1559 char c_type = h->sh.i_type==SLICE_TYPE_I ? (h->fenc->i_poc==0 ? 'I' : 'i')
1560 : h->sh.i_type==SLICE_TYPE_P ? 'P'
1561 : h->fenc->b_kept_as_ref ? 'B' : 'b';
1562 int dir_frame = h->stat.frame.i_direct_score[1] - h->stat.frame.i_direct_score[0];
1563 int dir_avg = h->stat.i_direct_score[1] - h->stat.i_direct_score[0];
1564 char c_direct = h->mb.b_direct_auto_write ?
1565 ( dir_frame>0 ? 's' : dir_frame<0 ? 't' :
1566 dir_avg>0 ? 's' : dir_avg<0 ? 't' : '-' )
1568 if( fprintf( rc->p_stat_file_out,
1569 "in:%d out:%d type:%c dur:%"PRId64" cpbdur:%"PRId64" q:%.2f tex:%d mv:%d misc:%d imb:%d pmb:%d smb:%d d:%c ref:",
1570 h->fenc->i_frame, h->i_frame,
1571 c_type, h->fenc->i_duration,
1572 h->fenc->i_cpb_duration, rc->qpa_rc,
1573 h->stat.frame.i_tex_bits,
1574 h->stat.frame.i_mv_bits,
1575 h->stat.frame.i_misc_bits,
1576 h->stat.frame.i_mb_count_i,
1577 h->stat.frame.i_mb_count_p,
1578 h->stat.frame.i_mb_count_skip,
1582 /* Only write information for reference reordering once. */
1583 int use_old_stats = h->param.rc.b_stat_read && rc->rce->refs > 1;
1584 for( int i = 0; i < (use_old_stats ? rc->rce->refs : h->i_ref[0]); i++ )
1586 int refcount = use_old_stats ? rc->rce->refcount[i]
1587 : PARAM_INTERLACED ? h->stat.frame.i_mb_count_ref[0][i*2]
1588 + h->stat.frame.i_mb_count_ref[0][i*2+1]
1589 : h->stat.frame.i_mb_count_ref[0][i];
1590 if( fprintf( rc->p_stat_file_out, "%d ", refcount ) < 0 )
1594 if( h->param.analyse.i_weighted_pred >= X264_WEIGHTP_SIMPLE && h->sh.weight[0][0].weightfn )
1596 if( fprintf( rc->p_stat_file_out, "w:%d,%d,%d",
1597 h->sh.weight[0][0].i_denom, h->sh.weight[0][0].i_scale, h->sh.weight[0][0].i_offset ) < 0 )
1599 if( h->sh.weight[0][1].weightfn || h->sh.weight[0][2].weightfn )
1601 if( fprintf( rc->p_stat_file_out, ",%d,%d,%d,%d,%d ",
1602 h->sh.weight[0][1].i_denom, h->sh.weight[0][1].i_scale, h->sh.weight[0][1].i_offset,
1603 h->sh.weight[0][2].i_scale, h->sh.weight[0][2].i_offset ) < 0 )
1606 else if( fprintf( rc->p_stat_file_out, " " ) < 0 )
1610 if( fprintf( rc->p_stat_file_out, ";\n") < 0 )
1613 /* Don't re-write the data in multi-pass mode. */
1614 if( h->param.rc.b_mb_tree && h->fenc->b_kept_as_ref && !h->param.rc.b_stat_read )
1616 uint8_t i_type = h->sh.i_type;
1617 /* Values are stored as big-endian FIX8.8 */
1618 for( int i = 0; i < h->mb.i_mb_count; i++ )
1619 rc->qp_buffer[0][i] = endian_fix16( h->fenc->f_qp_offset[i]*256.0 );
1620 if( fwrite( &i_type, 1, 1, rc->p_mbtree_stat_file_out ) < 1 )
1622 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 )
1629 if( h->sh.i_type != SLICE_TYPE_B )
1630 rc->cplxr_sum += bits * qp2qscale( rc->qpa_rc ) / rc->last_rceq;
1633 /* Depends on the fact that B-frame's QP is an offset from the following P-frame's.
1634 * Not perfectly accurate with B-refs, but good enough. */
1635 rc->cplxr_sum += bits * qp2qscale( rc->qpa_rc ) / (rc->last_rceq * fabs( h->param.rc.f_pb_factor ));
1637 rc->cplxr_sum *= rc->cbr_decay;
1638 rc->wanted_bits_window += h->fenc->f_duration * rc->bitrate;
1639 rc->wanted_bits_window *= rc->cbr_decay;
1643 rc->expected_bits_sum += qscale2bits( rc->rce, qp2qscale( rc->rce->new_qp ) );
1645 if( h->mb.b_variable_qp )
1647 if( h->sh.i_type == SLICE_TYPE_B )
1649 rc->bframe_bits += bits;
1650 if( h->fenc->b_last_minigop_bframe )
1652 update_predictor( rc->pred_b_from_p, qp2qscale( rc->qpa_rc ),
1653 h->fref[1][h->i_ref[1]-1]->i_satd, rc->bframe_bits / rc->bframes );
1654 rc->bframe_bits = 0;
1659 *filler = update_vbv( h, bits );
1660 rc->filler_bits_sum += *filler * 8;
1662 if( h->sps->vui.b_nal_hrd_parameters_present )
1664 if( h->fenc->i_frame == 0 )
1666 // access unit initialises the HRD
1667 h->fenc->hrd_timing.cpb_initial_arrival_time = 0;
1668 rc->initial_cpb_removal_delay = h->initial_cpb_removal_delay;
1669 rc->initial_cpb_removal_delay_offset = h->initial_cpb_removal_delay_offset;
1670 h->fenc->hrd_timing.cpb_removal_time = rc->nrt_first_access_unit = (double)rc->initial_cpb_removal_delay / 90000;
1674 h->fenc->hrd_timing.cpb_removal_time = rc->nrt_first_access_unit + (double)(h->fenc->i_cpb_delay - h->i_cpb_delay_pir_offset) *
1675 h->sps->vui.i_num_units_in_tick / h->sps->vui.i_time_scale;
1677 double cpb_earliest_arrival_time = h->fenc->hrd_timing.cpb_removal_time - (double)rc->initial_cpb_removal_delay / 90000;
1678 if( h->fenc->b_keyframe )
1680 rc->nrt_first_access_unit = h->fenc->hrd_timing.cpb_removal_time;
1681 rc->initial_cpb_removal_delay = h->initial_cpb_removal_delay;
1682 rc->initial_cpb_removal_delay_offset = h->initial_cpb_removal_delay_offset;
1685 cpb_earliest_arrival_time -= (double)rc->initial_cpb_removal_delay_offset / 90000;
1687 if( h->sps->vui.hrd.b_cbr_hrd )
1688 h->fenc->hrd_timing.cpb_initial_arrival_time = rc->previous_cpb_final_arrival_time;
1690 h->fenc->hrd_timing.cpb_initial_arrival_time = X264_MAX( rc->previous_cpb_final_arrival_time, cpb_earliest_arrival_time );
1692 int filler_bits = *filler ? X264_MAX( (FILLER_OVERHEAD - h->param.b_annexb), *filler )*8 : 0;
1694 h->fenc->hrd_timing.cpb_final_arrival_time = rc->previous_cpb_final_arrival_time = h->fenc->hrd_timing.cpb_initial_arrival_time +
1695 (double)(bits + filler_bits) / h->sps->vui.hrd.i_bit_rate_unscaled;
1697 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 +
1698 h->fenc->hrd_timing.cpb_removal_time;
1703 x264_log(h, X264_LOG_ERROR, "ratecontrol_end: stats file could not be written to\n");
1707 /****************************************************************************
1709 ***************************************************************************/
1712 * modify the bitrate curve from pass1 for one frame
1714 static double get_qscale(x264_t *h, ratecontrol_entry_t *rce, double rate_factor, int frame_num)
1716 x264_ratecontrol_t *rcc= h->rc;
1717 x264_zone_t *zone = get_zone( h, frame_num );
1719 if( h->param.rc.b_mb_tree )
1721 double timescale = (double)h->sps->vui.i_num_units_in_tick / h->sps->vui.i_time_scale;
1722 q = pow( BASE_FRAME_DURATION / CLIP_DURATION(rce->i_duration * timescale), 1 - h->param.rc.f_qcompress );
1725 q = pow( rce->blurred_complexity, 1 - rcc->qcompress );
1727 // avoid NaN's in the rc_eq
1728 if( !isfinite(q) || rce->tex_bits + rce->mv_bits == 0 )
1729 q = rcc->last_qscale_for[rce->pict_type];
1734 rcc->last_qscale = q;
1739 if( zone->b_force_qp )
1740 q = qp2qscale( zone->i_qp );
1742 q /= zone->f_bitrate_factor;
1748 static double get_diff_limited_q(x264_t *h, ratecontrol_entry_t *rce, double q, int frame_num)
1750 x264_ratecontrol_t *rcc = h->rc;
1751 const int pict_type = rce->pict_type;
1752 x264_zone_t *zone = get_zone( h, frame_num );
1754 // force I/B quants as a function of P quants
1755 const double last_p_q = rcc->last_qscale_for[SLICE_TYPE_P];
1756 const double last_non_b_q= rcc->last_qscale_for[rcc->last_non_b_pict_type];
1757 if( pict_type == SLICE_TYPE_I )
1760 double pq = qp2qscale( rcc->accum_p_qp / rcc->accum_p_norm );
1761 double ip_factor = fabs( h->param.rc.f_ip_factor );
1762 /* don't apply ip_factor if the following frame is also I */
1763 if( rcc->accum_p_norm <= 0 )
1765 else if( h->param.rc.f_ip_factor < 0 )
1767 else if( rcc->accum_p_norm >= 1 )
1770 q = rcc->accum_p_norm * pq / ip_factor + (1 - rcc->accum_p_norm) * iq;
1772 else if( pict_type == SLICE_TYPE_B )
1774 if( h->param.rc.f_pb_factor > 0 )
1776 if( !rce->kept_as_ref )
1777 q *= fabs( h->param.rc.f_pb_factor );
1779 else if( pict_type == SLICE_TYPE_P
1780 && rcc->last_non_b_pict_type == SLICE_TYPE_P
1781 && rce->tex_bits == 0 )
1786 /* last qscale / qdiff stuff */
1787 if( rcc->last_non_b_pict_type == pict_type &&
1788 (pict_type!=SLICE_TYPE_I || rcc->last_accum_p_norm < 1) )
1790 double last_q = rcc->last_qscale_for[pict_type];
1791 double max_qscale = last_q * rcc->lstep;
1792 double min_qscale = last_q / rcc->lstep;
1794 if ( q > max_qscale ) q = max_qscale;
1795 else if( q < min_qscale ) q = min_qscale;
1798 rcc->last_qscale_for[pict_type] = q;
1799 if( pict_type != SLICE_TYPE_B )
1800 rcc->last_non_b_pict_type = pict_type;
1801 if( pict_type == SLICE_TYPE_I )
1803 rcc->last_accum_p_norm = rcc->accum_p_norm;
1804 rcc->accum_p_norm = 0;
1805 rcc->accum_p_qp = 0;
1807 if( pict_type == SLICE_TYPE_P )
1809 float mask = 1 - pow( (float)rce->i_count / rcc->nmb, 2 );
1810 rcc->accum_p_qp = mask * (qscale2qp( q ) + rcc->accum_p_qp);
1811 rcc->accum_p_norm = mask * (1 + rcc->accum_p_norm);
1816 if( zone->b_force_qp )
1817 q = qp2qscale( zone->i_qp );
1819 q /= zone->f_bitrate_factor;
1825 static float predict_size( predictor_t *p, float q, float var )
1827 return (p->coeff*var + p->offset) / (q*p->count);
1830 static void update_predictor( predictor_t *p, float q, float var, float bits )
1835 float old_coeff = p->coeff / p->count;
1836 float new_coeff = bits*q / var;
1837 float new_coeff_clipped = x264_clip3f( new_coeff, old_coeff/range, old_coeff*range );
1838 float new_offset = bits*q - new_coeff_clipped * var;
1839 if( new_offset >= 0 )
1840 new_coeff = new_coeff_clipped;
1843 p->count *= p->decay;
1844 p->coeff *= p->decay;
1845 p->offset *= p->decay;
1847 p->coeff += new_coeff;
1848 p->offset += new_offset;
1851 // update VBV after encoding a frame
1852 static int update_vbv( x264_t *h, int bits )
1855 int bitrate = h->sps->vui.hrd.i_bit_rate_unscaled;
1856 x264_ratecontrol_t *rcc = h->rc;
1857 x264_ratecontrol_t *rct = h->thread[0]->rc;
1858 uint64_t buffer_size = (uint64_t)h->sps->vui.hrd.i_cpb_size_unscaled * h->sps->vui.i_time_scale;
1860 if( rcc->last_satd >= h->mb.i_mb_count )
1861 update_predictor( &rct->pred[h->sh.i_type], qp2qscale( rcc->qpa_rc ), rcc->last_satd, bits );
1866 rct->buffer_fill_final -= (uint64_t)bits * h->sps->vui.i_time_scale;
1868 if( rct->buffer_fill_final < 0 )
1869 x264_log( h, X264_LOG_WARNING, "VBV underflow (frame %d, %.0f bits)\n", h->i_frame, (double)rct->buffer_fill_final / h->sps->vui.i_time_scale );
1870 rct->buffer_fill_final = X264_MAX( rct->buffer_fill_final, 0 );
1871 rct->buffer_fill_final += (uint64_t)bitrate * h->sps->vui.i_num_units_in_tick * h->fenc->i_cpb_duration;
1873 if( h->sps->vui.hrd.b_cbr_hrd && rct->buffer_fill_final > buffer_size )
1875 int64_t scale = (int64_t)h->sps->vui.i_time_scale * 8;
1876 filler = (rct->buffer_fill_final - buffer_size + scale - 1) / scale;
1877 bits = X264_MAX( (FILLER_OVERHEAD - h->param.b_annexb), filler ) * 8;
1878 rct->buffer_fill_final -= (uint64_t)bits * h->sps->vui.i_time_scale;
1881 rct->buffer_fill_final = X264_MIN( rct->buffer_fill_final, buffer_size );
1886 void x264_hrd_fullness( x264_t *h )
1888 x264_ratecontrol_t *rct = h->thread[0]->rc;
1889 uint64_t denom = (uint64_t)h->sps->vui.hrd.i_bit_rate_unscaled * h->sps->vui.i_time_scale / rct->hrd_multiply_denom;
1890 uint64_t cpb_state = rct->buffer_fill_final;
1891 uint64_t cpb_size = (uint64_t)h->sps->vui.hrd.i_cpb_size_unscaled * h->sps->vui.i_time_scale;
1892 uint64_t multiply_factor = 180000 / rct->hrd_multiply_denom;
1894 if( rct->buffer_fill_final < 0 || rct->buffer_fill_final > cpb_size )
1896 x264_log( h, X264_LOG_WARNING, "CPB %s: %.0lf bits in a %.0lf-bit buffer\n",
1897 rct->buffer_fill_final < 0 ? "underflow" : "overflow", (float)rct->buffer_fill_final/denom, (float)cpb_size/denom );
1900 h->initial_cpb_removal_delay = (multiply_factor * cpb_state + denom) / (2*denom);
1901 h->initial_cpb_removal_delay_offset = (multiply_factor * cpb_size + denom) / (2*denom) - h->initial_cpb_removal_delay;
1904 // provisionally update VBV according to the planned size of all frames currently in progress
1905 static void update_vbv_plan( x264_t *h, int overhead )
1907 x264_ratecontrol_t *rcc = h->rc;
1908 rcc->buffer_fill = h->thread[0]->rc->buffer_fill_final / h->sps->vui.i_time_scale;
1909 if( h->i_thread_frames > 1 )
1911 int j = h->rc - h->thread[0]->rc;
1912 for( int i = 1; i < h->i_thread_frames; i++ )
1914 x264_t *t = h->thread[ (j+i)%h->i_thread_frames ];
1915 double bits = t->rc->frame_size_planned;
1916 if( !t->b_thread_active )
1918 bits = X264_MAX(bits, t->rc->frame_size_estimated);
1919 rcc->buffer_fill -= bits;
1920 rcc->buffer_fill = X264_MAX( rcc->buffer_fill, 0 );
1921 rcc->buffer_fill += t->rc->buffer_rate;
1922 rcc->buffer_fill = X264_MIN( rcc->buffer_fill, rcc->buffer_size );
1925 rcc->buffer_fill = X264_MIN( rcc->buffer_fill, rcc->buffer_size );
1926 rcc->buffer_fill -= overhead;
1929 // apply VBV constraints and clip qscale to between lmin and lmax
1930 static double clip_qscale( x264_t *h, int pict_type, double q )
1932 x264_ratecontrol_t *rcc = h->rc;
1933 double lmin = rcc->lmin[pict_type];
1934 double lmax = rcc->lmax[pict_type];
1935 if( rcc->rate_factor_max_increment )
1936 lmax = X264_MIN( lmax, qp2qscale( rcc->qp_novbv + rcc->rate_factor_max_increment ) );
1939 /* B-frames are not directly subject to VBV,
1940 * since they are controlled by the P-frames' QPs. */
1942 if( rcc->b_vbv && rcc->last_satd > 0 )
1944 /* Lookahead VBV: raise the quantizer as necessary such that no frames in
1945 * the lookahead overflow and such that the buffer is in a reasonable state
1946 * by the end of the lookahead. */
1947 if( h->param.rc.i_lookahead )
1951 /* Avoid an infinite loop. */
1952 for( int iterations = 0; iterations < 1000 && terminate != 3; iterations++ )
1955 double cur_bits = predict_size( &rcc->pred[h->sh.i_type], q, rcc->last_satd );
1956 double buffer_fill_cur = rcc->buffer_fill - cur_bits;
1958 double total_duration = 0;
1959 frame_q[0] = h->sh.i_type == SLICE_TYPE_I ? q * h->param.rc.f_ip_factor : q;
1960 frame_q[1] = frame_q[0] * h->param.rc.f_pb_factor;
1961 frame_q[2] = frame_q[0] / h->param.rc.f_ip_factor;
1963 /* Loop over the planned future frames. */
1964 for( int j = 0; buffer_fill_cur >= 0 && buffer_fill_cur <= rcc->buffer_size; j++ )
1966 total_duration += h->fenc->f_planned_cpb_duration[j];
1967 buffer_fill_cur += rcc->vbv_max_rate * h->fenc->f_planned_cpb_duration[j];
1968 int i_type = h->fenc->i_planned_type[j];
1969 int i_satd = h->fenc->i_planned_satd[j];
1970 if( i_type == X264_TYPE_AUTO )
1972 i_type = IS_X264_TYPE_I( i_type ) ? SLICE_TYPE_I : IS_X264_TYPE_B( i_type ) ? SLICE_TYPE_B : SLICE_TYPE_P;
1973 cur_bits = predict_size( &rcc->pred[i_type], frame_q[i_type], i_satd );
1974 buffer_fill_cur -= cur_bits;
1976 /* Try to get to get the buffer at least 50% filled, but don't set an impossible goal. */
1977 target_fill = X264_MIN( rcc->buffer_fill + total_duration * rcc->vbv_max_rate * 0.5, rcc->buffer_size * 0.5 );
1978 if( buffer_fill_cur < target_fill )
1984 /* Try to get the buffer no more than 80% filled, but don't set an impossible goal. */
1985 target_fill = x264_clip3f( rcc->buffer_fill - total_duration * rcc->vbv_max_rate * 0.5, rcc->buffer_size * 0.8, rcc->buffer_size );
1986 if( rcc->b_vbv_min_rate && buffer_fill_cur > target_fill )
1995 /* Fallback to old purely-reactive algorithm: no lookahead. */
1998 if( ( pict_type == SLICE_TYPE_P ||
1999 ( pict_type == SLICE_TYPE_I && rcc->last_non_b_pict_type == SLICE_TYPE_I ) ) &&
2000 rcc->buffer_fill/rcc->buffer_size < 0.5 )
2002 q /= x264_clip3f( 2.0*rcc->buffer_fill/rcc->buffer_size, 0.5, 1.0 );
2005 /* Now a hard threshold to make sure the frame fits in VBV.
2006 * This one is mostly for I-frames. */
2007 double bits = predict_size( &rcc->pred[h->sh.i_type], q, rcc->last_satd );
2009 /* For small VBVs, allow the frame to use up the entire VBV. */
2010 double max_fill_factor = h->param.rc.i_vbv_buffer_size >= 5*h->param.rc.i_vbv_max_bitrate / rcc->fps ? 2 : 1;
2011 /* For single-frame VBVs, request that the frame use up the entire VBV. */
2012 double min_fill_factor = rcc->single_frame_vbv ? 1 : 2;
2014 if( bits > rcc->buffer_fill/max_fill_factor )
2015 qf = x264_clip3f( rcc->buffer_fill/(max_fill_factor*bits), 0.2, 1.0 );
2018 if( bits < rcc->buffer_rate/min_fill_factor )
2019 q *= bits*min_fill_factor/rcc->buffer_rate;
2020 q = X264_MAX( q0, q );
2023 /* Apply MinCR restrictions */
2024 double bits = predict_size( &rcc->pred[h->sh.i_type], q, rcc->last_satd );
2025 if( bits > rcc->frame_size_maximum )
2026 q *= bits / rcc->frame_size_maximum;
2027 bits = predict_size( &rcc->pred[h->sh.i_type], q, rcc->last_satd );
2029 /* Check B-frame complexity, and use up any bits that would
2030 * overflow before the next P-frame. */
2031 if( h->sh.i_type == SLICE_TYPE_P && !rcc->single_frame_vbv )
2033 int nb = rcc->bframes;
2034 double pbbits = bits;
2035 double bbits = predict_size( rcc->pred_b_from_p, q * h->param.rc.f_pb_factor, rcc->last_satd );
2037 double bframe_cpb_duration = 0;
2038 double minigop_cpb_duration;
2039 for( int i = 0; i < nb; i++ )
2040 bframe_cpb_duration += h->fenc->f_planned_cpb_duration[1+i];
2042 if( bbits * nb > bframe_cpb_duration * rcc->vbv_max_rate )
2044 pbbits += nb * bbits;
2046 minigop_cpb_duration = bframe_cpb_duration + h->fenc->f_planned_cpb_duration[0];
2047 space = rcc->buffer_fill + minigop_cpb_duration*rcc->vbv_max_rate - rcc->buffer_size;
2048 if( pbbits < space )
2050 q *= X264_MAX( pbbits / space, bits / (0.5 * rcc->buffer_size) );
2052 q = X264_MAX( q0/2, q );
2055 if( !rcc->b_vbv_min_rate )
2056 q = X264_MAX( q0, q );
2061 else if( rcc->b_2pass )
2063 double min2 = log( lmin );
2064 double max2 = log( lmax );
2065 q = (log(q) - min2)/(max2-min2) - 0.5;
2066 q = 1.0/(1.0 + exp( -4*q ));
2067 q = q*(max2-min2) + min2;
2071 return x264_clip3f( q, lmin, lmax );
2074 // update qscale for 1 frame based on actual bits used so far
2075 static float rate_estimate_qscale( x264_t *h )
2078 x264_ratecontrol_t *rcc = h->rc;
2079 ratecontrol_entry_t UNINIT(rce);
2080 int pict_type = h->sh.i_type;
2081 int64_t total_bits = 8*(h->stat.i_frame_size[SLICE_TYPE_I]
2082 + h->stat.i_frame_size[SLICE_TYPE_P]
2083 + h->stat.i_frame_size[SLICE_TYPE_B])
2084 - rcc->filler_bits_sum;
2089 if( pict_type != rce.pict_type )
2091 x264_log( h, X264_LOG_ERROR, "slice=%c but 2pass stats say %c\n",
2092 slice_type_to_char[pict_type], slice_type_to_char[rce.pict_type] );
2096 if( pict_type == SLICE_TYPE_B )
2098 /* B-frames don't have independent ratecontrol, but rather get the
2099 * average QP of the two adjacent P-frames + an offset */
2101 int i0 = IS_X264_TYPE_I(h->fref_nearest[0]->i_type);
2102 int i1 = IS_X264_TYPE_I(h->fref_nearest[1]->i_type);
2103 int dt0 = abs(h->fenc->i_poc - h->fref_nearest[0]->i_poc);
2104 int dt1 = abs(h->fenc->i_poc - h->fref_nearest[1]->i_poc);
2105 float q0 = h->fref_nearest[0]->f_qp_avg_rc;
2106 float q1 = h->fref_nearest[1]->f_qp_avg_rc;
2108 if( h->fref_nearest[0]->i_type == X264_TYPE_BREF )
2109 q0 -= rcc->pb_offset/2;
2110 if( h->fref_nearest[1]->i_type == X264_TYPE_BREF )
2111 q1 -= rcc->pb_offset/2;
2114 q = (q0 + q1) / 2 + rcc->ip_offset;
2120 q = (q0*dt1 + q1*dt0) / (dt0 + dt1);
2122 if( h->fenc->b_kept_as_ref )
2123 q += rcc->pb_offset/2;
2125 q += rcc->pb_offset;
2127 if( rcc->b_2pass && rcc->b_vbv )
2128 rcc->frame_size_planned = qscale2bits( &rce, qp2qscale( q ) );
2130 rcc->frame_size_planned = predict_size( rcc->pred_b_from_p, qp2qscale( q ), h->fref[1][h->i_ref[1]-1]->i_satd );
2131 /* Limit planned size by MinCR */
2133 rcc->frame_size_planned = X264_MIN( rcc->frame_size_planned, rcc->frame_size_maximum );
2134 h->rc->frame_size_estimated = rcc->frame_size_planned;
2138 rcc->last_satd = x264_rc_analyse_slice( h );
2140 return qp2qscale( q );
2144 double abr_buffer = 2 * rcc->rate_tolerance * rcc->bitrate;
2148 double lmin = rcc->lmin[pict_type];
2149 double lmax = rcc->lmax[pict_type];
2151 int64_t predicted_bits = total_bits;
2155 if( h->i_thread_frames > 1 )
2157 int j = h->rc - h->thread[0]->rc;
2158 for( int i = 1; i < h->i_thread_frames; i++ )
2160 x264_t *t = h->thread[ (j+i)%h->i_thread_frames ];
2161 double bits = t->rc->frame_size_planned;
2162 if( !t->b_thread_active )
2164 bits = X264_MAX(bits, t->rc->frame_size_estimated);
2165 predicted_bits += (int64_t)bits;
2171 if( h->i_frame < h->i_thread_frames )
2172 predicted_bits += (int64_t)h->i_frame * rcc->bitrate / rcc->fps;
2174 predicted_bits += (int64_t)(h->i_thread_frames - 1) * rcc->bitrate / rcc->fps;
2177 /* Adjust ABR buffer based on distance to the end of the video. */
2178 if( rcc->num_entries > h->i_frame )
2180 double final_bits = rcc->entry[rcc->num_entries-1].expected_bits;
2181 double video_pos = rce.expected_bits / final_bits;
2182 double scale_factor = sqrt( (1 - video_pos) * rcc->num_entries );
2183 abr_buffer *= 0.5 * X264_MAX( scale_factor, 0.5 );
2186 diff = predicted_bits - (int64_t)rce.expected_bits;
2188 q /= x264_clip3f((double)(abr_buffer - diff) / abr_buffer, .5, 2);
2189 if( ((h->i_frame + 1 - h->i_thread_frames) >= rcc->fps) &&
2190 (rcc->expected_bits_sum > 0))
2192 /* Adjust quant based on the difference between
2193 * achieved and expected bitrate so far */
2194 double cur_time = (double)h->i_frame / rcc->num_entries;
2195 double w = x264_clip3f( cur_time*100, 0.0, 1.0 );
2196 q *= pow( (double)total_bits / rcc->expected_bits_sum, w );
2200 /* Do not overflow vbv */
2201 double expected_size = qscale2bits( &rce, q );
2202 double expected_vbv = rcc->buffer_fill + rcc->buffer_rate - expected_size;
2203 double expected_fullness = rce.expected_vbv / rcc->buffer_size;
2204 double qmax = q*(2 - expected_fullness);
2205 double size_constraint = 1 + expected_fullness;
2206 qmax = X264_MAX( qmax, rce.new_qscale );
2207 if( expected_fullness < .05 )
2209 qmax = X264_MIN(qmax, lmax);
2210 while( ((expected_vbv < rce.expected_vbv/size_constraint) && (q < qmax)) ||
2211 ((expected_vbv < 0) && (q < lmax)))
2214 expected_size = qscale2bits(&rce, q);
2215 expected_vbv = rcc->buffer_fill + rcc->buffer_rate - expected_size;
2217 rcc->last_satd = x264_rc_analyse_slice( h );
2219 q = x264_clip3f( q, lmin, lmax );
2221 else /* 1pass ABR */
2223 /* Calculate the quantizer which would have produced the desired
2224 * average bitrate if it had been applied to all frames so far.
2225 * Then modulate that quant based on the current frame's complexity
2226 * relative to the average complexity so far (using the 2pass RCEQ).
2227 * Then bias the quant up or down if total size so far was far from
2229 * Result: Depending on the value of rate_tolerance, there is a
2230 * tradeoff between quality and bitrate precision. But at large
2231 * tolerances, the bit distribution approaches that of 2pass. */
2233 double wanted_bits, overflow = 1;
2235 rcc->last_satd = x264_rc_analyse_slice( h );
2236 rcc->short_term_cplxsum *= 0.5;
2237 rcc->short_term_cplxcount *= 0.5;
2238 rcc->short_term_cplxsum += rcc->last_satd / (CLIP_DURATION(h->fenc->f_duration) / BASE_FRAME_DURATION);
2239 rcc->short_term_cplxcount ++;
2241 rce.tex_bits = rcc->last_satd;
2242 rce.blurred_complexity = rcc->short_term_cplxsum / rcc->short_term_cplxcount;
2244 rce.p_count = rcc->nmb;
2248 rce.pict_type = pict_type;
2249 rce.i_duration = h->fenc->i_duration;
2251 if( h->param.rc.i_rc_method == X264_RC_CRF )
2253 q = get_qscale( h, &rce, rcc->rate_factor_constant, h->fenc->i_frame );
2257 q = get_qscale( h, &rce, rcc->wanted_bits_window / rcc->cplxr_sum, h->fenc->i_frame );
2259 /* ABR code can potentially be counterproductive in CBR, so just don't bother.
2260 * Don't run it if the frame complexity is zero either. */
2261 if( !rcc->b_vbv_min_rate && rcc->last_satd )
2263 // FIXME is it simpler to keep track of wanted_bits in ratecontrol_end?
2264 int i_frame_done = h->i_frame + 1 - h->i_thread_frames;
2265 double time_done = i_frame_done / rcc->fps;
2266 if( h->param.b_vfr_input && i_frame_done > 0 )
2267 time_done = ((double)(h->fenc->i_reordered_pts - h->i_reordered_pts_delay)) * h->param.i_timebase_num / h->param.i_timebase_den;
2268 wanted_bits = time_done * rcc->bitrate;
2269 if( wanted_bits > 0 )
2271 abr_buffer *= X264_MAX( 1, sqrt( time_done ) );
2272 overflow = x264_clip3f( 1.0 + (total_bits - wanted_bits) / abr_buffer, .5, 2 );
2278 if( pict_type == SLICE_TYPE_I && h->param.i_keyint_max > 1
2279 /* should test _next_ pict type, but that isn't decided yet */
2280 && rcc->last_non_b_pict_type != SLICE_TYPE_I )
2282 q = qp2qscale( rcc->accum_p_qp / rcc->accum_p_norm );
2283 q /= fabs( h->param.rc.f_ip_factor );
2285 else if( h->i_frame > 0 )
2287 if( h->param.rc.i_rc_method != X264_RC_CRF )
2289 /* Asymmetric clipping, because symmetric would prevent
2290 * overflow control in areas of rapidly oscillating complexity */
2291 double lmin = rcc->last_qscale_for[pict_type] / rcc->lstep;
2292 double lmax = rcc->last_qscale_for[pict_type] * rcc->lstep;
2293 if( overflow > 1.1 && h->i_frame > 3 )
2295 else if( overflow < 0.9 )
2298 q = x264_clip3f(q, lmin, lmax);
2301 else if( h->param.rc.i_rc_method == X264_RC_CRF && rcc->qcompress != 1 )
2303 q = qp2qscale( ABR_INIT_QP ) / fabs( h->param.rc.f_ip_factor );
2305 rcc->qp_novbv = qscale2qp( q );
2307 //FIXME use get_diff_limited_q() ?
2308 q = clip_qscale( h, pict_type, q );
2311 rcc->last_qscale_for[pict_type] =
2312 rcc->last_qscale = q;
2314 if( !(rcc->b_2pass && !rcc->b_vbv) && h->fenc->i_frame == 0 )
2315 rcc->last_qscale_for[SLICE_TYPE_P] = q * fabs( h->param.rc.f_ip_factor );
2317 if( rcc->b_2pass && rcc->b_vbv )
2318 rcc->frame_size_planned = qscale2bits(&rce, q);
2320 rcc->frame_size_planned = predict_size( &rcc->pred[h->sh.i_type], q, rcc->last_satd );
2322 /* Always use up the whole VBV in this case. */
2323 if( rcc->single_frame_vbv )
2324 rcc->frame_size_planned = rcc->buffer_rate;
2325 /* Limit planned size by MinCR */
2327 rcc->frame_size_planned = X264_MIN( rcc->frame_size_planned, rcc->frame_size_maximum );
2328 h->rc->frame_size_estimated = rcc->frame_size_planned;
2333 void x264_threads_normalize_predictors( x264_t *h )
2335 double totalsize = 0;
2336 for( int i = 0; i < h->param.i_threads; i++ )
2337 totalsize += h->thread[i]->rc->slice_size_planned;
2338 double factor = h->rc->frame_size_planned / totalsize;
2339 for( int i = 0; i < h->param.i_threads; i++ )
2340 h->thread[i]->rc->slice_size_planned *= factor;
2343 void x264_threads_distribute_ratecontrol( x264_t *h )
2346 x264_ratecontrol_t *rc = h->rc;
2348 /* Initialize row predictors */
2349 if( h->i_frame == 0 )
2350 for( int i = 0; i < h->param.i_threads; i++ )
2352 x264_ratecontrol_t *t = h->thread[i]->rc;
2353 memcpy( t->row_preds, rc->row_preds, sizeof(rc->row_preds) );
2356 for( int i = 0; i < h->param.i_threads; i++ )
2358 x264_t *t = h->thread[i];
2359 memcpy( t->rc, rc, offsetof(x264_ratecontrol_t, row_pred) );
2360 t->rc->row_pred = &t->rc->row_preds[h->sh.i_type];
2361 /* Calculate the planned slice size. */
2362 if( rc->b_vbv && rc->frame_size_planned )
2365 for( row = t->i_threadslice_start; row < t->i_threadslice_end; row++ )
2366 size += h->fdec->i_row_satd[row];
2367 t->rc->slice_size_planned = predict_size( &rc->pred[h->sh.i_type + (i+1)*5], rc->qpm, size );
2370 t->rc->slice_size_planned = 0;
2372 if( rc->b_vbv && rc->frame_size_planned )
2374 x264_threads_normalize_predictors( h );
2376 if( rc->single_frame_vbv )
2378 /* Compensate for our max frame error threshold: give more bits (proportionally) to smaller slices. */
2379 for( int i = 0; i < h->param.i_threads; i++ )
2381 x264_t *t = h->thread[i];
2382 float max_frame_error = X264_MAX( 0.05, 1.0 / (t->i_threadslice_end - t->i_threadslice_start) );
2383 t->rc->slice_size_planned += 2 * max_frame_error * rc->frame_size_planned;
2385 x264_threads_normalize_predictors( h );
2388 for( int i = 0; i < h->param.i_threads; i++ )
2389 h->thread[i]->rc->frame_size_estimated = h->thread[i]->rc->slice_size_planned;
2393 void x264_threads_merge_ratecontrol( x264_t *h )
2395 x264_ratecontrol_t *rc = h->rc;
2398 for( int i = 0; i < h->param.i_threads; i++ )
2400 x264_t *t = h->thread[i];
2401 x264_ratecontrol_t *rct = h->thread[i]->rc;
2402 if( h->param.rc.i_vbv_buffer_size )
2405 for( int row = t->i_threadslice_start; row < t->i_threadslice_end; row++ )
2406 size += h->fdec->i_row_satd[row];
2407 int bits = t->stat.frame.i_mv_bits + t->stat.frame.i_tex_bits + t->stat.frame.i_misc_bits;
2408 int mb_count = (t->i_threadslice_end - t->i_threadslice_start) * h->mb.i_mb_width;
2409 update_predictor( &rc->pred[h->sh.i_type+(i+1)*5], qp2qscale( rct->qpa_rc/mb_count ), size, bits );
2413 rc->qpa_rc += rct->qpa_rc;
2414 rc->qpa_aq += rct->qpa_aq;
2418 void x264_thread_sync_ratecontrol( x264_t *cur, x264_t *prev, x264_t *next )
2422 #define COPY(var) memcpy(&cur->rc->var, &prev->rc->var, sizeof(cur->rc->var))
2423 /* these vars are updated in x264_ratecontrol_start()
2424 * so copy them from the context that most recently started (prev)
2425 * to the context that's about to start (cur). */
2430 COPY(last_qscale_for);
2431 COPY(last_non_b_pict_type);
2432 COPY(short_term_cplxsum);
2433 COPY(short_term_cplxcount);
2437 /* these vars can be updated by x264_ratecontrol_init_reconfigurable */
2442 COPY(single_frame_vbv);
2444 COPY(rate_factor_constant);
2445 COPY(rate_factor_max_increment);
2450 #define COPY(var) next->rc->var = cur->rc->var
2451 /* these vars are updated in x264_ratecontrol_end()
2452 * so copy them from the context that most recently ended (cur)
2453 * to the context that's about to end (next) */
2455 COPY(expected_bits_sum);
2456 COPY(filler_bits_sum);
2457 COPY(wanted_bits_window);
2459 COPY(initial_cpb_removal_delay);
2460 COPY(initial_cpb_removal_delay_offset);
2461 COPY(nrt_first_access_unit);
2462 COPY(previous_cpb_final_arrival_time);
2465 //FIXME row_preds[] (not strictly necessary, but would improve prediction)
2466 /* the rest of the variables are either constant or thread-local */
2469 static int find_underflow( x264_t *h, double *fills, int *t0, int *t1, int over )
2471 /* find an interval ending on an overflow or underflow (depending on whether
2472 * we're adding or removing bits), and starting on the earliest frame that
2473 * can influence the buffer fill of that end frame. */
2474 x264_ratecontrol_t *rcc = h->rc;
2475 const double buffer_min = (over ? .1 : .1) * rcc->buffer_size;
2476 const double buffer_max = .9 * rcc->buffer_size;
2477 double fill = fills[*t0-1];
2478 double parity = over ? 1. : -1.;
2479 int start = -1, end = -1;
2480 for( int i = *t0; i < rcc->num_entries; i++ )
2482 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 -
2483 qscale2bits( &rcc->entry[i], rcc->entry[i].new_qscale )) * parity;
2484 fill = x264_clip3f(fill, 0, rcc->buffer_size);
2486 if( fill <= buffer_min || i == 0 )
2492 else if( fill >= buffer_max && start >= 0 )
2497 return start >= 0 && end >= 0;
2500 static int fix_underflow( x264_t *h, int t0, int t1, double adjustment, double qscale_min, double qscale_max)
2502 x264_ratecontrol_t *rcc = h->rc;
2503 double qscale_orig, qscale_new;
2507 for( int i = t0; i <= t1; i++ )
2509 qscale_orig = rcc->entry[i].new_qscale;
2510 qscale_orig = x264_clip3f( qscale_orig, qscale_min, qscale_max );
2511 qscale_new = qscale_orig * adjustment;
2512 qscale_new = x264_clip3f( qscale_new, qscale_min, qscale_max );
2513 rcc->entry[i].new_qscale = qscale_new;
2514 adjusted = adjusted || (qscale_new != qscale_orig);
2519 static double count_expected_bits( x264_t *h )
2521 x264_ratecontrol_t *rcc = h->rc;
2522 double expected_bits = 0;
2523 for( int i = 0; i < rcc->num_entries; i++ )
2525 ratecontrol_entry_t *rce = &rcc->entry[i];
2526 rce->expected_bits = expected_bits;
2527 expected_bits += qscale2bits( rce, rce->new_qscale );
2529 return expected_bits;
2532 static int vbv_pass2( x264_t *h, double all_available_bits )
2534 /* for each interval of buffer_full .. underflow, uniformly increase the qp of all
2535 * frames in the interval until either buffer is full at some intermediate frame or the
2536 * last frame in the interval no longer underflows. Recompute intervals and repeat.
2537 * Then do the converse to put bits back into overflow areas until target size is met */
2539 x264_ratecontrol_t *rcc = h->rc;
2541 double expected_bits = 0;
2543 double prev_bits = 0;
2545 double qscale_min = qp2qscale( h->param.rc.i_qp_min );
2546 double qscale_max = qp2qscale( h->param.rc.i_qp_max );
2548 int adj_min, adj_max;
2549 CHECKED_MALLOC( fills, (rcc->num_entries+1)*sizeof(double) );
2553 /* adjust overall stream size */
2557 prev_bits = expected_bits;
2560 { /* not first iteration */
2561 adjustment = X264_MAX(X264_MIN(expected_bits / all_available_bits, 0.999), 0.9);
2562 fills[-1] = rcc->buffer_size * h->param.rc.f_vbv_buffer_init;
2566 while(adj_min && find_underflow( h, fills, &t0, &t1, 1 ))
2568 adj_min = fix_underflow( h, t0, t1, adjustment, qscale_min, qscale_max );
2573 fills[-1] = rcc->buffer_size * (1. - h->param.rc.f_vbv_buffer_init);
2575 /* fix underflows -- should be done after overflow, as we'd better undersize target than underflowing VBV */
2577 while( adj_max && find_underflow( h, fills, &t0, &t1, 0 ) )
2578 adj_max = fix_underflow( h, t0, t1, 1.001, qscale_min, qscale_max );
2580 expected_bits = count_expected_bits( h );
2581 } while( (expected_bits < .995*all_available_bits) && ((int64_t)(expected_bits+.5) > (int64_t)(prev_bits+.5)) );
2584 x264_log( h, X264_LOG_WARNING, "vbv-maxrate issue, qpmax or vbv-maxrate too low\n");
2586 /* store expected vbv filling values for tracking when encoding */
2587 for( int i = 0; i < rcc->num_entries; i++ )
2588 rcc->entry[i].expected_vbv = rcc->buffer_size - fills[i];
2590 x264_free( fills-1 );
2596 static int init_pass2( x264_t *h )
2598 x264_ratecontrol_t *rcc = h->rc;
2599 uint64_t all_const_bits = 0;
2600 double timescale = (double)h->sps->vui.i_num_units_in_tick / h->sps->vui.i_time_scale;
2601 double duration = 0;
2602 for( int i = 0; i < rcc->num_entries; i++ )
2603 duration += rcc->entry[i].i_duration;
2604 duration *= timescale;
2605 uint64_t all_available_bits = h->param.rc.i_bitrate * 1000. * duration;
2606 double rate_factor, step_mult;
2607 double qblur = h->param.rc.f_qblur;
2608 double cplxblur = h->param.rc.f_complexity_blur;
2609 const int filter_size = (int)(qblur*4) | 1;
2610 double expected_bits;
2611 double *qscale, *blurred_qscale;
2612 double base_cplx = h->mb.i_mb_count * (h->param.i_bframe ? 120 : 80);
2614 /* find total/average complexity & const_bits */
2615 for( int i = 0; i < rcc->num_entries; i++ )
2617 ratecontrol_entry_t *rce = &rcc->entry[i];
2618 all_const_bits += rce->misc_bits;
2621 if( all_available_bits < all_const_bits)
2623 x264_log( h, X264_LOG_ERROR, "requested bitrate is too low. estimated minimum is %d kbps\n",
2624 (int)(all_const_bits * rcc->fps / (rcc->num_entries * 1000.)) );
2628 /* Blur complexities, to reduce local fluctuation of QP.
2629 * We don't blur the QPs directly, because then one very simple frame
2630 * could drag down the QP of a nearby complex frame and give it more
2631 * bits than intended. */
2632 for( int i = 0; i < rcc->num_entries; i++ )
2634 ratecontrol_entry_t *rce = &rcc->entry[i];
2635 double weight_sum = 0;
2636 double cplx_sum = 0;
2637 double weight = 1.0;
2638 double gaussian_weight;
2639 /* weighted average of cplx of future frames */
2640 for( int j = 1; j < cplxblur*2 && j < rcc->num_entries-i; j++ )
2642 ratecontrol_entry_t *rcj = &rcc->entry[i+j];
2643 double frame_duration = CLIP_DURATION(rcj->i_duration * timescale) / BASE_FRAME_DURATION;
2644 weight *= 1 - pow( (float)rcj->i_count / rcc->nmb, 2 );
2645 if( weight < .0001 )
2647 gaussian_weight = weight * exp( -j*j/200.0 );
2648 weight_sum += gaussian_weight;
2649 cplx_sum += gaussian_weight * (qscale2bits( rcj, 1 ) - rcj->misc_bits) / frame_duration;
2651 /* weighted average of cplx of past frames */
2653 for( int j = 0; j <= cplxblur*2 && j <= i; j++ )
2655 ratecontrol_entry_t *rcj = &rcc->entry[i-j];
2656 double frame_duration = CLIP_DURATION(rcj->i_duration * timescale) / BASE_FRAME_DURATION;
2657 gaussian_weight = weight * exp( -j*j/200.0 );
2658 weight_sum += gaussian_weight;
2659 cplx_sum += gaussian_weight * (qscale2bits( rcj, 1 ) - rcj->misc_bits) / frame_duration;
2660 weight *= 1 - pow( (float)rcj->i_count / rcc->nmb, 2 );
2661 if( weight < .0001 )
2664 rce->blurred_complexity = cplx_sum / weight_sum;
2667 CHECKED_MALLOC( qscale, sizeof(double)*rcc->num_entries );
2668 if( filter_size > 1 )
2669 CHECKED_MALLOC( blurred_qscale, sizeof(double)*rcc->num_entries );
2671 blurred_qscale = qscale;
2673 /* Search for a factor which, when multiplied by the RCEQ values from
2674 * each frame, adds up to the desired total size.
2675 * There is no exact closed-form solution because of VBV constraints and
2676 * because qscale2bits is not invertible, but we can start with the simple
2677 * approximation of scaling the 1st pass by the ratio of bitrates.
2678 * The search range is probably overkill, but speed doesn't matter here. */
2681 for( int i = 0; i < rcc->num_entries; i++ )
2683 double q = get_qscale(h, &rcc->entry[i], 1.0, i);
2684 expected_bits += qscale2bits(&rcc->entry[i], q);
2685 rcc->last_qscale_for[rcc->entry[i].pict_type] = q;
2687 step_mult = all_available_bits / expected_bits;
2690 for( double step = 1E4 * step_mult; step > 1E-7 * step_mult; step *= 0.5)
2693 rate_factor += step;
2695 rcc->last_non_b_pict_type = -1;
2696 rcc->last_accum_p_norm = 1;
2697 rcc->accum_p_norm = 0;
2699 rcc->last_qscale_for[0] =
2700 rcc->last_qscale_for[1] =
2701 rcc->last_qscale_for[2] = pow( base_cplx, 1 - rcc->qcompress ) / rate_factor;
2704 for( int i = 0; i < rcc->num_entries; i++ )
2706 qscale[i] = get_qscale( h, &rcc->entry[i], rate_factor, -1 );
2707 rcc->last_qscale_for[rcc->entry[i].pict_type] = qscale[i];
2710 /* fixed I/B qscale relative to P */
2711 for( int i = rcc->num_entries-1; i >= 0; i-- )
2713 qscale[i] = get_diff_limited_q( h, &rcc->entry[i], qscale[i], i );
2714 assert(qscale[i] >= 0);
2718 if( filter_size > 1 )
2720 assert( filter_size%2 == 1 );
2721 for( int i = 0; i < rcc->num_entries; i++ )
2723 ratecontrol_entry_t *rce = &rcc->entry[i];
2724 double q = 0.0, sum = 0.0;
2726 for( int j = 0; j < filter_size; j++ )
2728 int idx = i+j-filter_size/2;
2730 double coeff = qblur==0 ? 1.0 : exp( -d*d/(qblur*qblur) );
2731 if( idx < 0 || idx >= rcc->num_entries )
2733 if( rce->pict_type != rcc->entry[idx].pict_type )
2735 q += qscale[idx] * coeff;
2738 blurred_qscale[i] = q/sum;
2742 /* find expected bits */
2743 for( int i = 0; i < rcc->num_entries; i++ )
2745 ratecontrol_entry_t *rce = &rcc->entry[i];
2746 rce->new_qscale = clip_qscale( h, rce->pict_type, blurred_qscale[i] );
2747 assert(rce->new_qscale >= 0);
2748 expected_bits += qscale2bits( rce, rce->new_qscale );
2751 if( expected_bits > all_available_bits )
2752 rate_factor -= step;
2755 x264_free( qscale );
2756 if( filter_size > 1 )
2757 x264_free( blurred_qscale );
2760 if( vbv_pass2( h, all_available_bits ) )
2762 expected_bits = count_expected_bits( h );
2764 if( fabs( expected_bits/all_available_bits - 1.0 ) > 0.01 )
2767 for( int i = 0; i < rcc->num_entries; i++ )
2768 avgq += rcc->entry[i].new_qscale;
2769 avgq = qscale2qp( avgq / rcc->num_entries );
2771 if( expected_bits > all_available_bits || !rcc->b_vbv )
2772 x264_log( h, X264_LOG_WARNING, "Error: 2pass curve failed to converge\n" );
2773 x264_log( h, X264_LOG_WARNING, "target: %.2f kbit/s, expected: %.2f kbit/s, avg QP: %.4f\n",
2774 (float)h->param.rc.i_bitrate,
2775 expected_bits * rcc->fps / (rcc->num_entries * 1000.),
2777 if( expected_bits < all_available_bits && avgq < h->param.rc.i_qp_min + 2 )
2779 if( h->param.rc.i_qp_min > 0 )
2780 x264_log( h, X264_LOG_WARNING, "try reducing target bitrate or reducing qp_min (currently %d)\n", h->param.rc.i_qp_min );
2782 x264_log( h, X264_LOG_WARNING, "try reducing target bitrate\n" );
2784 else if( expected_bits > all_available_bits && avgq > h->param.rc.i_qp_max - 2 )
2786 if( h->param.rc.i_qp_max < QP_MAX )
2787 x264_log( h, X264_LOG_WARNING, "try increasing target bitrate or increasing qp_max (currently %d)\n", h->param.rc.i_qp_max );
2789 x264_log( h, X264_LOG_WARNING, "try increasing target bitrate\n");
2791 else if( !(rcc->b_2pass && rcc->b_vbv) )
2792 x264_log( h, X264_LOG_WARNING, "internal error\n" );