ratecontrol.c 39.3 KB
Newer Older
1
/***************************************************-*- coding: iso-8859-1 -*-
Laurent Aimar's avatar
Laurent Aimar committed
2 3
 * ratecontrol.c: h264 encoder library (Rate Control)
 *****************************************************************************
Loren Merritt's avatar
Loren Merritt committed
4
 * Copyright (C) 2005 x264 project
Laurent Aimar's avatar
Laurent Aimar committed
5 6
 * $Id: ratecontrol.c,v 1.1 2004/06/03 19:27:08 fenrir Exp $
 *
Loren Merritt's avatar
Loren Merritt committed
7 8 9
 * Authors: Loren Merritt <lorenm@u.washington.edu>
 *          Michael Niedermayer <michaelni@gmx.at>
 *          Mns Rullgrd <mru@mru.ath.cx>
Laurent Aimar's avatar
Laurent Aimar committed
10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
 *****************************************************************************/

26
#define _ISOC99_SOURCE
27
#undef NDEBUG // always check asserts, the speed effect is far too small to disable them
Laurent Aimar's avatar
Laurent Aimar committed
28 29 30
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
31 32
#include <math.h>
#include <limits.h>
33
#include <assert.h>
Laurent Aimar's avatar
Laurent Aimar committed
34

35 36 37
#include "common/common.h"
#include "common/cpu.h"
#include "common/macroblock.h"
Laurent Aimar's avatar
Laurent Aimar committed
38 39
#include "ratecontrol.h"

40
#if defined(SYS_FREEBSD) || defined(SYS_BEOS)
41 42
#define exp2f(x) powf( 2, (x) )
#endif
43 44
#ifdef _MSC_VER
#define exp2f(x) pow( 2, (x) )
45
#define sqrtf sqrt
46
#endif
47 48 49
#ifdef WIN32 // POSIX says that rename() removes the destination, but win32 doesn't.
#define rename(src,dst) (unlink(dst), rename(src,dst))
#endif
50 51 52 53

typedef struct
{
    int pict_type;
54
    int kept_as_ref;
55 56 57 58 59 60 61 62 63 64 65
    float qscale;
    int mv_bits;
    int i_tex_bits;
    int p_tex_bits;
    int misc_bits;
    uint64_t expected_bits;
    float new_qscale;
    int new_qp;
    int i_count;
    int p_count;
    int s_count;
Loren Merritt's avatar
Loren Merritt committed
66
    float blurred_complexity;
67 68
} ratecontrol_entry_t;

Loren Merritt's avatar
Loren Merritt committed
69 70 71 72 73 74 75
typedef struct
{
    double coeff;
    double count;
    double decay;
} predictor_t;

76 77 78
struct x264_ratecontrol_t
{
    /* constants */
Loren Merritt's avatar
Loren Merritt committed
79 80
    int b_abr;
    int b_2pass;
81
    double fps;
Loren Merritt's avatar
Loren Merritt committed
82 83
    double bitrate;
    double rate_tolerance;
84
    int nmb;                    /* number of macroblocks in a frame */
85
    int qp_constant[5];
86

Loren Merritt's avatar
Loren Merritt committed
87 88
    /* current frame */
    ratecontrol_entry_t *rce;
89
    int qp;                     /* qp for current frame */
Loren Merritt's avatar
Loren Merritt committed
90 91
    float qpa;                  /* average of macroblocks' qp (same as qp if no adaptive quant) */
    int slice_type;
Måns Rullgård's avatar
Måns Rullgård committed
92
    int qp_force;
93

Loren Merritt's avatar
Loren Merritt committed
94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109
    /* VBV stuff */
    double buffer_size;
    double buffer_fill;
    double buffer_rate;         /* # of bits added to buffer_fill after each frame */
    predictor_t pred[5];        /* predict frame size from satd */

    /* ABR stuff */
    int    last_satd;
    double last_rceq;
    double cplxr_sum;           /* sum of bits*qscale/rceq */
    double expected_bits_sum;   /* sum of qscale2bits after rceq, ratefactor, and overflow */
    double wanted_bits_window;  /* target bitrate * window */
    double cbr_decay;
    double short_term_cplxsum;
    double short_term_cplxcount;

110 111
    /* 2pass stuff */
    FILE *p_stat_file_out;
112
    char *psz_stat_file_tmpname;
113 114

    int num_entries;            /* number of ratecontrol_entry_ts */
Loren Merritt's avatar
Loren Merritt committed
115
    ratecontrol_entry_t *entry; /* FIXME: copy needed data and free this once init is done */
116 117 118
    double last_qscale;
    double last_qscale_for[5];  /* last qscale for a specific pict type, used for max_diff & ipb factor stuff  */
    int last_non_b_pict_type;
119 120
    double accum_p_qp;          /* for determining I-frame quant */
    double accum_p_norm;
121
    double last_accum_p_norm;
122
    double lmin[5];             /* min qscale by frame type */
123
    double lmax[5];
Loren Merritt's avatar
Loren Merritt committed
124
    double lstep;               /* max change (multiply) in qscale per frame */
125 126 127 128
    double i_cplx_sum[5];       /* estimated total texture bits in intra MBs at qscale=1 */
    double p_cplx_sum[5];
    double mv_bits_sum[5];
    int frame_count[5];         /* number of frames of each type */
Loren Merritt's avatar
Loren Merritt committed
129 130 131

    int i_zones;
    x264_zone_t *zones;
132
};
Laurent Aimar's avatar
Laurent Aimar committed
133

134

135
static int parse_zones( x264_t *h );
136 137
static int init_pass2(x264_t *);
static float rate_estimate_qscale( x264_t *h, int pict_type );
Loren Merritt's avatar
Loren Merritt committed
138 139
static void update_vbv( x264_t *h, int bits );
int  x264_rc_analyse_slice( x264_t *h );
140 141 142

/* Terminology:
 * qp = h.264's quantizer
143
 * qscale = linearized quantizer = Lagrange multiplier
144 145 146 147 148 149 150 151 152 153
 */
static inline double qp2qscale(double qp)
{
    return 0.85 * pow(2.0, ( qp - 12.0 ) / 6.0);
}
static inline double qscale2qp(double qscale)
{
    return 12.0 + 6.0 * log(qscale/0.85) / log(2.0);
}

154 155 156 157
/* Texture bitrate is not quite inversely proportional to qscale,
 * probably due the the changing number of SKIP blocks.
 * MV bits level off at about qp<=12, because the lambda used
 * for motion estimation is constant there. */
158 159
static inline double qscale2bits(ratecontrol_entry_t *rce, double qscale)
{
Loren Merritt's avatar
Loren Merritt committed
160
    if(qscale<0.1)
161
        qscale = 0.1;
162 163
    return (rce->i_tex_bits + rce->p_tex_bits + .1) * pow( rce->qscale / qscale, 1.1 )
           + rce->mv_bits * pow( X264_MAX(rce->qscale, 12) / X264_MAX(qscale, 12), 0.5 );
164 165
}

166
/* There is no analytical inverse to the above formula. */
167
#if 0
168 169
static inline double bits2qscale(ratecontrol_entry_t *rce, double bits)
{
170
    if(bits<1.0)
171
        bits = 1.0;
172
    return (rce->i_tex_bits + rce->p_tex_bits + rce->mv_bits + .1) * rce->qscale / bits;
173
}
174
#endif
175 176


177
int x264_ratecontrol_new( x264_t *h )
Laurent Aimar's avatar
Laurent Aimar committed
178
{
179 180
    x264_ratecontrol_t *rc;
    int i;
181

182 183 184
    x264_cpu_restore( h->param.cpu );

    h->rc = rc = x264_malloc( sizeof( x264_ratecontrol_t ) );
185 186
    memset(rc, 0, sizeof(*rc));

Loren Merritt's avatar
Loren Merritt committed
187 188 189 190
    rc->b_abr = h->param.rc.b_cbr && !h->param.rc.b_stat_read;
    rc->b_2pass = h->param.rc.b_cbr && h->param.rc.b_stat_read;
    h->mb.b_variable_qp = 0;
    
Måns Rullgård's avatar
Måns Rullgård committed
191 192 193 194 195 196
    /* FIXME: use integers */
    if(h->param.i_fps_num > 0 && h->param.i_fps_den > 0)
        rc->fps = (float) h->param.i_fps_num / h->param.i_fps_den;
    else
        rc->fps = 25.0;

197
    rc->bitrate = h->param.rc.i_bitrate * 1000;
Loren Merritt's avatar
Loren Merritt committed
198
    rc->rate_tolerance = h->param.rc.f_rate_tolerance;
199
    rc->nmb = h->mb.i_mb_count;
Loren Merritt's avatar
Loren Merritt committed
200 201 202 203 204 205 206 207 208 209 210 211 212
    rc->last_non_b_pict_type = -1;
    rc->cbr_decay = 1.0;

    if( h->param.rc.i_vbv_max_bitrate < h->param.rc.i_bitrate &&
        h->param.rc.i_vbv_max_bitrate > 0)
        x264_log(h, X264_LOG_ERROR, "max bitrate less than average bitrate, ignored.\n");
    else if( h->param.rc.i_vbv_max_bitrate > 0 &&
             h->param.rc.i_vbv_buffer_size > 0 )
    {
        if( h->param.rc.i_vbv_buffer_size < 10 * h->param.rc.i_vbv_max_bitrate / rc->fps ) {
            h->param.rc.i_vbv_buffer_size = 10 * h->param.rc.i_vbv_max_bitrate / rc->fps;
            x264_log( h, X264_LOG_ERROR, "VBV buffer size too small, using %d kbit\n",
                      h->param.rc.i_vbv_buffer_size );
213
        }
Loren Merritt's avatar
Loren Merritt committed
214 215 216 217 218 219 220 221
        rc->buffer_rate = h->param.rc.i_vbv_max_bitrate * 1000 / rc->fps;
        rc->buffer_size = h->param.rc.i_vbv_buffer_size * 1000;
        rc->buffer_fill = rc->buffer_size * h->param.rc.f_vbv_buffer_init;
        rc->cbr_decay = 1.0 - rc->buffer_rate / rc->buffer_size
                      * 0.5 * X264_MAX(0, 1.5 - rc->buffer_rate * rc->fps / rc->bitrate);
    }
    else if( h->param.rc.i_vbv_max_bitrate || h->param.rc.i_vbv_buffer_size )
        x264_log(h, X264_LOG_ERROR, "VBV maxrate or buffer size specified, but not both.\n");
222 223 224 225
    if(rc->rate_tolerance < 0.01) {
        x264_log(h, X264_LOG_ERROR, "bitrate tolerance too small, using .01\n");
        rc->rate_tolerance = 0.01;
    }
226

Loren Merritt's avatar
Loren Merritt committed
227 228 229 230 231 232 233 234 235
    if( rc->b_abr )
    {
        /* FIXME shouldn't need to arbitrarily specify a QP,
         * but this is more robust than BPP measures */
#define ABR_INIT_QP 24
        rc->accum_p_norm = .01;
        rc->accum_p_qp = ABR_INIT_QP * rc->accum_p_norm;
        rc->cplxr_sum = .01;
        rc->wanted_bits_window = .01;
236 237
    }

Loren Merritt's avatar
Loren Merritt committed
238 239 240
    rc->qp_constant[SLICE_TYPE_P] = h->param.rc.i_qp_constant;
    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 );
    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 );
241

Loren Merritt's avatar
Loren Merritt committed
242
    rc->lstep = exp2f(h->param.rc.i_qp_step / 6.0);
243
    rc->last_qscale = qp2qscale(26);
244 245 246 247 248
    for( i = 0; i < 5; i++ )
    {
        rc->last_qscale_for[i] = qp2qscale(26);
        rc->lmin[i] = qp2qscale( h->param.rc.i_qp_min );
        rc->lmax[i] = qp2qscale( h->param.rc.i_qp_max );
Loren Merritt's avatar
Loren Merritt committed
249 250 251
        rc->pred[i].coeff= 2.0;
        rc->pred[i].count= 1.0;
        rc->pred[i].decay= 0.5;
252 253 254 255 256 257 258 259
    }
#if 0 // FIXME: do we want to assign lmin/lmax based on ip_factor, or leave them all the same?
    rc->lmin[SLICE_TYPE_I] /= fabs(h->param.f_ip_factor);
    rc->lmax[SLICE_TYPE_I] /= fabs(h->param.f_ip_factor);
    rc->lmin[SLICE_TYPE_B] *= fabs(h->param.f_pb_factor);
    rc->lmax[SLICE_TYPE_B] *= fabs(h->param.f_pb_factor);
#endif

260 261
    if( parse_zones( h ) < 0 )
        return -1;
Loren Merritt's avatar
Loren Merritt committed
262

263 264 265 266 267 268 269 270 271
    /* Load stat file and init 2pass algo */
    if( h->param.rc.b_stat_read )
    {
        int stats_size;
        char *p, *stats_in;
        FILE *stats_file;

        /* read 1st pass stats */
        assert( h->param.rc.psz_stat_in );
272
        stats_file = fopen( h->param.rc.psz_stat_in, "rb");
273 274 275 276 277 278 279 280 281 282 283 284 285 286 287
        if(!stats_file)
        {
            x264_log(h, X264_LOG_ERROR, "ratecontrol_init: can't open stats file\n");
            return -1;
        }
        // FIXME: error checking
        fseek(stats_file, 0, SEEK_END);
        stats_size = ftell(stats_file);
        fseek(stats_file, 0, SEEK_SET);
        stats_in = x264_malloc(stats_size+10);
        fread(stats_in, 1, stats_size, stats_file);
        fclose(stats_file);

        /* find number of pics */
        p = stats_in;
Loren Merritt's avatar
Loren Merritt committed
288
        for(i=-1; p; i++)
289
            p = strchr(p+1, ';');
Loren Merritt's avatar
Loren Merritt committed
290 291 292 293
        if(i==0)
        {
            x264_log(h, X264_LOG_ERROR, "empty stats file\n");
            return -1;
294 295 296 297
        }
        i += h->param.i_bframe;
        rc->entry = (ratecontrol_entry_t*) x264_malloc(i*sizeof(ratecontrol_entry_t));
        memset(rc->entry, 0, i*sizeof(ratecontrol_entry_t));
Loren Merritt's avatar
Loren Merritt committed
298
        /* FIXME: num_entries is sometimes treated as number of frames in the video */
299 300 301 302 303
        rc->num_entries= i;

        /* init all to skipped p frames */
        for(i=0; i<rc->num_entries; i++){
            ratecontrol_entry_t *rce = &rc->entry[i];
304
            rce->pict_type = SLICE_TYPE_P;
305 306 307 308 309 310 311 312 313
            rce->qscale = rce->new_qscale = qp2qscale(20);
            rce->misc_bits = rc->nmb + 10;
            rce->new_qp = 0;
        }

        /* read stats */
        p = stats_in;
        for(i=0; i < rc->num_entries - h->param.i_bframe; i++){
            ratecontrol_entry_t *rce;
314 315
            int frame_number;
            char pict_type;
316 317 318 319 320 321 322 323 324
            int e;
            char *next;
            float qp;

            next= strchr(p, ';');
            if(next){
                (*next)=0; //sscanf is unbelievably slow on looong strings
                next++;
            }
325
            e = sscanf(p, " in:%d ", &frame_number);
326

Loren Merritt's avatar
Loren Merritt committed
327 328 329 330 331
            if(frame_number < 0 || frame_number >= rc->num_entries)
            {
                x264_log(h, X264_LOG_ERROR, "bad frame number (%d) at stats line %d\n", frame_number, i);
                return -1;
            }
332
            rce = &rc->entry[frame_number];
333

334 335
            e += sscanf(p, " in:%*d out:%*d type:%c q:%f itex:%d ptex:%d mv:%d misc:%d imb:%d pmb:%d smb:%d",
                   &pict_type, &qp, &rce->i_tex_bits, &rce->p_tex_bits,
336
                   &rce->mv_bits, &rce->misc_bits, &rce->i_count, &rce->p_count, &rce->s_count);
337 338

            switch(pict_type){
339
                case 'I': rce->kept_as_ref = 1;
340 341
                case 'i': rce->pict_type = SLICE_TYPE_I; break;
                case 'P': rce->pict_type = SLICE_TYPE_P; break;
342 343
                case 'B': rce->kept_as_ref = 1;
                case 'b': rce->pict_type = SLICE_TYPE_B; break;
344 345
                default:  e = -1; break;
            }
346 347 348 349 350 351 352 353 354 355
            if(e != 10){
                x264_log(h, X264_LOG_ERROR, "statistics are damaged at line %d, parser out=%d\n", i, e);
                return -1;
            }
            rce->qscale = qp2qscale(qp);
            p = next;
        }

        x264_free(stats_in);

356 357 358
        if(h->param.rc.b_cbr)
        {
            if(init_pass2(h) < 0) return -1;
Loren Merritt's avatar
Loren Merritt committed
359
        } /* else we're using constant quant, so no need to run the bitrate allocation */
360 361 362
    }

    /* Open output file */
363 364
    /* If input and output files are the same, output to a temp file
     * and move it to the real name only when it's complete */
365 366
    if( h->param.rc.b_stat_write )
    {
367 368 369
        rc->psz_stat_file_tmpname = x264_malloc( strlen(h->param.rc.psz_stat_out) + 6 );
        strcpy( rc->psz_stat_file_tmpname, h->param.rc.psz_stat_out );
        strcat( rc->psz_stat_file_tmpname, ".temp" );
370 371

        rc->p_stat_file_out = fopen( rc->psz_stat_file_tmpname, "wb" );
372 373 374 375 376 377
        if( rc->p_stat_file_out == NULL )
        {
            x264_log(h, X264_LOG_ERROR, "ratecontrol_init: can't open stats file\n");
            return -1;
        }
    }
378 379

    return 0;
Laurent Aimar's avatar
Laurent Aimar committed
380 381
}

382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438
static int parse_zones( x264_t *h )
{
    x264_ratecontrol_t *rc = h->rc;
    int i;
    if( h->param.rc.psz_zones && !h->param.rc.i_zones )
    {
        char *p;
        h->param.rc.i_zones = 1;
        for( p = h->param.rc.psz_zones; *p; p++ )
            h->param.rc.i_zones += (*p == '/');
        h->param.rc.zones = x264_malloc( h->param.rc.i_zones * sizeof(x264_zone_t) );
        p = h->param.rc.psz_zones;
        for( i = 0; i < h->param.rc.i_zones; i++)
        {
            x264_zone_t *z = &h->param.rc.zones[i];
            if( 3 == sscanf(p, "%u,%u,q=%u", &z->i_start, &z->i_end, &z->i_qp) )
                z->b_force_qp = 1;
            else if( 3 == sscanf(p, "%u,%u,b=%f", &z->i_start, &z->i_end, &z->f_bitrate_factor) )
                z->b_force_qp = 0;
            else
            {
                char *slash = strchr(p, '/');
                if(slash) *slash = '\0';
                x264_log( h, X264_LOG_ERROR, "invalid zone: \"%s\"\n", p );
                return -1;
            }
            p = strchr(p, '/') + 1;
        }
    }

    if( h->param.rc.i_zones > 0 )
    {
        for( i = 0; i < h->param.rc.i_zones; i++ )
        {
            x264_zone_t z = h->param.rc.zones[i];
            if( z.i_start < 0 || z.i_start > z.i_end )
            {
                x264_log( h, X264_LOG_ERROR, "invalid zone: start=%d end=%d\n",
                          z.i_start, z.i_end );
                return -1;
            }
            else if( !z.b_force_qp && z.f_bitrate_factor <= 0 )
            {
                x264_log( h, X264_LOG_ERROR, "invalid zone: bitrate_factor=%f\n",
                          z.f_bitrate_factor );
                return -1;
            }
        }

        rc->i_zones = h->param.rc.i_zones;
        rc->zones = x264_malloc( rc->i_zones * sizeof(x264_zone_t) );
        memcpy( rc->zones, h->param.rc.zones, rc->i_zones * sizeof(x264_zone_t) );
    }

    return 0;
}

439
void x264_ratecontrol_delete( x264_t *h )
Laurent Aimar's avatar
Laurent Aimar committed
440
{
441
    x264_ratecontrol_t *rc = h->rc;
442 443

    if( rc->p_stat_file_out )
444
    {
445
        fclose( rc->p_stat_file_out );
446 447 448 449 450 451 452
        if( h->i_frame >= rc->num_entries - h->param.i_bframe )
            if( rename( rc->psz_stat_file_tmpname, h->param.rc.psz_stat_out ) != 0 )
            {
                x264_log( h, X264_LOG_ERROR, "failed to rename \"%s\" to \"%s\"\n",
                          rc->psz_stat_file_tmpname, h->param.rc.psz_stat_out );
            }
        x264_free( rc->psz_stat_file_tmpname );
453
    }
Loren Merritt's avatar
Loren Merritt committed
454 455
    x264_free( rc->entry );
    x264_free( rc->zones );
Laurent Aimar's avatar
Laurent Aimar committed
456 457 458
    x264_free( rc );
}

Loren Merritt's avatar
Loren Merritt committed
459
/* Before encoding a frame, choose a QP for it */
Måns Rullgård's avatar
Måns Rullgård committed
460
void x264_ratecontrol_start( x264_t *h, int i_slice_type, int i_force_qp )
Laurent Aimar's avatar
Laurent Aimar committed
461
{
462 463 464 465
    x264_ratecontrol_t *rc = h->rc;

    x264_cpu_restore( h->param.cpu );

Måns Rullgård's avatar
Måns Rullgård committed
466
    rc->qp_force = i_force_qp;
Loren Merritt's avatar
Loren Merritt committed
467
    rc->slice_type = i_slice_type;
Måns Rullgård's avatar
Måns Rullgård committed
468

Loren Merritt's avatar
Loren Merritt committed
469
    if( i_force_qp )
470
    {
Loren Merritt's avatar
Loren Merritt committed
471
        rc->qpa = rc->qp = i_force_qp - 1;
472
    }
Loren Merritt's avatar
Loren Merritt committed
473 474 475 476 477 478
    else if( rc->b_abr )
    {
        rc->qpa = rc->qp =
            x264_clip3( (int)(qscale2qp( rate_estimate_qscale( h, i_slice_type ) ) + .5), 0, 51 );
    }
    else if( rc->b_2pass )
479 480
    {
        int frame = h->fenc->i_frame;
481
        ratecontrol_entry_t *rce;
482
        assert( frame >= 0 && frame < rc->num_entries );
Loren Merritt's avatar
Loren Merritt committed
483
        rce = h->rc->rce = &h->rc->entry[frame];
484 485

        rce->new_qscale = rate_estimate_qscale( h, i_slice_type );
Loren Merritt's avatar
Loren Merritt committed
486 487
        rc->qpa = rc->qp = rce->new_qp =
            x264_clip3( (int)(qscale2qp(rce->new_qscale) + 0.5), 0, 51 );
488
    }
Loren Merritt's avatar
Loren Merritt committed
489 490 491 492 493
    else /* CQP */
    {
        int q;
        if( i_slice_type == SLICE_TYPE_B && h->fdec->b_kept_as_ref )
            q = ( rc->qp_constant[ SLICE_TYPE_B ] + rc->qp_constant[ SLICE_TYPE_P ] ) / 2;
494
        else
Loren Merritt's avatar
Loren Merritt committed
495 496
            q = rc->qp_constant[ i_slice_type ];
        rc->qpa = rc->qp = q;
Måns Rullgård's avatar
Måns Rullgård committed
497
    }
Laurent Aimar's avatar
Laurent Aimar committed
498 499
}

500
void x264_ratecontrol_mb( x264_t *h, int bits )
Laurent Aimar's avatar
Laurent Aimar committed
501
{
Loren Merritt's avatar
Loren Merritt committed
502
    /* currently no adaptive quant */
Laurent Aimar's avatar
Laurent Aimar committed
503 504
}

Loren Merritt's avatar
Loren Merritt committed
505
int x264_ratecontrol_qp( x264_t *h )
Laurent Aimar's avatar
Laurent Aimar committed
506
{
Loren Merritt's avatar
Loren Merritt committed
507
    return h->rc->qp;
508
}
Laurent Aimar's avatar
Laurent Aimar committed
509

Loren Merritt's avatar
Loren Merritt committed
510
/* In 2pass, force the same frame types as in the 1st pass */
511 512 513 514
int x264_ratecontrol_slice_type( x264_t *h, int frame_num )
{
    if( h->param.rc.b_stat_read )
    {
515 516 517 518 519
        if( frame_num >= h->rc->num_entries )
        {
            x264_log(h, X264_LOG_ERROR, "More input frames than in the 1st pass\n");
            return X264_TYPE_P;
        }
520
        switch( h->rc->entry[frame_num].pict_type )
521 522
        {
            case SLICE_TYPE_I:
523
                return h->rc->entry[frame_num].kept_as_ref ? X264_TYPE_IDR : X264_TYPE_I;
524 525

            case SLICE_TYPE_B:
526
                return h->rc->entry[frame_num].kept_as_ref ? X264_TYPE_BREF : X264_TYPE_B;
527 528 529 530 531 532 533 534 535 536 537 538

            case SLICE_TYPE_P:
            default:
                return X264_TYPE_P;
        }
    }
    else
    {
        return X264_TYPE_AUTO;
    }
}

Loren Merritt's avatar
Loren Merritt committed
539
/* After encoding one frame, save stats and update ratecontrol state */
540 541 542
void x264_ratecontrol_end( x264_t *h, int bits )
{
    x264_ratecontrol_t *rc = h->rc;
543
    const int *mbs = h->stat.frame.i_mb_count;
Loren Merritt's avatar
Loren Merritt committed
544
    int i;
Laurent Aimar's avatar
Laurent Aimar committed
545

546 547
    x264_cpu_restore( h->param.cpu );

548 549 550
    h->stat.frame.i_mb_count_skip = mbs[P_SKIP] + mbs[B_SKIP];
    h->stat.frame.i_mb_count_i = mbs[I_16x16] + mbs[I_8x8] + mbs[I_4x4];
    h->stat.frame.i_mb_count_p = mbs[P_L0] + mbs[P_8x8];
Loren Merritt's avatar
Loren Merritt committed
551
    for( i = B_DIRECT; i < B_8x8; i++ )
552
        h->stat.frame.i_mb_count_p += mbs[i];
Loren Merritt's avatar
Loren Merritt committed
553

554 555
    if( h->param.rc.b_stat_write )
    {
556
        char c_type = rc->slice_type==SLICE_TYPE_I ? (h->fenc->i_poc==0 ? 'I' : 'i')
557 558
                    : rc->slice_type==SLICE_TYPE_P ? 'P'
                    : h->fenc->b_kept_as_ref ? 'B' : 'b';
559
        fprintf( rc->p_stat_file_out,
Loren Merritt's avatar
Loren Merritt committed
560
                 "in:%d out:%d type:%c q:%.2f itex:%d ptex:%d mv:%d misc:%d imb:%d pmb:%d smb:%d;\n",
561
                 h->fenc->i_frame, h->i_frame-1,
562
                 c_type, rc->qpa,
563 564
                 h->stat.frame.i_itex_bits, h->stat.frame.i_ptex_bits,
                 h->stat.frame.i_hdr_bits, h->stat.frame.i_misc_bits,
565
                 h->stat.frame.i_mb_count_i,
Loren Merritt's avatar
Loren Merritt committed
566 567
                 h->stat.frame.i_mb_count_p,
                 h->stat.frame.i_mb_count_skip);
568 569
    }

Loren Merritt's avatar
Loren Merritt committed
570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590
    if( rc->b_abr )
    {
        if( rc->slice_type != SLICE_TYPE_B )
            rc->cplxr_sum += bits * qp2qscale(rc->qpa) / rc->last_rceq;
        else
        {
            /* Depends on the fact that B-frame's QP is an offset from the following P-frame's.
             * Not perfectly accurate with B-refs, but good enough. */
            rc->cplxr_sum += bits * qp2qscale(rc->qpa) / (rc->last_rceq * fabs(h->param.rc.f_pb_factor));
        }
        rc->cplxr_sum *= rc->cbr_decay;
        rc->wanted_bits_window += rc->bitrate / rc->fps;
        rc->wanted_bits_window *= rc->cbr_decay;

        rc->accum_p_qp   *= .95;
        rc->accum_p_norm *= .95;
        rc->accum_p_norm += 1;
        if( rc->slice_type == SLICE_TYPE_I )
            rc->accum_p_qp += rc->qpa * fabs(h->param.rc.f_ip_factor);
        else
            rc->accum_p_qp += rc->qpa;
Laurent Aimar's avatar
Laurent Aimar committed
591 592
    }

Loren Merritt's avatar
Loren Merritt committed
593 594 595
    if( rc->b_2pass )
    {
        rc->expected_bits_sum += qscale2bits( rc->rce, qp2qscale(rc->rce->new_qp) );
Laurent Aimar's avatar
Laurent Aimar committed
596 597
    }

Loren Merritt's avatar
Loren Merritt committed
598
    update_vbv( h, bits );
599

Loren Merritt's avatar
Loren Merritt committed
600 601
    if( rc->slice_type != SLICE_TYPE_B )
        rc->last_non_b_pict_type = rc->slice_type;
Laurent Aimar's avatar
Laurent Aimar committed
602
}
603 604 605 606

/****************************************************************************
 * 2 pass functions
 ***************************************************************************/
Loren Merritt's avatar
Loren Merritt committed
607

608 609 610 611 612 613
double x264_eval( char *s, double *const_value, const char **const_name,
                  double (**func1)(void *, double), const char **func1_name,
                  double (**func2)(void *, double, double), char **func2_name,
                  void *opaque );

/**
Loren Merritt's avatar
Loren Merritt committed
614
 * modify the bitrate curve from pass1 for one frame
615
 */
Loren Merritt's avatar
Loren Merritt committed
616
static double get_qscale(x264_t *h, ratecontrol_entry_t *rce, double rate_factor, int frame_num)
617 618
{
    x264_ratecontrol_t *rcc= h->rc;
619
    const int pict_type = rce->pict_type;
620
    double q;
Loren Merritt's avatar
Loren Merritt committed
621
    int i;
622 623 624 625 626

    double const_values[]={
        rce->i_tex_bits * rce->qscale,
        rce->p_tex_bits * rce->qscale,
        (rce->i_tex_bits + rce->p_tex_bits) * rce->qscale,
627
        rce->mv_bits * rce->qscale,
628 629 630 631 632 633 634 635 636 637 638 639
        (double)rce->i_count / rcc->nmb,
        (double)rce->p_count / rcc->nmb,
        (double)rce->s_count / rcc->nmb,
        rce->pict_type == SLICE_TYPE_I,
        rce->pict_type == SLICE_TYPE_P,
        rce->pict_type == SLICE_TYPE_B,
        h->param.rc.f_qcompress,
        rcc->i_cplx_sum[SLICE_TYPE_I] / rcc->frame_count[SLICE_TYPE_I],
        rcc->i_cplx_sum[SLICE_TYPE_P] / rcc->frame_count[SLICE_TYPE_P],
        rcc->p_cplx_sum[SLICE_TYPE_P] / rcc->frame_count[SLICE_TYPE_P],
        rcc->p_cplx_sum[SLICE_TYPE_B] / rcc->frame_count[SLICE_TYPE_B],
        (rcc->i_cplx_sum[pict_type] + rcc->p_cplx_sum[pict_type]) / rcc->frame_count[pict_type],
Loren Merritt's avatar
Loren Merritt committed
640
        rce->blurred_complexity,
641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659
        0
    };
    static const char *const_names[]={
        "iTex",
        "pTex",
        "tex",
        "mv",
        "iCount",
        "pCount",
        "sCount",
        "isI",
        "isP",
        "isB",
        "qComp",
        "avgIITex",
        "avgPITex",
        "avgPPTex",
        "avgBPTex",
        "avgTex",
660
        "blurCplx",
661 662 663
        NULL
    };
    static double (*func1[])(void *, double)={
664
//      (void *)bits2qscale,
665 666 667 668
        (void *)qscale2bits,
        NULL
    };
    static const char *func1_names[]={
669
//      "bits2qp",
670 671 672 673
        "qp2bits",
        NULL
    };

674
    q = x264_eval((char*)h->param.rc.psz_rc_eq, const_values, const_names, func1, func1_names, NULL, NULL, rce);
675

Loren Merritt's avatar
Loren Merritt committed
676
    // avoid NaN's in the rc_eq
677 678
    if(q != q || rce->i_tex_bits + rce->p_tex_bits + rce->mv_bits == 0)
        q = rcc->last_qscale;
Loren Merritt's avatar
Loren Merritt committed
679 680 681
    else {
        rcc->last_rceq = q;
        q /= rate_factor;
682
        rcc->last_qscale = q;
Loren Merritt's avatar
Loren Merritt committed
683 684 685 686 687 688 689 690 691 692 693 694 695 696
    }

    for( i = rcc->i_zones-1; i >= 0; i-- )
    {
        x264_zone_t *z = &rcc->zones[i];
        if( frame_num >= z->i_start && frame_num <= z->i_end )
        {
            if( z->b_force_qp )
                q = qp2qscale(z->i_qp);
            else
                q /= z->f_bitrate_factor;
            break;
        }
    }
697

698
    return q;
699 700 701 702 703
}

static double get_diff_limited_q(x264_t *h, ratecontrol_entry_t *rce, double q)
{
    x264_ratecontrol_t *rcc = h->rc;
704
    const int pict_type = rce->pict_type;
705 706 707 708

    // force I/B quants as a function of P quants
    const double last_p_q    = rcc->last_qscale_for[SLICE_TYPE_P];
    const double last_non_b_q= rcc->last_qscale_for[rcc->last_non_b_pict_type];
709 710
    if( pict_type == SLICE_TYPE_I )
    {
711 712 713 714 715 716 717 718 719 720 721 722
        double iq = q;
        double pq = qp2qscale( rcc->accum_p_qp / rcc->accum_p_norm );
        double ip_factor = fabs( h->param.rc.f_ip_factor );
        /* don't apply ip_factor if the following frame is also I */
        if( rcc->accum_p_norm <= 0 )
            q = iq;
        else if( h->param.rc.f_ip_factor < 0 )
            q = iq / ip_factor;
        else if( rcc->accum_p_norm >= 1 )
            q = pq / ip_factor;
        else
            q = rcc->accum_p_norm * pq / ip_factor + (1 - rcc->accum_p_norm) * iq;
723 724 725 726 727
    }
    else if( pict_type == SLICE_TYPE_B )
    {
        if( h->param.rc.f_pb_factor > 0 )
            q = last_non_b_q;
728 729
        if( !rce->kept_as_ref )
            q *= fabs( h->param.rc.f_pb_factor );
730 731 732 733 734
    }
    else if( pict_type == SLICE_TYPE_P
             && rcc->last_non_b_pict_type == SLICE_TYPE_P
             && rce->i_tex_bits + rce->p_tex_bits == 0 )
    {
735
        q = last_p_q;
736
    }
737 738

    /* last qscale / qdiff stuff */
739 740
    if(rcc->last_non_b_pict_type==pict_type
       && (pict_type!=SLICE_TYPE_I || rcc->last_accum_p_norm < 1))
741 742
    {
        double last_q = rcc->last_qscale_for[pict_type];
Loren Merritt's avatar
Loren Merritt committed
743 744
        double max_qscale = last_q * rcc->lstep;
        double min_qscale = last_q / rcc->lstep;
745 746 747 748 749

        if     (q > max_qscale) q = max_qscale;
        else if(q < min_qscale) q = min_qscale;
    }

Loren Merritt's avatar
Loren Merritt committed
750
    rcc->last_qscale_for[pict_type] = q;
751 752
    if(pict_type!=SLICE_TYPE_B)
        rcc->last_non_b_pict_type = pict_type;
753 754
    if(pict_type==SLICE_TYPE_I)
    {
755
        rcc->last_accum_p_norm = rcc->accum_p_norm;
756 757 758 759 760 761 762 763 764
        rcc->accum_p_norm = 0;
        rcc->accum_p_qp = 0;
    }
    if(pict_type==SLICE_TYPE_P)
    {
        float mask = 1 - pow( (float)rce->i_count / rcc->nmb, 2 );
        rcc->accum_p_qp   = mask * (qscale2qp(q) + rcc->accum_p_qp);
        rcc->accum_p_norm = mask * (1 + rcc->accum_p_norm);
    }
765 766 767
    return q;
}

Loren Merritt's avatar
Loren Merritt committed
768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797
static double predict_size( predictor_t *p, double q, double var )
{
     return p->coeff*var / (q*p->count);
}

static void update_predictor( predictor_t *p, double q, double var, double bits )
{
    p->count *= p->decay;
    p->coeff *= p->decay;
    p->count ++;
    p->coeff += bits*q / var;
}

static void update_vbv( x264_t *h, int bits )
{
    x264_ratecontrol_t *rcc = h->rc;
    if( !rcc->buffer_size )
        return;

    rcc->buffer_fill += rcc->buffer_rate - bits;
    if( rcc->buffer_fill < 0 && !rcc->b_2pass )
        x264_log( h, X264_LOG_WARNING, "VBV underflow (%.0f bits)\n", rcc->buffer_fill );
    rcc->buffer_fill = x264_clip3( rcc->buffer_fill, 0, rcc->buffer_size );

    if(rcc->last_satd > 100)
        update_predictor( &rcc->pred[rcc->slice_type], qp2qscale(rcc->qpa), rcc->last_satd, bits );
}

// apply VBV constraints and clip qscale to between lmin and lmax
static double clip_qscale( x264_t *h, int pict_type, double q )
798
{
Loren Merritt's avatar
Loren Merritt committed
799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828
    x264_ratecontrol_t *rcc = h->rc;
    double lmin = rcc->lmin[pict_type];
    double lmax = rcc->lmax[pict_type];
    double q0 = q;

    /* B-frames are not directly subject to VBV,
     * since they are controlled by the P-frames' QPs.
     * FIXME: in 2pass we could modify previous frames' QP too,
     *        instead of waiting for the buffer to fill */
    if( rcc->buffer_size &&
        ( pict_type == SLICE_TYPE_P ||
          ( pict_type == SLICE_TYPE_I && rcc->last_non_b_pict_type == SLICE_TYPE_I ) ) )
    {
        if( rcc->buffer_fill/rcc->buffer_size < 0.5 )
            q /= x264_clip3f( 2.0*rcc->buffer_fill/rcc->buffer_size, 0.5, 1.0 );
    }
    /* Now a hard threshold to make sure the frame fits in VBV.
     * This one is mostly for I-frames. */
    if( rcc->buffer_size && rcc->last_satd > 0 )
    {
        double bits = predict_size( &rcc->pred[rcc->slice_type], q, rcc->last_satd );
        double qf = 1.0;
        if( bits > rcc->buffer_fill/2 )
            qf = x264_clip3f( rcc->buffer_fill/(2*bits), 0.2, 1.0 );
        q /= qf;
        bits *= qf;
        if( bits < rcc->buffer_rate/2 )
            q *= bits*2/rcc->buffer_rate;
        q = X264_MAX( q0, q );
    }
829

Loren Merritt's avatar
Loren Merritt committed
830
    if(lmin==lmax)
Loren Merritt's avatar
Loren Merritt committed
831
        return lmin;
Loren Merritt's avatar
Loren Merritt committed
832 833
    else if(rcc->b_2pass)
    {
834 835
        double min2 = log(lmin);
        double max2 = log(lmax);
Loren Merritt's avatar
Loren Merritt committed
836 837
        q = (log(q) - min2)/(max2-min2) - 0.5;
        q = 1.0/(1.0 + exp(-4*q));
838
        q = q*(max2-min2) + min2;
Loren Merritt's avatar
Loren Merritt committed
839
        return exp(q);
840
    }
Loren Merritt's avatar
Loren Merritt committed
841 842
    else
        return x264_clip3f(q, lmin, lmax);
843 844 845 846 847 848 849
}

// update qscale for 1 frame based on actual bits used so far
static float rate_estimate_qscale(x264_t *h, int pict_type)
{
    float q;
    x264_ratecontrol_t *rcc = h->rc;
Loren Merritt's avatar
Loren Merritt committed
850
    ratecontrol_entry_t rce;
851 852 853 854 855 856
    double lmin = rcc->lmin[pict_type];
    double lmax = rcc->lmax[pict_type];
    int64_t total_bits = 8*(h->stat.i_slice_size[SLICE_TYPE_I]
                          + h->stat.i_slice_size[SLICE_TYPE_P]
                          + h->stat.i_slice_size[SLICE_TYPE_B]);

Loren Merritt's avatar
Loren Merritt committed
857 858 859 860 861 862 863 864 865
    if( rcc->b_2pass )
    {
        rce = *rcc->rce;
        if(pict_type != rce.pict_type)
        {
            x264_log(h, X264_LOG_ERROR, "slice=%c but 2pass stats say %c\n",
                     slice_type_to_char[pict_type], slice_type_to_char[rce.pict_type]);
        }
    }
866

Loren Merritt's avatar
Loren Merritt committed
867
    if( pict_type == SLICE_TYPE_B )
868
    {
Loren Merritt's avatar
Loren Merritt committed
869
        rcc->last_satd = 0;
Loren Merritt's avatar
Loren Merritt committed
870
        if(h->fenc->b_kept_as_ref)
Loren Merritt's avatar
Loren Merritt committed
871
            q = rcc->last_qscale * sqrtf(h->param.rc.f_pb_factor);
872
        else
Loren Merritt's avatar
Loren Merritt committed
873 874
            q = rcc->last_qscale * h->param.rc.f_pb_factor;
        return x264_clip3f(q, lmin, lmax);
875 876 877
    }
    else
    {
Loren Merritt's avatar
Loren Merritt committed
878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923
        double abr_buffer = 2 * rcc->rate_tolerance * rcc->bitrate;
        if( rcc->b_2pass )
        {
            //FIXME adjust abr_buffer based on distance to the end of the video
            int64_t diff = total_bits - (int64_t)rce.expected_bits;
            q = rce.new_qscale;
            q /= x264_clip3f((double)(abr_buffer - diff) / abr_buffer, .5, 2);
            if( h->fenc->i_frame > 30 )
            {
                /* Adjust quant based on the difference between
                 * achieved and expected bitrate so far */
                double time = (double)h->fenc->i_frame / rcc->num_entries;
                double w = x264_clip3f( time*100, 0.0, 1.0 );
                q *= pow( (double)total_bits / rcc->expected_bits_sum, w );
            }
            q = x264_clip3f( q, lmin, lmax );
        }
        else /* 1pass ABR */
        {
            /* Calculate the quantizer which would have produced the desired
             * average bitrate if it had been applied to all frames so far.
             * Then modulate that quant based on the current frame's complexity
             * relative to the average complexity so far (using the 2pass RCEQ).
             * Then bias the quant up or down if total size so far was far from
             * the target.
             * Result: Depending on the value of rate_tolerance, there is a
             * tradeoff between quality and bitrate precision. But at large
             * tolerances, the bit distribution approaches that of 2pass. */

            double wanted_bits, overflow, lmin, lmax;

            rcc->last_satd = x264_rc_analyse_slice( h );
            rcc->short_term_cplxsum *= 0.5;
            rcc->short_term_cplxcount *= 0.5;
            rcc->short_term_cplxsum += rcc->last_satd;
            rcc->short_term_cplxcount ++;

            rce.p_tex_bits = rcc->last_satd;
            rce.blurred_complexity = rcc->short_term_cplxsum / rcc->short_term_cplxcount;
            rce.i_tex_bits = 0;
            rce.mv_bits = 0;
            rce.p_count = rcc->nmb;
            rce.i_count = 0;
            rce.s_count = 0;
            rce.qscale = 1;
            rce.pict_type = pict_type;
Loren Merritt's avatar
Loren Merritt committed
924
            q = get_qscale(h, &rce, rcc->wanted_bits_window / rcc->cplxr_sum, h->fenc->i_frame);
Loren Merritt's avatar
Loren Merritt committed
925 926 927 928

            wanted_bits = h->fenc->i_frame * rcc->bitrate / rcc->fps;
            abr_buffer *= X264_MAX( 1, sqrt(h->fenc->i_frame/25) );
            overflow = x264_clip3f( 1.0 + (total_bits - wanted_bits) / abr_buffer, .5, 2 );
Loren Merritt's avatar
Loren Merritt committed
929
            q *= overflow;
Loren Merritt's avatar
Loren Merritt committed
930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961

            if( pict_type == SLICE_TYPE_I
                /* should test _next_ pict type, but that isn't decided yet */
                && rcc->last_non_b_pict_type != SLICE_TYPE_I )
            {
                q = qp2qscale( rcc->accum_p_qp / rcc->accum_p_norm );
                q /= fabs( h->param.rc.f_ip_factor );
                q = clip_qscale( h, pict_type, q );
            }
            else
            {
                if( h->stat.i_slice_count[SLICE_TYPE_P] < 5 )
                {
                    float w = h->stat.i_slice_count[SLICE_TYPE_P] / 5.;
                    float q2 = qp2qscale(ABR_INIT_QP);
                    q = q*w + q2*(1-w);
                }

                /* Asymmetric clipping, because symmetric would prevent
                 * overflow control in areas of rapidly oscillating complexity */
                lmin = rcc->last_qscale_for[pict_type] / rcc->lstep;
                lmax = rcc->last_qscale_for[pict_type] * rcc->lstep;
                if( overflow > 1.1 )
                    lmax *= rcc->lstep;
                else if( overflow < 0.9 )
                    lmin /= rcc->lstep;

                q = x264_clip3f(q, lmin, lmax);
                q = clip_qscale(h, pict_type, q);
                //FIXME use get_diff_limited_q() ?
            }
        }
962

Loren Merritt's avatar
Loren Merritt committed
963
        rcc->last_qscale_for[pict_type] =
964
        rcc->last_qscale = q;
Loren Merritt's avatar
Loren Merritt committed
965

966 967
        return q;
    }
968 969 970 971 972 973 974 975 976
}

static int init_pass2( x264_t *h )
{
    x264_ratecontrol_t *rcc = h->rc;
    uint64_t all_const_bits = 0;
    uint64_t all_available_bits = (uint64_t)(h->param.rc.i_bitrate * 1000 * (double)rcc->num_entries / rcc->fps);
    double rate_factor, step, step_mult;
    double qblur = h->param.rc.f_qblur;
Loren Merritt's avatar
Loren Merritt committed
977
    double cplxblur = h->param.rc.f_complexity_blur;
978 979 980 981 982 983 984 985
    const int filter_size = (int)(qblur*4) | 1;
    double expected_bits;
    double *qscale, *blurred_qscale;
    int i;

    /* find total/average complexity & const_bits */
    for(i=0; i<rcc->num_entries; i++){
        ratecontrol_entry_t *rce = &rcc->entry[i];
986
        all_const_bits += rce->misc_bits;
987 988
        rcc->i_cplx_sum[rce->pict_type] += rce->i_tex_bits * rce->qscale;
        rcc->p_cplx_sum[rce->pict_type] += rce->p_tex_bits * rce->qscale;
989
        rcc->mv_bits_sum[rce->pict_type] += rce->mv_bits * rce->qscale;
990
        rcc->frame_count[rce->pict_type] ++;
991 992 993 994 995 996 997 998 999
    }

    if( all_available_bits < all_const_bits)
    {
        x264_log(h, X264_LOG_ERROR, "requested bitrate is too low. estimated minimum is %d kbps\n",
                 (int)(all_const_bits * rcc->fps / (rcc->num_entries * 1000)));
        return -1;
    }

Loren Merritt's avatar
Loren Merritt committed
1000 1001 1002 1003
    /* Blur complexities, to reduce local fluctuation of QP.
     * We don't blur the QPs directly, because then one very simple frame
     * could drag down the QP of a nearby complex frame and give it more
     * bits than intended. */
Loren Merritt's avatar
Loren Merritt committed
1004 1005
    for(i=0; i<rcc->num_entries; i++){
        ratecontrol_entry_t *rce = &rcc->entry[i];
1006
        double weight_sum = 0;
Loren Merritt's avatar
Loren Merritt committed
1007
        double cplx_sum = 0;
1008
        double weight = 1.0;
Loren Merritt's avatar
Loren Merritt committed
1009 1010
        int j;
        /* weighted average of cplx of future frames */
1011
        for(j=1; j<cplxblur*2 && j<rcc->num_entries-i; j++){