ratecontrol.c 29.4 KB
Newer Older
1
/***************************************************-*- coding: iso-8859-1 -*-
Laurent Aimar's avatar
Laurent Aimar committed
2
3
4
5
6
 * ratecontrol.c: h264 encoder library (Rate Control)
 *****************************************************************************
 * Copyright (C) 2003 Laurent Aimar
 * $Id: ratecontrol.c,v 1.1 2004/06/03 19:27:08 fenrir Exp $
 *
7
 * Authors: Mns Rullgrd <mru@mru.ath.cx>
8
 * 2 pass code: Michael Niedermayer <michaelni@gmx.at>
9
 *              Loren Merritt <lorenm@u.washington.edu>
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

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

Eric Petit's avatar
Eric Petit committed
40
41
42
#ifdef SYS_MACOSX
#define exp2f(x) ( (float) exp2( (x) ) )
#endif
43
44
45
#ifdef SYS_FREEBSD
#define exp2f(x) powf( 2, (x) )
#endif
Eric Petit's avatar
Eric Petit committed
46

47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62

typedef struct
{
    int pict_type;
    float qscale;
    int mv_bits;
    int i_tex_bits;
    int p_tex_bits;
    int misc_bits;
    uint64_t expected_bits;
    int new_pict_type;
    float new_qscale;
    int new_qp;
    int i_count;
    int p_count;
    int s_count;
Loren Merritt's avatar
Loren Merritt committed
63
    float blurred_complexity;
64
65
} ratecontrol_entry_t;

66
67
68
struct x264_ratecontrol_t
{
    /* constants */
69
    double fps;
70
71
    int gop_size;
    int bitrate;
72
    int nmb;                    /* number of macroblocks in a frame */
73
74
75
    int buffer_size;
    int rcbufrate;
    int init_qp;
76
    int qp_constant[5];
77

78
    /* 1st pass stuff */
79
80
81
82
83
84
85
86
87
88
    int gop_qp;
    int buffer_fullness;
    int frames;                 /* frames in current gop */
    int pframes;
    int slice_type;
    int mb;                     /* MBs processed in current frame */
    int bits_gop;               /* allocated bits current gop */
    int bits_last_gop;          /* bits consumed in gop */
    int qp;                     /* qp for current frame */
    int qpm;                    /* qp for next MB */
89
    float qpa;                  /* average qp for last frame */
90
    int qps;
91
92
    float qp_avg_p;             /* average QP for P frames */
    float qp_last_p;
93
94
95
96
97
    int fbits;                  /* bits allocated for current frame */
    int ufbits;                 /* bits used for current frame */
    int nzcoeffs;               /* # of 0-quantized coefficients */
    int ncoeffs;                /* total # of coefficients */
    int overhead;
98
99
100
101
102

    /* 2pass stuff */
    FILE *p_stat_file_out;

    int num_entries;            /* number of ratecontrol_entry_ts */
Loren Merritt's avatar
Loren Merritt committed
103
    ratecontrol_entry_t *entry; /* FIXME: copy needed data and free this once init is done */
104
105
106
    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;
107
    double lmin[5];             /* min qscale by frame type */
108
    double lmax[5];
Loren Merritt's avatar
Loren Merritt committed
109
    double lstep;               /* max change (multiply) in qscale per frame */
110
111
112
113
    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 */
114
};
Laurent Aimar's avatar
Laurent Aimar committed
115

116
117
118
119
120
121

static int init_pass2(x264_t *);
static float rate_estimate_qscale( x264_t *h, int pict_type );

/* Terminology:
 * qp = h.264's quantizer
122
 * qscale = linearized quantizer = Lagrange multiplier
123
124
125
126
127
128
129
130
131
132
133
134
 */
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);
}

static inline double qscale2bits(ratecontrol_entry_t *rce, double qscale)
{
Loren Merritt's avatar
Loren Merritt committed
135
    if(qscale<0.1)
136
    {
Loren Merritt's avatar
Loren Merritt committed
137
        fprintf(stderr, "qscale<0.1\n");
138
139
        qscale = 0.1;
    }
Loren Merritt's avatar
Loren Merritt committed
140
    return (double)(rce->i_tex_bits + rce->p_tex_bits + .1) * rce->qscale / qscale;
141
142
143
144
145
146
147
148
149
}

static inline double bits2qscale(ratecontrol_entry_t *rce, double bits)
{
    if(bits<0.9)
    {
        fprintf(stderr, "bits<0.9\n");
        bits = 1.0;
    }
Loren Merritt's avatar
Loren Merritt committed
150
    return rce->qscale * (double)(rce->i_tex_bits + rce->p_tex_bits + .1) / bits;
151
152
153
}


154
int x264_ratecontrol_new( x264_t *h )
Laurent Aimar's avatar
Laurent Aimar committed
155
{
156
    x264_ratecontrol_t *rc;
157
    float bpp;
158
    int i;
159

160
161
162
163
    /* Needed(?) for 2 pass */
    x264_cpu_restore( h->param.cpu );

    h->rc = rc = x264_malloc( sizeof( x264_ratecontrol_t ) );
164
165
    memset(rc, 0, sizeof(*rc));

Måns Rullgård's avatar
Måns Rullgård committed
166
167
168
169
170
171
    /* 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;

172
    rc->gop_size = h->param.i_iframe;
173
    rc->bitrate = h->param.rc.i_bitrate * 1000;
174
175
    rc->nmb = ((h->param.i_width + 15) / 16) * ((h->param.i_height + 15) / 16);

176
    rc->qp = h->param.rc.i_qp_constant;
177
178
    rc->qpa = rc->qp;
    rc->qpm = rc->qp;
Laurent Aimar's avatar
Laurent Aimar committed
179

180
181
182
183
    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 );

184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
    /* Init 1pass CBR algo */
    if( h->param.rc.b_cbr ){
        rc->buffer_size = h->param.rc.i_rc_buffer_size * 1000;
        rc->buffer_fullness = h->param.rc.i_rc_init_buffer;
        rc->rcbufrate = rc->bitrate / rc->fps;

        if(rc->buffer_size < rc->rcbufrate){
            x264_log(h, X264_LOG_WARNING, "rc buffer size %i too small\n",
                     rc->buffer_size);
            rc->buffer_size = 0;
        }

        if(rc->buffer_size <= 0)
            rc->buffer_size = rc->bitrate / 2;

        if(rc->buffer_fullness > rc->buffer_size || rc->buffer_fullness < 0){
            x264_log(h, X264_LOG_WARNING, "invalid initial buffer fullness %i\n",
                     rc->buffer_fullness);
            rc->buffer_fullness = 0;
        }

        bpp = rc->bitrate / (rc->fps * h->param.i_width * h->param.i_height);
        if(bpp <= 0.6)
            rc->init_qp = 31;
        else if(bpp <= 1.4)
            rc->init_qp = 25;
        else if(bpp <= 2.4)
            rc->init_qp = 20;
        else
            rc->init_qp = 10;
        rc->gop_qp = rc->init_qp;

        rc->bits_last_gop = 0;

        x264_log(h, X264_LOG_DEBUG, "%f fps, %i bps, bufsize %i\n",
                 rc->fps, rc->bitrate, rc->buffer_size);
220
221
    }

222

Loren Merritt's avatar
Loren Merritt committed
223
    rc->lstep = exp2f(h->param.rc.i_qp_step / 6.0);
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
    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 );
    }
#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

    /* 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 );
246
        stats_file = fopen( h->param.rc.psz_stat_in, "rb");
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
        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;
        for(i=-1; p; i++){
            p = strchr(p+1, ';');
        }
        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));
        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];
            rce->pict_type = rce->new_pict_type = SLICE_TYPE_P;
            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;
            int picture_number;
            int e;
            char *next;
            float qp;

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

            assert(picture_number >= 0);
            assert(picture_number < rc->num_entries);
            rce = &rc->entry[picture_number];

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

        if(init_pass2(h) < 0) return -1;
    }

    /* Open output file */
    if( h->param.rc.b_stat_write )
    {
318
        rc->p_stat_file_out = fopen( h->param.rc.psz_stat_out, "wb" );
319
320
321
322
323
324
        if( rc->p_stat_file_out == NULL )
        {
            x264_log(h, X264_LOG_ERROR, "ratecontrol_init: can't open stats file\n");
            return -1;
        }
    }
325
326

    return 0;
Laurent Aimar's avatar
Laurent Aimar committed
327
328
}

329
void x264_ratecontrol_delete( x264_t *h )
Laurent Aimar's avatar
Laurent Aimar committed
330
{
331
    x264_ratecontrol_t *rc = h->rc;
332
333
334
335
336

    if( rc->p_stat_file_out )
        fclose( rc->p_stat_file_out );
    if( rc->entry )
        x264_free(rc->entry);
Laurent Aimar's avatar
Laurent Aimar committed
337
338
339
    x264_free( rc );
}

340
void x264_ratecontrol_start( x264_t *h, int i_slice_type )
Laurent Aimar's avatar
Laurent Aimar committed
341
{
342
343
344
345
346
347
348
349
    x264_ratecontrol_t *rc = h->rc;
    int gframes, iframes, pframes, bframes;
    int minbits, maxbits;
    int gbits, fbits;
    int zn = 0;
    float kp;
    int gbuf;

350
    rc->slice_type = i_slice_type;
351
352
353

    x264_cpu_restore( h->param.cpu );

354
355
356
357
358
359
360
361
    if( h->param.rc.b_stat_read )
    {
        int frame = h->fenc->i_frame;
        ratecontrol_entry_t *rce = &h->rc->entry[frame];

        assert( frame >= 0 && frame < rc->num_entries );

        rce->new_qscale = rate_estimate_qscale( h, i_slice_type );
362
363
        rc->qpm = rc->qpa = rc->qp = rce->new_qp =
            (int)(qscale2qp(rce->new_qscale) + 0.5);
364
365
366
367
        return;
    }
    else if( !h->param.rc.b_cbr )
    {
368
369
        rc->qpm = rc->qpa = rc->qp =
            rc->qp_constant[ i_slice_type ];
370
371
        return;
    }
372
373
374
375
376
377
378

    switch(i_slice_type){
    case SLICE_TYPE_I:
        gbuf = rc->buffer_fullness + (rc->gop_size-1) * rc->rcbufrate;
        rc->bits_gop = gbuf - rc->buffer_size / 2;

        if(!rc->mb && rc->pframes){
379
            int qp = rc->qp_avg_p / rc->pframes + 0.5;
380
381
382
383
384
385
386
387
388
#if 0 /* JM does this without explaining why */
            int gdq = (float) rc->gop_size / 15 + 0.5;
            if(gdq > 2)
                gdq = 2;
            qp -= gdq;
            if(qp > rc->qp_last_p - 2)
                qp--;
#endif
            qp = x264_clip3(qp, rc->gop_qp - 4, rc->gop_qp + 4);
Loren Merritt's avatar
Loren Merritt committed
389
            qp = x264_clip3(qp, h->param.rc.i_qp_min, h->param.rc.i_qp_max);
390
            rc->gop_qp = qp;
391
        } else if(rc->frames > 4){
392
393
394
            rc->gop_qp = rc->init_qp;
        }

395
        kp = h->param.rc.f_ip_factor * h->param.rc.f_pb_factor;
396

397
398
        x264_log(h, X264_LOG_DEBUG,"gbuf=%i bits_gop=%i frames=%i gop_qp=%i\n",
                 gbuf, rc->bits_gop, rc->frames, rc->gop_qp);
399

400
401
402
403
404
405
406
        rc->bits_last_gop = 0;
        rc->frames = 0;
        rc->pframes = 0;
        rc->qp_avg_p = 0;
        break;

    case SLICE_TYPE_P:
407
        kp = h->param.rc.f_pb_factor;
408
409
410
411
412
413
414
        break;

    case SLICE_TYPE_B:
        kp = 1.0;
        break;

    default:
415
416
        x264_log(h, X264_LOG_WARNING, "ratecontrol: unknown slice type %i\n",
                 i_slice_type);
417
418
419
420
421
422
423
424
425
426
427
        kp = 1.0;
        break;
    }

    gframes = rc->gop_size - rc->frames;
    iframes = gframes / rc->gop_size;
    pframes = gframes / (h->param.i_bframe + 1) - iframes;
    bframes = gframes - pframes - iframes;

    gbits = rc->bits_gop - rc->bits_last_gop;
    fbits = kp * gbits /
428
429
        (h->param.rc.f_ip_factor * h->param.rc.f_pb_factor * iframes +
         h->param.rc.f_pb_factor * pframes + bframes);
430
431
432
433
434
435
436
437
438

    minbits = rc->buffer_fullness + rc->rcbufrate - rc->buffer_size;
    if(minbits < 0)
        minbits = 0;
    maxbits = rc->buffer_fullness;
    rc->fbits = x264_clip3(fbits, minbits, maxbits);

    if(i_slice_type == SLICE_TYPE_I){
        rc->qp = rc->gop_qp;
439
    } else if(rc->ncoeffs && rc->ufbits){
440
441
442
443
444
445
446
447
448
449
        int dqp, nonzc;

        nonzc = (rc->ncoeffs - rc->nzcoeffs);
        if(nonzc == 0)
            zn = rc->ncoeffs;
        else if(rc->fbits < INT_MAX / nonzc)
            zn = rc->ncoeffs - rc->fbits * nonzc / rc->ufbits;
        else
            zn = 0;
        zn = x264_clip3(zn, 0, rc->ncoeffs);
450
        dqp = h->param.rc.i_rc_sens * exp2f(rc->qpa / 6) *
451
            (zn - rc->nzcoeffs) / rc->nzcoeffs;
452
        dqp = x264_clip3(dqp, -h->param.rc.i_qp_step, h->param.rc.i_qp_step);
453
        rc->qp = (int)(rc->qpa + dqp + .5);
454
455
    }

456
    if(rc->fbits > 0.9 * maxbits)
457
        rc->qp += 2;
458
459
    else if(rc->fbits > 0.8 * maxbits)
        rc->qp += 1;
460
461
    else if(rc->fbits < 1.1 * minbits)
        rc->qp -= 2;
462
463
    else if(rc->fbits < 1.2 * minbits)
        rc->qp -= 1;
464

465
    rc->qp = x264_clip3(rc->qp, h->param.rc.i_qp_min, h->param.rc.i_qp_max);
466
467
    rc->qpm = rc->qp;

468
469
    x264_log(h, X264_LOG_DEBUG, "fbits=%i, qp=%i, z=%i, min=%i, max=%i\n",
             rc->fbits, rc->qpm, zn, minbits, maxbits);
470
471
472
473
474
475
476

    rc->fbits -= rc->overhead;
    rc->ufbits = 0;
    rc->ncoeffs = 0;
    rc->nzcoeffs = 0;
    rc->mb = 0;
    rc->qps = 0;
Laurent Aimar's avatar
Laurent Aimar committed
477
478
}

479
void x264_ratecontrol_mb( x264_t *h, int bits )
Laurent Aimar's avatar
Laurent Aimar committed
480
{
481
482
    x264_ratecontrol_t *rc = h->rc;
    int rbits;
483
484
    int zn, enz, nonz;
    int rcoeffs;
485
486
487
    int dqp;
    int i;

488
    if( !h->param.rc.b_cbr || h->param.rc.b_stat_read )
489
490
        return;

491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
    x264_cpu_restore( h->param.cpu );

    rc->qps += rc->qpm;
    rc->ufbits += bits;
    rc->mb++;

    for(i = 0; i < 16 + 8; i++)
        rc->nzcoeffs += 16 - h->mb.cache.non_zero_count[x264_scan8[i]];
    rc->ncoeffs += 16 * (16 + 8);

    if(rc->mb < rc->nmb / 16)
        return;
    else if(rc->mb == rc->nmb)
        return;

506
    rcoeffs = (rc->nmb - rc->mb) * 16 * 24;
507
508
509
510
    rbits = rc->fbits - rc->ufbits;
/*     if(rbits < 0) */
/*      rbits = 0; */

511
512
513
514
515
516
517
518
519
/*     zn = (rc->nmb - rc->mb) * 16 * 24; */
    nonz = (rc->ncoeffs - rc->nzcoeffs);
    if(nonz == 0)
        zn = rcoeffs;
    else if(rc->ufbits && rbits < INT_MAX / nonz)
        zn = rcoeffs - rbits * nonz / rc->ufbits;
    else
        zn = 0;
    zn = x264_clip3(zn, 0, rcoeffs);
520
    enz = rc->nzcoeffs * (rc->nmb - rc->mb) / rc->mb;
521
    dqp = (float) 2*h->param.rc.i_rc_sens * exp2f((float) rc->qps / rc->mb / 6) *
522
523
524
525
        (zn - enz) / enz;
    rc->qpm = x264_clip3(rc->qpm + dqp, rc->qp - 3, rc->qp + 3);
    if(rbits <= 0)
        rc->qpm++;
526
    rc->qpm = x264_clip3(rc->qpm, h->param.rc.i_qp_min, h->param.rc.i_qp_max);
Laurent Aimar's avatar
Laurent Aimar committed
527
528
}

529
int  x264_ratecontrol_qp( x264_t *h )
Laurent Aimar's avatar
Laurent Aimar committed
530
{
531
532
    return h->rc->qpm;
}
Laurent Aimar's avatar
Laurent Aimar committed
533

534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
int x264_ratecontrol_slice_type( x264_t *h, int frame_num )
{
    if( h->param.rc.b_stat_read )
    {
        assert(frame_num < h->rc->num_entries);
        switch( h->rc->entry[frame_num].new_pict_type )
        {
            case SLICE_TYPE_I:
                return X264_TYPE_I;

            case SLICE_TYPE_B:
                return X264_TYPE_B;

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

558
559
560
void x264_ratecontrol_end( x264_t *h, int bits )
{
    x264_ratecontrol_t *rc = h->rc;
Laurent Aimar's avatar
Laurent Aimar committed
561

562
563
    x264_cpu_restore( h->param.cpu );

564
565
566
567
568
    if( h->param.rc.b_stat_write )
    {
        fprintf( rc->p_stat_file_out,
                 "in:%d out:%d type:%d q:%.3f itex:%d ptex:%d mv:%d misc:%d imb:%d pmb:%d smb:%d;\n",
                 h->fenc->i_frame, h->i_frame-1,
569
                 rc->slice_type, rc->qpa,
570
571
572
573
574
575
576
577
                 h->stat.frame.i_itex_bits, h->stat.frame.i_ptex_bits,
                 h->stat.frame.i_hdr_bits, h->stat.frame.i_misc_bits,
                 h->stat.frame.i_mb_count[I_4x4] + h->stat.frame.i_mb_count[I_16x16],
                 h->stat.frame.i_mb_count[P_L0]  + h->stat.frame.i_mb_count[P_8x8],
                 h->stat.frame.i_mb_count[P_SKIP]);
    }

    if( !h->param.rc.b_cbr || h->param.rc.b_stat_read )
578
        return;
Laurent Aimar's avatar
Laurent Aimar committed
579

580
581
    rc->buffer_fullness += rc->rcbufrate - bits;
    if(rc->buffer_fullness < 0){
582
583
        x264_log(h, X264_LOG_WARNING, "buffer underflow %i\n",
                 rc->buffer_fullness);
584
        rc->buffer_fullness = 0;
Laurent Aimar's avatar
Laurent Aimar committed
585
586
    }

587
    rc->qpa = (float)rc->qps / rc->mb;
588
589
590
591
    if(rc->slice_type == SLICE_TYPE_P){
        rc->qp_avg_p += rc->qpa;
        rc->qp_last_p = rc->qpa;
        rc->pframes++;
592
593
594
595
596
597
    } else if(rc->slice_type == SLICE_TYPE_I){
        float err = (float) rc->ufbits / rc->fbits;
        if(err > 1.1)
            rc->gop_qp++;
        else if(err < 0.9)
            rc->gop_qp--;
Laurent Aimar's avatar
Laurent Aimar committed
598
599
    }

600
601
    rc->overhead = bits - rc->ufbits;

602
    x264_log(h, X264_LOG_DEBUG, "bits=%i, qp=%.1f, z=%i, zr=%6.3f, buf=%i\n",
603
604
             bits, rc->qpa, rc->nzcoeffs, (float) rc->nzcoeffs / rc->ncoeffs,
             rc->buffer_fullness);
605
606
607
608

    rc->bits_last_gop += bits;
    rc->frames++;
    rc->mb = 0;
Laurent Aimar's avatar
Laurent Aimar committed
609
}
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644

/****************************************************************************
 * 2 pass functions
 ***************************************************************************/
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 );

/**
 * modifies the bitrate curve from pass1 for one frame
 */
static double get_qscale(x264_t *h, ratecontrol_entry_t *rce, double rate_factor)
{
    x264_ratecontrol_t *rcc= h->rc;
    double bits;
    const int pict_type = rce->new_pict_type;

    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,
        rce->mv_bits / rcc->nmb,
        (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
645
        rce->blurred_complexity,
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
        0
    };
    static const char *const_names[]={
        "iTex",
        "pTex",
        "tex",
        "mv",
        "iCount",
        "pCount",
        "sCount",
        "isI",
        "isP",
        "isB",
        "qComp",
        "avgIITex",
        "avgPITex",
        "avgPPTex",
        "avgBPTex",
        "avgTex",
Loren Merritt's avatar
Loren Merritt committed
665
        "blurTex",
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
        NULL
    };
    static double (*func1[])(void *, double)={
        (void *)bits2qscale,
        (void *)qscale2bits,
        NULL
    };
    static const char *func1_names[]={
        "bits2qp",
        "qp2bits",
        NULL
    };

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

Loren Merritt's avatar
Loren Merritt committed
681
682
683
684
    // avoid NaN's in the rc_eq
    if(bits != bits || rce->i_tex_bits + rce->p_tex_bits == 0)
        bits = 0;

685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
    bits *= rate_factor;
    if(bits<0.0) bits=0.0;
    bits += 1.0; //avoid 1/0 issues

    /* I/B difference */
    if( pict_type==SLICE_TYPE_I && h->param.rc.f_ip_factor > 0 )
        bits *= h->param.rc.f_ip_factor;
    else if( pict_type==SLICE_TYPE_B && h->param.rc.f_pb_factor > 0 )
        bits /= h->param.rc.f_pb_factor;

    return bits2qscale(rce, bits);
}

static double get_diff_limited_q(x264_t *h, ratecontrol_entry_t *rce, double q)
{
    x264_ratecontrol_t *rcc = h->rc;
    const int pict_type = rce->new_pict_type;

    // 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];
    if( pict_type == SLICE_TYPE_I && h->param.rc.f_ip_factor < 0 )
        q = last_p_q     / -h->param.rc.f_ip_factor;
    else if(pict_type==SLICE_TYPE_B && h->param.rc.f_pb_factor < 0)
        q = last_non_b_q * -h->param.rc.f_pb_factor;

    /* last qscale / qdiff stuff */
    if(rcc->last_non_b_pict_type==pict_type || pict_type!=SLICE_TYPE_I)
    {
        double last_q = rcc->last_qscale_for[pict_type];
Loren Merritt's avatar
Loren Merritt committed
715
716
        double max_qscale = last_q * rcc->lstep;
        double min_qscale = last_q / rcc->lstep;
717
718
719
720
721

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

Loren Merritt's avatar
Loren Merritt committed
722
    rcc->last_qscale_for[pict_type] = q;
723
724
725
726
727
    if(pict_type!=SLICE_TYPE_B)
        rcc->last_non_b_pict_type = pict_type;
    return q;
}

Loren Merritt's avatar
Loren Merritt committed
728
729
// clip a qscale to between lmin and lmax
static double clip_qscale( x264_t *h, ratecontrol_entry_t *rce, double q )
730
{
Loren Merritt's avatar
Loren Merritt committed
731
732
    double lmin = h->rc->lmin[rce->new_pict_type];
    double lmax = h->rc->lmax[rce->new_pict_type];
733

Loren Merritt's avatar
Loren Merritt committed
734
735
    if(lmin==lmax){
        return lmin;
736
737
738
    }else{
        double min2 = log(lmin);
        double max2 = log(lmax);
Loren Merritt's avatar
Loren Merritt committed
739
740
        q = (log(q) - min2)/(max2-min2) - 0.5;
        q = 1.0/(1.0 + exp(-4*q));
741
        q = q*(max2-min2) + min2;
Loren Merritt's avatar
Loren Merritt committed
742
        return exp(q);
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
    }
}

// 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;
    float br_compensation;
    double diff;
    int picture_number = h->fenc->i_frame;
    x264_ratecontrol_t *rcc = h->rc;
    ratecontrol_entry_t *rce;
    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]);

//printf("input_pic_num:%d pic_num:%d frame_rate:%d\n", s->input_picture_number, s->picture_number, s->frame_rate);

    rce = &rcc->entry[picture_number];

    if(pict_type!=SLICE_TYPE_I)
        assert(pict_type == rce->new_pict_type);

Loren Merritt's avatar
Loren Merritt committed
768
    diff = (int64_t)total_bits - (int64_t)rce->expected_bits;
769
770
771
772
    br_compensation = (rcc->buffer_size - diff) / rcc->buffer_size;
    if(br_compensation<=0.0) br_compensation=0.001;

    q = rce->new_qscale / br_compensation;
Loren Merritt's avatar
Loren Merritt committed
773
    q = x264_clip3f(q, lmin, lmax);
774
775
776
777
778
779
780
781
782
783
784
    rcc->last_qscale = q;
    return q;
}

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
785
    double cplxblur = h->param.rc.f_complexity_blur;
786
    const int filter_size = (int)(qblur*4) | 1;
Loren Merritt's avatar
Loren Merritt committed
787
    const int cplx_filter_size = (int)(cplxblur*2);
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
    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];
        rce->new_pict_type = rce->pict_type;
        all_const_bits += rce->mv_bits + rce->misc_bits;
        rcc->i_cplx_sum[rce->new_pict_type] += rce->i_tex_bits * rce->qscale;
        rcc->p_cplx_sum[rce->new_pict_type] += rce->p_tex_bits * rce->qscale;
        rcc->mv_bits_sum[rce->new_pict_type] += rce->mv_bits;
        rcc->frame_count[rce->new_pict_type] ++;
    }

    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
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
    if(cplxblur<.01)
        cplxblur = .01;
    for(i=0; i<rcc->num_entries; i++){
        ratecontrol_entry_t *rce = &rcc->entry[i];
        double weight, weight_sum = 0;
        double cplx_sum = 0;
        double mask = 1.0;
        int j;
        /* weighted average of cplx of future frames */
        for(j=1; j<cplx_filter_size && j<rcc->num_entries-i; j++){
            ratecontrol_entry_t *rcj = &rcc->entry[i+j];
            mask *= (double)(rcc->nmb + rcj->i_count) / rcc->nmb;
            weight = mask * exp(-j*j/(cplxblur*cplxblur));
            if(weight < .0001)
                break;
            weight_sum += weight;
            cplx_sum += weight * (rcj->i_tex_bits + rcj->p_tex_bits) * rce->qscale;
        }
        /* weighted average of cplx of past frames */
        mask = 1.0;
        for(j=0; j<cplx_filter_size && j<=i; j++){
            ratecontrol_entry_t *rcj = &rcc->entry[i-j];
            weight = mask * exp(-j*j/(cplxblur*cplxblur));
            weight_sum += weight;
            cplx_sum += weight * (rcj->i_tex_bits + rcj->p_tex_bits) * rce->qscale;
            mask *= (double)(rcc->nmb + rcj->i_count) / rcc->nmb;
            if(weight < .0001)
                break;
        }
        rce->blurred_complexity = cplx_sum / weight_sum;
    }

842
843
844
845
846
847
    qscale = x264_malloc(sizeof(double)*rcc->num_entries);
    if(filter_size > 1)
        blurred_qscale = x264_malloc(sizeof(double)*rcc->num_entries);
    else
        blurred_qscale = qscale;

Loren Merritt's avatar
Loren Merritt committed
848
    expected_bits = 1;
849
850
851
852
853
    for(i=0; i<rcc->num_entries; i++)
        expected_bits += qscale2bits(&rcc->entry[i], get_qscale(h, &rcc->entry[i], 1.0));
    step_mult = all_available_bits / expected_bits;

    rate_factor = 0;
Loren Merritt's avatar
Loren Merritt committed
854
    for(step = 1E4 * step_mult; step > 1E-7 * step_mult; step *= 0.5){
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
        expected_bits = 0;
        rate_factor += step;

        /* find qscale */
        for(i=0; i<rcc->num_entries; i++){
            qscale[i] = get_qscale(h, &rcc->entry[i], rate_factor);
        }

        /* fixed I/B QP relative to P mode */
        for(i=rcc->num_entries-1; i>=0; i--){
            qscale[i] = get_diff_limited_q(h, &rcc->entry[i], qscale[i]);
            assert(qscale[i] >= 0);
        }

        /* smooth curve */
        if(filter_size > 1){
            assert(filter_size%2==1);
            for(i=0; i<rcc->num_entries; i++){
                ratecontrol_entry_t *rce = &rcc->entry[i];
                const int pict_type = rce->new_pict_type;
                int j;
                double q=0.0, sum=0.0;

                for(j=0; j<filter_size; j++){
                    int index = i+j-filter_size/2;
                    double d = index-i;
                    double coeff = qblur==0 ? 1.0 : exp(-d*d/(qblur*qblur));
                    if(index < 0 || index >= rcc->num_entries) continue;
                    if(pict_type != rcc->entry[index].new_pict_type) continue;
                    q += qscale[index] * coeff;
                    sum += coeff;
                }
                blurred_qscale[i] = q/sum;
            }
        }

        /* find expected bits */
        for(i=0; i<rcc->num_entries; i++){
            ratecontrol_entry_t *rce = &rcc->entry[i];
            double bits;
Loren Merritt's avatar
Loren Merritt committed
895
            rce->new_qscale = clip_qscale(h, rce, blurred_qscale[i]);
896
897
898
899
900
901
902
            assert(rce->new_qscale >= 0);
            bits = qscale2bits(rce, rce->new_qscale) + rce->mv_bits + rce->misc_bits;

            rce->expected_bits = expected_bits;
            expected_bits += bits;
        }

903
//printf("expected:%llu available:%llu factor:%lf avgQ:%lf\n", (uint64_t)expected_bits, all_available_bits, rate_factor);
904
905
906
907
908
909
910
        if(expected_bits > all_available_bits) rate_factor -= step;
    }

    x264_free(qscale);
    if(filter_size > 1)
        x264_free(blurred_qscale);

911
    if(fabs(expected_bits/all_available_bits - 1.0) > 0.01)
912
    {
913
914
        double avgq = 0;
        for(i=0; i<rcc->num_entries; i++)
Loren Merritt's avatar
Loren Merritt committed
915
916
            avgq += rcc->entry[i].new_qscale;
        avgq = qscale2qp(avgq / rcc->num_entries);
917
918
919
920
921
922
923

        x264_log(h, X264_LOG_ERROR, "Error: 2pass curve failed to converge\n");
        x264_log(h, X264_LOG_ERROR, "expected bits: %llu, available: %llu, avg QP: %.4lf\n", (uint64_t)expected_bits, all_available_bits, avgq);
        if(expected_bits < all_available_bits && avgq < h->param.rc.i_qp_min + 1)
            x264_log(h, X264_LOG_ERROR, "try reducing bitrate or reducing qp_min\n");
        if(expected_bits > all_available_bits && avgq > h->param.rc.i_qp_min - 1)
            x264_log(h, X264_LOG_ERROR, "try increasing bitrate or increasing qp_max\n");
924
925
926
927
928
929
930
        return -1;
    }

    return 0;
}