ratecontrol.c 31.1 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
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"

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

typedef struct
{
    int pict_type;
51
    int idr;
52
53
54
55
56
57
58
59
60
61
62
    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
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
108
    double accum_p_qp;          /* for determining I-frame quant */
    double accum_p_norm;
109
    double last_accum_p_norm;
110
    double lmin[5];             /* min qscale by frame type */
111
    double lmax[5];
Loren Merritt's avatar
Loren Merritt committed
112
    double lstep;               /* max change (multiply) in qscale per frame */
113
114
115
116
    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 */
117
};
Laurent Aimar's avatar
Laurent Aimar committed
118

119
120
121
122
123
124

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

/* Terminology:
 * qp = h.264's quantizer
125
 * qscale = linearized quantizer = Lagrange multiplier
126
127
128
129
130
131
132
133
134
135
136
137
 */
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
138
    if(qscale<0.1)
139
    {
140
//      fprintf(stderr, "qscale<0.1\n");
141
142
        qscale = 0.1;
    }
Loren Merritt's avatar
Loren Merritt committed
143
    return (double)(rce->i_tex_bits + rce->p_tex_bits + .1) * rce->qscale / qscale;
144
145
146
147
148
149
}

static inline double bits2qscale(ratecontrol_entry_t *rce, double bits)
{
    if(bits<0.9)
    {
150
//      fprintf(stderr, "bits<0.9\n");
151
152
        bits = 1.0;
    }
Loren Merritt's avatar
Loren Merritt committed
153
    return rce->qscale * (double)(rce->i_tex_bits + rce->p_tex_bits + .1) / bits;
154
155
156
}


157
int x264_ratecontrol_new( x264_t *h )
Laurent Aimar's avatar
Laurent Aimar committed
158
{
159
    x264_ratecontrol_t *rc;
160
    float bpp;
161
    int i;
162

163
164
165
166
    /* Needed(?) for 2 pass */
    x264_cpu_restore( h->param.cpu );

    h->rc = rc = x264_malloc( sizeof( x264_ratecontrol_t ) );
167
168
    memset(rc, 0, sizeof(*rc));

Måns Rullgård's avatar
Måns Rullgård committed
169
170
171
172
173
174
    /* 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;

175
    rc->gop_size = h->param.i_keyint_max;
176
    rc->bitrate = h->param.rc.i_bitrate * 1000;
177
    rc->nmb = h->mb.i_mb_count;
178

179
180
181
182
    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 );

183
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
    /* 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);
219
220
    }

221

Loren Merritt's avatar
Loren Merritt committed
222
    rc->lstep = exp2f(h->param.rc.i_qp_step / 6.0);
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
    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 );
245
        stats_file = fopen( h->param.rc.psz_stat_in, "rb");
246
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
        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];
272
            rce->pict_type = SLICE_TYPE_P;
273
274
275
276
277
278
279
280
281
            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;
282
283
            int frame_number;
            char pict_type;
284
285
286
287
288
289
290
291
292
            int e;
            char *next;
            float qp;

            next= strchr(p, ';');
            if(next){
                (*next)=0; //sscanf is unbelievably slow on looong strings
                next++;
            }
293
            e = sscanf(p, " in:%d ", &frame_number);
294

295
296
297
            assert(frame_number >= 0);
            assert(frame_number < rc->num_entries);
            rce = &rc->entry[frame_number];
298

299
300
            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,
301
                   &rce->mv_bits, &rce->misc_bits, &rce->i_count, &rce->p_count, &rce->s_count);
302
303
304
305
306
307
308
309

            switch(pict_type){
                case 'I': rce->idr = 1;
                case 'i': rce->pict_type = SLICE_TYPE_I; break;
                case 'P': rce->pict_type = SLICE_TYPE_P; break;
                case 'B': rce->pict_type = SLICE_TYPE_B; break;
                default:  e = -1; break;
            }
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
            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 )
    {
326
        rc->p_stat_file_out = fopen( h->param.rc.psz_stat_out, "wb" );
327
328
329
330
331
332
        if( rc->p_stat_file_out == NULL )
        {
            x264_log(h, X264_LOG_ERROR, "ratecontrol_init: can't open stats file\n");
            return -1;
        }
    }
333
334

    return 0;
Laurent Aimar's avatar
Laurent Aimar committed
335
336
}

337
void x264_ratecontrol_delete( x264_t *h )
Laurent Aimar's avatar
Laurent Aimar committed
338
{
339
    x264_ratecontrol_t *rc = h->rc;
340
341
342
343
344

    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
345
346
347
    x264_free( rc );
}

348
void x264_ratecontrol_start( x264_t *h, int i_slice_type )
Laurent Aimar's avatar
Laurent Aimar committed
349
{
350
351
352
353
354
355
356
357
    x264_ratecontrol_t *rc = h->rc;
    int gframes, iframes, pframes, bframes;
    int minbits, maxbits;
    int gbits, fbits;
    int zn = 0;
    float kp;
    int gbuf;

358
    rc->slice_type = i_slice_type;
359
360
361

    x264_cpu_restore( h->param.cpu );

362
363
364
365
366
367
368
    if( !h->param.rc.b_cbr )
    {
        rc->qpm = rc->qpa = rc->qp =
            rc->qp_constant[ i_slice_type ];
        return;
    }
    else if( h->param.rc.b_stat_read )
369
370
    {
        int frame = h->fenc->i_frame;
371
        ratecontrol_entry_t *rce;
372
        assert( frame >= 0 && frame < rc->num_entries );
373
        rce = &h->rc->entry[frame];
374
375

        rce->new_qscale = rate_estimate_qscale( h, i_slice_type );
376
377
        rc->qpm = rc->qpa = rc->qp = rce->new_qp =
            (int)(qscale2qp(rce->new_qscale) + 0.5);
378
379
        return;
    }
380
381
382
383
384
385
386

    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){
387
            int qp = rc->qp_avg_p / rc->pframes + 0.5;
388
389
390
391
392
393
394
395
396
#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
397
            qp = x264_clip3(qp, h->param.rc.i_qp_min, h->param.rc.i_qp_max);
398
            rc->gop_qp = qp;
399
        } else if(rc->frames > 4){
400
401
402
            rc->gop_qp = rc->init_qp;
        }

403
        kp = h->param.rc.f_ip_factor * h->param.rc.f_pb_factor;
404

405
406
        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);
407

408
409
410
411
412
413
414
        rc->bits_last_gop = 0;
        rc->frames = 0;
        rc->pframes = 0;
        rc->qp_avg_p = 0;
        break;

    case SLICE_TYPE_P:
415
        kp = h->param.rc.f_pb_factor;
416
417
418
419
420
421
422
        break;

    case SLICE_TYPE_B:
        kp = 1.0;
        break;

    default:
423
424
        x264_log(h, X264_LOG_WARNING, "ratecontrol: unknown slice type %i\n",
                 i_slice_type);
425
426
427
428
429
430
431
432
433
434
435
        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 /
436
437
        (h->param.rc.f_ip_factor * h->param.rc.f_pb_factor * iframes +
         h->param.rc.f_pb_factor * pframes + bframes);
438
439
440
441
442
443
444
445
446

    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;
447
    } else if(rc->ncoeffs && rc->ufbits){
448
449
450
451
452
453
454
455
456
457
        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);
458
        dqp = h->param.rc.i_rc_sens * exp2f(rc->qpa / 6) *
459
            (zn - rc->nzcoeffs) / rc->nzcoeffs;
460
        dqp = x264_clip3(dqp, -h->param.rc.i_qp_step, h->param.rc.i_qp_step);
461
        rc->qp = (int)(rc->qpa + dqp + .5);
462
463
    }

464
    if(rc->fbits > 0.9 * maxbits)
465
        rc->qp += 2;
466
467
    else if(rc->fbits > 0.8 * maxbits)
        rc->qp += 1;
468
469
    else if(rc->fbits < 1.1 * minbits)
        rc->qp -= 2;
470
471
    else if(rc->fbits < 1.2 * minbits)
        rc->qp -= 1;
472

473
    rc->qp = x264_clip3(rc->qp, h->param.rc.i_qp_min, h->param.rc.i_qp_max);
474
475
    rc->qpm = rc->qp;

476
477
    x264_log(h, X264_LOG_DEBUG, "fbits=%i, qp=%i, z=%i, min=%i, max=%i\n",
             rc->fbits, rc->qpm, zn, minbits, maxbits);
478
479
480
481
482
483
484

    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
485
486
}

487
void x264_ratecontrol_mb( x264_t *h, int bits )
Laurent Aimar's avatar
Laurent Aimar committed
488
{
489
490
    x264_ratecontrol_t *rc = h->rc;
    int rbits;
491
492
    int zn, enz, nonz;
    int rcoeffs;
493
494
495
    int dqp;
    int i;

496
    if( !h->param.rc.b_cbr || h->param.rc.b_stat_read )
497
498
        return;

499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
    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;

514
    rcoeffs = (rc->nmb - rc->mb) * 16 * 24;
515
516
517
518
    rbits = rc->fbits - rc->ufbits;
/*     if(rbits < 0) */
/*      rbits = 0; */

519
520
521
522
523
524
525
526
527
/*     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);
528
    enz = rc->nzcoeffs * (rc->nmb - rc->mb) / rc->mb;
529
    dqp = (float) 2*h->param.rc.i_rc_sens * exp2f((float) rc->qps / rc->mb / 6) *
530
531
532
533
        (zn - enz) / enz;
    rc->qpm = x264_clip3(rc->qpm + dqp, rc->qp - 3, rc->qp + 3);
    if(rbits <= 0)
        rc->qpm++;
534
    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
535
536
}

537
int  x264_ratecontrol_qp( x264_t *h )
Laurent Aimar's avatar
Laurent Aimar committed
538
{
539
540
    return h->rc->qpm;
}
Laurent Aimar's avatar
Laurent Aimar committed
541

542
543
544
545
int x264_ratecontrol_slice_type( x264_t *h, int frame_num )
{
    if( h->param.rc.b_stat_read )
    {
546
547
548
549
550
        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;
        }
551
        switch( h->rc->entry[frame_num].pict_type )
552
553
        {
            case SLICE_TYPE_I:
554
                return h->rc->entry[frame_num].idr ? X264_TYPE_IDR : X264_TYPE_I;
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569

            case SLICE_TYPE_B:
                return X264_TYPE_B;

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

570
571
572
void x264_ratecontrol_end( x264_t *h, int bits )
{
    x264_ratecontrol_t *rc = h->rc;
Loren Merritt's avatar
Loren Merritt committed
573
    int i;
Laurent Aimar's avatar
Laurent Aimar committed
574

575
576
    x264_cpu_restore( h->param.cpu );

Loren Merritt's avatar
Loren Merritt committed
577
578
579
580
581
    h->stat.frame.i_mb_count_skip = h->stat.frame.i_mb_count[P_SKIP] + h->stat.frame.i_mb_count[B_SKIP];
    h->stat.frame.i_mb_count_p = h->stat.frame.i_mb_count[P_L0] + h->stat.frame.i_mb_count[P_8x8];
    for( i = B_DIRECT; i < B_8x8; i++ )
        h->stat.frame.i_mb_count_p += h->stat.frame.i_mb_count[i];

582
583
    if( h->param.rc.b_stat_write )
    {
584
585
        char c_type = rc->slice_type==SLICE_TYPE_I ? (h->fenc->i_poc==0 ? 'I' : 'i')
                    : rc->slice_type==SLICE_TYPE_P ? 'P' : 'B';
586
        fprintf( rc->p_stat_file_out,
587
                 "in:%d out:%d type:%c q:%.3f itex:%d ptex:%d mv:%d misc:%d imb:%d pmb:%d smb:%d;\n",
588
                 h->fenc->i_frame, h->i_frame-1,
589
                 c_type, rc->qpa,
590
591
592
                 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],
Loren Merritt's avatar
Loren Merritt committed
593
594
                 h->stat.frame.i_mb_count_p,
                 h->stat.frame.i_mb_count_skip);
595
596
597
    }

    if( !h->param.rc.b_cbr || h->param.rc.b_stat_read )
598
        return;
Laurent Aimar's avatar
Laurent Aimar committed
599

600
601
    rc->buffer_fullness += rc->rcbufrate - bits;
    if(rc->buffer_fullness < 0){
602
603
        x264_log(h, X264_LOG_WARNING, "buffer underflow %i\n",
                 rc->buffer_fullness);
604
        rc->buffer_fullness = 0;
Laurent Aimar's avatar
Laurent Aimar committed
605
606
    }

607
    rc->qpa = (float)rc->qps / rc->mb;
608
609
610
611
    if(rc->slice_type == SLICE_TYPE_P){
        rc->qp_avg_p += rc->qpa;
        rc->qp_last_p = rc->qpa;
        rc->pframes++;
612
613
614
615
616
617
    } 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
618
619
    }

620
621
    rc->overhead = bits - rc->ufbits;

622
    x264_log(h, X264_LOG_DEBUG, "bits=%i, qp=%.1f, z=%i, zr=%6.3f, buf=%i\n",
623
624
             bits, rc->qpa, rc->nzcoeffs, (float) rc->nzcoeffs / rc->ncoeffs,
             rc->buffer_fullness);
625
626
627
628

    rc->bits_last_gop += bits;
    rc->frames++;
    rc->mb = 0;
Laurent Aimar's avatar
Laurent Aimar committed
629
}
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645

/****************************************************************************
 * 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;
646
    const int pict_type = rce->pict_type;
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664

    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
665
        rce->blurred_complexity,
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
        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
685
        "blurTex",
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
        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
701
702
703
704
    // avoid NaN's in the rc_eq
    if(bits != bits || rce->i_tex_bits + rce->p_tex_bits == 0)
        bits = 0;

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

    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;
715
    const int pict_type = rce->pict_type;
716
717
718
719

    // 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];
720
721
    if( pict_type == SLICE_TYPE_I )
    {
722
723
724
725
726
727
728
729
730
731
732
733
        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;
734
735
736
737
738
    }
    else if( pict_type == SLICE_TYPE_B )
    {
        if( h->param.rc.f_pb_factor > 0 )
            q = last_non_b_q;
739
        q *= fabs( h->param.rc.f_pb_factor );
740
741
742
743
744
    }
    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 )
    {
745
        q = last_p_q;
746
    }
747
748

    /* last qscale / qdiff stuff */
749
750
751
752
    /* TODO take intro account whether the I-frame is a scene cut
     * or just a seek point */
    if(rcc->last_non_b_pict_type==pict_type
       && (pict_type!=SLICE_TYPE_I || rcc->last_accum_p_norm < 1))
753
754
    {
        double last_q = rcc->last_qscale_for[pict_type];
Loren Merritt's avatar
Loren Merritt committed
755
756
        double max_qscale = last_q * rcc->lstep;
        double min_qscale = last_q / rcc->lstep;
757
758
759
760
761

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

Loren Merritt's avatar
Loren Merritt committed
762
    rcc->last_qscale_for[pict_type] = q;
763
764
    if(pict_type!=SLICE_TYPE_B)
        rcc->last_non_b_pict_type = pict_type;
765
766
    if(pict_type==SLICE_TYPE_I)
    {
767
        rcc->last_accum_p_norm = rcc->accum_p_norm;
768
769
770
771
772
773
774
775
776
        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);
    }
777
778
779
    return q;
}

Loren Merritt's avatar
Loren Merritt committed
780
781
// clip a qscale to between lmin and lmax
static double clip_qscale( x264_t *h, ratecontrol_entry_t *rce, double q )
782
{
783
784
    double lmin = h->rc->lmin[rce->pict_type];
    double lmax = h->rc->lmax[rce->pict_type];
785

Loren Merritt's avatar
Loren Merritt committed
786
787
    if(lmin==lmax){
        return lmin;
788
789
790
    }else{
        double min2 = log(lmin);
        double max2 = log(lmax);
Loren Merritt's avatar
Loren Merritt committed
791
792
        q = (log(q) - min2)/(max2-min2) - 0.5;
        q = 1.0/(1.0 + exp(-4*q));
793
        q = q*(max2-min2) + min2;
Loren Merritt's avatar
Loren Merritt committed
794
        return exp(q);
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
    }
}

// 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];

817
    assert(pict_type == rce->pict_type);
818

819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
    if(rce->pict_type == SLICE_TYPE_B)
    {
        return rcc->last_qscale * h->param.rc.f_pb_factor;
    }
    else
    {
        diff = (int64_t)total_bits - (int64_t)rce->expected_bits;
        br_compensation = (rcc->buffer_size - diff) / rcc->buffer_size;
        br_compensation = x264_clip3f(br_compensation, .5, 2);

        q = rce->new_qscale / br_compensation;
        q = x264_clip3f(q, lmin, lmax);
        rcc->last_qscale = q;
        return q;
    }
834
835
836
837
838
839
840
841
842
}

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
843
    double cplxblur = h->param.rc.f_complexity_blur;
844
845
846
847
848
849
850
851
852
    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];
        all_const_bits += rce->mv_bits + rce->misc_bits;
853
854
855
856
        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;
        rcc->mv_bits_sum[rce->pict_type] += rce->mv_bits;
        rcc->frame_count[rce->pict_type] ++;
857
858
859
860
861
862
863
864
865
    }

    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
866
867
    for(i=0; i<rcc->num_entries; i++){
        ratecontrol_entry_t *rce = &rcc->entry[i];
868
        double weight_sum = 0;
Loren Merritt's avatar
Loren Merritt committed
869
        double cplx_sum = 0;
870
        double weight = 1.0;
Loren Merritt's avatar
Loren Merritt committed
871
872
        int j;
        /* weighted average of cplx of future frames */
873
        for(j=1; j<cplxblur*2 && j<rcc->num_entries-i; j++){
Loren Merritt's avatar
Loren Merritt committed
874
            ratecontrol_entry_t *rcj = &rcc->entry[i+j];
875
            weight *= 1 - pow( (float)rcj->i_count / rcc->nmb, 2 );
Loren Merritt's avatar
Loren Merritt committed
876
877
878
879
880
881
            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 */
882
883
        weight = 1.0;
        for(j=0; j<cplxblur*2 && j<=i; j++){
Loren Merritt's avatar
Loren Merritt committed
884
885
886
            ratecontrol_entry_t *rcj = &rcc->entry[i-j];
            weight_sum += weight;
            cplx_sum += weight * (rcj->i_tex_bits + rcj->p_tex_bits) * rce->qscale;
887
            weight *= 1 - pow( (float)rcj->i_count / rcc->nmb, 2 );
Loren Merritt's avatar
Loren Merritt committed
888
889
890
891
892
893
            if(weight < .0001)
                break;
        }
        rce->blurred_complexity = cplx_sum / weight_sum;
    }

894
895
896
897
898
899
    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
900
    expected_bits = 1;
901
902
903
904
905
    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
906
    for(step = 1E4 * step_mult; step > 1E-7 * step_mult; step *= 0.5){
907
908
909
        expected_bits = 0;
        rate_factor += step;

910
911
912
        rcc->last_non_b_pict_type = -1;
        rcc->last_accum_p_norm = 1;

913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
        /* 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];
                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;
937
                    if(rce->pict_type != rcc->entry[index].pict_type) continue;
938
939
940
941
942
943
944
945
946
947
948
                    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
949
            rce->new_qscale = clip_qscale(h, rce, blurred_qscale[i]);
950
951
952
953
954
955
956
            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;
        }

957
//printf("expected:%llu available:%llu factor:%lf avgQ:%lf\n", (uint64_t)expected_bits, all_available_bits, rate_factor);
958
959
960
961
962
963
964
        if(expected_bits > all_available_bits) rate_factor -= step;
    }

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

965
    if(fabs(expected_bits/all_available_bits - 1.0) > 0.01)
966
    {
967
968
        double avgq = 0;
        for(i=0; i<rcc->num_entries; i++)
Loren Merritt's avatar
Loren Merritt committed
969
970
            avgq += rcc->entry[i].new_qscale;
        avgq = qscale2qp(avgq / rcc->num_entries);
971
972
973
974
975
976
977

        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");
978
979
980
981
982
983
984
        return -1;
    }

    return 0;
}