git.sesse.net Git - ffmpeg/blob - libavcodec/ratecontrol.c

   1 /*
   2  * Rate control for video encoders
   3  *
   4  * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
   5  *
   6  * This file is part of FFmpeg.
   7  *
   8  * FFmpeg is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * FFmpeg is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with FFmpeg; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 /**
  24  * @file
  25  * Rate control for video encoders.
  26  */
  27
  28 #include "libavutil/intmath.h"
  29 #include "avcodec.h"
  30 #include "dsputil.h"
  31 #include "ratecontrol.h"
  32 #include "mpegvideo.h"
  33 #include "libavutil/eval.h"
  34
  35 #undef NDEBUG // Always check asserts, the speed effect is far too small to disable them.
  36 #include <assert.h>
  37
  38 #ifndef M_E
  39 #define M_E 2.718281828
  40 #endif
  41
  42 static int init_pass2(MpegEncContext *s);
  43 static double get_qscale(MpegEncContext *s, RateControlEntry *rce, double rate_factor, int frame_num);
  44
  45 void ff_write_pass1_stats(MpegEncContext *s){
  46     snprintf(s->avctx->stats_out, 256, "in:%d out:%d type:%d q:%d itex:%d ptex:%d mv:%d misc:%d fcode:%d bcode:%d mc-var:%d var:%d icount:%d skipcount:%d hbits:%d;\n",
  47              s->current_picture_ptr->f.display_picture_number, s->current_picture_ptr->f.coded_picture_number, s->pict_type,
  48              s->current_picture.f.quality, s->i_tex_bits, s->p_tex_bits, s->mv_bits, s->misc_bits,
  49              s->f_code, s->b_code, s->current_picture.mc_mb_var_sum, s->current_picture.mb_var_sum, s->i_count, s->skip_count, s->header_bits);
  50 }
  51
  52 static double get_fps(AVCodecContext *avctx){
  53     return 1.0 / av_q2d(avctx->time_base) / FFMAX(avctx->ticks_per_frame, 1);
  54 }
  55
  56 static inline double qp2bits(RateControlEntry *rce, double qp){
  57     if(qp<=0.0){
  58         av_log(NULL, AV_LOG_ERROR, "qp<=0.0\n");
  59     }
  60     return rce->qscale * (double)(rce->i_tex_bits + rce->p_tex_bits+1)/ qp;
  61 }
  62
  63 static inline double bits2qp(RateControlEntry *rce, double bits){
  64     if(bits<0.9){
  65         av_log(NULL, AV_LOG_ERROR, "bits<0.9\n");
  66     }
  67     return rce->qscale * (double)(rce->i_tex_bits + rce->p_tex_bits+1)/ bits;
  68 }
  69
  70 int ff_rate_control_init(MpegEncContext *s)
  71 {
  72     RateControlContext *rcc= &s->rc_context;
  73     int i, res;
  74     static const char * const const_names[]={
  75         "PI",
  76         "E",
  77         "iTex",
  78         "pTex",
  79         "tex",
  80         "mv",
  81         "fCode",
  82         "iCount",
  83         "mcVar",
  84         "var",
  85         "isI",
  86         "isP",
  87         "isB",
  88         "avgQP",
  89         "qComp",
  90 /*        "lastIQP",
  91         "lastPQP",
  92         "lastBQP",
  93         "nextNonBQP",*/
  94         "avgIITex",
  95         "avgPITex",
  96         "avgPPTex",
  97         "avgBPTex",
  98         "avgTex",
  99         NULL
 100     };
 101     static double (* const func1[])(void *, double)={
 102         (void *)bits2qp,
 103         (void *)qp2bits,
 104         NULL
 105     };
 106     static const char * const func1_names[]={
 107         "bits2qp",
 108         "qp2bits",
 109         NULL
 110     };
 111     emms_c();
 112
 113     if (!s->avctx->rc_max_available_vbv_use && s->avctx->rc_buffer_size) {
 114         if (s->avctx->rc_max_rate) {
 115             s->avctx->rc_max_available_vbv_use = av_clipf(s->avctx->rc_max_rate/(s->avctx->rc_buffer_size*get_fps(s->avctx)), 1.0/3, 1.0);
 116         } else
 117             s->avctx->rc_max_available_vbv_use = 1.0;
 118     }
 119
 120     res = av_expr_parse(&rcc->rc_eq_eval, s->avctx->rc_eq ? s->avctx->rc_eq : "tex^qComp", const_names, func1_names, func1, NULL, NULL, 0, s->avctx);
 121     if (res < 0) {
 122         av_log(s->avctx, AV_LOG_ERROR, "Error parsing rc_eq \"%s\"\n", s->avctx->rc_eq);
 123         return res;
 124     }
 125
 126     for(i=0; i<5; i++){
 127         rcc->pred[i].coeff= FF_QP2LAMBDA * 7.0;
 128         rcc->pred[i].count= 1.0;
 129
 130         rcc->pred[i].decay= 0.4;
 131         rcc->i_cplx_sum [i]=
 132         rcc->p_cplx_sum [i]=
 133         rcc->mv_bits_sum[i]=
 134         rcc->qscale_sum [i]=
 135         rcc->frame_count[i]= 1; // 1 is better because of 1/0 and such
 136         rcc->last_qscale_for[i]=FF_QP2LAMBDA * 5;
 137     }
 138     rcc->buffer_index= s->avctx->rc_initial_buffer_occupancy;
 139     if (!rcc->buffer_index)
 140         rcc->buffer_index = s->avctx->rc_buffer_size * 3 / 4;
 141
 142     if(s->flags&CODEC_FLAG_PASS2){
 143         int i;
 144         char *p;
 145
 146         /* find number of pics */
 147         p= s->avctx->stats_in;
 148         for(i=-1; p; i++){
 149             p= strchr(p+1, ';');
 150         }
 151         i+= s->max_b_frames;
 152         if(i<=0 || i>=INT_MAX / sizeof(RateControlEntry))
 153             return -1;
 154         rcc->entry = av_mallocz(i*sizeof(RateControlEntry));
 155         rcc->num_entries= i;
 156
 157         /* init all to skipped p frames (with b frames we might have a not encoded frame at the end FIXME) */
 158         for(i=0; i<rcc->num_entries; i++){
 159             RateControlEntry *rce= &rcc->entry[i];
 160             rce->pict_type= rce->new_pict_type=AV_PICTURE_TYPE_P;
 161             rce->qscale= rce->new_qscale=FF_QP2LAMBDA * 2;
 162             rce->misc_bits= s->mb_num + 10;
 163             rce->mb_var_sum= s->mb_num*100;
 164         }
 165
 166         /* read stats */
 167         p= s->avctx->stats_in;
 168         for(i=0; i<rcc->num_entries - s->max_b_frames; i++){
 169             RateControlEntry *rce;
 170             int picture_number;
 171             int e;
 172             char *next;
 173
 174             next= strchr(p, ';');
 175             if(next){
 176                 (*next)=0; //sscanf in unbelievably slow on looong strings //FIXME copy / do not write
 177                 next++;
 178             }
 179             e= sscanf(p, " in:%d ", &picture_number);
 180
 181             assert(picture_number >= 0);
 182             assert(picture_number < rcc->num_entries);
 183             rce= &rcc->entry[picture_number];
 184
 185             e+=sscanf(p, " in:%*d out:%*d type:%d q:%f itex:%d ptex:%d mv:%d misc:%d fcode:%d bcode:%d mc-var:%d var:%d icount:%d skipcount:%d hbits:%d",
 186                    &rce->pict_type, &rce->qscale, &rce->i_tex_bits, &rce->p_tex_bits, &rce->mv_bits, &rce->misc_bits,
 187                    &rce->f_code, &rce->b_code, &rce->mc_mb_var_sum, &rce->mb_var_sum, &rce->i_count, &rce->skip_count, &rce->header_bits);
 188             if(e!=14){
 189                 av_log(s->avctx, AV_LOG_ERROR, "statistics are damaged at line %d, parser out=%d\n", i, e);
 190                 return -1;
 191             }
 192
 193             p= next;
 194         }
 195
 196         if(init_pass2(s) < 0) return -1;
 197
 198         //FIXME maybe move to end
 199         if((s->flags&CODEC_FLAG_PASS2) && s->avctx->rc_strategy == FF_RC_STRATEGY_XVID) {
 200 #if CONFIG_LIBXVID
 201             return ff_xvid_rate_control_init(s);
 202 #else
 203             av_log(s->avctx, AV_LOG_ERROR, "Xvid ratecontrol requires libavcodec compiled with Xvid support.\n");
 204             return -1;
 205 #endif
 206         }
 207     }
 208
 209     if(!(s->flags&CODEC_FLAG_PASS2)){
 210
 211         rcc->short_term_qsum=0.001;
 212         rcc->short_term_qcount=0.001;
 213
 214         rcc->pass1_rc_eq_output_sum= 0.001;
 215         rcc->pass1_wanted_bits=0.001;
 216
 217         if(s->avctx->qblur > 1.0){
 218             av_log(s->avctx, AV_LOG_ERROR, "qblur too large\n");
 219             return -1;
 220         }
 221         /* init stuff with the user specified complexity */
 222         if(s->avctx->rc_initial_cplx){
 223             for(i=0; i<60*30; i++){
 224                 double bits= s->avctx->rc_initial_cplx * (i/10000.0 + 1.0)*s->mb_num;
 225                 RateControlEntry rce;
 226
 227                 if     (i%((s->gop_size+3)/4)==0) rce.pict_type= AV_PICTURE_TYPE_I;
 228                 else if(i%(s->max_b_frames+1))    rce.pict_type= AV_PICTURE_TYPE_B;
 229                 else                              rce.pict_type= AV_PICTURE_TYPE_P;
 230
 231                 rce.new_pict_type= rce.pict_type;
 232                 rce.mc_mb_var_sum= bits*s->mb_num/100000;
 233                 rce.mb_var_sum   = s->mb_num;
 234                 rce.qscale   = FF_QP2LAMBDA * 2;
 235                 rce.f_code   = 2;
 236                 rce.b_code   = 1;
 237                 rce.misc_bits= 1;
 238
 239                 if(s->pict_type== AV_PICTURE_TYPE_I){
 240                     rce.i_count   = s->mb_num;
 241                     rce.i_tex_bits= bits;
 242                     rce.p_tex_bits= 0;
 243                     rce.mv_bits= 0;
 244                 }else{
 245                     rce.i_count   = 0; //FIXME we do know this approx
 246                     rce.i_tex_bits= 0;
 247                     rce.p_tex_bits= bits*0.9;
 248                     rce.mv_bits= bits*0.1;
 249                 }
 250                 rcc->i_cplx_sum [rce.pict_type] += rce.i_tex_bits*rce.qscale;
 251                 rcc->p_cplx_sum [rce.pict_type] += rce.p_tex_bits*rce.qscale;
 252                 rcc->mv_bits_sum[rce.pict_type] += rce.mv_bits;
 253                 rcc->frame_count[rce.pict_type] ++;
 254
 255                 get_qscale(s, &rce, rcc->pass1_wanted_bits/rcc->pass1_rc_eq_output_sum, i);
 256                 rcc->pass1_wanted_bits+= s->bit_rate/get_fps(s->avctx); //FIXME misbehaves a little for variable fps
 257             }
 258         }
 259
 260     }
 261
 262     return 0;
 263 }
 264
 265 void ff_rate_control_uninit(MpegEncContext *s)
 266 {
 267     RateControlContext *rcc= &s->rc_context;
 268     emms_c();
 269
 270     av_expr_free(rcc->rc_eq_eval);
 271     av_freep(&rcc->entry);
 272
 273 #if CONFIG_LIBXVID
 274     if((s->flags&CODEC_FLAG_PASS2) && s->avctx->rc_strategy == FF_RC_STRATEGY_XVID)
 275         ff_xvid_rate_control_uninit(s);
 276 #endif
 277 }
 278
 279 int ff_vbv_update(MpegEncContext *s, int frame_size){
 280     RateControlContext *rcc= &s->rc_context;
 281     const double fps= get_fps(s->avctx);
 282     const int buffer_size= s->avctx->rc_buffer_size;
 283     const double min_rate= s->avctx->rc_min_rate/fps;
 284     const double max_rate= s->avctx->rc_max_rate/fps;
 285
 286     av_dlog(s, "%d %f %d %f %f\n",
 287             buffer_size, rcc->buffer_index, frame_size, min_rate, max_rate);
 288     if(buffer_size){
 289         int left;
 290
 291         rcc->buffer_index-= frame_size;
 292         if(rcc->buffer_index < 0){
 293             av_log(s->avctx, AV_LOG_ERROR, "rc buffer underflow\n");
 294             rcc->buffer_index= 0;
 295         }
 296
 297         left= buffer_size - rcc->buffer_index - 1;
 298         rcc->buffer_index += av_clip(left, min_rate, max_rate);
 299
 300         if(rcc->buffer_index > buffer_size){
 301             int stuffing= ceil((rcc->buffer_index - buffer_size)/8);
 302
 303             if(stuffing < 4 && s->codec_id == AV_CODEC_ID_MPEG4)
 304                 stuffing=4;
 305             rcc->buffer_index -= 8*stuffing;
 306
 307             if(s->avctx->debug & FF_DEBUG_RC)
 308                 av_log(s->avctx, AV_LOG_DEBUG, "stuffing %d bytes\n", stuffing);
 309
 310             return stuffing;
 311         }
 312     }
 313     return 0;
 314 }
 315
 316 /**
 317  * Modify the bitrate curve from pass1 for one frame.
 318  */
 319 static double get_qscale(MpegEncContext *s, RateControlEntry *rce, double rate_factor, int frame_num){
 320     RateControlContext *rcc= &s->rc_context;
 321     AVCodecContext *a= s->avctx;
 322     double q, bits;
 323     const int pict_type= rce->new_pict_type;
 324     const double mb_num= s->mb_num;
 325     int i;
 326
 327     double const_values[]={
 328         M_PI,
 329         M_E,
 330         rce->i_tex_bits*rce->qscale,
 331         rce->p_tex_bits*rce->qscale,
 332         (rce->i_tex_bits + rce->p_tex_bits)*(double)rce->qscale,
 333         rce->mv_bits/mb_num,
 334         rce->pict_type == AV_PICTURE_TYPE_B ? (rce->f_code + rce->b_code)*0.5 : rce->f_code,
 335         rce->i_count/mb_num,
 336         rce->mc_mb_var_sum/mb_num,
 337         rce->mb_var_sum/mb_num,
 338         rce->pict_type == AV_PICTURE_TYPE_I,
 339         rce->pict_type == AV_PICTURE_TYPE_P,
 340         rce->pict_type == AV_PICTURE_TYPE_B,
 341         rcc->qscale_sum[pict_type] / (double)rcc->frame_count[pict_type],
 342         a->qcompress,
 343 /*        rcc->last_qscale_for[AV_PICTURE_TYPE_I],
 344         rcc->last_qscale_for[AV_PICTURE_TYPE_P],
 345         rcc->last_qscale_for[AV_PICTURE_TYPE_B],
 346         rcc->next_non_b_qscale,*/
 347         rcc->i_cplx_sum[AV_PICTURE_TYPE_I] / (double)rcc->frame_count[AV_PICTURE_TYPE_I],
 348         rcc->i_cplx_sum[AV_PICTURE_TYPE_P] / (double)rcc->frame_count[AV_PICTURE_TYPE_P],
 349         rcc->p_cplx_sum[AV_PICTURE_TYPE_P] / (double)rcc->frame_count[AV_PICTURE_TYPE_P],
 350         rcc->p_cplx_sum[AV_PICTURE_TYPE_B] / (double)rcc->frame_count[AV_PICTURE_TYPE_B],
 351         (rcc->i_cplx_sum[pict_type] + rcc->p_cplx_sum[pict_type]) / (double)rcc->frame_count[pict_type],
 352         0
 353     };
 354
 355     bits = av_expr_eval(rcc->rc_eq_eval, const_values, rce);
 356     if (isnan(bits)) {
 357         av_log(s->avctx, AV_LOG_ERROR, "Error evaluating rc_eq \"%s\"\n", s->avctx->rc_eq);
 358         return -1;
 359     }
 360
 361     rcc->pass1_rc_eq_output_sum+= bits;
 362     bits*=rate_factor;
 363     if(bits<0.0) bits=0.0;
 364     bits+= 1.0; //avoid 1/0 issues
 365
 366     /* user override */
 367     for(i=0; i<s->avctx->rc_override_count; i++){
 368         RcOverride *rco= s->avctx->rc_override;
 369         if(rco[i].start_frame > frame_num) continue;
 370         if(rco[i].end_frame   < frame_num) continue;
 371
 372         if(rco[i].qscale)
 373             bits= qp2bits(rce, rco[i].qscale); //FIXME move at end to really force it?
 374         else
 375             bits*= rco[i].quality_factor;
 376     }
 377
 378     q= bits2qp(rce, bits);
 379
 380     /* I/B difference */
 381     if     (pict_type==AV_PICTURE_TYPE_I && s->avctx->i_quant_factor<0.0)
 382         q= -q*s->avctx->i_quant_factor + s->avctx->i_quant_offset;
 383     else if(pict_type==AV_PICTURE_TYPE_B && s->avctx->b_quant_factor<0.0)
 384         q= -q*s->avctx->b_quant_factor + s->avctx->b_quant_offset;
 385     if(q<1) q=1;
 386
 387     return q;
 388 }
 389
 390 static double get_diff_limited_q(MpegEncContext *s, RateControlEntry *rce, double q){
 391     RateControlContext *rcc= &s->rc_context;
 392     AVCodecContext *a= s->avctx;
 393     const int pict_type= rce->new_pict_type;
 394     const double last_p_q    = rcc->last_qscale_for[AV_PICTURE_TYPE_P];
 395     const double last_non_b_q= rcc->last_qscale_for[rcc->last_non_b_pict_type];
 396
 397     if     (pict_type==AV_PICTURE_TYPE_I && (a->i_quant_factor>0.0 || rcc->last_non_b_pict_type==AV_PICTURE_TYPE_P))
 398         q= last_p_q    *FFABS(a->i_quant_factor) + a->i_quant_offset;
 399     else if(pict_type==AV_PICTURE_TYPE_B && a->b_quant_factor>0.0)
 400         q= last_non_b_q*    a->b_quant_factor  + a->b_quant_offset;
 401     if(q<1) q=1;
 402
 403     /* last qscale / qdiff stuff */
 404     if(rcc->last_non_b_pict_type==pict_type || pict_type!=AV_PICTURE_TYPE_I){
 405         double last_q= rcc->last_qscale_for[pict_type];
 406         const int maxdiff= FF_QP2LAMBDA * a->max_qdiff;
 407
 408         if     (q > last_q + maxdiff) q= last_q + maxdiff;
 409         else if(q < last_q - maxdiff) q= last_q - maxdiff;
 410     }
 411
 412     rcc->last_qscale_for[pict_type]= q; //Note we cannot do that after blurring
 413
 414     if(pict_type!=AV_PICTURE_TYPE_B)
 415         rcc->last_non_b_pict_type= pict_type;
 416
 417     return q;
 418 }
 419
 420 /**
 421  * Get the qmin & qmax for pict_type.
 422  */
 423 static void get_qminmax(int *qmin_ret, int *qmax_ret, MpegEncContext *s, int pict_type){
 424     int qmin= s->avctx->lmin;
 425     int qmax= s->avctx->lmax;
 426
 427     assert(qmin <= qmax);
 428
 429     if(pict_type==AV_PICTURE_TYPE_B){
 430         qmin= (int)(qmin*FFABS(s->avctx->b_quant_factor)+s->avctx->b_quant_offset + 0.5);
 431         qmax= (int)(qmax*FFABS(s->avctx->b_quant_factor)+s->avctx->b_quant_offset + 0.5);
 432     }else if(pict_type==AV_PICTURE_TYPE_I){
 433         qmin= (int)(qmin*FFABS(s->avctx->i_quant_factor)+s->avctx->i_quant_offset + 0.5);
 434         qmax= (int)(qmax*FFABS(s->avctx->i_quant_factor)+s->avctx->i_quant_offset + 0.5);
 435     }
 436
 437     qmin= av_clip(qmin, 1, FF_LAMBDA_MAX);
 438     qmax= av_clip(qmax, 1, FF_LAMBDA_MAX);
 439
 440     if(qmax<qmin) qmax= qmin;
 441
 442     *qmin_ret= qmin;
 443     *qmax_ret= qmax;
 444 }
 445
 446 static double modify_qscale(MpegEncContext *s, RateControlEntry *rce, double q, int frame_num){
 447     RateControlContext *rcc= &s->rc_context;
 448     int qmin, qmax;
 449     const int pict_type= rce->new_pict_type;
 450     const double buffer_size= s->avctx->rc_buffer_size;
 451     const double fps= get_fps(s->avctx);
 452     const double min_rate= s->avctx->rc_min_rate / fps;
 453     const double max_rate= s->avctx->rc_max_rate / fps;
 454
 455     get_qminmax(&qmin, &qmax, s, pict_type);
 456
 457     /* modulation */
 458     if(s->avctx->rc_qmod_freq && frame_num%s->avctx->rc_qmod_freq==0 && pict_type==AV_PICTURE_TYPE_P)
 459         q*= s->avctx->rc_qmod_amp;
 460
 461     /* buffer overflow/underflow protection */
 462     if(buffer_size){
 463         double expected_size= rcc->buffer_index;
 464         double q_limit;
 465
 466         if(min_rate){
 467             double d= 2*(buffer_size - expected_size)/buffer_size;
 468             if(d>1.0) d=1.0;
 469             else if(d<0.0001) d=0.0001;
 470             q*= pow(d, 1.0/s->avctx->rc_buffer_aggressivity);
 471
 472             q_limit= bits2qp(rce, FFMAX((min_rate - buffer_size + rcc->buffer_index) * s->avctx->rc_min_vbv_overflow_use, 1));
 473             if(q > q_limit){
 474                 if(s->avctx->debug&FF_DEBUG_RC){
 475                     av_log(s->avctx, AV_LOG_DEBUG, "limiting QP %f -> %f\n", q, q_limit);
 476                 }
 477                 q= q_limit;
 478             }
 479         }
 480
 481         if(max_rate){
 482             double d= 2*expected_size/buffer_size;
 483             if(d>1.0) d=1.0;
 484             else if(d<0.0001) d=0.0001;
 485             q/= pow(d, 1.0/s->avctx->rc_buffer_aggressivity);
 486
 487             q_limit= bits2qp(rce, FFMAX(rcc->buffer_index * s->avctx->rc_max_available_vbv_use, 1));
 488             if(q < q_limit){
 489                 if(s->avctx->debug&FF_DEBUG_RC){
 490                     av_log(s->avctx, AV_LOG_DEBUG, "limiting QP %f -> %f\n", q, q_limit);
 491                 }
 492                 q= q_limit;
 493             }
 494         }
 495     }
 496     av_dlog(s, "q:%f max:%f min:%f size:%f index:%f agr:%f\n",
 497             q, max_rate, min_rate, buffer_size, rcc->buffer_index,
 498             s->avctx->rc_buffer_aggressivity);
 499     if(s->avctx->rc_qsquish==0.0 || qmin==qmax){
 500         if     (q<qmin) q=qmin;
 501         else if(q>qmax) q=qmax;
 502     }else{
 503         double min2= log(qmin);
 504         double max2= log(qmax);
 505
 506         q= log(q);
 507         q= (q - min2)/(max2-min2) - 0.5;
 508         q*= -4.0;
 509         q= 1.0/(1.0 + exp(q));
 510         q= q*(max2-min2) + min2;
 511
 512         q= exp(q);
 513     }
 514
 515     return q;
 516 }
 517
 518 //----------------------------------
 519 // 1 Pass Code
 520
 521 static double predict_size(Predictor *p, double q, double var)
 522 {
 523      return p->coeff*var / (q*p->count);
 524 }
 525
 526 static void update_predictor(Predictor *p, double q, double var, double size)
 527 {
 528     double new_coeff= size*q / (var + 1);
 529     if(var<10) return;
 530
 531     p->count*= p->decay;
 532     p->coeff*= p->decay;
 533     p->count++;
 534     p->coeff+= new_coeff;
 535 }
 536
 537 static void adaptive_quantization(MpegEncContext *s, double q){
 538     int i;
 539     const float lumi_masking= s->avctx->lumi_masking / (128.0*128.0);
 540     const float dark_masking= s->avctx->dark_masking / (128.0*128.0);
 541     const float temp_cplx_masking= s->avctx->temporal_cplx_masking;
 542     const float spatial_cplx_masking = s->avctx->spatial_cplx_masking;
 543     const float p_masking = s->avctx->p_masking;
 544     const float border_masking = s->avctx->border_masking;
 545     float bits_sum= 0.0;
 546     float cplx_sum= 0.0;
 547     float *cplx_tab = s->cplx_tab;
 548     float *bits_tab = s->bits_tab;
 549     const int qmin= s->avctx->mb_lmin;
 550     const int qmax= s->avctx->mb_lmax;
 551     Picture * const pic= &s->current_picture;
 552     const int mb_width = s->mb_width;
 553     const int mb_height = s->mb_height;
 554
 555     for(i=0; i<s->mb_num; i++){
 556         const int mb_xy= s->mb_index2xy[i];
 557         float temp_cplx= sqrt(pic->mc_mb_var[mb_xy]); //FIXME merge in pow()
 558         float spat_cplx= sqrt(pic->mb_var[mb_xy]);
 559         const int lumi= pic->mb_mean[mb_xy];
 560         float bits, cplx, factor;
 561         int mb_x = mb_xy % s->mb_stride;
 562         int mb_y = mb_xy / s->mb_stride;
 563         int mb_distance;
 564         float mb_factor = 0.0;
 565         if(spat_cplx < 4) spat_cplx= 4; //FIXME finetune
 566         if(temp_cplx < 4) temp_cplx= 4; //FIXME finetune
 567
 568         if((s->mb_type[mb_xy]&CANDIDATE_MB_TYPE_INTRA)){//FIXME hq mode
 569             cplx= spat_cplx;
 570             factor= 1.0 + p_masking;
 571         }else{
 572             cplx= temp_cplx;
 573             factor= pow(temp_cplx, - temp_cplx_masking);
 574         }
 575         factor*=pow(spat_cplx, - spatial_cplx_masking);
 576
 577         if(lumi>127)
 578             factor*= (1.0 - (lumi-128)*(lumi-128)*lumi_masking);
 579         else
 580             factor*= (1.0 - (lumi-128)*(lumi-128)*dark_masking);
 581
 582         if(mb_x < mb_width/5){
 583             mb_distance = mb_width/5 - mb_x;
 584             mb_factor = (float)mb_distance / (float)(mb_width/5);
 585         }else if(mb_x > 4*mb_width/5){
 586             mb_distance = mb_x - 4*mb_width/5;
 587             mb_factor = (float)mb_distance / (float)(mb_width/5);
 588         }
 589         if(mb_y < mb_height/5){
 590             mb_distance = mb_height/5 - mb_y;
 591             mb_factor = FFMAX(mb_factor, (float)mb_distance / (float)(mb_height/5));
 592         }else if(mb_y > 4*mb_height/5){
 593             mb_distance = mb_y - 4*mb_height/5;
 594             mb_factor = FFMAX(mb_factor, (float)mb_distance / (float)(mb_height/5));
 595         }
 596
 597         factor*= 1.0 - border_masking*mb_factor;
 598
 599         if(factor<0.00001) factor= 0.00001;
 600
 601         bits= cplx*factor;
 602         cplx_sum+= cplx;
 603         bits_sum+= bits;
 604         cplx_tab[i]= cplx;
 605         bits_tab[i]= bits;
 606     }
 607
 608     /* handle qmin/qmax clipping */
 609     if(s->flags&CODEC_FLAG_NORMALIZE_AQP){
 610         float factor= bits_sum/cplx_sum;
 611         for(i=0; i<s->mb_num; i++){
 612             float newq= q*cplx_tab[i]/bits_tab[i];
 613             newq*= factor;
 614
 615             if     (newq > qmax){
 616                 bits_sum -= bits_tab[i];
 617                 cplx_sum -= cplx_tab[i]*q/qmax;
 618             }
 619             else if(newq < qmin){
 620                 bits_sum -= bits_tab[i];
 621                 cplx_sum -= cplx_tab[i]*q/qmin;
 622             }
 623         }
 624         if(bits_sum < 0.001) bits_sum= 0.001;
 625         if(cplx_sum < 0.001) cplx_sum= 0.001;
 626     }
 627
 628     for(i=0; i<s->mb_num; i++){
 629         const int mb_xy= s->mb_index2xy[i];
 630         float newq= q*cplx_tab[i]/bits_tab[i];
 631         int intq;
 632
 633         if(s->flags&CODEC_FLAG_NORMALIZE_AQP){
 634             newq*= bits_sum/cplx_sum;
 635         }
 636
 637         intq= (int)(newq + 0.5);
 638
 639         if     (intq > qmax) intq= qmax;
 640         else if(intq < qmin) intq= qmin;
 641         s->lambda_table[mb_xy]= intq;
 642     }
 643 }
 644
 645 void ff_get_2pass_fcode(MpegEncContext *s){
 646     RateControlContext *rcc= &s->rc_context;
 647     int picture_number= s->picture_number;
 648     RateControlEntry *rce;
 649
 650     rce= &rcc->entry[picture_number];
 651     s->f_code= rce->f_code;
 652     s->b_code= rce->b_code;
 653 }
 654
 655 //FIXME rd or at least approx for dquant
 656
 657 float ff_rate_estimate_qscale(MpegEncContext *s, int dry_run)
 658 {
 659     float q;
 660     int qmin, qmax;
 661     float br_compensation;
 662     double diff;
 663     double short_term_q;
 664     double fps;
 665     int picture_number= s->picture_number;
 666     int64_t wanted_bits;
 667     RateControlContext *rcc= &s->rc_context;
 668     AVCodecContext *a= s->avctx;
 669     RateControlEntry local_rce, *rce;
 670     double bits;
 671     double rate_factor;
 672     int var;
 673     const int pict_type= s->pict_type;
 674     Picture * const pic= &s->current_picture;
 675     emms_c();
 676
 677 #if CONFIG_LIBXVID
 678     if((s->flags&CODEC_FLAG_PASS2) && s->avctx->rc_strategy == FF_RC_STRATEGY_XVID)
 679         return ff_xvid_rate_estimate_qscale(s, dry_run);
 680 #endif
 681
 682     get_qminmax(&qmin, &qmax, s, pict_type);
 683
 684     fps= get_fps(s->avctx);
 685         /* update predictors */
 686     if(picture_number>2 && !dry_run){
 687         const int last_var= s->last_pict_type == AV_PICTURE_TYPE_I ? rcc->last_mb_var_sum : rcc->last_mc_mb_var_sum;
 688         av_assert1(s->frame_bits >= s->stuffing_bits);
 689         update_predictor(&rcc->pred[s->last_pict_type], rcc->last_qscale, sqrt(last_var), s->frame_bits - s->stuffing_bits);
 690     }
 691
 692     if(s->flags&CODEC_FLAG_PASS2){
 693         assert(picture_number>=0);
 694         if(picture_number >= rcc->num_entries) {
 695             av_log(s, AV_LOG_ERROR, "Input is longer than 2-pass log file\n");
 696             return -1;
 697         }
 698         rce= &rcc->entry[picture_number];
 699         wanted_bits= rce->expected_bits;
 700     }else{
 701         Picture *dts_pic;
 702         rce= &local_rce;
 703
 704         //FIXME add a dts field to AVFrame and ensure its set and use it here instead of reordering
 705         //but the reordering is simpler for now until h.264 b pyramid must be handeld
 706         if(s->pict_type == AV_PICTURE_TYPE_B || s->low_delay)
 707             dts_pic= s->current_picture_ptr;
 708         else
 709             dts_pic= s->last_picture_ptr;
 710
 711         if (!dts_pic || dts_pic->f.pts == AV_NOPTS_VALUE)
 712             wanted_bits= (uint64_t)(s->bit_rate*(double)picture_number/fps);
 713         else
 714             wanted_bits = (uint64_t)(s->bit_rate*(double)dts_pic->f.pts / fps);
 715     }
 716
 717     diff= s->total_bits - wanted_bits;
 718     br_compensation= (a->bit_rate_tolerance - diff)/a->bit_rate_tolerance;
 719     if(br_compensation<=0.0) br_compensation=0.001;
 720
 721     var= pict_type == AV_PICTURE_TYPE_I ? pic->mb_var_sum : pic->mc_mb_var_sum;
 722
 723     short_term_q = 0; /* avoid warning */
 724     if(s->flags&CODEC_FLAG_PASS2){
 725         if(pict_type!=AV_PICTURE_TYPE_I)
 726             assert(pict_type == rce->new_pict_type);
 727
 728         q= rce->new_qscale / br_compensation;
 729         av_dlog(s, "%f %f %f last:%d var:%d type:%d//\n", q, rce->new_qscale,
 730                 br_compensation, s->frame_bits, var, pict_type);
 731     }else{
 732         rce->pict_type=
 733         rce->new_pict_type= pict_type;
 734         rce->mc_mb_var_sum= pic->mc_mb_var_sum;
 735         rce->mb_var_sum   = pic->   mb_var_sum;
 736         rce->qscale   = FF_QP2LAMBDA * 2;
 737         rce->f_code   = s->f_code;
 738         rce->b_code   = s->b_code;
 739         rce->misc_bits= 1;
 740
 741         bits= predict_size(&rcc->pred[pict_type], rce->qscale, sqrt(var));
 742         if(pict_type== AV_PICTURE_TYPE_I){
 743             rce->i_count   = s->mb_num;
 744             rce->i_tex_bits= bits;
 745             rce->p_tex_bits= 0;
 746             rce->mv_bits= 0;
 747         }else{
 748             rce->i_count   = 0; //FIXME we do know this approx
 749             rce->i_tex_bits= 0;
 750             rce->p_tex_bits= bits*0.9;
 751
 752             rce->mv_bits= bits*0.1;
 753         }
 754         rcc->i_cplx_sum [pict_type] += rce->i_tex_bits*rce->qscale;
 755         rcc->p_cplx_sum [pict_type] += rce->p_tex_bits*rce->qscale;
 756         rcc->mv_bits_sum[pict_type] += rce->mv_bits;
 757         rcc->frame_count[pict_type] ++;
 758
 759         bits= rce->i_tex_bits + rce->p_tex_bits;
 760         rate_factor= rcc->pass1_wanted_bits/rcc->pass1_rc_eq_output_sum * br_compensation;
 761
 762         q= get_qscale(s, rce, rate_factor, picture_number);
 763         if (q < 0)
 764             return -1;
 765
 766         assert(q>0.0);
 767         q= get_diff_limited_q(s, rce, q);
 768         assert(q>0.0);
 769
 770         if(pict_type==AV_PICTURE_TYPE_P || s->intra_only){ //FIXME type dependent blur like in 2-pass
 771             rcc->short_term_qsum*=a->qblur;
 772             rcc->short_term_qcount*=a->qblur;
 773
 774             rcc->short_term_qsum+= q;
 775             rcc->short_term_qcount++;
 776             q= short_term_q= rcc->short_term_qsum/rcc->short_term_qcount;
 777         }
 778         assert(q>0.0);
 779
 780         q= modify_qscale(s, rce, q, picture_number);
 781
 782         rcc->pass1_wanted_bits+= s->bit_rate/fps;
 783
 784         assert(q>0.0);
 785     }
 786
 787     if(s->avctx->debug&FF_DEBUG_RC){
 788         av_log(s->avctx, AV_LOG_DEBUG, "%c qp:%d<%2.1f<%d %d want:%d total:%d comp:%f st_q:%2.2f size:%d var:%d/%d br:%d fps:%d\n",
 789         av_get_picture_type_char(pict_type), qmin, q, qmax, picture_number, (int)wanted_bits/1000, (int)s->total_bits/1000,
 790         br_compensation, short_term_q, s->frame_bits, pic->mb_var_sum, pic->mc_mb_var_sum, s->bit_rate/1000, (int)fps
 791         );
 792     }
 793
 794     if     (q<qmin) q=qmin;
 795     else if(q>qmax) q=qmax;
 796
 797     if(s->adaptive_quant)
 798         adaptive_quantization(s, q);
 799     else
 800         q= (int)(q + 0.5);
 801
 802     if(!dry_run){
 803         rcc->last_qscale= q;
 804         rcc->last_mc_mb_var_sum= pic->mc_mb_var_sum;
 805         rcc->last_mb_var_sum= pic->mb_var_sum;
 806     }
 807     return q;
 808 }
 809
 810 //----------------------------------------------
 811 // 2-Pass code
 812
 813 static int init_pass2(MpegEncContext *s)
 814 {
 815     RateControlContext *rcc= &s->rc_context;
 816     AVCodecContext *a= s->avctx;
 817     int i, toobig;
 818     double fps= get_fps(s->avctx);
 819     double complexity[5]={0,0,0,0,0};   // aproximate bits at quant=1
 820     uint64_t const_bits[5]={0,0,0,0,0}; // quantizer independent bits
 821     uint64_t all_const_bits;
 822     uint64_t all_available_bits= (uint64_t)(s->bit_rate*(double)rcc->num_entries/fps);
 823     double rate_factor=0;
 824     double step;
 825     //int last_i_frame=-10000000;
 826     const int filter_size= (int)(a->qblur*4) | 1;
 827     double expected_bits;
 828     double *qscale, *blurred_qscale, qscale_sum;
 829
 830     /* find complexity & const_bits & decide the pict_types */
 831     for(i=0; i<rcc->num_entries; i++){
 832         RateControlEntry *rce= &rcc->entry[i];
 833
 834         rce->new_pict_type= rce->pict_type;
 835         rcc->i_cplx_sum [rce->pict_type] += rce->i_tex_bits*rce->qscale;
 836         rcc->p_cplx_sum [rce->pict_type] += rce->p_tex_bits*rce->qscale;
 837         rcc->mv_bits_sum[rce->pict_type] += rce->mv_bits;
 838         rcc->frame_count[rce->pict_type] ++;
 839
 840         complexity[rce->new_pict_type]+= (rce->i_tex_bits+ rce->p_tex_bits)*(double)rce->qscale;
 841         const_bits[rce->new_pict_type]+= rce->mv_bits + rce->misc_bits;
 842     }
 843     all_const_bits= const_bits[AV_PICTURE_TYPE_I] + const_bits[AV_PICTURE_TYPE_P] + const_bits[AV_PICTURE_TYPE_B];
 844
 845     if(all_available_bits < all_const_bits){
 846         av_log(s->avctx, AV_LOG_ERROR, "requested bitrate is too low\n");
 847         return -1;
 848     }
 849
 850     qscale= av_malloc(sizeof(double)*rcc->num_entries);
 851     blurred_qscale= av_malloc(sizeof(double)*rcc->num_entries);
 852     toobig = 0;
 853
 854     for(step=256*256; step>0.0000001; step*=0.5){
 855         expected_bits=0;
 856         rate_factor+= step;
 857
 858         rcc->buffer_index= s->avctx->rc_buffer_size/2;
 859
 860         /* find qscale */
 861         for(i=0; i<rcc->num_entries; i++){
 862             RateControlEntry *rce= &rcc->entry[i];
 863             qscale[i]= get_qscale(s, &rcc->entry[i], rate_factor, i);
 864             rcc->last_qscale_for[rce->pict_type] = qscale[i];
 865         }
 866         assert(filter_size%2==1);
 867
 868         /* fixed I/B QP relative to P mode */
 869         for(i=FFMAX(0, rcc->num_entries-300); i<rcc->num_entries; i++){
 870             RateControlEntry *rce= &rcc->entry[i];
 871
 872             qscale[i]= get_diff_limited_q(s, rce, qscale[i]);
 873         }
 874
 875         for(i=rcc->num_entries-1; i>=0; i--){
 876             RateControlEntry *rce= &rcc->entry[i];
 877
 878             qscale[i]= get_diff_limited_q(s, rce, qscale[i]);
 879         }
 880
 881         /* smooth curve */
 882         for(i=0; i<rcc->num_entries; i++){
 883             RateControlEntry *rce= &rcc->entry[i];
 884             const int pict_type= rce->new_pict_type;
 885             int j;
 886             double q=0.0, sum=0.0;
 887
 888             for(j=0; j<filter_size; j++){
 889                 int index= i+j-filter_size/2;
 890                 double d= index-i;
 891                 double coeff= a->qblur==0 ? 1.0 : exp(-d*d/(a->qblur * a->qblur));
 892
 893                 if(index < 0 || index >= rcc->num_entries) continue;
 894                 if(pict_type != rcc->entry[index].new_pict_type) continue;
 895                 q+= qscale[index] * coeff;
 896                 sum+= coeff;
 897             }
 898             blurred_qscale[i]= q/sum;
 899         }
 900
 901         /* find expected bits */
 902         for(i=0; i<rcc->num_entries; i++){
 903             RateControlEntry *rce= &rcc->entry[i];
 904             double bits;
 905             rce->new_qscale= modify_qscale(s, rce, blurred_qscale[i], i);
 906             bits= qp2bits(rce, rce->new_qscale) + rce->mv_bits + rce->misc_bits;
 907             bits += 8*ff_vbv_update(s, bits);
 908
 909             rce->expected_bits= expected_bits;
 910             expected_bits += bits;
 911         }
 912
 913         av_dlog(s->avctx,
 914                 "expected_bits: %f all_available_bits: %d rate_factor: %f\n",
 915                 expected_bits, (int)all_available_bits, rate_factor);
 916         if(expected_bits > all_available_bits) {
 917             rate_factor-= step;
 918             ++toobig;
 919         }
 920     }
 921     av_free(qscale);
 922     av_free(blurred_qscale);
 923
 924     /* check bitrate calculations and print info */
 925     qscale_sum = 0.0;
 926     for(i=0; i<rcc->num_entries; i++){
 927         av_dlog(s, "[lavc rc] entry[%d].new_qscale = %.3f  qp = %.3f\n",
 928                 i,
 929                 rcc->entry[i].new_qscale,
 930                 rcc->entry[i].new_qscale / FF_QP2LAMBDA);
 931         qscale_sum += av_clip(rcc->entry[i].new_qscale / FF_QP2LAMBDA, s->avctx->qmin, s->avctx->qmax);
 932     }
 933     assert(toobig <= 40);
 934     av_log(s->avctx, AV_LOG_DEBUG,
 935         "[lavc rc] requested bitrate: %d bps  expected bitrate: %d bps\n",
 936         s->bit_rate,
 937         (int)(expected_bits / ((double)all_available_bits/s->bit_rate)));
 938     av_log(s->avctx, AV_LOG_DEBUG,
 939         "[lavc rc] estimated target average qp: %.3f\n",
 940         (float)qscale_sum / rcc->num_entries);
 941     if (toobig == 0) {
 942         av_log(s->avctx, AV_LOG_INFO,
 943             "[lavc rc] Using all of requested bitrate is not "
 944             "necessary for this video with these parameters.\n");
 945     } else if (toobig == 40) {
 946         av_log(s->avctx, AV_LOG_ERROR,
 947             "[lavc rc] Error: bitrate too low for this video "
 948             "with these parameters.\n");
 949         return -1;
 950     } else if (fabs(expected_bits/all_available_bits - 1.0) > 0.01) {
 951         av_log(s->avctx, AV_LOG_ERROR,
 952             "[lavc rc] Error: 2pass curve failed to converge\n");
 953         return -1;
 954     }
 955
 956     return 0;
 957 }