-/*****************************************************************************
+/***************************************************-*- coding: iso-8859-1 -*-
* ratecontrol.c: h264 encoder library (Rate Control)
*****************************************************************************
- * Copyright (C) 2003 Laurent Aimar
+ * Copyright (C) 2005 x264 project
* $Id: ratecontrol.c,v 1.1 2004/06/03 19:27:08 fenrir Exp $
*
- * Authors: Måns Rullgård <mru@mru.ath.cx>
+ * Authors: Loren Merritt <lorenm@u.washington.edu>
+ * Michael Niedermayer <michaelni@gmx.at>
+ * Måns Rullgård <mru@mru.ath.cx>
*
* 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
*****************************************************************************/
#define _ISOC99_SOURCE
-
+#undef NDEBUG // always check asserts, the speed effect is far too small to disable them
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <limits.h>
+#include <assert.h>
-#include "../core/common.h"
-#include "../core/cpu.h"
+#include "common/common.h"
+#include "common/cpu.h"
#include "ratecontrol.h"
+#if defined(SYS_FREEBSD) || defined(SYS_BEOS) || defined(SYS_NETBSD)
+#define exp2f(x) powf( 2, (x) )
+#endif
+#if defined(_MSC_VER) || defined(SYS_SunOS)
+#define exp2f(x) pow( 2, (x) )
+#define sqrtf sqrt
+#endif
+#ifdef WIN32 // POSIX says that rename() removes the destination, but win32 doesn't.
+#define rename(src,dst) (unlink(dst), rename(src,dst))
+#endif
+
+typedef struct
+{
+ int pict_type;
+ int kept_as_ref;
+ 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;
+ float blurred_complexity;
+} ratecontrol_entry_t;
+
+typedef struct
+{
+ double coeff;
+ double count;
+ double decay;
+} predictor_t;
+
struct x264_ratecontrol_t
{
/* constants */
- float fps;
- int gop_size;
- int bitrate;
- int nmb; /* number of MBs */
- int buffer_size;
- int rcbufrate;
- int init_qp;
-
- 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 b_abr;
+ int b_2pass;
+ double fps;
+ double bitrate;
+ double rate_tolerance;
+ int nmb; /* number of macroblocks in a frame */
+ int qp_constant[5];
+
+ /* current frame */
+ ratecontrol_entry_t *rce;
int qp; /* qp for current frame */
- int qpm; /* qp for next MB */
- int qpa; /* average qp for last frame */
- int qps;
- int qp_avg_p; /* average QP for P frames */
- int qp_last_p;
- 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;
+ float qpa; /* average of macroblocks' qp (same as qp if no adaptive quant) */
+ int slice_type;
+ int qp_force;
+
+ /* VBV stuff */
+ double buffer_size;
+ double buffer_fill;
+ double buffer_rate; /* # of bits added to buffer_fill after each frame */
+ predictor_t pred[5]; /* predict frame size from satd */
+
+ /* ABR stuff */
+ int last_satd;
+ double last_rceq;
+ double cplxr_sum; /* sum of bits*qscale/rceq */
+ double expected_bits_sum; /* sum of qscale2bits after rceq, ratefactor, and overflow */
+ double wanted_bits_window; /* target bitrate * window */
+ double cbr_decay;
+ double short_term_cplxsum;
+ double short_term_cplxcount;
+ double rate_factor_constant;
+
+ /* 2pass stuff */
+ FILE *p_stat_file_out;
+ char *psz_stat_file_tmpname;
+
+ int num_entries; /* number of ratecontrol_entry_ts */
+ ratecontrol_entry_t *entry; /* FIXME: copy needed data and free this once init is done */
+ 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;
+ double accum_p_qp; /* for determining I-frame quant */
+ double accum_p_norm;
+ double last_accum_p_norm;
+ double lmin[5]; /* min qscale by frame type */
+ double lmax[5];
+ double lstep; /* max change (multiply) in qscale per frame */
+ 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 */
+
+ int i_zones;
+ x264_zone_t *zones;
};
+
+static int parse_zones( x264_t *h );
+static int init_pass2(x264_t *);
+static float rate_estimate_qscale( x264_t *h, int pict_type );
+static void update_vbv( x264_t *h, int bits );
+int x264_rc_analyse_slice( x264_t *h );
+
+/* Terminology:
+ * qp = h.264's quantizer
+ * qscale = linearized quantizer = Lagrange multiplier
+ */
+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);
+}
+
+/* Texture bitrate is not quite inversely proportional to qscale,
+ * probably due the the changing number of SKIP blocks.
+ * MV bits level off at about qp<=12, because the lambda used
+ * for motion estimation is constant there. */
+static inline double qscale2bits(ratecontrol_entry_t *rce, double qscale)
+{
+ if(qscale<0.1)
+ qscale = 0.1;
+ return (rce->i_tex_bits + rce->p_tex_bits + .1) * pow( rce->qscale / qscale, 1.1 )
+ + rce->mv_bits * pow( X264_MAX(rce->qscale, 12) / X264_MAX(qscale, 12), 0.5 );
+}
+
+
int x264_ratecontrol_new( x264_t *h )
{
- x264_ratecontrol_t *rc = x264_malloc( sizeof( x264_ratecontrol_t ) );
- float bpp;
+ x264_ratecontrol_t *rc;
+ int i;
+
+ x264_cpu_restore( h->param.cpu );
+ h->rc = rc = x264_malloc( sizeof( x264_ratecontrol_t ) );
memset(rc, 0, sizeof(*rc));
- rc->fps = h->param.f_fps > 0.1 ? h->param.f_fps : 25.0f;
- rc->gop_size = h->param.i_iframe;
- rc->bitrate = h->param.i_bitrate * 1000;
- rc->nmb = ((h->param.i_width + 15) / 16) * ((h->param.i_height + 15) / 16);
-
- rc->qp = h->param.i_qp_constant;
- rc->qpa = rc->qp;
- rc->qpm = rc->qp;
-
- rc->buffer_size = h->param.i_rc_buffer_size;
- if(rc->buffer_size <= 0)
- rc->buffer_size = rc->bitrate / 2;
- rc->buffer_fullness = h->param.i_rc_init_buffer;
- rc->rcbufrate = rc->bitrate / rc->fps;
-
- 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;
+ rc->b_abr = ( h->param.rc.b_cbr || h->param.rc.i_rf_constant ) && !h->param.rc.b_stat_read;
+ rc->b_2pass = h->param.rc.b_cbr && h->param.rc.b_stat_read;
+ h->mb.b_variable_qp = 0;
+
+ /* 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->init_qp = 10;
- rc->gop_qp = rc->init_qp;
+ rc->fps = 25.0;
+
+ rc->bitrate = h->param.rc.i_bitrate * 1000;
+ rc->rate_tolerance = h->param.rc.f_rate_tolerance;
+ rc->nmb = h->mb.i_mb_count;
+ rc->last_non_b_pict_type = -1;
+ rc->cbr_decay = 1.0;
+
+ if( rc->b_2pass && h->param.rc.i_rf_constant )
+ x264_log(h, X264_LOG_ERROR, "constant rate-factor is incompatible with 2pass.\n");
+ if( h->param.rc.i_vbv_max_bitrate && !h->param.rc.b_cbr && !h->param.rc.i_rf_constant )
+ x264_log(h, X264_LOG_ERROR, "VBV is incompatible with constant QP.\n");
+ if( h->param.rc.i_vbv_max_bitrate < h->param.rc.i_bitrate &&
+ h->param.rc.i_vbv_max_bitrate > 0)
+ x264_log(h, X264_LOG_ERROR, "max bitrate less than average bitrate, ignored.\n");
+ else if( h->param.rc.i_vbv_max_bitrate > 0 &&
+ h->param.rc.i_vbv_buffer_size > 0 )
+ {
+ if( h->param.rc.i_vbv_buffer_size < 10 * h->param.rc.i_vbv_max_bitrate / rc->fps ) {
+ h->param.rc.i_vbv_buffer_size = 10 * h->param.rc.i_vbv_max_bitrate / rc->fps;
+ x264_log( h, X264_LOG_ERROR, "VBV buffer size too small, using %d kbit\n",
+ h->param.rc.i_vbv_buffer_size );
+ }
+ rc->buffer_rate = h->param.rc.i_vbv_max_bitrate * 1000 / rc->fps;
+ rc->buffer_size = h->param.rc.i_vbv_buffer_size * 1000;
+ rc->buffer_fill = rc->buffer_size * h->param.rc.f_vbv_buffer_init;
+ rc->cbr_decay = 1.0 - rc->buffer_rate / rc->buffer_size
+ * 0.5 * X264_MAX(0, 1.5 - rc->buffer_rate * rc->fps / rc->bitrate);
+ }
+ else if( h->param.rc.i_vbv_max_bitrate || h->param.rc.i_vbv_buffer_size )
+ x264_log(h, X264_LOG_ERROR, "VBV maxrate or buffer size specified, but not both.\n");
+ if(rc->rate_tolerance < 0.01) {
+ x264_log(h, X264_LOG_ERROR, "bitrate tolerance too small, using .01\n");
+ rc->rate_tolerance = 0.01;
+ }
- rc->bits_last_gop = 0;
+ if( rc->b_abr )
+ {
+ /* FIXME shouldn't need to arbitrarily specify a QP,
+ * but this is more robust than BPP measures */
+#define ABR_INIT_QP ( h->param.rc.i_rf_constant > 0 ? h->param.rc.i_rf_constant : 24 )
+ rc->accum_p_norm = .01;
+ rc->accum_p_qp = ABR_INIT_QP * rc->accum_p_norm;
+ rc->cplxr_sum = .01;
+ rc->wanted_bits_window = .01;
+ }
-/* fprintf(stderr, "%f fps, %i bps, bufsize %i\n", */
-/* rc->fps, rc->bitrate, rc->buffer_size); */
+ if( h->param.rc.i_rf_constant )
+ {
+ /* arbitrary rescaling to make CRF somewhat similar to QP */
+ double base_cplx = h->mb.i_mb_count * (h->param.i_bframe ? 120 : 80);
+ rc->rate_factor_constant = pow( base_cplx, 1 - h->param.rc.f_qcompress )
+ / qp2qscale( h->param.rc.i_rf_constant );
+ }
+
+ 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 );
+
+ rc->lstep = exp2f(h->param.rc.i_qp_step / 6.0);
+ rc->last_qscale = qp2qscale(26);
+ 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 );
+ rc->pred[i].coeff= 2.0;
+ rc->pred[i].count= 1.0;
+ rc->pred[i].decay= 0.5;
+ }
+
+ if( parse_zones( h ) < 0 )
+ return -1;
+
+ /* Load stat file and init 2pass algo */
+ if( h->param.rc.b_stat_read )
+ {
+ char *p, *stats_in;
+
+ /* read 1st pass stats */
+ assert( h->param.rc.psz_stat_in );
+ stats_in = x264_slurp_file( h->param.rc.psz_stat_in );
+ if( !stats_in )
+ {
+ x264_log(h, X264_LOG_ERROR, "ratecontrol_init: can't open stats file\n");
+ return -1;
+ }
+
+ /* find number of pics */
+ p = stats_in;
+ for(i=-1; p; i++)
+ p = strchr(p+1, ';');
+ if(i==0)
+ {
+ x264_log(h, X264_LOG_ERROR, "empty stats file\n");
+ return -1;
+ }
+ rc->num_entries = i;
+
+ if( h->param.i_frame_total < rc->num_entries && h->param.i_frame_total > 0 )
+ {
+ x264_log( h, X264_LOG_WARNING, "2nd pass has fewer frames than 1st pass (%d vs %d)\n",
+ h->param.i_frame_total, rc->num_entries );
+ }
+ if( h->param.i_frame_total > rc->num_entries + h->param.i_bframe )
+ {
+ x264_log( h, X264_LOG_ERROR, "2nd pass has more frames than 1st pass (%d vs %d)\n",
+ h->param.i_frame_total, rc->num_entries );
+ return -1;
+ }
+
+ /* FIXME: ugly padding because VfW drops delayed B-frames */
+ rc->num_entries += h->param.i_bframe;
+
+ rc->entry = (ratecontrol_entry_t*) x264_malloc(rc->num_entries * sizeof(ratecontrol_entry_t));
+ memset(rc->entry, 0, rc->num_entries * sizeof(ratecontrol_entry_t));
+
+ /* init all to skipped p frames */
+ for(i=0; i<rc->num_entries; i++){
+ ratecontrol_entry_t *rce = &rc->entry[i];
+ rce->pict_type = SLICE_TYPE_P;
+ rce->qscale = rce->new_qscale = qp2qscale(20);
+ rce->misc_bits = rc->nmb + 10;
+ rce->new_qp = 0;
+ }
- h->rc = rc;
+ /* read stats */
+ p = stats_in;
+ for(i=0; i < rc->num_entries - h->param.i_bframe; i++){
+ ratecontrol_entry_t *rce;
+ int frame_number;
+ char pict_type;
+ 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 ", &frame_number);
+
+ if(frame_number < 0 || frame_number >= rc->num_entries)
+ {
+ x264_log(h, X264_LOG_ERROR, "bad frame number (%d) at stats line %d\n", frame_number, i);
+ return -1;
+ }
+ rce = &rc->entry[frame_number];
+
+ 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,
+ &rce->mv_bits, &rce->misc_bits, &rce->i_count, &rce->p_count, &rce->s_count);
+
+ switch(pict_type){
+ case 'I': rce->kept_as_ref = 1;
+ case 'i': rce->pict_type = SLICE_TYPE_I; break;
+ case 'P': rce->pict_type = SLICE_TYPE_P; break;
+ case 'B': rce->kept_as_ref = 1;
+ case 'b': rce->pict_type = SLICE_TYPE_B; break;
+ default: e = -1; break;
+ }
+ 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(h->param.rc.b_cbr)
+ {
+ if(init_pass2(h) < 0) return -1;
+ } /* else we're using constant quant, so no need to run the bitrate allocation */
+ }
+
+ /* Open output file */
+ /* If input and output files are the same, output to a temp file
+ * and move it to the real name only when it's complete */
+ if( h->param.rc.b_stat_write )
+ {
+ rc->psz_stat_file_tmpname = x264_malloc( strlen(h->param.rc.psz_stat_out) + 6 );
+ strcpy( rc->psz_stat_file_tmpname, h->param.rc.psz_stat_out );
+ strcat( rc->psz_stat_file_tmpname, ".temp" );
+
+ rc->p_stat_file_out = fopen( rc->psz_stat_file_tmpname, "wb" );
+ if( rc->p_stat_file_out == NULL )
+ {
+ x264_log(h, X264_LOG_ERROR, "ratecontrol_init: can't open stats file\n");
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+static int parse_zones( x264_t *h )
+{
+ x264_ratecontrol_t *rc = h->rc;
+ int i;
+ if( h->param.rc.psz_zones && !h->param.rc.i_zones )
+ {
+ char *p;
+ h->param.rc.i_zones = 1;
+ for( p = h->param.rc.psz_zones; *p; p++ )
+ h->param.rc.i_zones += (*p == '/');
+ h->param.rc.zones = x264_malloc( h->param.rc.i_zones * sizeof(x264_zone_t) );
+ p = h->param.rc.psz_zones;
+ for( i = 0; i < h->param.rc.i_zones; i++)
+ {
+ x264_zone_t *z = &h->param.rc.zones[i];
+ if( 3 == sscanf(p, "%u,%u,q=%u", &z->i_start, &z->i_end, &z->i_qp) )
+ z->b_force_qp = 1;
+ else if( 3 == sscanf(p, "%u,%u,b=%f", &z->i_start, &z->i_end, &z->f_bitrate_factor) )
+ z->b_force_qp = 0;
+ else
+ {
+ char *slash = strchr(p, '/');
+ if(slash) *slash = '\0';
+ x264_log( h, X264_LOG_ERROR, "invalid zone: \"%s\"\n", p );
+ return -1;
+ }
+ p = strchr(p, '/') + 1;
+ }
+ }
+
+ if( h->param.rc.i_zones > 0 )
+ {
+ for( i = 0; i < h->param.rc.i_zones; i++ )
+ {
+ x264_zone_t z = h->param.rc.zones[i];
+ if( z.i_start < 0 || z.i_start > z.i_end )
+ {
+ x264_log( h, X264_LOG_ERROR, "invalid zone: start=%d end=%d\n",
+ z.i_start, z.i_end );
+ return -1;
+ }
+ else if( !z.b_force_qp && z.f_bitrate_factor <= 0 )
+ {
+ x264_log( h, X264_LOG_ERROR, "invalid zone: bitrate_factor=%f\n",
+ z.f_bitrate_factor );
+ return -1;
+ }
+ }
+
+ rc->i_zones = h->param.rc.i_zones;
+ rc->zones = x264_malloc( rc->i_zones * sizeof(x264_zone_t) );
+ memcpy( rc->zones, h->param.rc.zones, rc->i_zones * sizeof(x264_zone_t) );
+ }
return 0;
}
void x264_ratecontrol_delete( x264_t *h )
{
x264_ratecontrol_t *rc = h->rc;
+
+ if( rc->p_stat_file_out )
+ {
+ fclose( rc->p_stat_file_out );
+ if( h->i_frame >= rc->num_entries - h->param.i_bframe )
+ if( rename( rc->psz_stat_file_tmpname, h->param.rc.psz_stat_out ) != 0 )
+ {
+ x264_log( h, X264_LOG_ERROR, "failed to rename \"%s\" to \"%s\"\n",
+ rc->psz_stat_file_tmpname, h->param.rc.psz_stat_out );
+ }
+ x264_free( rc->psz_stat_file_tmpname );
+ }
+ x264_free( rc->entry );
+ x264_free( rc->zones );
x264_free( rc );
}
-void x264_ratecontrol_start( x264_t *h, int i_slice_type )
+/* Before encoding a frame, choose a QP for it */
+void x264_ratecontrol_start( x264_t *h, int i_slice_type, int i_force_qp )
{
x264_ratecontrol_t *rc = h->rc;
- int gframes, iframes, pframes, bframes;
- int minbits, maxbits;
- int gbits, fbits;
- int zn = 0;
- float kp;
- int gbuf;
-
- if(!h->param.b_cbr)
- return;
x264_cpu_restore( h->param.cpu );
+ rc->qp_force = i_force_qp;
rc->slice_type = i_slice_type;
- 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){
- int qp = (float) rc->qp_avg_p / rc->pframes + 0.5;
-#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);
- qp =
- x264_clip3(qp, h->param.i_qp_min, h->param.i_qp_max);
- rc->gop_qp = qp;
- } else {
- rc->gop_qp = rc->init_qp;
- }
+ if( i_force_qp )
+ {
+ rc->qpa = rc->qp = i_force_qp - 1;
+ }
+ else if( rc->b_abr )
+ {
+ rc->qpa = rc->qp =
+ x264_clip3( (int)(qscale2qp( rate_estimate_qscale( h, i_slice_type ) ) + .5), 0, 51 );
+ }
+ else if( rc->b_2pass )
+ {
+ int frame = h->fenc->i_frame;
+ ratecontrol_entry_t *rce;
+ assert( frame >= 0 && frame < rc->num_entries );
+ rce = h->rc->rce = &h->rc->entry[frame];
- kp = h->param.f_ip_factor * h->param.f_pb_factor;
-
- rc->bits_last_gop = 0;
- rc->frames = 0;
- rc->pframes = 0;
- rc->qp_avg_p = 0;
- break;
-
- case SLICE_TYPE_P:
- kp = h->param.f_pb_factor;
- break;
-
- case SLICE_TYPE_B:
- kp = 1.0;
- break;
-
- default:
- fprintf(stderr, "x264: ratecontrol: unknown slice type %i\n",
- i_slice_type);
- 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 /
- (h->param.f_ip_factor * h->param.f_pb_factor * iframes +
- h->param.f_pb_factor * pframes + bframes);
-
- 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;
- } else if(rc->ncoeffs){
- int dqp;
-
- zn = rc->ncoeffs -
- rc->fbits * (rc->ncoeffs - rc->nzcoeffs) / rc->ufbits;
- dqp = h->param.i_rc_sens * exp2f((float) rc->qpa / 6) *
- (zn - rc->nzcoeffs) / rc->nzcoeffs;
- dqp = x264_clip3(dqp, -h->param.i_qp_step, h->param.i_qp_step);
- rc->qp = rc->qpa + dqp;
- }
-
- if(rc->fbits > 0.8 * maxbits)
- rc->qp += 1;
- else if(rc->fbits > 0.9 * maxbits)
- rc->qp += 2;
- else if(rc->fbits < 1.2 * minbits)
- rc->qp -= 1;
- else if(rc->fbits < 1.1 * minbits)
- rc->qp -= 2;
-
- rc->qp = x264_clip3(rc->qp, h->param.i_qp_min, h->param.i_qp_max);
- rc->qpm = rc->qp;
-
-/* fprintf(stderr, "fbits=%i, qp=%i, z=%i, min=%i, max=%i\n", */
-/* rc->fbits, rc->qpm, zn, minbits, maxbits); */
-
- rc->fbits -= rc->overhead;
- rc->ufbits = 0;
- rc->ncoeffs = 0;
- rc->nzcoeffs = 0;
- rc->mb = 0;
- rc->qps = 0;
+ rce->new_qscale = rate_estimate_qscale( h, i_slice_type );
+ rc->qpa = rc->qp = rce->new_qp =
+ x264_clip3( (int)(qscale2qp(rce->new_qscale) + 0.5), 0, 51 );
+ }
+ else /* CQP */
+ {
+ int q;
+ if( i_slice_type == SLICE_TYPE_B && h->fdec->b_kept_as_ref )
+ q = ( rc->qp_constant[ SLICE_TYPE_B ] + rc->qp_constant[ SLICE_TYPE_P ] ) / 2;
+ else
+ q = rc->qp_constant[ i_slice_type ];
+ rc->qpa = rc->qp = q;
+ }
}
void x264_ratecontrol_mb( x264_t *h, int bits )
+{
+ /* currently no adaptive quant */
+}
+
+int x264_ratecontrol_qp( x264_t *h )
+{
+ return h->rc->qp;
+}
+
+/* In 2pass, force the same frame types as in the 1st pass */
+int x264_ratecontrol_slice_type( x264_t *h, int frame_num )
+{
+ x264_ratecontrol_t *rc = h->rc;
+ if( h->param.rc.b_stat_read )
+ {
+ if( frame_num >= rc->num_entries )
+ {
+ /* We could try to initialize everything required for ABR and
+ * adaptive B-frames, but that would be complicated.
+ * So just calculate the average QP used so far. */
+
+ h->param.rc.i_qp_constant = (h->stat.i_slice_count[SLICE_TYPE_P] == 0) ? 24
+ : 1 + h->stat.i_slice_qp[SLICE_TYPE_P] / h->stat.i_slice_count[SLICE_TYPE_P];
+ rc->qp_constant[SLICE_TYPE_P] = x264_clip3( h->param.rc.i_qp_constant, 0, 51 );
+ 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 );
+
+ x264_log(h, X264_LOG_ERROR, "2nd pass has more frames than 1st pass (%d)\n", rc->num_entries);
+ x264_log(h, X264_LOG_ERROR, "continuing anyway, at constant QP=%d\n", h->param.rc.i_qp_constant);
+ if( h->param.b_bframe_adaptive )
+ x264_log(h, X264_LOG_ERROR, "disabling adaptive B-frames\n");
+
+ rc->b_abr = 0;
+ rc->b_2pass = 0;
+ h->param.rc.b_cbr = 0;
+ h->param.rc.b_stat_read = 0;
+ h->param.b_bframe_adaptive = 0;
+ if( h->param.i_bframe > 1 )
+ h->param.i_bframe = 1;
+ return X264_TYPE_P;
+ }
+ switch( rc->entry[frame_num].pict_type )
+ {
+ case SLICE_TYPE_I:
+ return rc->entry[frame_num].kept_as_ref ? X264_TYPE_IDR : X264_TYPE_I;
+
+ case SLICE_TYPE_B:
+ return rc->entry[frame_num].kept_as_ref ? X264_TYPE_BREF : X264_TYPE_B;
+
+ case SLICE_TYPE_P:
+ default:
+ return X264_TYPE_P;
+ }
+ }
+ else
+ {
+ return X264_TYPE_AUTO;
+ }
+}
+
+/* After encoding one frame, save stats and update ratecontrol state */
+void x264_ratecontrol_end( x264_t *h, int bits )
{
x264_ratecontrol_t *rc = h->rc;
- int rbits;
- int zn, enz;
- int dqp;
+ const int *mbs = h->stat.frame.i_mb_count;
int i;
x264_cpu_restore( h->param.cpu );
- rc->qps += rc->qpm;
- rc->ufbits += bits;
- rc->mb++;
+ h->stat.frame.i_mb_count_skip = mbs[P_SKIP] + mbs[B_SKIP];
+ h->stat.frame.i_mb_count_i = mbs[I_16x16] + mbs[I_8x8] + mbs[I_4x4];
+ h->stat.frame.i_mb_count_p = mbs[P_L0] + mbs[P_8x8];
+ for( i = B_DIRECT; i < B_8x8; i++ )
+ h->stat.frame.i_mb_count_p += mbs[i];
- 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( h->param.rc.b_stat_write )
+ {
+ char c_type = rc->slice_type==SLICE_TYPE_I ? (h->fenc->i_poc==0 ? 'I' : 'i')
+ : rc->slice_type==SLICE_TYPE_P ? 'P'
+ : h->fenc->b_kept_as_ref ? 'B' : 'b';
+ fprintf( rc->p_stat_file_out,
+ "in:%d out:%d type:%c q:%.2f itex:%d ptex:%d mv:%d misc:%d imb:%d pmb:%d smb:%d;\n",
+ h->fenc->i_frame, h->i_frame-1,
+ c_type, rc->qpa,
+ 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,
+ h->stat.frame.i_mb_count_p,
+ h->stat.frame.i_mb_count_skip);
+ }
- if(rc->mb < rc->nmb / 16)
- return;
- else if(rc->mb == rc->nmb)
- return;
+ if( rc->b_abr )
+ {
+ if( rc->slice_type != SLICE_TYPE_B )
+ rc->cplxr_sum += bits * qp2qscale(rc->qpa) / rc->last_rceq;
+ else
+ {
+ /* Depends on the fact that B-frame's QP is an offset from the following P-frame's.
+ * Not perfectly accurate with B-refs, but good enough. */
+ rc->cplxr_sum += bits * qp2qscale(rc->qpa) / (rc->last_rceq * fabs(h->param.rc.f_pb_factor));
+ }
+ rc->cplxr_sum *= rc->cbr_decay;
+ rc->wanted_bits_window += rc->bitrate / rc->fps;
+ rc->wanted_bits_window *= rc->cbr_decay;
+
+ rc->accum_p_qp *= .95;
+ rc->accum_p_norm *= .95;
+ rc->accum_p_norm += 1;
+ if( rc->slice_type == SLICE_TYPE_I )
+ rc->accum_p_qp += rc->qpa * fabs(h->param.rc.f_ip_factor);
+ else
+ rc->accum_p_qp += rc->qpa;
+ }
+
+ if( rc->b_2pass )
+ {
+ rc->expected_bits_sum += qscale2bits( rc->rce, qp2qscale(rc->rce->new_qp) );
+ }
+
+ update_vbv( h, bits );
- rbits = rc->fbits - rc->ufbits;
-/* if(rbits < 0) */
-/* rbits = 0; */
-
- zn = (rc->nmb - rc->mb) * 16 * 24;
- if(rc->ufbits)
- zn -= rbits * (rc->ncoeffs - rc->nzcoeffs) / rc->ufbits;
- enz = rc->nzcoeffs * (rc->nmb - rc->mb) / rc->mb;
- dqp = (float) 2*h->param.i_rc_sens * exp2f((float) rc->qps / rc->mb / 6) *
- (zn - enz) / enz;
- rc->qpm = x264_clip3(rc->qpm + dqp, rc->qp - 3, rc->qp + 3);
- if(rbits <= 0)
- rc->qpm++;
- rc->qpm = x264_clip3(rc->qpm, h->param.i_qp_min, h->param.i_qp_max);
+ if( rc->slice_type != SLICE_TYPE_B )
+ rc->last_non_b_pict_type = rc->slice_type;
}
-int x264_ratecontrol_qp( x264_t *h )
+/****************************************************************************
+ * 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 );
+
+/**
+ * modify the bitrate curve from pass1 for one frame
+ */
+static double get_qscale(x264_t *h, ratecontrol_entry_t *rce, double rate_factor, int frame_num)
{
- return h->rc->qpm;
+ x264_ratecontrol_t *rcc= h->rc;
+ const int pict_type = rce->pict_type;
+ double q;
+ int i;
+
+ 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 * rce->qscale,
+ (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],
+ rce->blurred_complexity,
+ 0
+ };
+ static const char *const_names[]={
+ "iTex",
+ "pTex",
+ "tex",
+ "mv",
+ "iCount",
+ "pCount",
+ "sCount",
+ "isI",
+ "isP",
+ "isB",
+ "qComp",
+ "avgIITex",
+ "avgPITex",
+ "avgPPTex",
+ "avgBPTex",
+ "avgTex",
+ "blurCplx",
+ NULL
+ };
+ static double (*func1[])(void *, double)={
+// (void *)bits2qscale,
+ (void *)qscale2bits,
+ NULL
+ };
+ static const char *func1_names[]={
+// "bits2qp",
+ "qp2bits",
+ NULL
+ };
+
+ q = x264_eval((char*)h->param.rc.psz_rc_eq, const_values, const_names, func1, func1_names, NULL, NULL, rce);
+
+ // avoid NaN's in the rc_eq
+ if(q != q || rce->i_tex_bits + rce->p_tex_bits + rce->mv_bits == 0)
+ q = rcc->last_qscale;
+ else {
+ rcc->last_rceq = q;
+ q /= rate_factor;
+ rcc->last_qscale = q;
+ }
+
+ for( i = rcc->i_zones-1; i >= 0; i-- )
+ {
+ x264_zone_t *z = &rcc->zones[i];
+ if( frame_num >= z->i_start && frame_num <= z->i_end )
+ {
+ if( z->b_force_qp )
+ q = qp2qscale(z->i_qp);
+ else
+ q /= z->f_bitrate_factor;
+ break;
+ }
+ }
+
+ return q;
}
-void x264_ratecontrol_end( x264_t *h, int bits )
+static double get_diff_limited_q(x264_t *h, ratecontrol_entry_t *rce, double q)
{
- x264_ratecontrol_t *rc = h->rc;
+ x264_ratecontrol_t *rcc = h->rc;
+ const int pict_type = rce->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 )
+ {
+ 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;
+ }
+ else if( pict_type == SLICE_TYPE_B )
+ {
+ if( h->param.rc.f_pb_factor > 0 )
+ q = last_non_b_q;
+ if( !rce->kept_as_ref )
+ q *= fabs( h->param.rc.f_pb_factor );
+ }
+ 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 )
+ {
+ q = last_p_q;
+ }
+
+ /* last qscale / qdiff stuff */
+ if(rcc->last_non_b_pict_type==pict_type
+ && (pict_type!=SLICE_TYPE_I || rcc->last_accum_p_norm < 1))
+ {
+ double last_q = rcc->last_qscale_for[pict_type];
+ double max_qscale = last_q * rcc->lstep;
+ double min_qscale = last_q / rcc->lstep;
+
+ if (q > max_qscale) q = max_qscale;
+ else if(q < min_qscale) q = min_qscale;
+ }
+
+ rcc->last_qscale_for[pict_type] = q;
+ if(pict_type!=SLICE_TYPE_B)
+ rcc->last_non_b_pict_type = pict_type;
+ if(pict_type==SLICE_TYPE_I)
+ {
+ rcc->last_accum_p_norm = rcc->accum_p_norm;
+ 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);
+ }
+ return q;
+}
+
+static double predict_size( predictor_t *p, double q, double var )
+{
+ return p->coeff*var / (q*p->count);
+}
+
+static void update_predictor( predictor_t *p, double q, double var, double bits )
+{
+ p->count *= p->decay;
+ p->coeff *= p->decay;
+ p->count ++;
+ p->coeff += bits*q / var;
+}
- if(!h->param.b_cbr)
+static void update_vbv( x264_t *h, int bits )
+{
+ x264_ratecontrol_t *rcc = h->rc;
+ if( !rcc->buffer_size )
return;
- rc->buffer_fullness += rc->rcbufrate - bits;
- if(rc->buffer_fullness < 0){
- fprintf(stderr, "x264: buffer underflow %i\n", rc->buffer_fullness);
- rc->buffer_fullness = 0;
+ rcc->buffer_fill += rcc->buffer_rate - bits;
+ if( rcc->buffer_fill < 0 && !rcc->b_2pass )
+ x264_log( h, X264_LOG_WARNING, "VBV underflow (%.0f bits)\n", rcc->buffer_fill );
+ rcc->buffer_fill = x264_clip3( rcc->buffer_fill, 0, rcc->buffer_size );
+
+ if(rcc->last_satd > 100)
+ update_predictor( &rcc->pred[rcc->slice_type], qp2qscale(rcc->qpa), rcc->last_satd, bits );
+}
+
+// apply VBV constraints and clip qscale to between lmin and lmax
+static double clip_qscale( x264_t *h, int pict_type, double q )
+{
+ x264_ratecontrol_t *rcc = h->rc;
+ double lmin = rcc->lmin[pict_type];
+ double lmax = rcc->lmax[pict_type];
+ double q0 = q;
+
+ /* B-frames are not directly subject to VBV,
+ * since they are controlled by the P-frames' QPs.
+ * FIXME: in 2pass we could modify previous frames' QP too,
+ * instead of waiting for the buffer to fill */
+ if( rcc->buffer_size &&
+ ( pict_type == SLICE_TYPE_P ||
+ ( pict_type == SLICE_TYPE_I && rcc->last_non_b_pict_type == SLICE_TYPE_I ) ) )
+ {
+ if( rcc->buffer_fill/rcc->buffer_size < 0.5 )
+ q /= x264_clip3f( 2.0*rcc->buffer_fill/rcc->buffer_size, 0.5, 1.0 );
+ }
+ /* Now a hard threshold to make sure the frame fits in VBV.
+ * This one is mostly for I-frames. */
+ if( rcc->buffer_size && rcc->last_satd > 0 )
+ {
+ double bits = predict_size( &rcc->pred[rcc->slice_type], q, rcc->last_satd );
+ double qf = 1.0;
+ if( bits > rcc->buffer_fill/2 )
+ qf = x264_clip3f( rcc->buffer_fill/(2*bits), 0.2, 1.0 );
+ q /= qf;
+ bits *= qf;
+ if( bits < rcc->buffer_rate/2 )
+ q *= bits*2/rcc->buffer_rate;
+ q = X264_MAX( q0, q );
}
- rc->qpa = rc->qps / rc->mb;
- if(rc->slice_type == SLICE_TYPE_P){
- rc->qp_avg_p += rc->qpa;
- rc->qp_last_p = rc->qpa;
- rc->pframes++;
+ if(lmin==lmax)
+ return lmin;
+ else if(rcc->b_2pass)
+ {
+ double min2 = log(lmin);
+ double max2 = log(lmax);
+ q = (log(q) - min2)/(max2-min2) - 0.5;
+ q = 1.0/(1.0 + exp(-4*q));
+ q = q*(max2-min2) + min2;
+ return exp(q);
}
+ else
+ return x264_clip3f(q, lmin, lmax);
+}
- rc->overhead = bits - rc->ufbits;
+// update qscale for 1 frame based on actual bits used so far
+static float rate_estimate_qscale(x264_t *h, int pict_type)
+{
+ float q;
+ x264_ratecontrol_t *rcc = h->rc;
+ 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]);
-/* fprintf(stderr, " bits=%i, qp=%i, z=%i, zr=%6.3f, buf=%i\n", */
-/* bits, rc->qpa, rc->nzcoeffs, */
-/* (float) rc->nzcoeffs / rc->ncoeffs, rc->buffer_fullness); */
+ if( rcc->b_2pass )
+ {
+ rce = *rcc->rce;
+ if(pict_type != rce.pict_type)
+ {
+ x264_log(h, X264_LOG_ERROR, "slice=%c but 2pass stats say %c\n",
+ slice_type_to_char[pict_type], slice_type_to_char[rce.pict_type]);
+ }
+ }
- rc->bits_last_gop += bits;
- rc->frames++;
- rc->mb = 0;
+ if( pict_type == SLICE_TYPE_B )
+ {
+ rcc->last_satd = 0;
+ if(h->fenc->b_kept_as_ref)
+ q = rcc->last_qscale * sqrtf(h->param.rc.f_pb_factor);
+ else
+ q = rcc->last_qscale * h->param.rc.f_pb_factor;
+ return x264_clip3f(q, lmin, lmax);
+ }
+ else
+ {
+ double abr_buffer = 2 * rcc->rate_tolerance * rcc->bitrate;
+ if( rcc->b_2pass )
+ {
+ //FIXME adjust abr_buffer based on distance to the end of the video
+ int64_t diff = total_bits - (int64_t)rce.expected_bits;
+ q = rce.new_qscale;
+ q /= x264_clip3f((double)(abr_buffer - diff) / abr_buffer, .5, 2);
+ if( h->fenc->i_frame > 30 )
+ {
+ /* Adjust quant based on the difference between
+ * achieved and expected bitrate so far */
+ double time = (double)h->fenc->i_frame / rcc->num_entries;
+ double w = x264_clip3f( time*100, 0.0, 1.0 );
+ q *= pow( (double)total_bits / rcc->expected_bits_sum, w );
+ }
+ q = x264_clip3f( q, lmin, lmax );
+ }
+ else /* 1pass ABR */
+ {
+ /* Calculate the quantizer which would have produced the desired
+ * average bitrate if it had been applied to all frames so far.
+ * Then modulate that quant based on the current frame's complexity
+ * relative to the average complexity so far (using the 2pass RCEQ).
+ * Then bias the quant up or down if total size so far was far from
+ * the target.
+ * Result: Depending on the value of rate_tolerance, there is a
+ * tradeoff between quality and bitrate precision. But at large
+ * tolerances, the bit distribution approaches that of 2pass. */
+
+ double wanted_bits, overflow, lmin, lmax;
+
+ rcc->last_satd = x264_rc_analyse_slice( h );
+ rcc->short_term_cplxsum *= 0.5;
+ rcc->short_term_cplxcount *= 0.5;
+ rcc->short_term_cplxsum += rcc->last_satd;
+ rcc->short_term_cplxcount ++;
+
+ rce.p_tex_bits = rcc->last_satd;
+ rce.blurred_complexity = rcc->short_term_cplxsum / rcc->short_term_cplxcount;
+ rce.i_tex_bits = 0;
+ rce.mv_bits = 0;
+ rce.p_count = rcc->nmb;
+ rce.i_count = 0;
+ rce.s_count = 0;
+ rce.qscale = 1;
+ rce.pict_type = pict_type;
+
+ if( h->param.rc.i_rf_constant )
+ {
+ q = get_qscale( h, &rce, rcc->rate_factor_constant, h->fenc->i_frame );
+ overflow = 1;
+ }
+ else
+ {
+ q = get_qscale( h, &rce, rcc->wanted_bits_window / rcc->cplxr_sum, h->fenc->i_frame );
+
+ wanted_bits = h->fenc->i_frame * rcc->bitrate / rcc->fps;
+ abr_buffer *= X264_MAX( 1, sqrt(h->fenc->i_frame/25) );
+ overflow = x264_clip3f( 1.0 + (total_bits - wanted_bits) / abr_buffer, .5, 2 );
+ q *= overflow;
+ }
+
+ if( pict_type == SLICE_TYPE_I && h->param.i_keyint_max > 1
+ /* should test _next_ pict type, but that isn't decided yet */
+ && rcc->last_non_b_pict_type != SLICE_TYPE_I )
+ {
+ q = qp2qscale( rcc->accum_p_qp / rcc->accum_p_norm );
+ q /= fabs( h->param.rc.f_ip_factor );
+ q = clip_qscale( h, pict_type, q );
+ }
+ else
+ {
+ if( h->stat.i_slice_count[h->param.i_keyint_max > 1 ? SLICE_TYPE_P : SLICE_TYPE_I] < 5 )
+ {
+ float w = h->stat.i_slice_count[SLICE_TYPE_P] / 5.;
+ float q2 = qp2qscale(ABR_INIT_QP);
+ q = q*w + q2*(1-w);
+ }
+
+ /* Asymmetric clipping, because symmetric would prevent
+ * overflow control in areas of rapidly oscillating complexity */
+ lmin = rcc->last_qscale_for[pict_type] / rcc->lstep;
+ lmax = rcc->last_qscale_for[pict_type] * rcc->lstep;
+ if( overflow > 1.1 )
+ lmax *= rcc->lstep;
+ else if( overflow < 0.9 )
+ lmin /= rcc->lstep;
+
+ q = x264_clip3f(q, lmin, lmax);
+ q = clip_qscale(h, pict_type, q);
+ //FIXME use get_diff_limited_q() ?
+ }
+ }
+
+ rcc->last_qscale_for[pict_type] =
+ 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;
+ double cplxblur = h->param.rc.f_complexity_blur;
+ 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->misc_bits;
+ 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 * rce->qscale;
+ rcc->frame_count[rce->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;
+ }
+
+ /* Blur complexities, to reduce local fluctuation of QP.
+ * We don't blur the QPs directly, because then one very simple frame
+ * could drag down the QP of a nearby complex frame and give it more
+ * bits than intended. */
+ for(i=0; i<rcc->num_entries; i++){
+ ratecontrol_entry_t *rce = &rcc->entry[i];
+ double weight_sum = 0;
+ double cplx_sum = 0;
+ double weight = 1.0;
+ int j;
+ /* weighted average of cplx of future frames */
+ for(j=1; j<cplxblur*2 && j<rcc->num_entries-i; j++){
+ ratecontrol_entry_t *rcj = &rcc->entry[i+j];
+ weight *= 1 - pow( (float)rcj->i_count / rcc->nmb, 2 );
+ if(weight < .0001)
+ break;
+ weight_sum += weight;
+ cplx_sum += weight * qscale2bits(rcj, 1);
+ }
+ /* weighted average of cplx of past frames */
+ weight = 1.0;
+ for(j=0; j<=cplxblur*2 && j<=i; j++){
+ ratecontrol_entry_t *rcj = &rcc->entry[i-j];
+ weight_sum += weight;
+ cplx_sum += weight * qscale2bits(rcj, 1);
+ weight *= 1 - pow( (float)rcj->i_count / rcc->nmb, 2 );
+ if(weight < .0001)
+ break;
+ }
+ rce->blurred_complexity = cplx_sum / weight_sum;
+ }
+
+ 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;
+
+ /* Search for a factor which, when multiplied by the RCEQ values from
+ * each frame, adds up to the desired total size.
+ * There is no exact closed-form solution because of VBV constraints and
+ * because qscale2bits is not invertible, but we can start with the simple
+ * approximation of scaling the 1st pass by the ratio of bitrates.
+ * The search range is probably overkill, but speed doesn't matter here. */
+
+ expected_bits = 1;
+ for(i=0; i<rcc->num_entries; i++)
+ expected_bits += qscale2bits(&rcc->entry[i], get_qscale(h, &rcc->entry[i], 1.0, i));
+ step_mult = all_available_bits / expected_bits;
+
+ rate_factor = 0;
+ for(step = 1E4 * step_mult; step > 1E-7 * step_mult; step *= 0.5){
+ expected_bits = 0;
+ rate_factor += step;
+
+ rcc->last_non_b_pict_type = -1;
+ rcc->last_accum_p_norm = 1;
+ rcc->accum_p_norm = 0;
+ rcc->buffer_fill = rcc->buffer_size * h->param.rc.f_vbv_buffer_init;
+
+ /* find qscale */
+ for(i=0; i<rcc->num_entries; i++){
+ qscale[i] = get_qscale(h, &rcc->entry[i], rate_factor, i);
+ }
+
+ /* fixed I/B qscale relative to P */
+ 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;
+ if(rce->pict_type != rcc->entry[index].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;
+ rce->new_qscale = clip_qscale(h, rce->pict_type, blurred_qscale[i]);
+ assert(rce->new_qscale >= 0);
+ bits = qscale2bits(rce, rce->new_qscale) + rce->misc_bits;
+
+ rce->expected_bits = expected_bits;
+ expected_bits += bits;
+ update_vbv(h, bits);
+ }
+
+//printf("expected:%llu available:%llu factor:%lf avgQ:%lf\n", (uint64_t)expected_bits, all_available_bits, rate_factor);
+ if(expected_bits > all_available_bits) rate_factor -= step;
+ }
+
+ x264_free(qscale);
+ if(filter_size > 1)
+ x264_free(blurred_qscale);
+
+ if(fabs(expected_bits/all_available_bits - 1.0) > 0.01)
+ {
+ double avgq = 0;
+ for(i=0; i<rcc->num_entries; i++)
+ avgq += rcc->entry[i].new_qscale;
+ avgq = qscale2qp(avgq / rcc->num_entries);
+
+ x264_log(h, X264_LOG_ERROR, "Error: 2pass curve failed to converge\n");
+ x264_log(h, X264_LOG_ERROR, "target: %.2f kbit/s, expected: %.2f kbit/s, avg QP: %.4f\n",
+ (float)h->param.rc.i_bitrate,
+ expected_bits * rcc->fps / (rcc->num_entries * 1000.),
+ avgq);
+ if(expected_bits < all_available_bits && avgq < h->param.rc.i_qp_min + 2)
+ {
+ if(h->param.rc.i_qp_min > 0)
+ x264_log(h, X264_LOG_ERROR, "try reducing target bitrate or reducing qp_min (currently %d)\n", h->param.rc.i_qp_min);
+ else
+ x264_log(h, X264_LOG_ERROR, "try reducing target bitrate\n");
+ }
+ else if(expected_bits > all_available_bits && avgq > h->param.rc.i_qp_max - 2)
+ {
+ if(h->param.rc.i_qp_max < 51)
+ x264_log(h, X264_LOG_ERROR, "try increasing target bitrate or increasing qp_max (currently %d)\n", h->param.rc.i_qp_max);
+ else
+ x264_log(h, X264_LOG_ERROR, "try increasing target bitrate\n");
+ }
+ else
+ x264_log(h, X264_LOG_ERROR, "internal error\n");
+ }
+
+ return 0;
+}
+
+
projects / x264 / blobdiff