The Tor Browser: comparison media/libvpx/vp8/encoder/firstpass.c

--1:000000000000
+:e1a066fb9f6e
+/*
+*  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
+*
+*  Use of this source code is governed by a BSD-style license
+*  that can be found in the LICENSE file in the root of the source
+*  tree. An additional intellectual property rights grant can be found
+*  in the file PATENTS.  All contributing project authors may
+*  be found in the AUTHORS file in the root of the source tree.
+*/
+#include <math.h>
+#include <limits.h>
+#include <stdio.h>
+#include "./vpx_scale_rtcd.h"
+#include "block.h"
+#include "onyx_int.h"
+#include "vp8/common/variance.h"
+#include "encodeintra.h"
+#include "vp8/common/setupintrarecon.h"
+#include "vp8/common/systemdependent.h"
+#include "mcomp.h"
+#include "firstpass.h"
+#include "vpx_scale/vpx_scale.h"
+#include "encodemb.h"
+#include "vp8/common/extend.h"
+#include "vpx_mem/vpx_mem.h"
+#include "vp8/common/swapyv12buffer.h"
+#include "rdopt.h"
+#include "vp8/common/quant_common.h"
+#include "encodemv.h"
+#include "encodeframe.h"
+/* #define OUTPUT_FPF 1 */
+extern void vp8cx_frame_init_quantizer(VP8_COMP *cpi);
+extern void vp8_set_mbmode_and_mvs(MACROBLOCK *x, MB_PREDICTION_MODE mb, int_mv *mv);
+extern void vp8_alloc_compressor_data(VP8_COMP *cpi);
+#define GFQ_ADJUSTMENT vp8_gf_boost_qadjustment[Q]
+extern int vp8_kf_boost_qadjustment[QINDEX_RANGE];
+extern const int vp8_gf_boost_qadjustment[QINDEX_RANGE];
+#define IIFACTOR   1.5
+#define IIKFACTOR1 1.40
+#define IIKFACTOR2 1.5
+#define RMAX       14.0
+#define GF_RMAX    48.0
+#define KF_MB_INTRA_MIN 300
+#define GF_MB_INTRA_MIN 200
+#define DOUBLE_DIVIDE_CHECK(X) ((X)<0?(X)-.000001:(X)+.000001)
+#define POW1 (double)cpi->oxcf.two_pass_vbrbias/100.0
+#define POW2 (double)cpi->oxcf.two_pass_vbrbias/100.0
+#define NEW_BOOST 1
+static int vscale_lookup[7] = {0, 1, 1, 2, 2, 3, 3};
+static int hscale_lookup[7] = {0, 0, 1, 1, 2, 2, 3};
+static const int cq_level[QINDEX_RANGE] =
+{
+0,0,1,1,2,3,3,4,4,5,6,6,7,8,8,9,
+9,10,11,11,12,13,13,14,15,15,16,17,17,18,19,20,
+20,21,22,22,23,24,24,25,26,27,27,28,29,30,30,31,
+32,33,33,34,35,36,36,37,38,39,39,40,41,42,42,43,
+44,45,46,46,47,48,49,50,50,51,52,53,54,55,55,56,
+57,58,59,60,60,61,62,63,64,65,66,67,67,68,69,70,
+71,72,73,74,75,75,76,77,78,79,80,81,82,83,84,85,
+86,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100
+};
+static void find_next_key_frame(VP8_COMP *cpi, FIRSTPASS_STATS *this_frame);
+/* Resets the first pass file to the given position using a relative seek
+* from the current position
+*/
+static void reset_fpf_position(VP8_COMP *cpi, FIRSTPASS_STATS *Position)
+{
+cpi->twopass.stats_in = Position;
+}
+static int lookup_next_frame_stats(VP8_COMP *cpi, FIRSTPASS_STATS *next_frame)
+{
+if (cpi->twopass.stats_in >= cpi->twopass.stats_in_end)
+return EOF;
+*next_frame = *cpi->twopass.stats_in;
+return 1;
+}
+/* Read frame stats at an offset from the current position */
+static int read_frame_stats( VP8_COMP *cpi,
+FIRSTPASS_STATS *frame_stats,
+int offset )
+{
+FIRSTPASS_STATS * fps_ptr = cpi->twopass.stats_in;
+/* Check legality of offset */
+if ( offset >= 0 )
+{
+if ( &fps_ptr[offset] >= cpi->twopass.stats_in_end )
+return EOF;
+}
+else if ( offset < 0 )
+{
+if ( &fps_ptr[offset] < cpi->twopass.stats_in_start )
+return EOF;
+}
+*frame_stats = fps_ptr[offset];
+return 1;
+}
+static int input_stats(VP8_COMP *cpi, FIRSTPASS_STATS *fps)
+{
+if (cpi->twopass.stats_in >= cpi->twopass.stats_in_end)
+return EOF;
+*fps = *cpi->twopass.stats_in;
+cpi->twopass.stats_in =
+(void*)((char *)cpi->twopass.stats_in + sizeof(FIRSTPASS_STATS));
+return 1;
+}
+static void output_stats(const VP8_COMP            *cpi,
+struct vpx_codec_pkt_list *pktlist,
+FIRSTPASS_STATS            *stats)
+{
+struct vpx_codec_cx_pkt pkt;
+pkt.kind = VPX_CODEC_STATS_PKT;
+pkt.data.twopass_stats.buf = stats;
+pkt.data.twopass_stats.sz = sizeof(FIRSTPASS_STATS);
+vpx_codec_pkt_list_add(pktlist, &pkt);
+/* TEMP debug code */
+#if OUTPUT_FPF
+{
+FILE *fpfile;
+fpfile = fopen("firstpass.stt", "a");
+fprintf(fpfile, "%12.0f %12.0f %12.0f %12.4f %12.4f %12.4f %12.4f"
+" %12.4f %12.4f %12.4f %12.4f %12.4f %12.4f %12.4f %12.4f"
+" %12.0f %12.0f %12.4f\n",
+stats->frame,
+stats->intra_error,
+stats->coded_error,
+stats->ssim_weighted_pred_err,
+stats->pcnt_inter,
+stats->pcnt_motion,
+stats->pcnt_second_ref,
+stats->pcnt_neutral,
+stats->MVr,
+stats->mvr_abs,
+stats->MVc,
+stats->mvc_abs,
+stats->MVrv,
+stats->MVcv,
+stats->mv_in_out_count,
+stats->new_mv_count,
+stats->count,
+stats->duration);
+fclose(fpfile);
+}
+#endif
+}
+static void zero_stats(FIRSTPASS_STATS *section)
+{
+section->frame      = 0.0;
+section->intra_error = 0.0;
+section->coded_error = 0.0;
+section->ssim_weighted_pred_err = 0.0;
+section->pcnt_inter  = 0.0;
+section->pcnt_motion  = 0.0;
+section->pcnt_second_ref = 0.0;
+section->pcnt_neutral = 0.0;
+section->MVr        = 0.0;
+section->mvr_abs     = 0.0;
+section->MVc        = 0.0;
+section->mvc_abs     = 0.0;
+section->MVrv       = 0.0;
+section->MVcv       = 0.0;
+section->mv_in_out_count  = 0.0;
+section->new_mv_count = 0.0;
+section->count      = 0.0;
+section->duration   = 1.0;
+}
+static void accumulate_stats(FIRSTPASS_STATS *section, FIRSTPASS_STATS *frame)
+{
+section->frame += frame->frame;
+section->intra_error += frame->intra_error;
+section->coded_error += frame->coded_error;
+section->ssim_weighted_pred_err += frame->ssim_weighted_pred_err;
+section->pcnt_inter  += frame->pcnt_inter;
+section->pcnt_motion += frame->pcnt_motion;
+section->pcnt_second_ref += frame->pcnt_second_ref;
+section->pcnt_neutral += frame->pcnt_neutral;
+section->MVr        += frame->MVr;
+section->mvr_abs     += frame->mvr_abs;
+section->MVc        += frame->MVc;
+section->mvc_abs     += frame->mvc_abs;
+section->MVrv       += frame->MVrv;
+section->MVcv       += frame->MVcv;
+section->mv_in_out_count  += frame->mv_in_out_count;
+section->new_mv_count += frame->new_mv_count;
+section->count      += frame->count;
+section->duration   += frame->duration;
+}
+static void subtract_stats(FIRSTPASS_STATS *section, FIRSTPASS_STATS *frame)
+{
+section->frame -= frame->frame;
+section->intra_error -= frame->intra_error;
+section->coded_error -= frame->coded_error;
+section->ssim_weighted_pred_err -= frame->ssim_weighted_pred_err;
+section->pcnt_inter  -= frame->pcnt_inter;
+section->pcnt_motion -= frame->pcnt_motion;
+section->pcnt_second_ref -= frame->pcnt_second_ref;
+section->pcnt_neutral -= frame->pcnt_neutral;
+section->MVr        -= frame->MVr;
+section->mvr_abs     -= frame->mvr_abs;
+section->MVc        -= frame->MVc;
+section->mvc_abs     -= frame->mvc_abs;
+section->MVrv       -= frame->MVrv;
+section->MVcv       -= frame->MVcv;
+section->mv_in_out_count  -= frame->mv_in_out_count;
+section->new_mv_count -= frame->new_mv_count;
+section->count      -= frame->count;
+section->duration   -= frame->duration;
+}
+static void avg_stats(FIRSTPASS_STATS *section)
+{
+if (section->count < 1.0)
+return;
+section->intra_error /= section->count;
+section->coded_error /= section->count;
+section->ssim_weighted_pred_err /= section->count;
+section->pcnt_inter  /= section->count;
+section->pcnt_second_ref /= section->count;
+section->pcnt_neutral /= section->count;
+section->pcnt_motion /= section->count;
+section->MVr        /= section->count;
+section->mvr_abs     /= section->count;
+section->MVc        /= section->count;
+section->mvc_abs     /= section->count;
+section->MVrv       /= section->count;
+section->MVcv       /= section->count;
+section->mv_in_out_count   /= section->count;
+section->duration   /= section->count;
+}
+/* Calculate a modified Error used in distributing bits between easier
+* and harder frames
+*/
+static double calculate_modified_err(VP8_COMP *cpi, FIRSTPASS_STATS *this_frame)
+{
+double av_err = ( cpi->twopass.total_stats.ssim_weighted_pred_err /
+cpi->twopass.total_stats.count );
+double this_err = this_frame->ssim_weighted_pred_err;
+double modified_err;
+if (this_err > av_err)
+modified_err = av_err * pow((this_err / DOUBLE_DIVIDE_CHECK(av_err)), POW1);
+else
+modified_err = av_err * pow((this_err / DOUBLE_DIVIDE_CHECK(av_err)), POW2);
+return modified_err;
+}
+static const double weight_table[256] = {
+0.020000, 0.020000, 0.020000, 0.020000, 0.020000, 0.020000, 0.020000, 0.020000,
+0.020000, 0.020000, 0.020000, 0.020000, 0.020000, 0.020000, 0.020000, 0.020000,
+0.020000, 0.020000, 0.020000, 0.020000, 0.020000, 0.020000, 0.020000, 0.020000,
+0.020000, 0.020000, 0.020000, 0.020000, 0.020000, 0.020000, 0.020000, 0.020000,
+0.020000, 0.031250, 0.062500, 0.093750, 0.125000, 0.156250, 0.187500, 0.218750,
+0.250000, 0.281250, 0.312500, 0.343750, 0.375000, 0.406250, 0.437500, 0.468750,
+0.500000, 0.531250, 0.562500, 0.593750, 0.625000, 0.656250, 0.687500, 0.718750,
+0.750000, 0.781250, 0.812500, 0.843750, 0.875000, 0.906250, 0.937500, 0.968750,
+1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
+1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
+1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
+1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
+1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
+1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
+1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
+1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
+1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
+1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
+1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
+1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
+1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
+1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
+1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
+1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
+1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
+1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
+1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
+1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
+1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
+1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
+1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000,
+1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000, 1.000000
+};
+static double simple_weight(YV12_BUFFER_CONFIG *source)
+{
+int i, j;
+unsigned char *src = source->y_buffer;
+double sum_weights = 0.0;
+/* Loop throught the Y plane raw examining levels and creating a weight
+* for the image
+*/
+i = source->y_height;
+do
+{
+j = source->y_width;
+do
+{
+sum_weights += weight_table[ *src];
+src++;
+}while(--j);
+src -= source->y_width;
+src += source->y_stride;
+}while(--i);
+sum_weights /= (source->y_height * source->y_width);
+return sum_weights;
+}
+/* This function returns the current per frame maximum bitrate target */
+static int frame_max_bits(VP8_COMP *cpi)
+{
+/* Max allocation for a single frame based on the max section guidelines
+* passed in and how many bits are left
+*/
+int max_bits;
+/* For CBR we need to also consider buffer fullness.
+* If we are running below the optimal level then we need to gradually
+* tighten up on max_bits.
+*/
+if (cpi->oxcf.end_usage == USAGE_STREAM_FROM_SERVER)
+{
+double buffer_fullness_ratio = (double)cpi->buffer_level / DOUBLE_DIVIDE_CHECK((double)cpi->oxcf.optimal_buffer_level);
+/* For CBR base this on the target average bits per frame plus the
+* maximum sedction rate passed in by the user
+*/
+max_bits = (int)(cpi->av_per_frame_bandwidth * ((double)cpi->oxcf.two_pass_vbrmax_section / 100.0));
+/* If our buffer is below the optimum level */
+if (buffer_fullness_ratio < 1.0)
+{
+/* The lower of max_bits / 4 or cpi->av_per_frame_bandwidth / 4. */
+int min_max_bits = ((cpi->av_per_frame_bandwidth >> 2) < (max_bits >> 2)) ? cpi->av_per_frame_bandwidth >> 2 : max_bits >> 2;
+max_bits = (int)(max_bits * buffer_fullness_ratio);
+/* Lowest value we will set ... which should allow the buffer to
+* refill.
+*/
+if (max_bits < min_max_bits)
+max_bits = min_max_bits;
+}
+}
+/* VBR */
+else
+{
+/* For VBR base this on the bits and frames left plus the
+* two_pass_vbrmax_section rate passed in by the user
+*/
+max_bits = (int)(((double)cpi->twopass.bits_left / (cpi->twopass.total_stats.count - (double)cpi->common.current_video_frame)) * ((double)cpi->oxcf.two_pass_vbrmax_section / 100.0));
+}
+/* Trap case where we are out of bits */
+if (max_bits < 0)
+max_bits = 0;
+return max_bits;
+}
+void vp8_init_first_pass(VP8_COMP *cpi)
+{
+zero_stats(&cpi->twopass.total_stats);
+}
+void vp8_end_first_pass(VP8_COMP *cpi)
+{
+output_stats(cpi, cpi->output_pkt_list, &cpi->twopass.total_stats);
+}
+static void zz_motion_search( VP8_COMP *cpi, MACROBLOCK * x,
+YV12_BUFFER_CONFIG * raw_buffer,
+int * raw_motion_err,
+YV12_BUFFER_CONFIG * recon_buffer,
+int * best_motion_err, int recon_yoffset)
+{
+MACROBLOCKD * const xd = & x->e_mbd;
+BLOCK *b = &x->block[0];
+BLOCKD *d = &x->e_mbd.block[0];
+unsigned char *src_ptr = (*(b->base_src) + b->src);
+int src_stride = b->src_stride;
+unsigned char *raw_ptr;
+int raw_stride = raw_buffer->y_stride;
+unsigned char *ref_ptr;
+int ref_stride = x->e_mbd.pre.y_stride;
+/* Set up pointers for this macro block raw buffer */
+raw_ptr = (unsigned char *)(raw_buffer->y_buffer + recon_yoffset
++ d->offset);
+vp8_mse16x16 ( src_ptr, src_stride, raw_ptr, raw_stride,
+(unsigned int *)(raw_motion_err));
+/* Set up pointers for this macro block recon buffer */
+xd->pre.y_buffer = recon_buffer->y_buffer + recon_yoffset;
+ref_ptr = (unsigned char *)(xd->pre.y_buffer + d->offset );
+vp8_mse16x16 ( src_ptr, src_stride, ref_ptr, ref_stride,
+(unsigned int *)(best_motion_err));
+}
+static void first_pass_motion_search(VP8_COMP *cpi, MACROBLOCK *x,
+int_mv *ref_mv, MV *best_mv,
+YV12_BUFFER_CONFIG *recon_buffer,
+int *best_motion_err, int recon_yoffset )
+{
+MACROBLOCKD *const xd = & x->e_mbd;
+BLOCK *b = &x->block[0];
+BLOCKD *d = &x->e_mbd.block[0];
+int num00;
+int_mv tmp_mv;
+int_mv ref_mv_full;
+int tmp_err;
+int step_param = 3; /* Dont search over full range for first pass */
+int further_steps = (MAX_MVSEARCH_STEPS - 1) - step_param;
+int n;
+vp8_variance_fn_ptr_t v_fn_ptr = cpi->fn_ptr[BLOCK_16X16];
+int new_mv_mode_penalty = 256;
+/* override the default variance function to use MSE */
+v_fn_ptr.vf    = vp8_mse16x16;
+/* Set up pointers for this macro block recon buffer */
+xd->pre.y_buffer = recon_buffer->y_buffer + recon_yoffset;
+/* Initial step/diamond search centred on best mv */
+tmp_mv.as_int = 0;
+ref_mv_full.as_mv.col = ref_mv->as_mv.col>>3;
+ref_mv_full.as_mv.row = ref_mv->as_mv.row>>3;
+tmp_err = cpi->diamond_search_sad(x, b, d, &ref_mv_full, &tmp_mv, step_param,
+x->sadperbit16, &num00, &v_fn_ptr,
+x->mvcost, ref_mv);
+if ( tmp_err < INT_MAX-new_mv_mode_penalty )
+tmp_err += new_mv_mode_penalty;
+if (tmp_err < *best_motion_err)
+{
+*best_motion_err = tmp_err;
+best_mv->row = tmp_mv.as_mv.row;
+best_mv->col = tmp_mv.as_mv.col;
+}
+/* Further step/diamond searches as necessary */
+n = num00;
+num00 = 0;
+while (n < further_steps)
+{
+n++;
+if (num00)
+num00--;
+else
+{
+tmp_err = cpi->diamond_search_sad(x, b, d, &ref_mv_full, &tmp_mv,
+step_param + n, x->sadperbit16,
+&num00, &v_fn_ptr, x->mvcost,
+ref_mv);
+if ( tmp_err < INT_MAX-new_mv_mode_penalty )
+tmp_err += new_mv_mode_penalty;
+if (tmp_err < *best_motion_err)
+{
+*best_motion_err = tmp_err;
+best_mv->row = tmp_mv.as_mv.row;
+best_mv->col = tmp_mv.as_mv.col;
+}
+}
+}
+}
+void vp8_first_pass(VP8_COMP *cpi)
+{
+int mb_row, mb_col;
+MACROBLOCK *const x = & cpi->mb;
+VP8_COMMON *const cm = & cpi->common;
+MACROBLOCKD *const xd = & x->e_mbd;
+int recon_yoffset, recon_uvoffset;
+YV12_BUFFER_CONFIG *lst_yv12 = &cm->yv12_fb[cm->lst_fb_idx];
+YV12_BUFFER_CONFIG *new_yv12 = &cm->yv12_fb[cm->new_fb_idx];
+YV12_BUFFER_CONFIG *gld_yv12 = &cm->yv12_fb[cm->gld_fb_idx];
+int recon_y_stride = lst_yv12->y_stride;
+int recon_uv_stride = lst_yv12->uv_stride;
+int64_t intra_error = 0;
+int64_t coded_error = 0;
+int sum_mvr = 0, sum_mvc = 0;
+int sum_mvr_abs = 0, sum_mvc_abs = 0;
+int sum_mvrs = 0, sum_mvcs = 0;
+int mvcount = 0;
+int intercount = 0;
+int second_ref_count = 0;
+int intrapenalty = 256;
+int neutral_count = 0;
+int new_mv_count = 0;
+int sum_in_vectors = 0;
+uint32_t lastmv_as_int = 0;
+int_mv zero_ref_mv;
+zero_ref_mv.as_int = 0;
+vp8_clear_system_state();
+x->src = * cpi->Source;
+xd->pre = *lst_yv12;
+xd->dst = *new_yv12;
+x->partition_info = x->pi;
+xd->mode_info_context = cm->mi;
+if(!cm->use_bilinear_mc_filter)
+{
+xd->subpixel_predict        = vp8_sixtap_predict4x4;
+xd->subpixel_predict8x4     = vp8_sixtap_predict8x4;
+xd->subpixel_predict8x8     = vp8_sixtap_predict8x8;
+xd->subpixel_predict16x16   = vp8_sixtap_predict16x16;
+}
+else
+{
+xd->subpixel_predict        = vp8_bilinear_predict4x4;
+xd->subpixel_predict8x4     = vp8_bilinear_predict8x4;
+xd->subpixel_predict8x8     = vp8_bilinear_predict8x8;
+xd->subpixel_predict16x16   = vp8_bilinear_predict16x16;
+}
+vp8_build_block_offsets(x);
+/* set up frame new frame for intra coded blocks */
+vp8_setup_intra_recon(new_yv12);
+vp8cx_frame_init_quantizer(cpi);
+/* Initialise the MV cost table to the defaults */
+{
+int flag[2] = {1, 1};
+vp8_initialize_rd_consts(cpi, x, vp8_dc_quant(cm->base_qindex, cm->y1dc_delta_q));
+vpx_memcpy(cm->fc.mvc, vp8_default_mv_context, sizeof(vp8_default_mv_context));
+vp8_build_component_cost_table(cpi->mb.mvcost, (const MV_CONTEXT *) cm->fc.mvc, flag);
+}
+/* for each macroblock row in image */
+for (mb_row = 0; mb_row < cm->mb_rows; mb_row++)
+{
+int_mv best_ref_mv;
+best_ref_mv.as_int = 0;
+/* reset above block coeffs */
+xd->up_available = (mb_row != 0);
+recon_yoffset = (mb_row * recon_y_stride * 16);
+recon_uvoffset = (mb_row * recon_uv_stride * 8);
+/* Set up limit values for motion vectors to prevent them extending
+* outside the UMV borders
+*/
+x->mv_row_min = -((mb_row * 16) + (VP8BORDERINPIXELS - 16));
+x->mv_row_max = ((cm->mb_rows - 1 - mb_row) * 16) + (VP8BORDERINPIXELS - 16);
+/* for each macroblock col in image */
+for (mb_col = 0; mb_col < cm->mb_cols; mb_col++)
+{
+int this_error;
+int gf_motion_error = INT_MAX;
+int use_dc_pred = (mb_col || mb_row) && (!mb_col || !mb_row);
+xd->dst.y_buffer = new_yv12->y_buffer + recon_yoffset;
+xd->dst.u_buffer = new_yv12->u_buffer + recon_uvoffset;
+xd->dst.v_buffer = new_yv12->v_buffer + recon_uvoffset;
+xd->left_available = (mb_col != 0);
+/* Copy current mb to a buffer */
+vp8_copy_mem16x16(x->src.y_buffer, x->src.y_stride, x->thismb, 16);
+/* do intra 16x16 prediction */
+this_error = vp8_encode_intra(cpi, x, use_dc_pred);
+/* "intrapenalty" below deals with situations where the intra
+* and inter error scores are very low (eg a plain black frame)
+* We do not have special cases in first pass for 0,0 and
+* nearest etc so all inter modes carry an overhead cost
+* estimate fot the mv. When the error score is very low this
+* causes us to pick all or lots of INTRA modes and throw lots
+* of key frames. This penalty adds a cost matching that of a
+* 0,0 mv to the intra case.
+*/
+this_error += intrapenalty;
+/* Cumulative intra error total */
+intra_error += (int64_t)this_error;
+/* Set up limit values for motion vectors to prevent them
+* extending outside the UMV borders
+*/
+x->mv_col_min = -((mb_col * 16) + (VP8BORDERINPIXELS - 16));
+x->mv_col_max = ((cm->mb_cols - 1 - mb_col) * 16) + (VP8BORDERINPIXELS - 16);
+/* Other than for the first frame do a motion search */
+if (cm->current_video_frame > 0)
+{
+BLOCKD *d = &x->e_mbd.block[0];
+MV tmp_mv = {0, 0};
+int tmp_err;
+int motion_error = INT_MAX;
+int raw_motion_error = INT_MAX;
+/* Simple 0,0 motion with no mv overhead */
+zz_motion_search( cpi, x, cpi->last_frame_unscaled_source,
+&raw_motion_error, lst_yv12, &motion_error,
+recon_yoffset );
+d->bmi.mv.as_mv.row = 0;
+d->bmi.mv.as_mv.col = 0;
+if (raw_motion_error < cpi->oxcf.encode_breakout)
+goto skip_motion_search;
+/* Test last reference frame using the previous best mv as the
+* starting point (best reference) for the search
+*/
+first_pass_motion_search(cpi, x, &best_ref_mv,
+&d->bmi.mv.as_mv, lst_yv12,
+&motion_error, recon_yoffset);
+/* If the current best reference mv is not centred on 0,0
+* then do a 0,0 based search as well
+*/
+if (best_ref_mv.as_int)
+{
+tmp_err = INT_MAX;
+first_pass_motion_search(cpi, x, &zero_ref_mv, &tmp_mv,
+lst_yv12, &tmp_err, recon_yoffset);
+if ( tmp_err < motion_error )
+{
+motion_error = tmp_err;
+d->bmi.mv.as_mv.row = tmp_mv.row;
+d->bmi.mv.as_mv.col = tmp_mv.col;
+}
+}
+/* Experimental search in a second reference frame ((0,0)
+* based only)
+*/
+if (cm->current_video_frame > 1)
+{
+first_pass_motion_search(cpi, x, &zero_ref_mv, &tmp_mv, gld_yv12, &gf_motion_error, recon_yoffset);
+if ((gf_motion_error < motion_error) && (gf_motion_error < this_error))
+{
+second_ref_count++;
+}
+/* Reset to last frame as reference buffer */
+xd->pre.y_buffer = lst_yv12->y_buffer + recon_yoffset;
+xd->pre.u_buffer = lst_yv12->u_buffer + recon_uvoffset;
+xd->pre.v_buffer = lst_yv12->v_buffer + recon_uvoffset;
+}
+skip_motion_search:
+/* Intra assumed best */
+best_ref_mv.as_int = 0;
+if (motion_error <= this_error)
+{
+/* Keep a count of cases where the inter and intra were
+* very close and very low. This helps with scene cut
+* detection for example in cropped clips with black bars
+* at the sides or top and bottom.
+*/
+if( (((this_error-intrapenalty) * 9) <=
+(motion_error*10)) &&
+(this_error < (2*intrapenalty)) )
+{
+neutral_count++;
+}
+d->bmi.mv.as_mv.row *= 8;
+d->bmi.mv.as_mv.col *= 8;
+this_error = motion_error;
+vp8_set_mbmode_and_mvs(x, NEWMV, &d->bmi.mv);
+vp8_encode_inter16x16y(x);
+sum_mvr += d->bmi.mv.as_mv.row;
+sum_mvr_abs += abs(d->bmi.mv.as_mv.row);
+sum_mvc += d->bmi.mv.as_mv.col;
+sum_mvc_abs += abs(d->bmi.mv.as_mv.col);
+sum_mvrs += d->bmi.mv.as_mv.row * d->bmi.mv.as_mv.row;
+sum_mvcs += d->bmi.mv.as_mv.col * d->bmi.mv.as_mv.col;
+intercount++;
+best_ref_mv.as_int = d->bmi.mv.as_int;
+/* Was the vector non-zero */
+if (d->bmi.mv.as_int)
+{
+mvcount++;
+/* Was it different from the last non zero vector */
+if ( d->bmi.mv.as_int != lastmv_as_int )
+new_mv_count++;
+lastmv_as_int = d->bmi.mv.as_int;
+/* Does the Row vector point inwards or outwards */
+if (mb_row < cm->mb_rows / 2)
+{
+if (d->bmi.mv.as_mv.row > 0)
+sum_in_vectors--;
+else if (d->bmi.mv.as_mv.row < 0)
+sum_in_vectors++;
+}
+else if (mb_row > cm->mb_rows / 2)
+{
+if (d->bmi.mv.as_mv.row > 0)
+sum_in_vectors++;
+else if (d->bmi.mv.as_mv.row < 0)
+sum_in_vectors--;
+}
+/* Does the Row vector point inwards or outwards */
+if (mb_col < cm->mb_cols / 2)
+{
+if (d->bmi.mv.as_mv.col > 0)
+sum_in_vectors--;
+else if (d->bmi.mv.as_mv.col < 0)
+sum_in_vectors++;
+}
+else if (mb_col > cm->mb_cols / 2)
+{
+if (d->bmi.mv.as_mv.col > 0)
+sum_in_vectors++;
+else if (d->bmi.mv.as_mv.col < 0)
+sum_in_vectors--;
+}
+}
+}
+}
+coded_error += (int64_t)this_error;
+/* adjust to the next column of macroblocks */
+x->src.y_buffer += 16;
+x->src.u_buffer += 8;
+x->src.v_buffer += 8;
+recon_yoffset += 16;
+recon_uvoffset += 8;
+}
+/* adjust to the next row of mbs */
+x->src.y_buffer += 16 * x->src.y_stride - 16 * cm->mb_cols;
+x->src.u_buffer += 8 * x->src.uv_stride - 8 * cm->mb_cols;
+x->src.v_buffer += 8 * x->src.uv_stride - 8 * cm->mb_cols;
+/* extend the recon for intra prediction */
+vp8_extend_mb_row(new_yv12, xd->dst.y_buffer + 16, xd->dst.u_buffer + 8, xd->dst.v_buffer + 8);
+vp8_clear_system_state();
+}
+vp8_clear_system_state();
+{
+double weight = 0.0;
+FIRSTPASS_STATS fps;
+fps.frame      = cm->current_video_frame ;
+fps.intra_error = (double)(intra_error >> 8);
+fps.coded_error = (double)(coded_error >> 8);
+weight = simple_weight(cpi->Source);
+if (weight < 0.1)
+weight = 0.1;
+fps.ssim_weighted_pred_err = fps.coded_error * weight;
+fps.pcnt_inter  = 0.0;
+fps.pcnt_motion = 0.0;
+fps.MVr        = 0.0;
+fps.mvr_abs     = 0.0;
+fps.MVc        = 0.0;
+fps.mvc_abs     = 0.0;
+fps.MVrv       = 0.0;
+fps.MVcv       = 0.0;
+fps.mv_in_out_count  = 0.0;
+fps.new_mv_count = 0.0;
+fps.count      = 1.0;
+fps.pcnt_inter   = 1.0 * (double)intercount / cm->MBs;
+fps.pcnt_second_ref = 1.0 * (double)second_ref_count / cm->MBs;
+fps.pcnt_neutral = 1.0 * (double)neutral_count / cm->MBs;
+if (mvcount > 0)
+{
+fps.MVr = (double)sum_mvr / (double)mvcount;
+fps.mvr_abs = (double)sum_mvr_abs / (double)mvcount;
+fps.MVc = (double)sum_mvc / (double)mvcount;
+fps.mvc_abs = (double)sum_mvc_abs / (double)mvcount;
+fps.MVrv = ((double)sum_mvrs - (fps.MVr * fps.MVr / (double)mvcount)) / (double)mvcount;
+fps.MVcv = ((double)sum_mvcs - (fps.MVc * fps.MVc / (double)mvcount)) / (double)mvcount;
+fps.mv_in_out_count = (double)sum_in_vectors / (double)(mvcount * 2);
+fps.new_mv_count = new_mv_count;
+fps.pcnt_motion = 1.0 * (double)mvcount / cpi->common.MBs;
+}
+/* TODO:  handle the case when duration is set to 0, or something less
+* than the full time between subsequent cpi->source_time_stamps
+*/
+fps.duration = (double)(cpi->source->ts_end
+- cpi->source->ts_start);
+/* don't want to do output stats with a stack variable! */
+memcpy(&cpi->twopass.this_frame_stats,
+&fps,
+sizeof(FIRSTPASS_STATS));
+output_stats(cpi, cpi->output_pkt_list, &cpi->twopass.this_frame_stats);
+accumulate_stats(&cpi->twopass.total_stats, &fps);
+}
+/* Copy the previous Last Frame into the GF buffer if specific
+* conditions for doing so are met
+*/
+if ((cm->current_video_frame > 0) &&
+(cpi->twopass.this_frame_stats.pcnt_inter > 0.20) &&
+((cpi->twopass.this_frame_stats.intra_error /
+DOUBLE_DIVIDE_CHECK(cpi->twopass.this_frame_stats.coded_error)) >
+2.0))
+{
+vp8_yv12_copy_frame(lst_yv12, gld_yv12);
+}
+/* swap frame pointers so last frame refers to the frame we just
+* compressed
+*/
+vp8_swap_yv12_buffer(lst_yv12, new_yv12);
+vp8_yv12_extend_frame_borders(lst_yv12);
+/* Special case for the first frame. Copy into the GF buffer as a
+* second reference.
+*/
+if (cm->current_video_frame == 0)
+{
+vp8_yv12_copy_frame(lst_yv12, gld_yv12);
+}
+/* use this to see what the first pass reconstruction looks like */
+if (0)
+{
+char filename[512];
+FILE *recon_file;
+sprintf(filename, "enc%04d.yuv", (int) cm->current_video_frame);
+if (cm->current_video_frame == 0)
+recon_file = fopen(filename, "wb");
+else
+recon_file = fopen(filename, "ab");
+(void) fwrite(lst_yv12->buffer_alloc, lst_yv12->frame_size, 1,
+recon_file);
+fclose(recon_file);
+}
+cm->current_video_frame++;
+}
+extern const int vp8_bits_per_mb[2][QINDEX_RANGE];
+/* Estimate a cost per mb attributable to overheads such as the coding of
+* modes and motion vectors.
+* Currently simplistic in its assumptions for testing.
+*/
+static double bitcost( double prob )
+{
+if (prob > 0.000122)
+return -log(prob) / log(2.0);
+else
+return 13.0;
+}
+static int64_t estimate_modemvcost(VP8_COMP *cpi,
+FIRSTPASS_STATS * fpstats)
+{
+int mv_cost;
+int64_t mode_cost;
+double av_pct_inter = fpstats->pcnt_inter / fpstats->count;
+double av_pct_motion = fpstats->pcnt_motion / fpstats->count;
+double av_intra = (1.0 - av_pct_inter);
+double zz_cost;
+double motion_cost;
+double intra_cost;
+zz_cost = bitcost(av_pct_inter - av_pct_motion);
+motion_cost = bitcost(av_pct_motion);
+intra_cost = bitcost(av_intra);
+/* Estimate of extra bits per mv overhead for mbs
+* << 9 is the normalization to the (bits * 512) used in vp8_bits_per_mb
+*/
+mv_cost = ((int)(fpstats->new_mv_count / fpstats->count) * 8) << 9;
+/* Crude estimate of overhead cost from modes
+* << 9 is the normalization to (bits * 512) used in vp8_bits_per_mb
+*/
+mode_cost =((((av_pct_inter - av_pct_motion) * zz_cost) +
+(av_pct_motion * motion_cost) +
+(av_intra * intra_cost)) * cpi->common.MBs) * 512;
+return mv_cost + mode_cost;
+}
+static double calc_correction_factor( double err_per_mb,
+double err_devisor,
+double pt_low,
+double pt_high,
+int Q )
+{
+double power_term;
+double error_term = err_per_mb / err_devisor;
+double correction_factor;
+/* Adjustment based on Q to power term. */
+power_term = pt_low + (Q * 0.01);
+power_term = (power_term > pt_high) ? pt_high : power_term;
+/* Adjustments to error term */
+/* TBD */
+/* Calculate correction factor */
+correction_factor = pow(error_term, power_term);
+/* Clip range */
+correction_factor =
+(correction_factor < 0.05)
+? 0.05 : (correction_factor > 5.0) ? 5.0 : correction_factor;
+return correction_factor;
+}
+static int estimate_max_q(VP8_COMP *cpi,
+FIRSTPASS_STATS * fpstats,
+int section_target_bandwitdh,
+int overhead_bits )
+{
+int Q;
+int num_mbs = cpi->common.MBs;
+int target_norm_bits_per_mb;
+double section_err = (fpstats->coded_error / fpstats->count);
+double err_per_mb = section_err / num_mbs;
+double err_correction_factor;
+double speed_correction = 1.0;
+int overhead_bits_per_mb;
+if (section_target_bandwitdh <= 0)
+return cpi->twopass.maxq_max_limit;       /* Highest value allowed */
+target_norm_bits_per_mb =
+(section_target_bandwitdh < (1 << 20))
+? (512 * section_target_bandwitdh) / num_mbs
+: 512 * (section_target_bandwitdh / num_mbs);
+/* Calculate a corrective factor based on a rolling ratio of bits spent
+* vs target bits
+*/
+if ((cpi->rolling_target_bits > 0) &&
+(cpi->active_worst_quality < cpi->worst_quality))
+{
+double rolling_ratio;
+rolling_ratio = (double)cpi->rolling_actual_bits /
+(double)cpi->rolling_target_bits;
+if (rolling_ratio < 0.95)
+cpi->twopass.est_max_qcorrection_factor -= 0.005;
+else if (rolling_ratio > 1.05)
+cpi->twopass.est_max_qcorrection_factor += 0.005;
+cpi->twopass.est_max_qcorrection_factor =
+(cpi->twopass.est_max_qcorrection_factor < 0.1)
+? 0.1
+: (cpi->twopass.est_max_qcorrection_factor > 10.0)
+? 10.0 : cpi->twopass.est_max_qcorrection_factor;
+}
+/* Corrections for higher compression speed settings
+* (reduced compression expected)
+*/
+if ((cpi->compressor_speed == 3) || (cpi->compressor_speed == 1))
+{
+if (cpi->oxcf.cpu_used <= 5)
+speed_correction = 1.04 + (cpi->oxcf.cpu_used * 0.04);
+else
+speed_correction = 1.25;
+}
+/* Estimate of overhead bits per mb */
+/* Correction to overhead bits for min allowed Q. */
+overhead_bits_per_mb = overhead_bits / num_mbs;
+overhead_bits_per_mb = (int)(overhead_bits_per_mb *
+pow( 0.98, (double)cpi->twopass.maxq_min_limit ));
+/* Try and pick a max Q that will be high enough to encode the
+* content at the given rate.
+*/
+for (Q = cpi->twopass.maxq_min_limit; Q < cpi->twopass.maxq_max_limit; Q++)
+{
+int bits_per_mb_at_this_q;
+/* Error per MB based correction factor */
+err_correction_factor =
+calc_correction_factor(err_per_mb, 150.0, 0.40, 0.90, Q);
+bits_per_mb_at_this_q =
+vp8_bits_per_mb[INTER_FRAME][Q] + overhead_bits_per_mb;
+bits_per_mb_at_this_q = (int)(.5 + err_correction_factor
+* speed_correction * cpi->twopass.est_max_qcorrection_factor
+* cpi->twopass.section_max_qfactor
+* (double)bits_per_mb_at_this_q);
+/* Mode and motion overhead */
+/* As Q rises in real encode loop rd code will force overhead down
+* We make a crude adjustment for this here as *.98 per Q step.
+*/
+overhead_bits_per_mb = (int)((double)overhead_bits_per_mb * 0.98);
+if (bits_per_mb_at_this_q <= target_norm_bits_per_mb)
+break;
+}
+/* Restriction on active max q for constrained quality mode. */
+if ( (cpi->oxcf.end_usage == USAGE_CONSTRAINED_QUALITY) &&
+(Q < cpi->cq_target_quality) )
+{
+Q = cpi->cq_target_quality;
+}
+/* Adjust maxq_min_limit and maxq_max_limit limits based on
+* average q observed in clip for non kf/gf.arf frames
+* Give average a chance to settle though.
+*/
+if ( (cpi->ni_frames >
+((int)cpi->twopass.total_stats.count >> 8)) &&
+(cpi->ni_frames > 150) )
+{
+cpi->twopass.maxq_max_limit = ((cpi->ni_av_qi + 32) < cpi->worst_quality)
+? (cpi->ni_av_qi + 32) : cpi->worst_quality;
+cpi->twopass.maxq_min_limit = ((cpi->ni_av_qi - 32) > cpi->best_quality)
+? (cpi->ni_av_qi - 32) : cpi->best_quality;
+}
+return Q;
+}
+/* For cq mode estimate a cq level that matches the observed
+* complexity and data rate.
+*/
+static int estimate_cq( VP8_COMP *cpi,
+FIRSTPASS_STATS * fpstats,
+int section_target_bandwitdh,
+int overhead_bits )
+{
+int Q;
+int num_mbs = cpi->common.MBs;
+int target_norm_bits_per_mb;
+double section_err = (fpstats->coded_error / fpstats->count);
+double err_per_mb = section_err / num_mbs;
+double err_correction_factor;
+double speed_correction = 1.0;
+double clip_iiratio;
+double clip_iifactor;
+int overhead_bits_per_mb;
+if (0)
+{
+FILE *f = fopen("epmp.stt", "a");
+fprintf(f, "%10.2f\n", err_per_mb );
+fclose(f);
+}
+target_norm_bits_per_mb = (section_target_bandwitdh < (1 << 20))
+? (512 * section_target_bandwitdh) / num_mbs
+: 512 * (section_target_bandwitdh / num_mbs);
+/* Estimate of overhead bits per mb */
+overhead_bits_per_mb = overhead_bits / num_mbs;
+/* Corrections for higher compression speed settings
+* (reduced compression expected)
+*/
+if ((cpi->compressor_speed == 3) || (cpi->compressor_speed == 1))
+{
+if (cpi->oxcf.cpu_used <= 5)
+speed_correction = 1.04 + (cpi->oxcf.cpu_used * 0.04);
+else
+speed_correction = 1.25;
+}
+/* II ratio correction factor for clip as a whole */
+clip_iiratio = cpi->twopass.total_stats.intra_error /
+DOUBLE_DIVIDE_CHECK(cpi->twopass.total_stats.coded_error);
+clip_iifactor = 1.0 - ((clip_iiratio - 10.0) * 0.025);
+if (clip_iifactor < 0.80)
+clip_iifactor = 0.80;
+/* Try and pick a Q that can encode the content at the given rate. */
+for (Q = 0; Q < MAXQ; Q++)
+{
+int bits_per_mb_at_this_q;
+/* Error per MB based correction factor */
+err_correction_factor =
+calc_correction_factor(err_per_mb, 100.0, 0.40, 0.90, Q);
+bits_per_mb_at_this_q =
+vp8_bits_per_mb[INTER_FRAME][Q] + overhead_bits_per_mb;
+bits_per_mb_at_this_q =
+(int)( .5 + err_correction_factor *
+speed_correction *
+clip_iifactor *
+(double)bits_per_mb_at_this_q);
+/* Mode and motion overhead */
+/* As Q rises in real encode loop rd code will force overhead down
+* We make a crude adjustment for this here as *.98 per Q step.
+*/
+overhead_bits_per_mb = (int)((double)overhead_bits_per_mb * 0.98);
+if (bits_per_mb_at_this_q <= target_norm_bits_per_mb)
+break;
+}
+/* Clip value to range "best allowed to (worst allowed - 1)" */
+Q = cq_level[Q];
+if ( Q >= cpi->worst_quality )
+Q = cpi->worst_quality - 1;
+if ( Q < cpi->best_quality )
+Q = cpi->best_quality;
+return Q;
+}
+static int estimate_q(VP8_COMP *cpi, double section_err, int section_target_bandwitdh)
+{
+int Q;
+int num_mbs = cpi->common.MBs;
+int target_norm_bits_per_mb;
+double err_per_mb = section_err / num_mbs;
+double err_correction_factor;
+double speed_correction = 1.0;
+target_norm_bits_per_mb = (section_target_bandwitdh < (1 << 20)) ? (512 * section_target_bandwitdh) / num_mbs : 512 * (section_target_bandwitdh / num_mbs);
+/* Corrections for higher compression speed settings
+* (reduced compression expected)
+*/
+if ((cpi->compressor_speed == 3) || (cpi->compressor_speed == 1))
+{
+if (cpi->oxcf.cpu_used <= 5)
+speed_correction = 1.04 + (cpi->oxcf.cpu_used * 0.04);
+else
+speed_correction = 1.25;
+}
+/* Try and pick a Q that can encode the content at the given rate. */
+for (Q = 0; Q < MAXQ; Q++)
+{
+int bits_per_mb_at_this_q;
+/* Error per MB based correction factor */
+err_correction_factor =
+calc_correction_factor(err_per_mb, 150.0, 0.40, 0.90, Q);
+bits_per_mb_at_this_q =
+(int)( .5 + ( err_correction_factor *
+speed_correction *
+cpi->twopass.est_max_qcorrection_factor *
+(double)vp8_bits_per_mb[INTER_FRAME][Q] / 1.0 ) );
+if (bits_per_mb_at_this_q <= target_norm_bits_per_mb)
+break;
+}
+return Q;
+}
+/* Estimate a worst case Q for a KF group */
+static int estimate_kf_group_q(VP8_COMP *cpi, double section_err, int section_target_bandwitdh, double group_iiratio)
+{
+int Q;
+int num_mbs = cpi->common.MBs;
+int target_norm_bits_per_mb = (512 * section_target_bandwitdh) / num_mbs;
+int bits_per_mb_at_this_q;
+double err_per_mb = section_err / num_mbs;
+double err_correction_factor;
+double speed_correction = 1.0;
+double current_spend_ratio = 1.0;
+double pow_highq = (POW1 < 0.6) ? POW1 + 0.3 : 0.90;
+double pow_lowq = (POW1 < 0.7) ? POW1 + 0.1 : 0.80;
+double iiratio_correction_factor = 1.0;
+double combined_correction_factor;
+/* Trap special case where the target is <= 0 */
+if (target_norm_bits_per_mb <= 0)
+return MAXQ * 2;
+/* Calculate a corrective factor based on a rolling ratio of bits spent
+*  vs target bits
+* This is clamped to the range 0.1 to 10.0
+*/
+if (cpi->long_rolling_target_bits <= 0)
+current_spend_ratio = 10.0;
+else
+{
+current_spend_ratio = (double)cpi->long_rolling_actual_bits / (double)cpi->long_rolling_target_bits;
+current_spend_ratio = (current_spend_ratio > 10.0) ? 10.0 : (current_spend_ratio < 0.1) ? 0.1 : current_spend_ratio;
+}
+/* Calculate a correction factor based on the quality of prediction in
+* the sequence as indicated by intra_inter error score ratio (IIRatio)
+* The idea here is to favour subsampling in the hardest sections vs
+* the easyest.
+*/
+iiratio_correction_factor = 1.0 - ((group_iiratio - 6.0) * 0.1);
+if (iiratio_correction_factor < 0.5)
+iiratio_correction_factor = 0.5;
+/* Corrections for higher compression speed settings
+* (reduced compression expected)
+*/
+if ((cpi->compressor_speed == 3) || (cpi->compressor_speed == 1))
+{
+if (cpi->oxcf.cpu_used <= 5)
+speed_correction = 1.04 + (cpi->oxcf.cpu_used * 0.04);
+else
+speed_correction = 1.25;
+}
+/* Combine the various factors calculated above */
+combined_correction_factor = speed_correction * iiratio_correction_factor * current_spend_ratio;
+/* Try and pick a Q that should be high enough to encode the content at
+* the given rate.
+*/
+for (Q = 0; Q < MAXQ; Q++)
+{
+/* Error per MB based correction factor */
+err_correction_factor =
+calc_correction_factor(err_per_mb, 150.0, pow_lowq, pow_highq, Q);
+bits_per_mb_at_this_q =
+(int)(.5 + ( err_correction_factor *
+combined_correction_factor *
+(double)vp8_bits_per_mb[INTER_FRAME][Q]) );
+if (bits_per_mb_at_this_q <= target_norm_bits_per_mb)
+break;
+}
+/* If we could not hit the target even at Max Q then estimate what Q
+* would have been required
+*/
+while ((bits_per_mb_at_this_q > target_norm_bits_per_mb)  && (Q < (MAXQ * 2)))
+{
+bits_per_mb_at_this_q = (int)(0.96 * bits_per_mb_at_this_q);
+Q++;
+}
+if (0)
+{
+FILE *f = fopen("estkf_q.stt", "a");
+fprintf(f, "%8d %8d %8d %8.2f %8.3f %8.2f %8.3f %8.3f %8.3f %8d\n", cpi->common.current_video_frame, bits_per_mb_at_this_q,
+target_norm_bits_per_mb, err_per_mb, err_correction_factor,
+current_spend_ratio, group_iiratio, iiratio_correction_factor,
+(double)cpi->buffer_level / (double)cpi->oxcf.optimal_buffer_level, Q);
+fclose(f);
+}
+return Q;
+}
+extern void vp8_new_framerate(VP8_COMP *cpi, double framerate);
+void vp8_init_second_pass(VP8_COMP *cpi)
+{
+FIRSTPASS_STATS this_frame;
+FIRSTPASS_STATS *start_pos;
+double two_pass_min_rate = (double)(cpi->oxcf.target_bandwidth * cpi->oxcf.two_pass_vbrmin_section / 100);
+zero_stats(&cpi->twopass.total_stats);
+zero_stats(&cpi->twopass.total_left_stats);
+if (!cpi->twopass.stats_in_end)
+return;
+cpi->twopass.total_stats = *cpi->twopass.stats_in_end;
+cpi->twopass.total_left_stats = cpi->twopass.total_stats;
+/* each frame can have a different duration, as the frame rate in the
+* source isn't guaranteed to be constant.   The frame rate prior to
+* the first frame encoded in the second pass is a guess.  However the
+* sum duration is not. Its calculated based on the actual durations of
+* all frames from the first pass.
+*/
+vp8_new_framerate(cpi, 10000000.0 * cpi->twopass.total_stats.count / cpi->twopass.total_stats.duration);
+cpi->output_framerate = cpi->framerate;
+cpi->twopass.bits_left = (int64_t)(cpi->twopass.total_stats.duration * cpi->oxcf.target_bandwidth / 10000000.0) ;
+cpi->twopass.bits_left -= (int64_t)(cpi->twopass.total_stats.duration * two_pass_min_rate / 10000000.0);
+/* Calculate a minimum intra value to be used in determining the IIratio
+* scores used in the second pass. We have this minimum to make sure
+* that clips that are static but "low complexity" in the intra domain
+* are still boosted appropriately for KF/GF/ARF
+*/
+cpi->twopass.kf_intra_err_min = KF_MB_INTRA_MIN * cpi->common.MBs;
+cpi->twopass.gf_intra_err_min = GF_MB_INTRA_MIN * cpi->common.MBs;
+/* Scan the first pass file and calculate an average Intra / Inter error
+* score ratio for the sequence
+*/
+{
+double sum_iiratio = 0.0;
+double IIRatio;
+start_pos = cpi->twopass.stats_in; /* Note starting "file" position */
+while (input_stats(cpi, &this_frame) != EOF)
+{
+IIRatio = this_frame.intra_error / DOUBLE_DIVIDE_CHECK(this_frame.coded_error);
+IIRatio = (IIRatio < 1.0) ? 1.0 : (IIRatio > 20.0) ? 20.0 : IIRatio;
+sum_iiratio += IIRatio;
+}
+cpi->twopass.avg_iiratio = sum_iiratio / DOUBLE_DIVIDE_CHECK((double)cpi->twopass.total_stats.count);
+/* Reset file position */
+reset_fpf_position(cpi, start_pos);
+}
+/* Scan the first pass file and calculate a modified total error based
+* upon the bias/power function used to allocate bits
+*/
+{
+start_pos = cpi->twopass.stats_in;  /* Note starting "file" position */
+cpi->twopass.modified_error_total = 0.0;
+cpi->twopass.modified_error_used = 0.0;
+while (input_stats(cpi, &this_frame) != EOF)
+{
+cpi->twopass.modified_error_total += calculate_modified_err(cpi, &this_frame);
+}
+cpi->twopass.modified_error_left = cpi->twopass.modified_error_total;
+reset_fpf_position(cpi, start_pos);  /* Reset file position */
+}
+}
+void vp8_end_second_pass(VP8_COMP *cpi)
+{
+}
+/* This function gives and estimate of how badly we believe the prediction
+* quality is decaying from frame to frame.
+*/
+static double get_prediction_decay_rate(VP8_COMP *cpi, FIRSTPASS_STATS *next_frame)
+{
+double prediction_decay_rate;
+double motion_decay;
+double motion_pct = next_frame->pcnt_motion;
+/* Initial basis is the % mbs inter coded */
+prediction_decay_rate = next_frame->pcnt_inter;
+/* High % motion -> somewhat higher decay rate */
+motion_decay = (1.0 - (motion_pct / 20.0));
+if (motion_decay < prediction_decay_rate)
+prediction_decay_rate = motion_decay;
+/* Adjustment to decay rate based on speed of motion */
+{
+double this_mv_rabs;
+double this_mv_cabs;
+double distance_factor;
+this_mv_rabs = fabs(next_frame->mvr_abs * motion_pct);
+this_mv_cabs = fabs(next_frame->mvc_abs * motion_pct);
+distance_factor = sqrt((this_mv_rabs * this_mv_rabs) +
+(this_mv_cabs * this_mv_cabs)) / 250.0;
+distance_factor = ((distance_factor > 1.0)
+? 0.0 : (1.0 - distance_factor));
+if (distance_factor < prediction_decay_rate)
+prediction_decay_rate = distance_factor;
+}
+return prediction_decay_rate;
+}
+/* Function to test for a condition where a complex transition is followed
+* by a static section. For example in slide shows where there is a fade
+* between slides. This is to help with more optimal kf and gf positioning.
+*/
+static int detect_transition_to_still(
+VP8_COMP *cpi,
+int frame_interval,
+int still_interval,
+double loop_decay_rate,
+double decay_accumulator )
+{
+int trans_to_still = 0;
+/* Break clause to detect very still sections after motion
+* For example a static image after a fade or other transition
+* instead of a clean scene cut.
+*/
+if ( (frame_interval > MIN_GF_INTERVAL) &&
+(loop_decay_rate >= 0.999) &&
+(decay_accumulator < 0.9) )
+{
+int j;
+FIRSTPASS_STATS * position = cpi->twopass.stats_in;
+FIRSTPASS_STATS tmp_next_frame;
+double decay_rate;
+/* Look ahead a few frames to see if static condition persists... */
+for ( j = 0; j < still_interval; j++ )
+{
+if (EOF == input_stats(cpi, &tmp_next_frame))
+break;
+decay_rate = get_prediction_decay_rate(cpi, &tmp_next_frame);
+if ( decay_rate < 0.999 )
+break;
+}
+/* Reset file position */
+reset_fpf_position(cpi, position);
+/* Only if it does do we signal a transition to still */
+if ( j == still_interval )
+trans_to_still = 1;
+}
+return trans_to_still;
+}
+/* This function detects a flash through the high relative pcnt_second_ref
+* score in the frame following a flash frame. The offset passed in should
+* reflect this
+*/
+static int detect_flash( VP8_COMP *cpi, int offset )
+{
+FIRSTPASS_STATS next_frame;
+int flash_detected = 0;
+/* Read the frame data. */
+/* The return is 0 (no flash detected) if not a valid frame */
+if ( read_frame_stats(cpi, &next_frame, offset) != EOF )
+{
+/* What we are looking for here is a situation where there is a
+* brief break in prediction (such as a flash) but subsequent frames
+* are reasonably well predicted by an earlier (pre flash) frame.
+* The recovery after a flash is indicated by a high pcnt_second_ref
+* comapred to pcnt_inter.
+*/
+if ( (next_frame.pcnt_second_ref > next_frame.pcnt_inter) &&
+(next_frame.pcnt_second_ref >= 0.5 ) )
+{
+flash_detected = 1;
+/*if (1)
+{
+FILE *f = fopen("flash.stt", "a");
+fprintf(f, "%8.0f %6.2f %6.2f\n",
+next_frame.frame,
+next_frame.pcnt_inter,
+next_frame.pcnt_second_ref);
+fclose(f);
+}*/
+}
+}
+return flash_detected;
+}
+/* Update the motion related elements to the GF arf boost calculation */
+static void accumulate_frame_motion_stats(
+VP8_COMP *cpi,
+FIRSTPASS_STATS * this_frame,
+double * this_frame_mv_in_out,
+double * mv_in_out_accumulator,
+double * abs_mv_in_out_accumulator,
+double * mv_ratio_accumulator )
+{
+double this_frame_mvr_ratio;
+double this_frame_mvc_ratio;
+double motion_pct;
+/* Accumulate motion stats. */
+motion_pct = this_frame->pcnt_motion;
+/* Accumulate Motion In/Out of frame stats */
+*this_frame_mv_in_out = this_frame->mv_in_out_count * motion_pct;
+*mv_in_out_accumulator += this_frame->mv_in_out_count * motion_pct;
+*abs_mv_in_out_accumulator +=
+fabs(this_frame->mv_in_out_count * motion_pct);
+/* Accumulate a measure of how uniform (or conversely how random)
+* the motion field is. (A ratio of absmv / mv)
+*/
+if (motion_pct > 0.05)
+{
+this_frame_mvr_ratio = fabs(this_frame->mvr_abs) /
+DOUBLE_DIVIDE_CHECK(fabs(this_frame->MVr));
+this_frame_mvc_ratio = fabs(this_frame->mvc_abs) /
+DOUBLE_DIVIDE_CHECK(fabs(this_frame->MVc));
+*mv_ratio_accumulator +=
+(this_frame_mvr_ratio < this_frame->mvr_abs)
+? (this_frame_mvr_ratio * motion_pct)
+: this_frame->mvr_abs * motion_pct;
+*mv_ratio_accumulator +=
+(this_frame_mvc_ratio < this_frame->mvc_abs)
+? (this_frame_mvc_ratio * motion_pct)
+: this_frame->mvc_abs * motion_pct;
+}
+}
+/* Calculate a baseline boost number for the current frame. */
+static double calc_frame_boost(
+VP8_COMP *cpi,
+FIRSTPASS_STATS * this_frame,
+double this_frame_mv_in_out )
+{
+double frame_boost;
+/* Underlying boost factor is based on inter intra error ratio */
+if (this_frame->intra_error > cpi->twopass.gf_intra_err_min)
+frame_boost = (IIFACTOR * this_frame->intra_error /
+DOUBLE_DIVIDE_CHECK(this_frame->coded_error));
+else
+frame_boost = (IIFACTOR * cpi->twopass.gf_intra_err_min /
+DOUBLE_DIVIDE_CHECK(this_frame->coded_error));
+/* Increase boost for frames where new data coming into frame
+* (eg zoom out). Slightly reduce boost if there is a net balance
+* of motion out of the frame (zoom in).
+* The range for this_frame_mv_in_out is -1.0 to +1.0
+*/
+if (this_frame_mv_in_out > 0.0)
+frame_boost += frame_boost * (this_frame_mv_in_out * 2.0);
+/* In extreme case boost is halved */
+else
+frame_boost += frame_boost * (this_frame_mv_in_out / 2.0);
+/* Clip to maximum */
+if (frame_boost > GF_RMAX)
+frame_boost = GF_RMAX;
+return frame_boost;
+}
+#if NEW_BOOST
+static int calc_arf_boost(
+VP8_COMP *cpi,
+int offset,
+int f_frames,
+int b_frames,
+int *f_boost,
+int *b_boost )
+{
+FIRSTPASS_STATS this_frame;
+int i;
+double boost_score = 0.0;
+double mv_ratio_accumulator = 0.0;
+double decay_accumulator = 1.0;
+double this_frame_mv_in_out = 0.0;
+double mv_in_out_accumulator = 0.0;
+double abs_mv_in_out_accumulator = 0.0;
+double r;
+int flash_detected = 0;
+/* Search forward from the proposed arf/next gf position */
+for ( i = 0; i < f_frames; i++ )
+{
+if ( read_frame_stats(cpi, &this_frame, (i+offset)) == EOF )
+break;
+/* Update the motion related elements to the boost calculation */
+accumulate_frame_motion_stats( cpi, &this_frame,
+&this_frame_mv_in_out, &mv_in_out_accumulator,
+&abs_mv_in_out_accumulator, &mv_ratio_accumulator );
+/* Calculate the baseline boost number for this frame */
+r = calc_frame_boost( cpi, &this_frame, this_frame_mv_in_out );
+/* We want to discount the the flash frame itself and the recovery
+* frame that follows as both will have poor scores.
+*/
+flash_detected = detect_flash(cpi, (i+offset)) ||
+detect_flash(cpi, (i+offset+1));
+/* Cumulative effect of prediction quality decay */
+if ( !flash_detected )
+{
+decay_accumulator =
+decay_accumulator *
+get_prediction_decay_rate(cpi, &this_frame);
+decay_accumulator =
+decay_accumulator < 0.1 ? 0.1 : decay_accumulator;
+}
+boost_score += (decay_accumulator * r);
+/* Break out conditions. */
+if  ( (!flash_detected) &&
+((mv_ratio_accumulator > 100.0) ||
+(abs_mv_in_out_accumulator > 3.0) ||
+(mv_in_out_accumulator < -2.0) ) )
+{
+break;
+}
+}
+*f_boost = (int)(boost_score * 100.0) >> 4;
+/* Reset for backward looking loop */
+boost_score = 0.0;
+mv_ratio_accumulator = 0.0;
+decay_accumulator = 1.0;
+this_frame_mv_in_out = 0.0;
+mv_in_out_accumulator = 0.0;
+abs_mv_in_out_accumulator = 0.0;
+/* Search forward from the proposed arf/next gf position */
+for ( i = -1; i >= -b_frames; i-- )
+{
+if ( read_frame_stats(cpi, &this_frame, (i+offset)) == EOF )
+break;
+/* Update the motion related elements to the boost calculation */
+accumulate_frame_motion_stats( cpi, &this_frame,
+&this_frame_mv_in_out, &mv_in_out_accumulator,
+&abs_mv_in_out_accumulator, &mv_ratio_accumulator );
+/* Calculate the baseline boost number for this frame */
+r = calc_frame_boost( cpi, &this_frame, this_frame_mv_in_out );
+/* We want to discount the the flash frame itself and the recovery
+* frame that follows as both will have poor scores.
+*/
+flash_detected = detect_flash(cpi, (i+offset)) ||
+detect_flash(cpi, (i+offset+1));
+/* Cumulative effect of prediction quality decay */
+if ( !flash_detected )
+{
+decay_accumulator =
+decay_accumulator *
+get_prediction_decay_rate(cpi, &this_frame);
+decay_accumulator =
+decay_accumulator < 0.1 ? 0.1 : decay_accumulator;
+}
+boost_score += (decay_accumulator * r);
+/* Break out conditions. */
+if  ( (!flash_detected) &&
+((mv_ratio_accumulator > 100.0) ||
+(abs_mv_in_out_accumulator > 3.0) ||
+(mv_in_out_accumulator < -2.0) ) )
+{
+break;
+}
+}
+*b_boost = (int)(boost_score * 100.0) >> 4;
+return (*f_boost + *b_boost);
+}
+#endif
+/* Analyse and define a gf/arf group . */
+static void define_gf_group(VP8_COMP *cpi, FIRSTPASS_STATS *this_frame)
+{
+FIRSTPASS_STATS next_frame;
+FIRSTPASS_STATS *start_pos;
+int i;
+double r;
+double boost_score = 0.0;
+double old_boost_score = 0.0;
+double gf_group_err = 0.0;
+double gf_first_frame_err = 0.0;
+double mod_frame_err = 0.0;
+double mv_ratio_accumulator = 0.0;
+double decay_accumulator = 1.0;
+double loop_decay_rate = 1.00;          /* Starting decay rate */
+double this_frame_mv_in_out = 0.0;
+double mv_in_out_accumulator = 0.0;
+double abs_mv_in_out_accumulator = 0.0;
+double mod_err_per_mb_accumulator = 0.0;
+int max_bits = frame_max_bits(cpi);     /* Max for a single frame */
+unsigned int allow_alt_ref =
+cpi->oxcf.play_alternate && cpi->oxcf.lag_in_frames;
+int alt_boost = 0;
+int f_boost = 0;
+int b_boost = 0;
+int flash_detected;
+cpi->twopass.gf_group_bits = 0;
+cpi->twopass.gf_decay_rate = 0;
+vp8_clear_system_state();
+start_pos = cpi->twopass.stats_in;
+vpx_memset(&next_frame, 0, sizeof(next_frame)); /* assure clean */
+/* Load stats for the current frame. */
+mod_frame_err = calculate_modified_err(cpi, this_frame);
+/* Note the error of the frame at the start of the group (this will be
+* the GF frame error if we code a normal gf
+*/
+gf_first_frame_err = mod_frame_err;
+/* Special treatment if the current frame is a key frame (which is also
+* a gf). If it is then its error score (and hence bit allocation) need
+* to be subtracted out from the calculation for the GF group
+*/
+if (cpi->common.frame_type == KEY_FRAME)
+gf_group_err -= gf_first_frame_err;
+/* Scan forward to try and work out how many frames the next gf group
+* should contain and what level of boost is appropriate for the GF
+* or ARF that will be coded with the group
+*/
+i = 0;
+while (((i < cpi->twopass.static_scene_max_gf_interval) ||
+((cpi->twopass.frames_to_key - i) < MIN_GF_INTERVAL)) &&
+(i < cpi->twopass.frames_to_key))
+{
+i++;
+/* Accumulate error score of frames in this gf group */
+mod_frame_err = calculate_modified_err(cpi, this_frame);
+gf_group_err += mod_frame_err;
+mod_err_per_mb_accumulator +=
+mod_frame_err / DOUBLE_DIVIDE_CHECK((double)cpi->common.MBs);
+if (EOF == input_stats(cpi, &next_frame))
+break;
+/* Test for the case where there is a brief flash but the prediction
+* quality back to an earlier frame is then restored.
+*/
+flash_detected = detect_flash(cpi, 0);
+/* Update the motion related elements to the boost calculation */
+accumulate_frame_motion_stats( cpi, &next_frame,
+&this_frame_mv_in_out, &mv_in_out_accumulator,
+&abs_mv_in_out_accumulator, &mv_ratio_accumulator );
+/* Calculate a baseline boost number for this frame */
+r = calc_frame_boost( cpi, &next_frame, this_frame_mv_in_out );
+/* Cumulative effect of prediction quality decay */
+if ( !flash_detected )
+{
+loop_decay_rate = get_prediction_decay_rate(cpi, &next_frame);
+decay_accumulator = decay_accumulator * loop_decay_rate;
+decay_accumulator =
+decay_accumulator < 0.1 ? 0.1 : decay_accumulator;
+}
+boost_score += (decay_accumulator * r);
+/* Break clause to detect very still sections after motion
+* For example a staic image after a fade or other transition.
+*/
+if ( detect_transition_to_still( cpi, i, 5,
+loop_decay_rate,
+decay_accumulator ) )
+{
+allow_alt_ref = 0;
+boost_score = old_boost_score;
+break;
+}
+/* Break out conditions. */
+if  (
+/* Break at cpi->max_gf_interval unless almost totally static */
+(i >= cpi->max_gf_interval && (decay_accumulator < 0.995)) ||
+(
+/* Dont break out with a very short interval */
+(i > MIN_GF_INTERVAL) &&
+/* Dont break out very close to a key frame */
+((cpi->twopass.frames_to_key - i) >= MIN_GF_INTERVAL) &&
+((boost_score > 20.0) || (next_frame.pcnt_inter < 0.75)) &&
+(!flash_detected) &&
+((mv_ratio_accumulator > 100.0) ||
+(abs_mv_in_out_accumulator > 3.0) ||
+(mv_in_out_accumulator < -2.0) ||
+((boost_score - old_boost_score) < 2.0))
+) )
+{
+boost_score = old_boost_score;
+break;
+}
+vpx_memcpy(this_frame, &next_frame, sizeof(*this_frame));
+old_boost_score = boost_score;
+}
+cpi->twopass.gf_decay_rate =
+(i > 0) ? (int)(100.0 * (1.0 - decay_accumulator)) / i : 0;
+/* When using CBR apply additional buffer related upper limits */
+if (cpi->oxcf.end_usage == USAGE_STREAM_FROM_SERVER)
+{
+double max_boost;
+/* For cbr apply buffer related limits */
+if (cpi->drop_frames_allowed)
+{
+int64_t df_buffer_level = cpi->oxcf.drop_frames_water_mark *
+(cpi->oxcf.optimal_buffer_level / 100);
+if (cpi->buffer_level > df_buffer_level)
+max_boost = ((double)((cpi->buffer_level - df_buffer_level) * 2 / 3) * 16.0) / DOUBLE_DIVIDE_CHECK((double)cpi->av_per_frame_bandwidth);
+else
+max_boost = 0.0;
+}
+else if (cpi->buffer_level > 0)
+{
+max_boost = ((double)(cpi->buffer_level * 2 / 3) * 16.0) / DOUBLE_DIVIDE_CHECK((double)cpi->av_per_frame_bandwidth);
+}
+else
+{
+max_boost = 0.0;
+}
+if (boost_score > max_boost)
+boost_score = max_boost;
+}
+/* Dont allow conventional gf too near the next kf */
+if ((cpi->twopass.frames_to_key - i) < MIN_GF_INTERVAL)
+{
+while (i < cpi->twopass.frames_to_key)
+{
+i++;
+if (EOF == input_stats(cpi, this_frame))
+break;
+if (i < cpi->twopass.frames_to_key)
+{
+mod_frame_err = calculate_modified_err(cpi, this_frame);
+gf_group_err += mod_frame_err;
+}
+}
+}
+cpi->gfu_boost = (int)(boost_score * 100.0) >> 4;
+#if NEW_BOOST
+/* Alterrnative boost calculation for alt ref */
+alt_boost = calc_arf_boost( cpi, 0, (i-1), (i-1), &f_boost, &b_boost );
+#endif
+/* Should we use the alternate refernce frame */
+if (allow_alt_ref &&
+(i >= MIN_GF_INTERVAL) &&
+/* dont use ARF very near next kf */
+(i <= (cpi->twopass.frames_to_key - MIN_GF_INTERVAL)) &&
+#if NEW_BOOST
+((next_frame.pcnt_inter > 0.75) ||
+(next_frame.pcnt_second_ref > 0.5)) &&
+((mv_in_out_accumulator / (double)i > -0.2) ||
+(mv_in_out_accumulator > -2.0)) &&
+(b_boost > 100) &&
+(f_boost > 100) )
+#else
+(next_frame.pcnt_inter > 0.75) &&
+((mv_in_out_accumulator / (double)i > -0.2) ||
+(mv_in_out_accumulator > -2.0)) &&
+(cpi->gfu_boost > 100) &&
+(cpi->twopass.gf_decay_rate <=
+(ARF_DECAY_THRESH + (cpi->gfu_boost / 200))) )
+#endif
+{
+int Boost;
+int allocation_chunks;
+int Q = (cpi->oxcf.fixed_q < 0)
+? cpi->last_q[INTER_FRAME] : cpi->oxcf.fixed_q;
+int tmp_q;
+int arf_frame_bits = 0;
+int group_bits;
+#if NEW_BOOST
+cpi->gfu_boost = alt_boost;
+#endif
+/* Estimate the bits to be allocated to the group as a whole */
+if ((cpi->twopass.kf_group_bits > 0) &&
+(cpi->twopass.kf_group_error_left > 0))
+{
+group_bits = (int)((double)cpi->twopass.kf_group_bits *
+(gf_group_err / (double)cpi->twopass.kf_group_error_left));
+}
+else
+group_bits = 0;
+/* Boost for arf frame */
+#if NEW_BOOST
+Boost = (alt_boost * GFQ_ADJUSTMENT) / 100;
+#else
+Boost = (cpi->gfu_boost * 3 * GFQ_ADJUSTMENT) / (2 * 100);
+#endif
+Boost += (i * 50);
+/* Set max and minimum boost and hence minimum allocation */
+if (Boost > ((cpi->baseline_gf_interval + 1) * 200))
+Boost = ((cpi->baseline_gf_interval + 1) * 200);
+else if (Boost < 125)
+Boost = 125;
+allocation_chunks = (i * 100) + Boost;
+/* Normalize Altboost and allocations chunck down to prevent overflow */
+while (Boost > 1000)
+{
+Boost /= 2;
+allocation_chunks /= 2;
+}
+/* Calculate the number of bits to be spent on the arf based on the
+* boost number
+*/
+arf_frame_bits = (int)((double)Boost * (group_bits /
+(double)allocation_chunks));
+/* Estimate if there are enough bits available to make worthwhile use
+* of an arf.
+*/
+tmp_q = estimate_q(cpi, mod_frame_err, (int)arf_frame_bits);
+/* Only use an arf if it is likely we will be able to code
+* it at a lower Q than the surrounding frames.
+*/
+if (tmp_q < cpi->worst_quality)
+{
+int half_gf_int;
+int frames_after_arf;
+int frames_bwd = cpi->oxcf.arnr_max_frames - 1;
+int frames_fwd = cpi->oxcf.arnr_max_frames - 1;
+cpi->source_alt_ref_pending = 1;
+/*
+* For alt ref frames the error score for the end frame of the
+* group (the alt ref frame) should not contribute to the group
+* total and hence the number of bit allocated to the group.
+* Rather it forms part of the next group (it is the GF at the
+* start of the next group)
+* gf_group_err -= mod_frame_err;
+*
+* For alt ref frames alt ref frame is technically part of the
+* GF frame for the next group but we always base the error
+* calculation and bit allocation on the current group of frames.
+*
+* Set the interval till the next gf or arf.
+* For ARFs this is the number of frames to be coded before the
+* future frame that is coded as an ARF.
+* The future frame itself is part of the next group
+*/
+cpi->baseline_gf_interval = i;
+/*
+* Define the arnr filter width for this group of frames:
+* We only filter frames that lie within a distance of half
+* the GF interval from the ARF frame. We also have to trap
+* cases where the filter extends beyond the end of clip.
+* Note: this_frame->frame has been updated in the loop
+* so it now points at the ARF frame.
+*/
+half_gf_int = cpi->baseline_gf_interval >> 1;
+frames_after_arf = (int)(cpi->twopass.total_stats.count -
+this_frame->frame - 1);
+switch (cpi->oxcf.arnr_type)
+{
+case 1: /* Backward filter */
+frames_fwd = 0;
+if (frames_bwd > half_gf_int)
+frames_bwd = half_gf_int;
+break;
+case 2: /* Forward filter */
+if (frames_fwd > half_gf_int)
+frames_fwd = half_gf_int;
+if (frames_fwd > frames_after_arf)
+frames_fwd = frames_after_arf;
+frames_bwd = 0;
+break;
+case 3: /* Centered filter */
+default:
+frames_fwd >>= 1;
+if (frames_fwd > frames_after_arf)
+frames_fwd = frames_after_arf;
+if (frames_fwd > half_gf_int)
+frames_fwd = half_gf_int;
+frames_bwd = frames_fwd;
+/* For even length filter there is one more frame backward
+* than forward: e.g. len=6 ==> bbbAff, len=7 ==> bbbAfff.
+*/
+if (frames_bwd < half_gf_int)
+frames_bwd += (cpi->oxcf.arnr_max_frames+1) & 0x1;
+break;
+}
+cpi->active_arnr_frames = frames_bwd + 1 + frames_fwd;
+}
+else
+{
+cpi->source_alt_ref_pending = 0;
+cpi->baseline_gf_interval = i;
+}
+}
+else
+{
+cpi->source_alt_ref_pending = 0;
+cpi->baseline_gf_interval = i;
+}
+/*
+* Now decide how many bits should be allocated to the GF group as  a
+* proportion of those remaining in the kf group.
+* The final key frame group in the clip is treated as a special case
+* where cpi->twopass.kf_group_bits is tied to cpi->twopass.bits_left.
+* This is also important for short clips where there may only be one
+* key frame.
+*/
+if (cpi->twopass.frames_to_key >= (int)(cpi->twopass.total_stats.count -
+cpi->common.current_video_frame))
+{
+cpi->twopass.kf_group_bits =
+(cpi->twopass.bits_left > 0) ? cpi->twopass.bits_left : 0;
+}
+/* Calculate the bits to be allocated to the group as a whole */
+if ((cpi->twopass.kf_group_bits > 0) &&
+(cpi->twopass.kf_group_error_left > 0))
+{
+cpi->twopass.gf_group_bits =
+(int64_t)(cpi->twopass.kf_group_bits *
+(gf_group_err / cpi->twopass.kf_group_error_left));
+}
+else
+cpi->twopass.gf_group_bits = 0;
+cpi->twopass.gf_group_bits =
+(cpi->twopass.gf_group_bits < 0)
+? 0
+: (cpi->twopass.gf_group_bits > cpi->twopass.kf_group_bits)
+? cpi->twopass.kf_group_bits : cpi->twopass.gf_group_bits;
+/* Clip cpi->twopass.gf_group_bits based on user supplied data rate
+* variability limit (cpi->oxcf.two_pass_vbrmax_section)
+*/
+if (cpi->twopass.gf_group_bits >
+(int64_t)max_bits * cpi->baseline_gf_interval)
+cpi->twopass.gf_group_bits =
+(int64_t)max_bits * cpi->baseline_gf_interval;
+/* Reset the file position */
+reset_fpf_position(cpi, start_pos);
+/* Update the record of error used so far (only done once per gf group) */
+cpi->twopass.modified_error_used += gf_group_err;
+/* Assign  bits to the arf or gf. */
+for (i = 0; i <= (cpi->source_alt_ref_pending && cpi->common.frame_type != KEY_FRAME); i++) {
+int Boost;
+int allocation_chunks;
+int Q = (cpi->oxcf.fixed_q < 0) ? cpi->last_q[INTER_FRAME] : cpi->oxcf.fixed_q;
+int gf_bits;
+/* For ARF frames */
+if (cpi->source_alt_ref_pending && i == 0)
+{
+#if NEW_BOOST
+Boost = (alt_boost * GFQ_ADJUSTMENT) / 100;
+#else
+Boost = (cpi->gfu_boost * 3 * GFQ_ADJUSTMENT) / (2 * 100);
+#endif
+Boost += (cpi->baseline_gf_interval * 50);
+/* Set max and minimum boost and hence minimum allocation */
+if (Boost > ((cpi->baseline_gf_interval + 1) * 200))
+Boost = ((cpi->baseline_gf_interval + 1) * 200);
+else if (Boost < 125)
+Boost = 125;
+allocation_chunks =
+((cpi->baseline_gf_interval + 1) * 100) + Boost;
+}
+/* Else for standard golden frames */
+else
+{
+/* boost based on inter / intra ratio of subsequent frames */
+Boost = (cpi->gfu_boost * GFQ_ADJUSTMENT) / 100;
+/* Set max and minimum boost and hence minimum allocation */
+if (Boost > (cpi->baseline_gf_interval * 150))
+Boost = (cpi->baseline_gf_interval * 150);
+else if (Boost < 125)
+Boost = 125;
+allocation_chunks =
+(cpi->baseline_gf_interval * 100) + (Boost - 100);
+}
+/* Normalize Altboost and allocations chunck down to prevent overflow */
+while (Boost > 1000)
+{
+Boost /= 2;
+allocation_chunks /= 2;
+}
+/* Calculate the number of bits to be spent on the gf or arf based on
+* the boost number
+*/
+gf_bits = (int)((double)Boost *
+(cpi->twopass.gf_group_bits /
+(double)allocation_chunks));
+/* If the frame that is to be boosted is simpler than the average for
+* the gf/arf group then use an alternative calculation
+* based on the error score of the frame itself
+*/
+if (mod_frame_err < gf_group_err / (double)cpi->baseline_gf_interval)
+{
+double  alt_gf_grp_bits;
+int     alt_gf_bits;
+alt_gf_grp_bits =
+(double)cpi->twopass.kf_group_bits  *
+(mod_frame_err * (double)cpi->baseline_gf_interval) /
+DOUBLE_DIVIDE_CHECK((double)cpi->twopass.kf_group_error_left);
+alt_gf_bits = (int)((double)Boost * (alt_gf_grp_bits /
+(double)allocation_chunks));
+if (gf_bits > alt_gf_bits)
+{
+gf_bits = alt_gf_bits;
+}
+}
+/* Else if it is harder than other frames in the group make sure it at
+* least receives an allocation in keeping with its relative error
+* score, otherwise it may be worse off than an "un-boosted" frame
+*/
+else
+{
+int alt_gf_bits =
+(int)((double)cpi->twopass.kf_group_bits *
+mod_frame_err /
+DOUBLE_DIVIDE_CHECK((double)cpi->twopass.kf_group_error_left));
+if (alt_gf_bits > gf_bits)
+{
+gf_bits = alt_gf_bits;
+}
+}
+/* Apply an additional limit for CBR */
+if (cpi->oxcf.end_usage == USAGE_STREAM_FROM_SERVER)
+{
+if (cpi->twopass.gf_bits > (int)(cpi->buffer_level >> 1))
+cpi->twopass.gf_bits = (int)(cpi->buffer_level >> 1);
+}
+/* Dont allow a negative value for gf_bits */
+if (gf_bits < 0)
+gf_bits = 0;
+/* Add in minimum for a frame */
+gf_bits += cpi->min_frame_bandwidth;
+if (i == 0)
+{
+cpi->twopass.gf_bits = gf_bits;
+}
+if (i == 1 || (!cpi->source_alt_ref_pending && (cpi->common.frame_type != KEY_FRAME)))
+{
+/* Per frame bit target for this frame */
+cpi->per_frame_bandwidth = gf_bits;
+}
+}
+{
+/* Adjust KF group bits and error remainin */
+cpi->twopass.kf_group_error_left -= (int64_t)gf_group_err;
+cpi->twopass.kf_group_bits -= cpi->twopass.gf_group_bits;
+if (cpi->twopass.kf_group_bits < 0)
+cpi->twopass.kf_group_bits = 0;
+/* Note the error score left in the remaining frames of the group.
+* For normal GFs we want to remove the error score for the first
+* frame of the group (except in Key frame case where this has
+* already happened)
+*/
+if (!cpi->source_alt_ref_pending && cpi->common.frame_type != KEY_FRAME)
+cpi->twopass.gf_group_error_left = (int)(gf_group_err -
+gf_first_frame_err);
+else
+cpi->twopass.gf_group_error_left = (int) gf_group_err;
+cpi->twopass.gf_group_bits -= cpi->twopass.gf_bits - cpi->min_frame_bandwidth;
+if (cpi->twopass.gf_group_bits < 0)
+cpi->twopass.gf_group_bits = 0;
+/* This condition could fail if there are two kfs very close together
+* despite (MIN_GF_INTERVAL) and would cause a devide by 0 in the
+* calculation of cpi->twopass.alt_extra_bits.
+*/
+if ( cpi->baseline_gf_interval >= 3 )
+{
+#if NEW_BOOST
+int boost = (cpi->source_alt_ref_pending)
+? b_boost : cpi->gfu_boost;
+#else
+int boost = cpi->gfu_boost;
+#endif
+if ( boost >= 150 )
+{
+int pct_extra;
+pct_extra = (boost - 100) / 50;
+pct_extra = (pct_extra > 20) ? 20 : pct_extra;
+cpi->twopass.alt_extra_bits =
+(cpi->twopass.gf_group_bits * pct_extra) / 100;
+cpi->twopass.gf_group_bits -= cpi->twopass.alt_extra_bits;
+cpi->twopass.alt_extra_bits /=
+((cpi->baseline_gf_interval-1)>>1);
+}
+else
+cpi->twopass.alt_extra_bits = 0;
+}
+else
+cpi->twopass.alt_extra_bits = 0;
+}
+/* Adjustments based on a measure of complexity of the section */
+if (cpi->common.frame_type != KEY_FRAME)
+{
+FIRSTPASS_STATS sectionstats;
+double Ratio;
+zero_stats(&sectionstats);
+reset_fpf_position(cpi, start_pos);
+for (i = 0 ; i < cpi->baseline_gf_interval ; i++)
+{
+input_stats(cpi, &next_frame);
+accumulate_stats(&sectionstats, &next_frame);
+}
+avg_stats(&sectionstats);
+cpi->twopass.section_intra_rating = (unsigned int)
+(sectionstats.intra_error /
+DOUBLE_DIVIDE_CHECK(sectionstats.coded_error));
+Ratio = sectionstats.intra_error / DOUBLE_DIVIDE_CHECK(sectionstats.coded_error);
+cpi->twopass.section_max_qfactor = 1.0 - ((Ratio - 10.0) * 0.025);
+if (cpi->twopass.section_max_qfactor < 0.80)
+cpi->twopass.section_max_qfactor = 0.80;
+reset_fpf_position(cpi, start_pos);
+}
+}
+/* Allocate bits to a normal frame that is neither a gf an arf or a key frame. */
+static void assign_std_frame_bits(VP8_COMP *cpi, FIRSTPASS_STATS *this_frame)
+{
+int    target_frame_size;
+double modified_err;
+double err_fraction;
+int max_bits = frame_max_bits(cpi);  /* Max for a single frame */
+/* Calculate modified prediction error used in bit allocation */
+modified_err = calculate_modified_err(cpi, this_frame);
+/* What portion of the remaining GF group error is used by this frame */
+if (cpi->twopass.gf_group_error_left > 0)
+err_fraction = modified_err / cpi->twopass.gf_group_error_left;
+else
+err_fraction = 0.0;
+/* How many of those bits available for allocation should we give it? */
+target_frame_size = (int)((double)cpi->twopass.gf_group_bits * err_fraction);
+/* Clip to target size to 0 - max_bits (or cpi->twopass.gf_group_bits)
+* at the top end.
+*/
+if (target_frame_size < 0)
+target_frame_size = 0;
+else
+{
+if (target_frame_size > max_bits)
+target_frame_size = max_bits;
+if (target_frame_size > cpi->twopass.gf_group_bits)
+target_frame_size = cpi->twopass.gf_group_bits;
+}
+/* Adjust error and bits remaining */
+cpi->twopass.gf_group_error_left -= (int)modified_err;
+cpi->twopass.gf_group_bits -= target_frame_size;
+if (cpi->twopass.gf_group_bits < 0)
+cpi->twopass.gf_group_bits = 0;
+/* Add in the minimum number of bits that is set aside for every frame. */
+target_frame_size += cpi->min_frame_bandwidth;
+/* Every other frame gets a few extra bits */
+if ( (cpi->frames_since_golden & 0x01) &&
+(cpi->frames_till_gf_update_due > 0) )
+{
+target_frame_size += cpi->twopass.alt_extra_bits;
+}
+/* Per frame bit target for this frame */
+cpi->per_frame_bandwidth = target_frame_size;
+}
+void vp8_second_pass(VP8_COMP *cpi)
+{
+int tmp_q;
+int frames_left = (int)(cpi->twopass.total_stats.count - cpi->common.current_video_frame);
+FIRSTPASS_STATS this_frame = {0};
+FIRSTPASS_STATS this_frame_copy;
+double this_frame_intra_error;
+double this_frame_coded_error;
+int overhead_bits;
+if (!cpi->twopass.stats_in)
+{
+return ;
+}
+vp8_clear_system_state();
+if (EOF == input_stats(cpi, &this_frame))
+return;
+this_frame_intra_error = this_frame.intra_error;
+this_frame_coded_error = this_frame.coded_error;
+/* keyframe and section processing ! */
+if (cpi->twopass.frames_to_key == 0)
+{
+/* Define next KF group and assign bits to it */
+vpx_memcpy(&this_frame_copy, &this_frame, sizeof(this_frame));
+find_next_key_frame(cpi, &this_frame_copy);
+/* Special case: Error error_resilient_mode mode does not make much
+* sense for two pass but with its current meaning but this code is
+* designed to stop outlandish behaviour if someone does set it when
+* using two pass. It effectively disables GF groups. This is
+* temporary code till we decide what should really happen in this
+* case.
+*/
+if (cpi->oxcf.error_resilient_mode)
+{
+cpi->twopass.gf_group_bits = cpi->twopass.kf_group_bits;
+cpi->twopass.gf_group_error_left =
+(int)cpi->twopass.kf_group_error_left;
+cpi->baseline_gf_interval = cpi->twopass.frames_to_key;
+cpi->frames_till_gf_update_due = cpi->baseline_gf_interval;
+cpi->source_alt_ref_pending = 0;
+}
+}
+/* Is this a GF / ARF (Note that a KF is always also a GF) */
+if (cpi->frames_till_gf_update_due == 0)
+{
+/* Define next gf group and assign bits to it */
+vpx_memcpy(&this_frame_copy, &this_frame, sizeof(this_frame));
+define_gf_group(cpi, &this_frame_copy);
+/* If we are going to code an altref frame at the end of the group
+* and the current frame is not a key frame.... If the previous
+* group used an arf this frame has already benefited from that arf
+* boost and it should not be given extra bits If the previous
+* group was NOT coded using arf we may want to apply some boost to
+* this GF as well
+*/
+if (cpi->source_alt_ref_pending && (cpi->common.frame_type != KEY_FRAME))
+{
+/* Assign a standard frames worth of bits from those allocated
+* to the GF group
+*/
+int bak = cpi->per_frame_bandwidth;
+vpx_memcpy(&this_frame_copy, &this_frame, sizeof(this_frame));
+assign_std_frame_bits(cpi, &this_frame_copy);
+cpi->per_frame_bandwidth = bak;
+}
+}
+/* Otherwise this is an ordinary frame */
+else
+{
+/* Special case: Error error_resilient_mode mode does not make much
+* sense for two pass but with its current meaning but this code is
+* designed to stop outlandish behaviour if someone does set it
+* when using two pass. It effectively disables GF groups. This is
+* temporary code till we decide what should really happen in this
+* case.
+*/
+if (cpi->oxcf.error_resilient_mode)
+{
+cpi->frames_till_gf_update_due = cpi->twopass.frames_to_key;
+if (cpi->common.frame_type != KEY_FRAME)
+{
+/* Assign bits from those allocated to the GF group */
+vpx_memcpy(&this_frame_copy, &this_frame, sizeof(this_frame));
+assign_std_frame_bits(cpi, &this_frame_copy);
+}
+}
+else
+{
+/* Assign bits from those allocated to the GF group */
+vpx_memcpy(&this_frame_copy, &this_frame, sizeof(this_frame));
+assign_std_frame_bits(cpi, &this_frame_copy);
+}
+}
+/* Keep a globally available copy of this and the next frame's iiratio. */
+cpi->twopass.this_iiratio = (unsigned int)(this_frame_intra_error /
+DOUBLE_DIVIDE_CHECK(this_frame_coded_error));
+{
+FIRSTPASS_STATS next_frame;
+if ( lookup_next_frame_stats(cpi, &next_frame) != EOF )
+{
+cpi->twopass.next_iiratio = (unsigned int)(next_frame.intra_error /
+DOUBLE_DIVIDE_CHECK(next_frame.coded_error));
+}
+}
+/* Set nominal per second bandwidth for this frame */
+cpi->target_bandwidth = (int)
+(cpi->per_frame_bandwidth * cpi->output_framerate);
+if (cpi->target_bandwidth < 0)
+cpi->target_bandwidth = 0;
+/* Account for mv, mode and other overheads. */
+overhead_bits = (int)estimate_modemvcost(
+cpi, &cpi->twopass.total_left_stats );
+/* Special case code for first frame. */
+if (cpi->common.current_video_frame == 0)
+{
+cpi->twopass.est_max_qcorrection_factor = 1.0;
+/* Set a cq_level in constrained quality mode. */
+if ( cpi->oxcf.end_usage == USAGE_CONSTRAINED_QUALITY )
+{
+int est_cq;
+est_cq =
+estimate_cq( cpi,
+&cpi->twopass.total_left_stats,
+(int)(cpi->twopass.bits_left / frames_left),
+overhead_bits );
+cpi->cq_target_quality = cpi->oxcf.cq_level;
+if ( est_cq > cpi->cq_target_quality )
+cpi->cq_target_quality = est_cq;
+}
+/* guess at maxq needed in 2nd pass */
+cpi->twopass.maxq_max_limit = cpi->worst_quality;
+cpi->twopass.maxq_min_limit = cpi->best_quality;
+tmp_q = estimate_max_q(
+cpi,
+&cpi->twopass.total_left_stats,
+(int)(cpi->twopass.bits_left / frames_left),
+overhead_bits );
+/* Limit the maxq value returned subsequently.
+* This increases the risk of overspend or underspend if the initial
+* estimate for the clip is bad, but helps prevent excessive
+* variation in Q, especially near the end of a clip
+* where for example a small overspend may cause Q to crash
+*/
+cpi->twopass.maxq_max_limit = ((tmp_q + 32) < cpi->worst_quality)
+? (tmp_q + 32) : cpi->worst_quality;
+cpi->twopass.maxq_min_limit = ((tmp_q - 32) > cpi->best_quality)
+? (tmp_q - 32) : cpi->best_quality;
+cpi->active_worst_quality         = tmp_q;
+cpi->ni_av_qi                     = tmp_q;
+}
+/* The last few frames of a clip almost always have to few or too many
+* bits and for the sake of over exact rate control we dont want to make
+* radical adjustments to the allowed quantizer range just to use up a
+* few surplus bits or get beneath the target rate.
+*/
+else if ( (cpi->common.current_video_frame <
+(((unsigned int)cpi->twopass.total_stats.count * 255)>>8)) &&
+((cpi->common.current_video_frame + cpi->baseline_gf_interval) <
+(unsigned int)cpi->twopass.total_stats.count) )
+{
+if (frames_left < 1)
+frames_left = 1;
+tmp_q = estimate_max_q(
+cpi,
+&cpi->twopass.total_left_stats,
+(int)(cpi->twopass.bits_left / frames_left),
+overhead_bits );
+/* Move active_worst_quality but in a damped way */
+if (tmp_q > cpi->active_worst_quality)
+cpi->active_worst_quality ++;
+else if (tmp_q < cpi->active_worst_quality)
+cpi->active_worst_quality --;
+cpi->active_worst_quality =
+((cpi->active_worst_quality * 3) + tmp_q + 2) / 4;
+}
+cpi->twopass.frames_to_key --;
+/* Update the total stats remaining sturcture */
+subtract_stats(&cpi->twopass.total_left_stats, &this_frame );
+}
+static int test_candidate_kf(VP8_COMP *cpi,  FIRSTPASS_STATS *last_frame, FIRSTPASS_STATS *this_frame, FIRSTPASS_STATS *next_frame)
+{
+int is_viable_kf = 0;
+/* Does the frame satisfy the primary criteria of a key frame
+*      If so, then examine how well it predicts subsequent frames
+*/
+if ((this_frame->pcnt_second_ref < 0.10) &&
+(next_frame->pcnt_second_ref < 0.10) &&
+((this_frame->pcnt_inter < 0.05) ||
+(
+((this_frame->pcnt_inter - this_frame->pcnt_neutral) < .25) &&
+((this_frame->intra_error / DOUBLE_DIVIDE_CHECK(this_frame->coded_error)) < 2.5) &&
+((fabs(last_frame->coded_error - this_frame->coded_error) / DOUBLE_DIVIDE_CHECK(this_frame->coded_error) > .40) ||
+(fabs(last_frame->intra_error - this_frame->intra_error) / DOUBLE_DIVIDE_CHECK(this_frame->intra_error) > .40) ||
+((next_frame->intra_error / DOUBLE_DIVIDE_CHECK(next_frame->coded_error)) > 3.5)
+)
+)
+)
+)
+{
+int i;
+FIRSTPASS_STATS *start_pos;
+FIRSTPASS_STATS local_next_frame;
+double boost_score = 0.0;
+double old_boost_score = 0.0;
+double decay_accumulator = 1.0;
+double next_iiratio;
+vpx_memcpy(&local_next_frame, next_frame, sizeof(*next_frame));
+/* Note the starting file position so we can reset to it */
+start_pos = cpi->twopass.stats_in;
+/* Examine how well the key frame predicts subsequent frames */
+for (i = 0 ; i < 16; i++)
+{
+next_iiratio = (IIKFACTOR1 * local_next_frame.intra_error / DOUBLE_DIVIDE_CHECK(local_next_frame.coded_error)) ;
+if (next_iiratio > RMAX)
+next_iiratio = RMAX;
+/* Cumulative effect of decay in prediction quality */
+if (local_next_frame.pcnt_inter > 0.85)
+decay_accumulator = decay_accumulator * local_next_frame.pcnt_inter;
+else
+decay_accumulator = decay_accumulator * ((0.85 + local_next_frame.pcnt_inter) / 2.0);
+/* Keep a running total */
+boost_score += (decay_accumulator * next_iiratio);
+/* Test various breakout clauses */
+if ((local_next_frame.pcnt_inter < 0.05) ||
+(next_iiratio < 1.5) ||
+(((local_next_frame.pcnt_inter -
+local_next_frame.pcnt_neutral) < 0.20) &&
+(next_iiratio < 3.0)) ||
+((boost_score - old_boost_score) < 0.5) ||
+(local_next_frame.intra_error < 200)
+)
+{
+break;
+}
+old_boost_score = boost_score;
+/* Get the next frame details */
+if (EOF == input_stats(cpi, &local_next_frame))
+break;
+}
+/* If there is tolerable prediction for at least the next 3 frames
+* then break out else discard this pottential key frame and move on
+*/
+if (boost_score > 5.0 && (i > 3))
+is_viable_kf = 1;
+else
+{
+/* Reset the file position */
+reset_fpf_position(cpi, start_pos);
+is_viable_kf = 0;
+}
+}
+return is_viable_kf;
+}
+static void find_next_key_frame(VP8_COMP *cpi, FIRSTPASS_STATS *this_frame)
+{
+int i,j;
+FIRSTPASS_STATS last_frame;
+FIRSTPASS_STATS first_frame;
+FIRSTPASS_STATS next_frame;
+FIRSTPASS_STATS *start_position;
+double decay_accumulator = 1.0;
+double boost_score = 0;
+double old_boost_score = 0.0;
+double loop_decay_rate;
+double kf_mod_err = 0.0;
+double kf_group_err = 0.0;
+double kf_group_intra_err = 0.0;
+double kf_group_coded_err = 0.0;
+double recent_loop_decay[8] = {1.0,1.0,1.0,1.0,1.0,1.0,1.0,1.0};
+vpx_memset(&next_frame, 0, sizeof(next_frame));
+vp8_clear_system_state();
+start_position = cpi->twopass.stats_in;
+cpi->common.frame_type = KEY_FRAME;
+/* is this a forced key frame by interval */
+cpi->this_key_frame_forced = cpi->next_key_frame_forced;
+/* Clear the alt ref active flag as this can never be active on a key
+* frame
+*/
+cpi->source_alt_ref_active = 0;
+/* Kf is always a gf so clear frames till next gf counter */
+cpi->frames_till_gf_update_due = 0;
+cpi->twopass.frames_to_key = 1;
+/* Take a copy of the initial frame details */
+vpx_memcpy(&first_frame, this_frame, sizeof(*this_frame));
+cpi->twopass.kf_group_bits = 0;
+cpi->twopass.kf_group_error_left = 0;
+kf_mod_err = calculate_modified_err(cpi, this_frame);
+/* find the next keyframe */
+i = 0;
+while (cpi->twopass.stats_in < cpi->twopass.stats_in_end)
+{
+/* Accumulate kf group error */
+kf_group_err += calculate_modified_err(cpi, this_frame);
+/* These figures keep intra and coded error counts for all frames
+* including key frames in the group. The effect of the key frame
+* itself can be subtracted out using the first_frame data
+* collected above
+*/
+kf_group_intra_err += this_frame->intra_error;
+kf_group_coded_err += this_frame->coded_error;
+/* load a the next frame's stats */
+vpx_memcpy(&last_frame, this_frame, sizeof(*this_frame));
+input_stats(cpi, this_frame);
+/* Provided that we are not at the end of the file... */
+if (cpi->oxcf.auto_key
+&& lookup_next_frame_stats(cpi, &next_frame) != EOF)
+{
+/* Normal scene cut check */
+if ( ( i >= MIN_GF_INTERVAL ) &&
+test_candidate_kf(cpi, &last_frame, this_frame, &next_frame) )
+{
+break;
+}
+/* How fast is prediction quality decaying */
+loop_decay_rate = get_prediction_decay_rate(cpi, &next_frame);
+/* We want to know something about the recent past... rather than
+* as used elsewhere where we are concened with decay in prediction
+* quality since the last GF or KF.
+*/
+recent_loop_decay[i%8] = loop_decay_rate;
+decay_accumulator = 1.0;
+for (j = 0; j < 8; j++)
+{
+decay_accumulator = decay_accumulator * recent_loop_decay[j];
+}
+/* Special check for transition or high motion followed by a
+* static scene.
+*/
+if ( detect_transition_to_still( cpi, i,
+(cpi->key_frame_frequency-i),
+loop_decay_rate,
+decay_accumulator ) )
+{
+break;
+}
+/* Step on to the next frame */
+cpi->twopass.frames_to_key ++;
+/* If we don't have a real key frame within the next two
+* forcekeyframeevery intervals then break out of the loop.
+*/
+if (cpi->twopass.frames_to_key >= 2 *(int)cpi->key_frame_frequency)
+break;
+} else
+cpi->twopass.frames_to_key ++;
+i++;
+}
+/* If there is a max kf interval set by the user we must obey it.
+* We already breakout of the loop above at 2x max.
+* This code centers the extra kf if the actual natural
+* interval is between 1x and 2x
+*/
+if (cpi->oxcf.auto_key
+&& cpi->twopass.frames_to_key > (int)cpi->key_frame_frequency )
+{
+FIRSTPASS_STATS *current_pos = cpi->twopass.stats_in;
+FIRSTPASS_STATS tmp_frame;
+cpi->twopass.frames_to_key /= 2;
+/* Copy first frame details */
+vpx_memcpy(&tmp_frame, &first_frame, sizeof(first_frame));
+/* Reset to the start of the group */
+reset_fpf_position(cpi, start_position);
+kf_group_err = 0;
+kf_group_intra_err = 0;
+kf_group_coded_err = 0;
+/* Rescan to get the correct error data for the forced kf group */
+for( i = 0; i < cpi->twopass.frames_to_key; i++ )
+{
+/* Accumulate kf group errors */
+kf_group_err += calculate_modified_err(cpi, &tmp_frame);
+kf_group_intra_err += tmp_frame.intra_error;
+kf_group_coded_err += tmp_frame.coded_error;
+/* Load a the next frame's stats */
+input_stats(cpi, &tmp_frame);
+}
+/* Reset to the start of the group */
+reset_fpf_position(cpi, current_pos);
+cpi->next_key_frame_forced = 1;
+}
+else
+cpi->next_key_frame_forced = 0;
+/* Special case for the last frame of the file */
+if (cpi->twopass.stats_in >= cpi->twopass.stats_in_end)
+{
+/* Accumulate kf group error */
+kf_group_err += calculate_modified_err(cpi, this_frame);
+/* These figures keep intra and coded error counts for all frames
+* including key frames in the group. The effect of the key frame
+* itself can be subtracted out using the first_frame data
+* collected above
+*/
+kf_group_intra_err += this_frame->intra_error;
+kf_group_coded_err += this_frame->coded_error;
+}
+/* Calculate the number of bits that should be assigned to the kf group. */
+if ((cpi->twopass.bits_left > 0) && (cpi->twopass.modified_error_left > 0.0))
+{
+/* Max for a single normal frame (not key frame) */
+int max_bits = frame_max_bits(cpi);
+/* Maximum bits for the kf group */
+int64_t max_grp_bits;
+/* Default allocation based on bits left and relative
+* complexity of the section
+*/
+cpi->twopass.kf_group_bits = (int64_t)( cpi->twopass.bits_left *
+( kf_group_err /
+cpi->twopass.modified_error_left ));
+/* Clip based on maximum per frame rate defined by the user. */
+max_grp_bits = (int64_t)max_bits * (int64_t)cpi->twopass.frames_to_key;
+if (cpi->twopass.kf_group_bits > max_grp_bits)
+cpi->twopass.kf_group_bits = max_grp_bits;
+/* Additional special case for CBR if buffer is getting full. */
+if (cpi->oxcf.end_usage == USAGE_STREAM_FROM_SERVER)
+{
+int64_t opt_buffer_lvl = cpi->oxcf.optimal_buffer_level;
+int64_t buffer_lvl = cpi->buffer_level;
+/* If the buffer is near or above the optimal and this kf group is
+* not being allocated much then increase the allocation a bit.
+*/
+if (buffer_lvl >= opt_buffer_lvl)
+{
+int64_t high_water_mark = (opt_buffer_lvl +
+cpi->oxcf.maximum_buffer_size) >> 1;
+int64_t av_group_bits;
+/* Av bits per frame * number of frames */
+av_group_bits = (int64_t)cpi->av_per_frame_bandwidth *
+(int64_t)cpi->twopass.frames_to_key;
+/* We are at or above the maximum. */
+if (cpi->buffer_level >= high_water_mark)
+{
+int64_t min_group_bits;
+min_group_bits = av_group_bits +
+(int64_t)(buffer_lvl -
+high_water_mark);
+if (cpi->twopass.kf_group_bits < min_group_bits)
+cpi->twopass.kf_group_bits = min_group_bits;
+}
+/* We are above optimal but below the maximum */
+else if (cpi->twopass.kf_group_bits < av_group_bits)
+{
+int64_t bits_below_av = av_group_bits -
+cpi->twopass.kf_group_bits;
+cpi->twopass.kf_group_bits +=
+(int64_t)((double)bits_below_av *
+(double)(buffer_lvl - opt_buffer_lvl) /
+(double)(high_water_mark - opt_buffer_lvl));
+}
+}
+}
+}
+else
+cpi->twopass.kf_group_bits = 0;
+/* Reset the first pass file position */
+reset_fpf_position(cpi, start_position);
+/* determine how big to make this keyframe based on how well the
+* subsequent frames use inter blocks
+*/
+decay_accumulator = 1.0;
+boost_score = 0.0;
+loop_decay_rate = 1.00;       /* Starting decay rate */
+for (i = 0 ; i < cpi->twopass.frames_to_key ; i++)
+{
+double r;
+if (EOF == input_stats(cpi, &next_frame))
+break;
+if (next_frame.intra_error > cpi->twopass.kf_intra_err_min)
+r = (IIKFACTOR2 * next_frame.intra_error /
+DOUBLE_DIVIDE_CHECK(next_frame.coded_error));
+else
+r = (IIKFACTOR2 * cpi->twopass.kf_intra_err_min /
+DOUBLE_DIVIDE_CHECK(next_frame.coded_error));
+if (r > RMAX)
+r = RMAX;
+/* How fast is prediction quality decaying */
+loop_decay_rate = get_prediction_decay_rate(cpi, &next_frame);
+decay_accumulator = decay_accumulator * loop_decay_rate;
+decay_accumulator = decay_accumulator < 0.1 ? 0.1 : decay_accumulator;
+boost_score += (decay_accumulator * r);
+if ((i > MIN_GF_INTERVAL) &&
+((boost_score - old_boost_score) < 1.0))
+{
+break;
+}
+old_boost_score = boost_score;
+}
+if (1)
+{
+FIRSTPASS_STATS sectionstats;
+double Ratio;
+zero_stats(&sectionstats);
+reset_fpf_position(cpi, start_position);
+for (i = 0 ; i < cpi->twopass.frames_to_key ; i++)
+{
+input_stats(cpi, &next_frame);
+accumulate_stats(&sectionstats, &next_frame);
+}
+avg_stats(&sectionstats);
+cpi->twopass.section_intra_rating = (unsigned int)
+(sectionstats.intra_error
+/ DOUBLE_DIVIDE_CHECK(sectionstats.coded_error));
+Ratio = sectionstats.intra_error / DOUBLE_DIVIDE_CHECK(sectionstats.coded_error);
+cpi->twopass.section_max_qfactor = 1.0 - ((Ratio - 10.0) * 0.025);
+if (cpi->twopass.section_max_qfactor < 0.80)
+cpi->twopass.section_max_qfactor = 0.80;
+}
+/* When using CBR apply additional buffer fullness related upper limits */
+if (cpi->oxcf.end_usage == USAGE_STREAM_FROM_SERVER)
+{
+double max_boost;
+if (cpi->drop_frames_allowed)
+{
+int df_buffer_level = (int)(cpi->oxcf.drop_frames_water_mark
+* (cpi->oxcf.optimal_buffer_level / 100));
+if (cpi->buffer_level > df_buffer_level)
+max_boost = ((double)((cpi->buffer_level - df_buffer_level) * 2 / 3) * 16.0) / DOUBLE_DIVIDE_CHECK((double)cpi->av_per_frame_bandwidth);
+else
+max_boost = 0.0;
+}
+else if (cpi->buffer_level > 0)
+{
+max_boost = ((double)(cpi->buffer_level * 2 / 3) * 16.0) / DOUBLE_DIVIDE_CHECK((double)cpi->av_per_frame_bandwidth);
+}
+else
+{
+max_boost = 0.0;
+}
+if (boost_score > max_boost)
+boost_score = max_boost;
+}
+/* Reset the first pass file position */
+reset_fpf_position(cpi, start_position);
+/* Work out how many bits to allocate for the key frame itself */
+if (1)
+{
+int kf_boost = (int)boost_score;
+int allocation_chunks;
+int Counter = cpi->twopass.frames_to_key;
+int alt_kf_bits;
+YV12_BUFFER_CONFIG *lst_yv12 = &cpi->common.yv12_fb[cpi->common.lst_fb_idx];
+/* Min boost based on kf interval */
+#if 0
+while ((kf_boost < 48) && (Counter > 0))
+{
+Counter -= 2;
+kf_boost ++;
+}
+#endif
+if (kf_boost < 48)
+{
+kf_boost += ((Counter + 1) >> 1);
+if (kf_boost > 48) kf_boost = 48;
+}
+/* bigger frame sizes need larger kf boosts, smaller frames smaller
+* boosts...
+*/
+if ((lst_yv12->y_width * lst_yv12->y_height) > (320 * 240))
+kf_boost += 2 * (lst_yv12->y_width * lst_yv12->y_height) / (320 * 240);
+else if ((lst_yv12->y_width * lst_yv12->y_height) < (320 * 240))
+kf_boost -= 4 * (320 * 240) / (lst_yv12->y_width * lst_yv12->y_height);
+/* Min KF boost */
+kf_boost = (int)((double)kf_boost * 100.0) >> 4; /* Scale 16 to 100 */
+if (kf_boost < 250)
+kf_boost = 250;
+/*
+* We do three calculations for kf size.
+* The first is based on the error score for the whole kf group.
+* The second (optionaly) on the key frames own error if this is
+* smaller than the average for the group.
+* The final one insures that the frame receives at least the
+* allocation it would have received based on its own error score vs
+* the error score remaining
+* Special case if the sequence appears almost totaly static
+* as measured by the decay accumulator. In this case we want to
+* spend almost all of the bits on the key frame.
+* cpi->twopass.frames_to_key-1 because key frame itself is taken
+* care of by kf_boost.
+*/
+if ( decay_accumulator >= 0.99 )
+{
+allocation_chunks =
+((cpi->twopass.frames_to_key - 1) * 10) + kf_boost;
+}
+else
+{
+allocation_chunks =
+((cpi->twopass.frames_to_key - 1) * 100) + kf_boost;
+}
+/* Normalize Altboost and allocations chunck down to prevent overflow */
+while (kf_boost > 1000)
+{
+kf_boost /= 2;
+allocation_chunks /= 2;
+}
+cpi->twopass.kf_group_bits = (cpi->twopass.kf_group_bits < 0) ? 0 : cpi->twopass.kf_group_bits;
+/* Calculate the number of bits to be spent on the key frame */
+cpi->twopass.kf_bits  = (int)((double)kf_boost * ((double)cpi->twopass.kf_group_bits / (double)allocation_chunks));
+/* Apply an additional limit for CBR */
+if (cpi->oxcf.end_usage == USAGE_STREAM_FROM_SERVER)
+{
+if (cpi->twopass.kf_bits > (int)((3 * cpi->buffer_level) >> 2))
+cpi->twopass.kf_bits = (int)((3 * cpi->buffer_level) >> 2);
+}
+/* If the key frame is actually easier than the average for the
+* kf group (which does sometimes happen... eg a blank intro frame)
+* Then use an alternate calculation based on the kf error score
+* which should give a smaller key frame.
+*/
+if (kf_mod_err < kf_group_err / cpi->twopass.frames_to_key)
+{
+double  alt_kf_grp_bits =
+((double)cpi->twopass.bits_left *
+(kf_mod_err * (double)cpi->twopass.frames_to_key) /
+DOUBLE_DIVIDE_CHECK(cpi->twopass.modified_error_left));
+alt_kf_bits = (int)((double)kf_boost *
+(alt_kf_grp_bits / (double)allocation_chunks));
+if (cpi->twopass.kf_bits > alt_kf_bits)
+{
+cpi->twopass.kf_bits = alt_kf_bits;
+}
+}
+/* Else if it is much harder than other frames in the group make sure
+* it at least receives an allocation in keeping with its relative
+* error score
+*/
+else
+{
+alt_kf_bits =
+(int)((double)cpi->twopass.bits_left *
+(kf_mod_err /
+DOUBLE_DIVIDE_CHECK(cpi->twopass.modified_error_left)));
+if (alt_kf_bits > cpi->twopass.kf_bits)
+{
+cpi->twopass.kf_bits = alt_kf_bits;
+}
+}
+cpi->twopass.kf_group_bits -= cpi->twopass.kf_bits;
+/* Add in the minimum frame allowance */
+cpi->twopass.kf_bits += cpi->min_frame_bandwidth;
+/* Peer frame bit target for this frame */
+cpi->per_frame_bandwidth = cpi->twopass.kf_bits;
+/* Convert to a per second bitrate */
+cpi->target_bandwidth = (int)(cpi->twopass.kf_bits *
+cpi->output_framerate);
+}
+/* Note the total error score of the kf group minus the key frame itself */
+cpi->twopass.kf_group_error_left = (int)(kf_group_err - kf_mod_err);
+/* Adjust the count of total modified error left. The count of bits left
+* is adjusted elsewhere based on real coded frame sizes
+*/
+cpi->twopass.modified_error_left -= kf_group_err;
+if (cpi->oxcf.allow_spatial_resampling)
+{
+int resample_trigger = 0;
+int last_kf_resampled = 0;
+int kf_q;
+int scale_val = 0;
+int hr, hs, vr, vs;
+int new_width = cpi->oxcf.Width;
+int new_height = cpi->oxcf.Height;
+int projected_buffer_level = (int)cpi->buffer_level;
+int tmp_q;
+double projected_bits_perframe;
+double group_iiratio = (kf_group_intra_err - first_frame.intra_error) / (kf_group_coded_err - first_frame.coded_error);
+double err_per_frame = kf_group_err / cpi->twopass.frames_to_key;
+double bits_per_frame;
+double av_bits_per_frame;
+double effective_size_ratio;
+if ((cpi->common.Width != cpi->oxcf.Width) || (cpi->common.Height != cpi->oxcf.Height))
+last_kf_resampled = 1;
+/* Set back to unscaled by defaults */
+cpi->common.horiz_scale = NORMAL;
+cpi->common.vert_scale = NORMAL;
+/* Calculate Average bits per frame. */
+av_bits_per_frame = cpi->oxcf.target_bandwidth / DOUBLE_DIVIDE_CHECK((double)cpi->framerate);
+/* CBR... Use the clip average as the target for deciding resample */
+if (cpi->oxcf.end_usage == USAGE_STREAM_FROM_SERVER)
+{
+bits_per_frame = av_bits_per_frame;
+}
+/* In VBR we want to avoid downsampling in easy section unless we
+* are under extreme pressure So use the larger of target bitrate
+* for this section or average bitrate for sequence
+*/
+else
+{
+/* This accounts for how hard the section is... */
+bits_per_frame = (double)
+(cpi->twopass.kf_group_bits / cpi->twopass.frames_to_key);
+/* Dont turn to resampling in easy sections just because they
+* have been assigned a small number of bits
+*/
+if (bits_per_frame < av_bits_per_frame)
+bits_per_frame = av_bits_per_frame;
+}
+/* bits_per_frame should comply with our minimum */
+if (bits_per_frame < (cpi->oxcf.target_bandwidth * cpi->oxcf.two_pass_vbrmin_section / 100))
+bits_per_frame = (cpi->oxcf.target_bandwidth * cpi->oxcf.two_pass_vbrmin_section / 100);
+/* Work out if spatial resampling is necessary */
+kf_q = estimate_kf_group_q(cpi, err_per_frame,
+(int)bits_per_frame, group_iiratio);
+/* If we project a required Q higher than the maximum allowed Q then
+* make a guess at the actual size of frames in this section
+*/
+projected_bits_perframe = bits_per_frame;
+tmp_q = kf_q;
+while (tmp_q > cpi->worst_quality)
+{
+projected_bits_perframe *= 1.04;
+tmp_q--;
+}
+/* Guess at buffer level at the end of the section */
+projected_buffer_level = (int)
+(cpi->buffer_level - (int)
+((projected_bits_perframe - av_bits_per_frame) *
+cpi->twopass.frames_to_key));
+if (0)
+{
+FILE *f = fopen("Subsamle.stt", "a");
+fprintf(f, " %8d %8d %8d %8d %12.0f %8d %8d %8d\n",  cpi->common.current_video_frame, kf_q, cpi->common.horiz_scale, cpi->common.vert_scale,  kf_group_err / cpi->twopass.frames_to_key, (int)(cpi->twopass.kf_group_bits / cpi->twopass.frames_to_key), new_height, new_width);
+fclose(f);
+}
+/* The trigger for spatial resampling depends on the various
+* parameters such as whether we are streaming (CBR) or VBR.
+*/
+if (cpi->oxcf.end_usage == USAGE_STREAM_FROM_SERVER)
+{
+/* Trigger resample if we are projected to fall below down
+* sample level or resampled last time and are projected to
+* remain below the up sample level
+*/
+if ((projected_buffer_level < (cpi->oxcf.resample_down_water_mark * cpi->oxcf.optimal_buffer_level / 100)) ||
+(last_kf_resampled && (projected_buffer_level < (cpi->oxcf.resample_up_water_mark * cpi->oxcf.optimal_buffer_level / 100))))
+resample_trigger = 1;
+else
+resample_trigger = 0;
+}
+else
+{
+int64_t clip_bits = (int64_t)(cpi->twopass.total_stats.count * cpi->oxcf.target_bandwidth / DOUBLE_DIVIDE_CHECK((double)cpi->framerate));
+int64_t over_spend = cpi->oxcf.starting_buffer_level - cpi->buffer_level;
+/* If triggered last time the threshold for triggering again is
+* reduced:
+*
+* Projected Q higher than allowed and Overspend > 5% of total
+* bits
+*/
+if ((last_kf_resampled && (kf_q > cpi->worst_quality)) ||
+((kf_q > cpi->worst_quality) &&
+(over_spend > clip_bits / 20)))
+resample_trigger = 1;
+else
+resample_trigger = 0;
+}
+if (resample_trigger)
+{
+while ((kf_q >= cpi->worst_quality) && (scale_val < 6))
+{
+scale_val ++;
+cpi->common.vert_scale   = vscale_lookup[scale_val];
+cpi->common.horiz_scale  = hscale_lookup[scale_val];
+Scale2Ratio(cpi->common.horiz_scale, &hr, &hs);
+Scale2Ratio(cpi->common.vert_scale, &vr, &vs);
+new_width = ((hs - 1) + (cpi->oxcf.Width * hr)) / hs;
+new_height = ((vs - 1) + (cpi->oxcf.Height * vr)) / vs;
+/* Reducing the area to 1/4 does not reduce the complexity
+* (err_per_frame) to 1/4... effective_sizeratio attempts
+* to provide a crude correction for this
+*/
+effective_size_ratio = (double)(new_width * new_height) / (double)(cpi->oxcf.Width * cpi->oxcf.Height);
+effective_size_ratio = (1.0 + (3.0 * effective_size_ratio)) / 4.0;
+/* Now try again and see what Q we get with the smaller
+* image size
+*/
+kf_q = estimate_kf_group_q(cpi,
+err_per_frame * effective_size_ratio,
+(int)bits_per_frame, group_iiratio);
+if (0)
+{
+FILE *f = fopen("Subsamle.stt", "a");
+fprintf(f, "******** %8d %8d %8d %12.0f %8d %8d %8d\n",  kf_q, cpi->common.horiz_scale, cpi->common.vert_scale,  kf_group_err / cpi->twopass.frames_to_key, (int)(cpi->twopass.kf_group_bits / cpi->twopass.frames_to_key), new_height, new_width);
+fclose(f);
+}
+}
+}
+if ((cpi->common.Width != new_width) || (cpi->common.Height != new_height))
+{
+cpi->common.Width = new_width;
+cpi->common.Height = new_height;
+vp8_alloc_compressor_data(cpi);
+}
+}
+}

The Tor Browser / file comparison

comparison: media/libvpx/vp8/encoder/firstpass.c

media/libvpx/vp8/encoder/firstpass.c