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 /*

  *  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;