Add m-esr52 at 52.6.0

1 files changed, 1609 insertions, 0 deletions

diff --git a/media/libvpx/vp8/encoder/ratectrl.c b/media/libvpx/vp8/encoder/ratectrl.c
new file mode 100644
index 000000000..e8796a1fc
--- /dev/null
+++ b/media/libvpx/vp8/encoder/ratectrl.c
@@ -0,0 +1,1609 @@
+/*
+ *  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 <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <limits.h>
+#include <assert.h>
+
+#include "math.h"
+#include "vp8/common/common.h"
+#include "ratectrl.h"
+#include "vp8/common/entropymode.h"
+#include "vpx_mem/vpx_mem.h"
+#include "vp8/common/systemdependent.h"
+#include "encodemv.h"
+
+
+#define MIN_BPB_FACTOR          0.01
+#define MAX_BPB_FACTOR          50
+
+extern const MB_PREDICTION_MODE vp8_mode_order[MAX_MODES];
+
+
+
+#ifdef MODE_STATS
+extern int y_modes[5];
+extern int uv_modes[4];
+extern int b_modes[10];
+
+extern int inter_y_modes[10];
+extern int inter_uv_modes[4];
+extern int inter_b_modes[10];
+#endif
+
+/* Bits Per MB at different Q (Multiplied by 512) */
+#define BPER_MB_NORMBITS    9
+
+/* Work in progress recalibration of baseline rate tables based on
+ * the assumption that bits per mb is inversely proportional to the
+ * quantizer value.
+ */
+const int vp8_bits_per_mb[2][QINDEX_RANGE] =
+{
+    /* Intra case 450000/Qintra */
+    {
+        1125000,900000, 750000, 642857, 562500, 500000, 450000, 450000,
+        409090, 375000, 346153, 321428, 300000, 281250, 264705, 264705,
+        250000, 236842, 225000, 225000, 214285, 214285, 204545, 204545,
+        195652, 195652, 187500, 180000, 180000, 173076, 166666, 160714,
+        155172, 150000, 145161, 140625, 136363, 132352, 128571, 125000,
+        121621, 121621, 118421, 115384, 112500, 109756, 107142, 104651,
+        102272, 100000, 97826,  97826,  95744,  93750,  91836,  90000,
+        88235,  86538,  84905,  83333,  81818,  80357,  78947,  77586,
+        76271,  75000,  73770,  72580,  71428,  70312,  69230,  68181,
+        67164,  66176,  65217,  64285,  63380,  62500,  61643,  60810,
+        60000,  59210,  59210,  58441,  57692,  56962,  56250,  55555,
+        54878,  54216,  53571,  52941,  52325,  51724,  51136,  50561,
+        49450,  48387,  47368,  46875,  45918,  45000,  44554,  44117,
+        43269,  42452,  41666,  40909,  40178,  39473,  38793,  38135,
+        36885,  36290,  35714,  35156,  34615,  34090,  33582,  33088,
+        32608,  32142,  31468,  31034,  30405,  29801,  29220,  28662,
+    },
+    /* Inter case 285000/Qinter */
+    {
+        712500, 570000, 475000, 407142, 356250, 316666, 285000, 259090,
+        237500, 219230, 203571, 190000, 178125, 167647, 158333, 150000,
+        142500, 135714, 129545, 123913, 118750, 114000, 109615, 105555,
+        101785, 98275,  95000,  91935,  89062,  86363,  83823,  81428,
+        79166,  77027,  75000,  73076,  71250,  69512,  67857,  66279,
+        64772,  63333,  61956,  60638,  59375,  58163,  57000,  55882,
+        54807,  53773,  52777,  51818,  50892,  50000,  49137,  47500,
+        45967,  44531,  43181,  41911,  40714,  39583,  38513,  37500,
+        36538,  35625,  34756,  33928,  33139,  32386,  31666,  30978,
+        30319,  29687,  29081,  28500,  27941,  27403,  26886,  26388,
+        25909,  25446,  25000,  24568,  23949,  23360,  22800,  22265,
+        21755,  21268,  20802,  20357,  19930,  19520,  19127,  18750,
+        18387,  18037,  17701,  17378,  17065,  16764,  16473,  16101,
+        15745,  15405,  15079,  14766,  14467,  14179,  13902,  13636,
+        13380,  13133,  12895,  12666,  12445,  12179,  11924,  11632,
+        11445,  11220,  11003,  10795,  10594,  10401,  10215,  10035,
+    }
+};
+
+static const int kf_boost_qadjustment[QINDEX_RANGE] =
+{
+    128, 129, 130, 131, 132, 133, 134, 135,
+    136, 137, 138, 139, 140, 141, 142, 143,
+    144, 145, 146, 147, 148, 149, 150, 151,
+    152, 153, 154, 155, 156, 157, 158, 159,
+    160, 161, 162, 163, 164, 165, 166, 167,
+    168, 169, 170, 171, 172, 173, 174, 175,
+    176, 177, 178, 179, 180, 181, 182, 183,
+    184, 185, 186, 187, 188, 189, 190, 191,
+    192, 193, 194, 195, 196, 197, 198, 199,
+    200, 200, 201, 201, 202, 203, 203, 203,
+    204, 204, 205, 205, 206, 206, 207, 207,
+    208, 208, 209, 209, 210, 210, 211, 211,
+    212, 212, 213, 213, 214, 214, 215, 215,
+    216, 216, 217, 217, 218, 218, 219, 219,
+    220, 220, 220, 220, 220, 220, 220, 220,
+    220, 220, 220, 220, 220, 220, 220, 220,
+};
+
+/* #define GFQ_ADJUSTMENT (Q+100) */
+#define GFQ_ADJUSTMENT vp8_gf_boost_qadjustment[Q]
+const int vp8_gf_boost_qadjustment[QINDEX_RANGE] =
+{
+    80, 82, 84, 86, 88, 90, 92, 94,
+    96, 97, 98, 99, 100, 101, 102, 103,
+    104, 105, 106, 107, 108, 109, 110, 111,
+    112, 113, 114, 115, 116, 117, 118, 119,
+    120, 121, 122, 123, 124, 125, 126, 127,
+    128, 129, 130, 131, 132, 133, 134, 135,
+    136, 137, 138, 139, 140, 141, 142, 143,
+    144, 145, 146, 147, 148, 149, 150, 151,
+    152, 153, 154, 155, 156, 157, 158, 159,
+    160, 161, 162, 163, 164, 165, 166, 167,
+    168, 169, 170, 171, 172, 173, 174, 175,
+    176, 177, 178, 179, 180, 181, 182, 183,
+    184, 184, 185, 185, 186, 186, 187, 187,
+    188, 188, 189, 189, 190, 190, 191, 191,
+    192, 192, 193, 193, 194, 194, 194, 194,
+    195, 195, 196, 196, 197, 197, 198, 198
+};
+
+/*
+const int vp8_gf_boost_qadjustment[QINDEX_RANGE] =
+{
+    100,101,102,103,104,105,105,106,
+    106,107,107,108,109,109,110,111,
+    112,113,114,115,116,117,118,119,
+    120,121,122,123,124,125,126,127,
+    128,129,130,131,132,133,134,135,
+    136,137,138,139,140,141,142,143,
+    144,145,146,147,148,149,150,151,
+    152,153,154,155,156,157,158,159,
+    160,161,162,163,164,165,166,167,
+    168,169,170,170,171,171,172,172,
+    173,173,173,174,174,174,175,175,
+    175,176,176,176,177,177,177,177,
+    178,178,179,179,180,180,181,181,
+    182,182,183,183,184,184,185,185,
+    186,186,187,187,188,188,189,189,
+    190,190,191,191,192,192,193,193,
+};
+*/
+
+static const int kf_gf_boost_qlimits[QINDEX_RANGE] =
+{
+    150, 155, 160, 165, 170, 175, 180, 185,
+    190, 195, 200, 205, 210, 215, 220, 225,
+    230, 235, 240, 245, 250, 255, 260, 265,
+    270, 275, 280, 285, 290, 295, 300, 305,
+    310, 320, 330, 340, 350, 360, 370, 380,
+    390, 400, 410, 420, 430, 440, 450, 460,
+    470, 480, 490, 500, 510, 520, 530, 540,
+    550, 560, 570, 580, 590, 600, 600, 600,
+    600, 600, 600, 600, 600, 600, 600, 600,
+    600, 600, 600, 600, 600, 600, 600, 600,
+    600, 600, 600, 600, 600, 600, 600, 600,
+    600, 600, 600, 600, 600, 600, 600, 600,
+    600, 600, 600, 600, 600, 600, 600, 600,
+    600, 600, 600, 600, 600, 600, 600, 600,
+    600, 600, 600, 600, 600, 600, 600, 600,
+    600, 600, 600, 600, 600, 600, 600, 600,
+};
+
+static const int gf_adjust_table[101] =
+{
+    100,
+    115, 130, 145, 160, 175, 190, 200, 210, 220, 230,
+    240, 260, 270, 280, 290, 300, 310, 320, 330, 340,
+    350, 360, 370, 380, 390, 400, 400, 400, 400, 400,
+    400, 400, 400, 400, 400, 400, 400, 400, 400, 400,
+    400, 400, 400, 400, 400, 400, 400, 400, 400, 400,
+    400, 400, 400, 400, 400, 400, 400, 400, 400, 400,
+    400, 400, 400, 400, 400, 400, 400, 400, 400, 400,
+    400, 400, 400, 400, 400, 400, 400, 400, 400, 400,
+    400, 400, 400, 400, 400, 400, 400, 400, 400, 400,
+    400, 400, 400, 400, 400, 400, 400, 400, 400, 400,
+};
+
+static const int gf_intra_usage_adjustment[20] =
+{
+    125, 120, 115, 110, 105, 100,  95,  85,  80,  75,
+    70,  65,  60,  55,  50,  50,  50,  50,  50,  50,
+};
+
+static const int gf_interval_table[101] =
+{
+    7,
+    7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+    7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+    7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+    8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+    8, 8, 8, 8, 8, 8, 8, 8, 8, 8,
+    9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
+    9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
+    10, 10, 10, 10, 10, 10, 10, 10, 10, 10,
+    10, 10, 10, 10, 10, 10, 10, 10, 10, 10,
+    11, 11, 11, 11, 11, 11, 11, 11, 11, 11,
+};
+
+static const unsigned int prior_key_frame_weight[KEY_FRAME_CONTEXT] = { 1, 2, 3, 4, 5 };
+
+
+void vp8_save_coding_context(VP8_COMP *cpi)
+{
+    CODING_CONTEXT *const cc = & cpi->coding_context;
+
+    /* Stores a snapshot of key state variables which can subsequently be
+     * restored with a call to vp8_restore_coding_context. These functions are
+     * intended for use in a re-code loop in vp8_compress_frame where the
+     * quantizer value is adjusted between loop iterations.
+     */
+
+    cc->frames_since_key          = cpi->frames_since_key;
+    cc->filter_level             = cpi->common.filter_level;
+    cc->frames_till_gf_update_due   = cpi->frames_till_gf_update_due;
+    cc->frames_since_golden       = cpi->frames_since_golden;
+
+    vp8_copy(cc->mvc,      cpi->common.fc.mvc);
+    vp8_copy(cc->mvcosts,  cpi->rd_costs.mvcosts);
+
+    vp8_copy(cc->ymode_prob,   cpi->common.fc.ymode_prob);
+    vp8_copy(cc->uv_mode_prob,  cpi->common.fc.uv_mode_prob);
+
+    vp8_copy(cc->ymode_count, cpi->mb.ymode_count);
+    vp8_copy(cc->uv_mode_count, cpi->mb.uv_mode_count);
+
+
+    /* Stats */
+#ifdef MODE_STATS
+    vp8_copy(cc->y_modes,       y_modes);
+    vp8_copy(cc->uv_modes,      uv_modes);
+    vp8_copy(cc->b_modes,       b_modes);
+    vp8_copy(cc->inter_y_modes,  inter_y_modes);
+    vp8_copy(cc->inter_uv_modes, inter_uv_modes);
+    vp8_copy(cc->inter_b_modes,  inter_b_modes);
+#endif
+
+    cc->this_frame_percent_intra = cpi->this_frame_percent_intra;
+}
+
+
+void vp8_restore_coding_context(VP8_COMP *cpi)
+{
+    CODING_CONTEXT *const cc = & cpi->coding_context;
+
+    /* Restore key state variables to the snapshot state stored in the
+     * previous call to vp8_save_coding_context.
+     */
+
+    cpi->frames_since_key         =   cc->frames_since_key;
+    cpi->common.filter_level     =   cc->filter_level;
+    cpi->frames_till_gf_update_due  =   cc->frames_till_gf_update_due;
+    cpi->frames_since_golden       =   cc->frames_since_golden;
+
+    vp8_copy(cpi->common.fc.mvc, cc->mvc);
+
+    vp8_copy(cpi->rd_costs.mvcosts, cc->mvcosts);
+
+    vp8_copy(cpi->common.fc.ymode_prob,   cc->ymode_prob);
+    vp8_copy(cpi->common.fc.uv_mode_prob,  cc->uv_mode_prob);
+
+    vp8_copy(cpi->mb.ymode_count, cc->ymode_count);
+    vp8_copy(cpi->mb.uv_mode_count, cc->uv_mode_count);
+
+    /* Stats */
+#ifdef MODE_STATS
+    vp8_copy(y_modes, cc->y_modes);
+    vp8_copy(uv_modes, cc->uv_modes);
+    vp8_copy(b_modes, cc->b_modes);
+    vp8_copy(inter_y_modes, cc->inter_y_modes);
+    vp8_copy(inter_uv_modes, cc->inter_uv_modes);
+    vp8_copy(inter_b_modes, cc->inter_b_modes);
+#endif
+
+
+    cpi->this_frame_percent_intra = cc->this_frame_percent_intra;
+}
+
+
+void vp8_setup_key_frame(VP8_COMP *cpi)
+{
+    /* Setup for Key frame: */
+
+    vp8_default_coef_probs(& cpi->common);
+
+    memcpy(cpi->common.fc.mvc, vp8_default_mv_context, sizeof(vp8_default_mv_context));
+    {
+        int flag[2] = {1, 1};
+        vp8_build_component_cost_table(cpi->mb.mvcost, (const MV_CONTEXT *) cpi->common.fc.mvc, flag);
+    }
+
+    /* Make sure we initialize separate contexts for altref,gold, and normal.
+     * TODO shouldn't need 3 different copies of structure to do this!
+     */
+    memcpy(&cpi->lfc_a, &cpi->common.fc, sizeof(cpi->common.fc));
+    memcpy(&cpi->lfc_g, &cpi->common.fc, sizeof(cpi->common.fc));
+    memcpy(&cpi->lfc_n, &cpi->common.fc, sizeof(cpi->common.fc));
+
+    cpi->common.filter_level = cpi->common.base_qindex * 3 / 8 ;
+
+    /* Provisional interval before next GF */
+    if (cpi->auto_gold)
+        cpi->frames_till_gf_update_due = cpi->baseline_gf_interval;
+    else
+        cpi->frames_till_gf_update_due = DEFAULT_GF_INTERVAL;
+
+    cpi->common.refresh_golden_frame = 1;
+    cpi->common.refresh_alt_ref_frame = 1;
+}
+
+
+static int estimate_bits_at_q(int frame_kind, int Q, int MBs,
+                              double correction_factor)
+{
+    int Bpm = (int)(.5 + correction_factor * vp8_bits_per_mb[frame_kind][Q]);
+
+    /* Attempt to retain reasonable accuracy without overflow. The cutoff is
+     * chosen such that the maximum product of Bpm and MBs fits 31 bits. The
+     * largest Bpm takes 20 bits.
+     */
+    if (MBs > (1 << 11))
+        return (Bpm >> BPER_MB_NORMBITS) * MBs;
+    else
+        return (Bpm * MBs) >> BPER_MB_NORMBITS;
+}
+
+
+static void calc_iframe_target_size(VP8_COMP *cpi)
+{
+    /* boost defaults to half second */
+    int kf_boost;
+    uint64_t target;
+
+    /* Clear down mmx registers to allow floating point in what follows */
+    vp8_clear_system_state();
+
+    if (cpi->oxcf.fixed_q >= 0)
+    {
+        int Q = cpi->oxcf.key_q;
+
+        target = estimate_bits_at_q(INTRA_FRAME, Q, cpi->common.MBs,
+                                    cpi->key_frame_rate_correction_factor);
+    }
+    else if (cpi->pass == 2)
+    {
+        /* New Two pass RC */
+        target = cpi->per_frame_bandwidth;
+    }
+    /* First Frame is a special case */
+    else if (cpi->common.current_video_frame == 0)
+    {
+        /* 1 Pass there is no information on which to base size so use
+         * bandwidth per second * fraction of the initial buffer
+         * level
+         */
+        target = cpi->oxcf.starting_buffer_level / 2;
+
+        if(target > cpi->oxcf.target_bandwidth * 3 / 2)
+            target = cpi->oxcf.target_bandwidth * 3 / 2;
+    }
+    else
+    {
+        /* if this keyframe was forced, use a more recent Q estimate */
+        int Q = (cpi->common.frame_flags & FRAMEFLAGS_KEY)
+                ? cpi->avg_frame_qindex : cpi->ni_av_qi;
+
+        int initial_boost = 32; /* |3.0 * per_frame_bandwidth| */
+        /* Boost depends somewhat on frame rate: only used for 1 layer case. */
+        if (cpi->oxcf.number_of_layers == 1) {
+          kf_boost = MAX(initial_boost, (int)(2 * cpi->output_framerate - 16));
+        }
+        else {
+          /* Initial factor: set target size to: |3.0 * per_frame_bandwidth|. */
+          kf_boost = initial_boost;
+        }
+
+        /* adjustment up based on q: this factor ranges from ~1.2 to 2.2. */
+        kf_boost = kf_boost * kf_boost_qadjustment[Q] / 100;
+
+        /* frame separation adjustment ( down) */
+        if (cpi->frames_since_key  < cpi->output_framerate / 2)
+            kf_boost = (int)(kf_boost
+                       * cpi->frames_since_key / (cpi->output_framerate / 2));
+
+        /* Minimal target size is |2* per_frame_bandwidth|. */
+        if (kf_boost < 16)
+            kf_boost = 16;
+
+        target = ((16 + kf_boost) * cpi->per_frame_bandwidth) >> 4;
+    }
+
+
+    if (cpi->oxcf.rc_max_intra_bitrate_pct)
+    {
+        unsigned int max_rate = cpi->per_frame_bandwidth
+                                * cpi->oxcf.rc_max_intra_bitrate_pct / 100;
+
+        if (target > max_rate)
+            target = max_rate;
+    }
+
+    cpi->this_frame_target = (int)target;
+
+    /* TODO: if we separate rate targeting from Q targetting, move this.
+     * Reset the active worst quality to the baseline value for key frames.
+     */
+    if (cpi->pass != 2)
+        cpi->active_worst_quality = cpi->worst_quality;
+
+#if 0
+    {
+        FILE *f;
+
+        f = fopen("kf_boost.stt", "a");
+        fprintf(f, " %8u %10d %10d %10d\n",
+                cpi->common.current_video_frame,  cpi->gfu_boost, cpi->baseline_gf_interval, cpi->source_alt_ref_pending);
+
+        fclose(f);
+    }
+#endif
+}
+
+
+/* Do the best we can to define the parameters for the next GF based on what
+ * information we have available.
+ */
+static void calc_gf_params(VP8_COMP *cpi)
+{
+    int Q = (cpi->oxcf.fixed_q < 0) ? cpi->last_q[INTER_FRAME] : cpi->oxcf.fixed_q;
+    int Boost = 0;
+
+    int gf_frame_useage = 0;      /* Golden frame useage since last GF */
+    int tot_mbs = cpi->recent_ref_frame_usage[INTRA_FRAME]  +
+                  cpi->recent_ref_frame_usage[LAST_FRAME]   +
+                  cpi->recent_ref_frame_usage[GOLDEN_FRAME] +
+                  cpi->recent_ref_frame_usage[ALTREF_FRAME];
+
+    int pct_gf_active = (100 * cpi->gf_active_count) / (cpi->common.mb_rows * cpi->common.mb_cols);
+
+    if (tot_mbs)
+        gf_frame_useage = (cpi->recent_ref_frame_usage[GOLDEN_FRAME] + cpi->recent_ref_frame_usage[ALTREF_FRAME]) * 100 / tot_mbs;
+
+    if (pct_gf_active > gf_frame_useage)
+        gf_frame_useage = pct_gf_active;
+
+    /* Not two pass */
+    if (cpi->pass != 2)
+    {
+        /* Single Pass lagged mode: TBD */
+        if (0)
+        {
+        }
+
+        /* Single Pass compression: Has to use current and historical data */
+        else
+        {
+#if 0
+            /* Experimental code */
+            int index = cpi->one_pass_frame_index;
+            int frames_to_scan = (cpi->max_gf_interval <= MAX_LAG_BUFFERS) ? cpi->max_gf_interval : MAX_LAG_BUFFERS;
+
+            /* ************** Experimental code - incomplete */
+            /*
+            double decay_val = 1.0;
+            double IIAccumulator = 0.0;
+            double last_iiaccumulator = 0.0;
+            double IIRatio;
+
+            cpi->one_pass_frame_index = cpi->common.current_video_frame%MAX_LAG_BUFFERS;
+
+            for ( i = 0; i < (frames_to_scan - 1); i++ )
+            {
+                if ( index < 0 )
+                    index = MAX_LAG_BUFFERS;
+                index --;
+
+                if ( cpi->one_pass_frame_stats[index].frame_coded_error > 0.0 )
+                {
+                    IIRatio = cpi->one_pass_frame_stats[index].frame_intra_error / cpi->one_pass_frame_stats[index].frame_coded_error;
+
+                    if ( IIRatio > 30.0 )
+                        IIRatio = 30.0;
+                }
+                else
+                    IIRatio = 30.0;
+
+                IIAccumulator += IIRatio * decay_val;
+
+                decay_val = decay_val * cpi->one_pass_frame_stats[index].frame_pcnt_inter;
+
+                if (    (i > MIN_GF_INTERVAL) &&
+                        ((IIAccumulator - last_iiaccumulator) < 2.0) )
+                {
+                    break;
+                }
+                last_iiaccumulator = IIAccumulator;
+            }
+
+            Boost = IIAccumulator*100.0/16.0;
+            cpi->baseline_gf_interval = i;
+
+            */
+#else
+
+            /*************************************************************/
+            /* OLD code */
+
+            /* Adjust boost based upon ambient Q */
+            Boost = GFQ_ADJUSTMENT;
+
+            /* Adjust based upon most recently measure intra useage */
+            Boost = Boost * gf_intra_usage_adjustment[(cpi->this_frame_percent_intra < 15) ? cpi->this_frame_percent_intra : 14] / 100;
+
+            /* Adjust gf boost based upon GF usage since last GF */
+            Boost = Boost * gf_adjust_table[gf_frame_useage] / 100;
+#endif
+        }
+
+        /* golden frame boost without recode loop often goes awry.  be
+         * safe by keeping numbers down.
+         */
+        if (!cpi->sf.recode_loop)
+        {
+            if (cpi->compressor_speed == 2)
+                Boost = Boost / 2;
+        }
+
+        /* Apply an upper limit based on Q for 1 pass encodes */
+        if (Boost > kf_gf_boost_qlimits[Q] && (cpi->pass == 0))
+            Boost = kf_gf_boost_qlimits[Q];
+
+        /* Apply lower limits to boost. */
+        else if (Boost < 110)
+            Boost = 110;
+
+        /* Note the boost used */
+        cpi->last_boost = Boost;
+
+    }
+
+    /* Estimate next interval
+     * This is updated once the real frame size/boost is known.
+     */
+    if (cpi->oxcf.fixed_q == -1)
+    {
+        if (cpi->pass == 2)         /* 2 Pass */
+        {
+            cpi->frames_till_gf_update_due = cpi->baseline_gf_interval;
+        }
+        else                            /* 1 Pass */
+        {
+            cpi->frames_till_gf_update_due = cpi->baseline_gf_interval;
+
+            if (cpi->last_boost > 750)
+                cpi->frames_till_gf_update_due++;
+
+            if (cpi->last_boost > 1000)
+                cpi->frames_till_gf_update_due++;
+
+            if (cpi->last_boost > 1250)
+                cpi->frames_till_gf_update_due++;
+
+            if (cpi->last_boost >= 1500)
+                cpi->frames_till_gf_update_due ++;
+
+            if (gf_interval_table[gf_frame_useage] > cpi->frames_till_gf_update_due)
+                cpi->frames_till_gf_update_due = gf_interval_table[gf_frame_useage];
+
+            if (cpi->frames_till_gf_update_due > cpi->max_gf_interval)
+                cpi->frames_till_gf_update_due = cpi->max_gf_interval;
+        }
+    }
+    else
+        cpi->frames_till_gf_update_due = cpi->baseline_gf_interval;
+
+    /* ARF on or off */
+    if (cpi->pass != 2)
+    {
+        /* For now Alt ref is not allowed except in 2 pass modes. */
+        cpi->source_alt_ref_pending = 0;
+
+        /*if ( cpi->oxcf.fixed_q == -1)
+        {
+            if ( cpi->oxcf.play_alternate && (cpi->last_boost > (100 + (AF_THRESH*cpi->frames_till_gf_update_due)) ) )
+                cpi->source_alt_ref_pending = 1;
+            else
+                cpi->source_alt_ref_pending = 0;
+        }*/
+    }
+}
+
+
+static void calc_pframe_target_size(VP8_COMP *cpi)
+{
+    int min_frame_target;
+    int old_per_frame_bandwidth = cpi->per_frame_bandwidth;
+
+    if ( cpi->current_layer > 0)
+        cpi->per_frame_bandwidth =
+            cpi->layer_context[cpi->current_layer].avg_frame_size_for_layer;
+
+    min_frame_target = 0;
+
+    if (cpi->pass == 2)
+    {
+        min_frame_target = cpi->min_frame_bandwidth;
+
+        if (min_frame_target < (cpi->av_per_frame_bandwidth >> 5))
+            min_frame_target = cpi->av_per_frame_bandwidth >> 5;
+    }
+    else if (min_frame_target < cpi->per_frame_bandwidth / 4)
+        min_frame_target = cpi->per_frame_bandwidth / 4;
+
+
+    /* Special alt reference frame case */
+    if((cpi->common.refresh_alt_ref_frame) && (cpi->oxcf.number_of_layers == 1))
+    {
+        if (cpi->pass == 2)
+        {
+            /* Per frame bit target for the alt ref frame */
+            cpi->per_frame_bandwidth = cpi->twopass.gf_bits;
+            cpi->this_frame_target = cpi->per_frame_bandwidth;
+        }
+
+        /* One Pass ??? TBD */
+    }
+
+    /* Normal frames (gf,and inter) */
+    else
+    {
+        /* 2 pass */
+        if (cpi->pass == 2)
+        {
+            cpi->this_frame_target = cpi->per_frame_bandwidth;
+        }
+        /* 1 pass */
+        else
+        {
+            int Adjustment;
+            /* Make rate adjustment to recover bits spent in key frame
+             * Test to see if the key frame inter data rate correction
+             * should still be in force
+             */
+            if (cpi->kf_overspend_bits > 0)
+            {
+                Adjustment = (cpi->kf_bitrate_adjustment <= cpi->kf_overspend_bits) ? cpi->kf_bitrate_adjustment : cpi->kf_overspend_bits;
+
+                if (Adjustment > (cpi->per_frame_bandwidth - min_frame_target))
+                    Adjustment = (cpi->per_frame_bandwidth - min_frame_target);
+
+                cpi->kf_overspend_bits -= Adjustment;
+
+                /* Calculate an inter frame bandwidth target for the next
+                 * few frames designed to recover any extra bits spent on
+                 * the key frame.
+                 */
+                cpi->this_frame_target = cpi->per_frame_bandwidth - Adjustment;
+
+                if (cpi->this_frame_target < min_frame_target)
+                    cpi->this_frame_target = min_frame_target;
+            }
+            else
+                cpi->this_frame_target = cpi->per_frame_bandwidth;
+
+            /* If appropriate make an adjustment to recover bits spent on a
+             * recent GF
+             */
+            if ((cpi->gf_overspend_bits > 0) && (cpi->this_frame_target > min_frame_target))
+            {
+                Adjustment = (cpi->non_gf_bitrate_adjustment <= cpi->gf_overspend_bits) ? cpi->non_gf_bitrate_adjustment : cpi->gf_overspend_bits;
+
+                if (Adjustment > (cpi->this_frame_target - min_frame_target))
+                    Adjustment = (cpi->this_frame_target - min_frame_target);
+
+                cpi->gf_overspend_bits -= Adjustment;
+                cpi->this_frame_target -= Adjustment;
+            }
+
+            /* Apply small + and - boosts for non gf frames */
+            if ((cpi->last_boost > 150) && (cpi->frames_till_gf_update_due > 0) &&
+                (cpi->current_gf_interval >= (MIN_GF_INTERVAL << 1)))
+            {
+                /* % Adjustment limited to the range 1% to 10% */
+                Adjustment = (cpi->last_boost - 100) >> 5;
+
+                if (Adjustment < 1)
+                    Adjustment = 1;
+                else if (Adjustment > 10)
+                    Adjustment = 10;
+
+                /* Convert to bits */
+                Adjustment = (cpi->this_frame_target * Adjustment) / 100;
+
+                if (Adjustment > (cpi->this_frame_target - min_frame_target))
+                    Adjustment = (cpi->this_frame_target - min_frame_target);
+
+                if (cpi->frames_since_golden == (cpi->current_gf_interval >> 1))
+                {
+                    Adjustment = (cpi->current_gf_interval - 1) * Adjustment;
+                    // Limit adjustment to 10% of current target.
+                    if (Adjustment > (10 * cpi->this_frame_target) / 100)
+                        Adjustment = (10 * cpi->this_frame_target) / 100;
+                    cpi->this_frame_target += Adjustment;
+                }
+                else
+                    cpi->this_frame_target -= Adjustment;
+            }
+        }
+    }
+
+    /* Sanity check that the total sum of adjustments is not above the
+     * maximum allowed That is that having allowed for KF and GF penalties
+     * we have not pushed the current interframe target to low. If the
+     * adjustment we apply here is not capable of recovering all the extra
+     * bits we have spent in the KF or GF then the remainder will have to
+     * be recovered over a longer time span via other buffer / rate control
+     * mechanisms.
+     */
+    if (cpi->this_frame_target < min_frame_target)
+        cpi->this_frame_target = min_frame_target;
+
+    if (!cpi->common.refresh_alt_ref_frame)
+        /* Note the baseline target data rate for this inter frame. */
+        cpi->inter_frame_target = cpi->this_frame_target;
+
+    /* One Pass specific code */
+    if (cpi->pass == 0)
+    {
+        /* Adapt target frame size with respect to any buffering constraints: */
+        if (cpi->buffered_mode)
+        {
+            int one_percent_bits = (int)
+                (1 + cpi->oxcf.optimal_buffer_level / 100);
+
+            if ((cpi->buffer_level < cpi->oxcf.optimal_buffer_level) ||
+                (cpi->bits_off_target < cpi->oxcf.optimal_buffer_level))
+            {
+                int percent_low = 0;
+
+                /* Decide whether or not we need to adjust the frame data
+                 * rate target.
+                 *
+                 * If we are are below the optimal buffer fullness level
+                 * and adherence to buffering constraints is important to
+                 * the end usage then adjust the per frame target.
+                 */
+                if ((cpi->oxcf.end_usage == USAGE_STREAM_FROM_SERVER) &&
+                    (cpi->buffer_level < cpi->oxcf.optimal_buffer_level))
+                {
+                    percent_low = (int)
+                        ((cpi->oxcf.optimal_buffer_level - cpi->buffer_level) /
+                        one_percent_bits);
+                }
+                /* Are we overshooting the long term clip data rate... */
+                else if (cpi->bits_off_target < 0)
+                {
+                    /* Adjust per frame data target downwards to compensate. */
+                    percent_low = (int)(100 * -cpi->bits_off_target /
+                                       (cpi->total_byte_count * 8));
+                }
+
+                if (percent_low > cpi->oxcf.under_shoot_pct)
+                    percent_low = cpi->oxcf.under_shoot_pct;
+                else if (percent_low < 0)
+                    percent_low = 0;
+
+                /* lower the target bandwidth for this frame. */
+                cpi->this_frame_target -=
+                        (cpi->this_frame_target * percent_low) / 200;
+
+                /* Are we using allowing control of active_worst_allowed_q
+                 * according to buffer level.
+                 */
+                if (cpi->auto_worst_q && cpi->ni_frames > 150)
+                {
+                    int64_t critical_buffer_level;
+
+                    /* For streaming applications the most important factor is
+                     * cpi->buffer_level as this takes into account the
+                     * specified short term buffering constraints. However,
+                     * hitting the long term clip data rate target is also
+                     * important.
+                     */
+                    if (cpi->oxcf.end_usage == USAGE_STREAM_FROM_SERVER)
+                    {
+                        /* Take the smaller of cpi->buffer_level and
+                         * cpi->bits_off_target
+                         */
+                        critical_buffer_level =
+                            (cpi->buffer_level < cpi->bits_off_target)
+                            ? cpi->buffer_level : cpi->bits_off_target;
+                    }
+                    /* For local file playback short term buffering constraints
+                     * are less of an issue
+                     */
+                    else
+                    {
+                        /* Consider only how we are doing for the clip as a
+                         * whole
+                         */
+                        critical_buffer_level = cpi->bits_off_target;
+                    }
+
+                    /* Set the active worst quality based upon the selected
+                     * buffer fullness number.
+                     */
+                    if (critical_buffer_level < cpi->oxcf.optimal_buffer_level)
+                    {
+                        if ( critical_buffer_level >
+                             (cpi->oxcf.optimal_buffer_level >> 2) )
+                        {
+                            int64_t qadjustment_range =
+                                      cpi->worst_quality - cpi->ni_av_qi;
+                            int64_t above_base =
+                                      (critical_buffer_level -
+                                       (cpi->oxcf.optimal_buffer_level >> 2));
+
+                            /* Step active worst quality down from
+                             * cpi->ni_av_qi when (critical_buffer_level ==
+                             * cpi->optimal_buffer_level) to
+                             * cpi->worst_quality when
+                             * (critical_buffer_level ==
+                             *     cpi->optimal_buffer_level >> 2)
+                             */
+                            cpi->active_worst_quality =
+                                cpi->worst_quality -
+                                (int)((qadjustment_range * above_base) /
+                                 (cpi->oxcf.optimal_buffer_level*3>>2));
+                        }
+                        else
+                        {
+                            cpi->active_worst_quality = cpi->worst_quality;
+                        }
+                    }
+                    else
+                    {
+                        cpi->active_worst_quality = cpi->ni_av_qi;
+                    }
+                }
+                else
+                {
+                    cpi->active_worst_quality = cpi->worst_quality;
+                }
+            }
+            else
+            {
+                int percent_high = 0;
+
+                if ((cpi->oxcf.end_usage == USAGE_STREAM_FROM_SERVER)
+                     && (cpi->buffer_level > cpi->oxcf.optimal_buffer_level))
+                {
+                    percent_high = (int)((cpi->buffer_level
+                                    - cpi->oxcf.optimal_buffer_level)
+                                   / one_percent_bits);
+                }
+                else if (cpi->bits_off_target > cpi->oxcf.optimal_buffer_level)
+                {
+                    percent_high = (int)((100 * cpi->bits_off_target)
+                                         / (cpi->total_byte_count * 8));
+                }
+
+                if (percent_high > cpi->oxcf.over_shoot_pct)
+                    percent_high = cpi->oxcf.over_shoot_pct;
+                else if (percent_high < 0)
+                    percent_high = 0;
+
+                cpi->this_frame_target += (cpi->this_frame_target *
+                                          percent_high) / 200;
+
+                /* Are we allowing control of active_worst_allowed_q according
+                 * to buffer level.
+                 */
+                if (cpi->auto_worst_q && cpi->ni_frames > 150)
+                {
+                    /* When using the relaxed buffer model stick to the
+                     * user specified value
+                     */
+                    cpi->active_worst_quality = cpi->ni_av_qi;
+                }
+                else
+                {
+                    cpi->active_worst_quality = cpi->worst_quality;
+                }
+            }
+
+            /* Set active_best_quality to prevent quality rising too high */
+            cpi->active_best_quality = cpi->best_quality;
+
+            /* Worst quality obviously must not be better than best quality */
+            if (cpi->active_worst_quality <= cpi->active_best_quality)
+                cpi->active_worst_quality = cpi->active_best_quality + 1;
+
+            if(cpi->active_worst_quality > 127)
+                cpi->active_worst_quality = 127;
+        }
+        /* Unbuffered mode (eg. video conferencing) */
+        else
+        {
+            /* Set the active worst quality */
+            cpi->active_worst_quality = cpi->worst_quality;
+        }
+
+        /* Special trap for constrained quality mode
+         * "active_worst_quality" may never drop below cq level
+         * for any frame type.
+         */
+        if ( cpi->oxcf.end_usage == USAGE_CONSTRAINED_QUALITY &&
+             cpi->active_worst_quality < cpi->cq_target_quality)
+        {
+            cpi->active_worst_quality = cpi->cq_target_quality;
+        }
+    }
+
+    /* Test to see if we have to drop a frame
+     * The auto-drop frame code is only used in buffered mode.
+     * In unbufferd mode (eg vide conferencing) the descision to
+     * code or drop a frame is made outside the codec in response to real
+     * world comms or buffer considerations.
+     */
+    if (cpi->drop_frames_allowed &&
+        (cpi->oxcf.end_usage == USAGE_STREAM_FROM_SERVER) &&
+        ((cpi->common.frame_type != KEY_FRAME)))
+    {
+        /* Check for a buffer underun-crisis in which case we have to drop
+         * a frame
+         */
+        if ((cpi->buffer_level < 0))
+        {
+#if 0
+            FILE *f = fopen("dec.stt", "a");
+            fprintf(f, "%10d %10d %10d %10d ***** BUFFER EMPTY\n",
+                    (int) cpi->common.current_video_frame,
+                    cpi->decimation_factor, cpi->common.horiz_scale,
+                    (cpi->buffer_level * 100) / cpi->oxcf.optimal_buffer_level);
+            fclose(f);
+#endif
+            cpi->drop_frame = 1;
+
+            /* Update the buffer level variable. */
+            cpi->bits_off_target += cpi->av_per_frame_bandwidth;
+            if (cpi->bits_off_target > cpi->oxcf.maximum_buffer_size)
+              cpi->bits_off_target = (int)cpi->oxcf.maximum_buffer_size;
+            cpi->buffer_level = cpi->bits_off_target;
+
+            if (cpi->oxcf.number_of_layers > 1) {
+              unsigned int i;
+
+              // Propagate bits saved by dropping the frame to higher layers.
+              for (i = cpi->current_layer + 1; i < cpi->oxcf.number_of_layers;
+                  i++) {
+                LAYER_CONTEXT *lc = &cpi->layer_context[i];
+                lc->bits_off_target += (int)(lc->target_bandwidth /
+                                             lc->framerate);
+                if (lc->bits_off_target > lc->maximum_buffer_size)
+                  lc->bits_off_target = lc->maximum_buffer_size;
+                lc->buffer_level = lc->bits_off_target;
+              }
+            }
+        }
+    }
+
+    /* Adjust target frame size for Golden Frames: */
+    if (cpi->oxcf.error_resilient_mode == 0 &&
+        (cpi->frames_till_gf_update_due == 0) && !cpi->drop_frame)
+    {
+        int Q = (cpi->oxcf.fixed_q < 0) ? cpi->last_q[INTER_FRAME] : cpi->oxcf.fixed_q;
+
+        int gf_frame_useage = 0;      /* Golden frame useage since last GF */
+        int tot_mbs = cpi->recent_ref_frame_usage[INTRA_FRAME]  +
+                      cpi->recent_ref_frame_usage[LAST_FRAME]   +
+                      cpi->recent_ref_frame_usage[GOLDEN_FRAME] +
+                      cpi->recent_ref_frame_usage[ALTREF_FRAME];
+
+        int pct_gf_active = (100 * cpi->gf_active_count) / (cpi->common.mb_rows * cpi->common.mb_cols);
+
+        if (tot_mbs)
+            gf_frame_useage = (cpi->recent_ref_frame_usage[GOLDEN_FRAME] + cpi->recent_ref_frame_usage[ALTREF_FRAME]) * 100 / tot_mbs;
+
+        if (pct_gf_active > gf_frame_useage)
+            gf_frame_useage = pct_gf_active;
+
+        /* Is a fixed manual GF frequency being used */
+        if (cpi->auto_gold)
+        {
+            /* For one pass throw a GF if recent frame intra useage is
+             * low or the GF useage is high
+             */
+            if ((cpi->pass == 0) && (cpi->this_frame_percent_intra < 15 || gf_frame_useage >= 5))
+                cpi->common.refresh_golden_frame = 1;
+
+            /* Two pass GF descision */
+            else if (cpi->pass == 2)
+                cpi->common.refresh_golden_frame = 1;
+        }
+
+#if 0
+
+        /* Debug stats */
+        if (0)
+        {
+            FILE *f;
+
+            f = fopen("gf_useaget.stt", "a");
+            fprintf(f, " %8ld %10ld %10ld %10ld %10ld\n",
+                    cpi->common.current_video_frame,  cpi->gfu_boost, GFQ_ADJUSTMENT, cpi->gfu_boost, gf_frame_useage);
+            fclose(f);
+        }
+
+#endif
+
+        if (cpi->common.refresh_golden_frame == 1)
+        {
+#if 0
+
+            if (0)
+            {
+                FILE *f;
+
+                f = fopen("GFexit.stt", "a");
+                fprintf(f, "%8ld GF coded\n", cpi->common.current_video_frame);
+                fclose(f);
+            }
+
+#endif
+
+            if (cpi->auto_adjust_gold_quantizer)
+            {
+                calc_gf_params(cpi);
+            }
+
+            /* If we are using alternate ref instead of gf then do not apply the
+             * boost It will instead be applied to the altref update Jims
+             * modified boost
+             */
+            if (!cpi->source_alt_ref_active)
+            {
+                if (cpi->oxcf.fixed_q < 0)
+                {
+                    if (cpi->pass == 2)
+                    {
+                        /* The spend on the GF is defined in the two pass
+                         * code for two pass encodes
+                         */
+                        cpi->this_frame_target = cpi->per_frame_bandwidth;
+                    }
+                    else
+                    {
+                        int Boost = cpi->last_boost;
+                        int frames_in_section = cpi->frames_till_gf_update_due + 1;
+                        int allocation_chunks = (frames_in_section * 100) + (Boost - 100);
+                        int bits_in_section = cpi->inter_frame_target * frames_in_section;
+
+                        /* Normalize Altboost and allocations chunck down to
+                         * prevent overflow
+                         */
+                        while (Boost > 1000)
+                        {
+                            Boost /= 2;
+                            allocation_chunks /= 2;
+                        }
+
+                        /* Avoid loss of precision but avoid overflow */
+                        if ((bits_in_section >> 7) > allocation_chunks)
+                            cpi->this_frame_target = Boost * (bits_in_section / allocation_chunks);
+                        else
+                            cpi->this_frame_target = (Boost * bits_in_section) / allocation_chunks;
+                    }
+                }
+                else
+                    cpi->this_frame_target =
+                        (estimate_bits_at_q(1, Q, cpi->common.MBs, 1.0)
+                         * cpi->last_boost) / 100;
+
+            }
+            /* If there is an active ARF at this location use the minimum
+             * bits on this frame even if it is a contructed arf.
+             * The active maximum quantizer insures that an appropriate
+             * number of bits will be spent if needed for contstructed ARFs.
+             */
+            else
+            {
+                cpi->this_frame_target = 0;
+            }
+
+            cpi->current_gf_interval = cpi->frames_till_gf_update_due;
+
+        }
+    }
+
+    cpi->per_frame_bandwidth = old_per_frame_bandwidth;
+}
+
+
+void vp8_update_rate_correction_factors(VP8_COMP *cpi, int damp_var)
+{
+    int    Q = cpi->common.base_qindex;
+    int    correction_factor = 100;
+    double rate_correction_factor;
+    double adjustment_limit;
+
+    int    projected_size_based_on_q = 0;
+
+    /* Clear down mmx registers to allow floating point in what follows */
+    vp8_clear_system_state();
+
+    if (cpi->common.frame_type == KEY_FRAME)
+    {
+        rate_correction_factor = cpi->key_frame_rate_correction_factor;
+    }
+    else
+    {
+        if (cpi->oxcf.number_of_layers == 1 &&
+           (cpi->common.refresh_alt_ref_frame ||
+            cpi->common.refresh_golden_frame))
+            rate_correction_factor = cpi->gf_rate_correction_factor;
+        else
+            rate_correction_factor = cpi->rate_correction_factor;
+    }
+
+    /* Work out how big we would have expected the frame to be at this Q
+     * given the current correction factor. Stay in double to avoid int
+     * overflow when values are large
+     */
+    projected_size_based_on_q = (int)(((.5 + rate_correction_factor * vp8_bits_per_mb[cpi->common.frame_type][Q]) * cpi->common.MBs) / (1 << BPER_MB_NORMBITS));
+
+    /* Make some allowance for cpi->zbin_over_quant */
+    if (cpi->mb.zbin_over_quant > 0)
+    {
+        int Z = cpi->mb.zbin_over_quant;
+        double Factor = 0.99;
+        double factor_adjustment = 0.01 / 256.0;
+
+        while (Z > 0)
+        {
+            Z --;
+            projected_size_based_on_q =
+                (int)(Factor * projected_size_based_on_q);
+            Factor += factor_adjustment;
+
+            if (Factor  >= 0.999)
+                Factor = 0.999;
+        }
+    }
+
+    /* Work out a size correction factor. */
+    if (projected_size_based_on_q > 0)
+        correction_factor = (100 * cpi->projected_frame_size) / projected_size_based_on_q;
+
+    /* More heavily damped adjustment used if we have been oscillating
+     * either side of target
+     */
+    switch (damp_var)
+    {
+    case 0:
+        adjustment_limit = 0.75;
+        break;
+    case 1:
+        adjustment_limit = 0.375;
+        break;
+    case 2:
+    default:
+        adjustment_limit = 0.25;
+        break;
+    }
+
+    if (correction_factor > 102)
+    {
+        /* We are not already at the worst allowable quality */
+        correction_factor = (int)(100.5 + ((correction_factor - 100) * adjustment_limit));
+        rate_correction_factor = ((rate_correction_factor * correction_factor) / 100);
+
+        /* Keep rate_correction_factor within limits */
+        if (rate_correction_factor > MAX_BPB_FACTOR)
+            rate_correction_factor = MAX_BPB_FACTOR;
+    }
+    else if (correction_factor < 99)
+    {
+        /* We are not already at the best allowable quality */
+        correction_factor = (int)(100.5 - ((100 - correction_factor) * adjustment_limit));
+        rate_correction_factor = ((rate_correction_factor * correction_factor) / 100);
+
+        /* Keep rate_correction_factor within limits */
+        if (rate_correction_factor < MIN_BPB_FACTOR)
+            rate_correction_factor = MIN_BPB_FACTOR;
+    }
+
+    if (cpi->common.frame_type == KEY_FRAME)
+        cpi->key_frame_rate_correction_factor = rate_correction_factor;
+    else
+    {
+        if (cpi->oxcf.number_of_layers == 1 &&
+           (cpi->common.refresh_alt_ref_frame ||
+            cpi->common.refresh_golden_frame))
+            cpi->gf_rate_correction_factor = rate_correction_factor;
+        else
+            cpi->rate_correction_factor = rate_correction_factor;
+    }
+}
+
+
+int vp8_regulate_q(VP8_COMP *cpi, int target_bits_per_frame)
+{
+    int Q = cpi->active_worst_quality;
+
+    if (cpi->force_maxqp == 1) {
+      cpi->active_worst_quality = cpi->worst_quality;
+      return cpi->worst_quality;
+    }
+
+    /* Reset Zbin OQ value */
+    cpi->mb.zbin_over_quant = 0;
+
+    if (cpi->oxcf.fixed_q >= 0)
+    {
+        Q = cpi->oxcf.fixed_q;
+
+        if (cpi->common.frame_type == KEY_FRAME)
+        {
+            Q = cpi->oxcf.key_q;
+        }
+        else if (cpi->oxcf.number_of_layers == 1 &&
+            cpi->common.refresh_alt_ref_frame)
+        {
+            Q = cpi->oxcf.alt_q;
+        }
+        else if (cpi->oxcf.number_of_layers == 1  &&
+            cpi->common.refresh_golden_frame)
+        {
+            Q = cpi->oxcf.gold_q;
+        }
+    }
+    else
+    {
+        int i;
+        int last_error = INT_MAX;
+        int target_bits_per_mb;
+        int bits_per_mb_at_this_q;
+        double correction_factor;
+
+        /* Select the appropriate correction factor based upon type of frame. */
+        if (cpi->common.frame_type == KEY_FRAME)
+            correction_factor = cpi->key_frame_rate_correction_factor;
+        else
+        {
+            if (cpi->oxcf.number_of_layers == 1 &&
+               (cpi->common.refresh_alt_ref_frame ||
+                cpi->common.refresh_golden_frame))
+                correction_factor = cpi->gf_rate_correction_factor;
+            else
+                correction_factor = cpi->rate_correction_factor;
+        }
+
+        /* Calculate required scaling factor based on target frame size and
+         * size of frame produced using previous Q
+         */
+        if (target_bits_per_frame >= (INT_MAX >> BPER_MB_NORMBITS))
+            /* Case where we would overflow int */
+            target_bits_per_mb = (target_bits_per_frame / cpi->common.MBs) << BPER_MB_NORMBITS;
+        else
+            target_bits_per_mb = (target_bits_per_frame << BPER_MB_NORMBITS) / cpi->common.MBs;
+
+        i = cpi->active_best_quality;
+
+        do
+        {
+            bits_per_mb_at_this_q = (int)(.5 + correction_factor * vp8_bits_per_mb[cpi->common.frame_type][i]);
+
+            if (bits_per_mb_at_this_q <= target_bits_per_mb)
+            {
+                if ((target_bits_per_mb - bits_per_mb_at_this_q) <= last_error)
+                    Q = i;
+                else
+                    Q = i - 1;
+
+                break;
+            }
+            else
+                last_error = bits_per_mb_at_this_q - target_bits_per_mb;
+        }
+        while (++i <= cpi->active_worst_quality);
+
+
+        /* If we are at MAXQ then enable Q over-run which seeks to claw
+         * back additional bits through things like the RD multiplier
+         * and zero bin size.
+         */
+        if (Q >= MAXQ)
+        {
+            int zbin_oqmax;
+
+            double Factor = 0.99;
+            double factor_adjustment = 0.01 / 256.0;
+
+            if (cpi->common.frame_type == KEY_FRAME)
+                zbin_oqmax = 0;
+            else if (cpi->oxcf.number_of_layers == 1 &&
+                (cpi->common.refresh_alt_ref_frame ||
+                (cpi->common.refresh_golden_frame &&
+                 !cpi->source_alt_ref_active)))
+                zbin_oqmax = 16;
+            else
+                zbin_oqmax = ZBIN_OQ_MAX;
+
+            /*{
+                double Factor = (double)target_bits_per_mb/(double)bits_per_mb_at_this_q;
+                double Oq;
+
+                Factor = Factor/1.2683;
+
+                Oq = pow( Factor, (1.0/-0.165) );
+
+                if ( Oq > zbin_oqmax )
+                    Oq = zbin_oqmax;
+
+                cpi->zbin_over_quant = (int)Oq;
+            }*/
+
+            /* Each incrment in the zbin is assumed to have a fixed effect
+             * on bitrate. This is not of course true. The effect will be
+             * highly clip dependent and may well have sudden steps. The
+             * idea here is to acheive higher effective quantizers than the
+             * normal maximum by expanding the zero bin and hence
+             * decreasing the number of low magnitude non zero coefficients.
+             */
+            while (cpi->mb.zbin_over_quant < zbin_oqmax)
+            {
+                cpi->mb.zbin_over_quant ++;
+
+                if (cpi->mb.zbin_over_quant > zbin_oqmax)
+                    cpi->mb.zbin_over_quant = zbin_oqmax;
+
+                /* Adjust bits_per_mb_at_this_q estimate */
+                bits_per_mb_at_this_q = (int)(Factor * bits_per_mb_at_this_q);
+                Factor += factor_adjustment;
+
+                if (Factor  >= 0.999)
+                    Factor = 0.999;
+
+                /* Break out if we get down to the target rate */
+                if (bits_per_mb_at_this_q <= target_bits_per_mb)
+                    break;
+            }
+
+        }
+    }
+
+    return Q;
+}
+
+
+static int estimate_keyframe_frequency(VP8_COMP *cpi)
+{
+    int i;
+
+    /* Average key frame frequency */
+    int av_key_frame_frequency = 0;
+
+    /* First key frame at start of sequence is a special case. We have no
+     * frequency data.
+     */
+    if (cpi->key_frame_count == 1)
+    {
+        /* Assume a default of 1 kf every 2 seconds, or the max kf interval,
+         * whichever is smaller.
+         */
+        int key_freq = cpi->oxcf.key_freq>0 ? cpi->oxcf.key_freq : 1;
+        av_key_frame_frequency = 1 + (int)cpi->output_framerate * 2;
+
+        if (cpi->oxcf.auto_key && av_key_frame_frequency > key_freq)
+            av_key_frame_frequency = key_freq;
+
+        cpi->prior_key_frame_distance[KEY_FRAME_CONTEXT - 1]
+            = av_key_frame_frequency;
+    }
+    else
+    {
+        unsigned int total_weight = 0;
+        int last_kf_interval =
+                (cpi->frames_since_key > 0) ? cpi->frames_since_key : 1;
+
+        /* reset keyframe context and calculate weighted average of last
+         * KEY_FRAME_CONTEXT keyframes
+         */
+        for (i = 0; i < KEY_FRAME_CONTEXT; i++)
+        {
+            if (i < KEY_FRAME_CONTEXT - 1)
+                cpi->prior_key_frame_distance[i]
+                    = cpi->prior_key_frame_distance[i+1];
+            else
+                cpi->prior_key_frame_distance[i] = last_kf_interval;
+
+            av_key_frame_frequency += prior_key_frame_weight[i]
+                                      * cpi->prior_key_frame_distance[i];
+            total_weight += prior_key_frame_weight[i];
+        }
+
+        av_key_frame_frequency  /= total_weight;
+
+    }
+    // TODO (marpan): Given the checks above, |av_key_frame_frequency|
+    // should always be above 0. But for now we keep the sanity check in.
+    if (av_key_frame_frequency == 0)
+        av_key_frame_frequency = 1;
+    return av_key_frame_frequency;
+}
+
+
+void vp8_adjust_key_frame_context(VP8_COMP *cpi)
+{
+    /* Clear down mmx registers to allow floating point in what follows */
+    vp8_clear_system_state();
+
+    /* Do we have any key frame overspend to recover? */
+    /* Two-pass overspend handled elsewhere. */
+    if ((cpi->pass != 2)
+         && (cpi->projected_frame_size > cpi->per_frame_bandwidth))
+    {
+        int overspend;
+
+        /* Update the count of key frame overspend to be recovered in
+         * subsequent frames. A portion of the KF overspend is treated as gf
+         * overspend (and hence recovered more quickly) as the kf is also a
+         * gf. Otherwise the few frames following each kf tend to get more
+         * bits allocated than those following other gfs.
+         */
+        overspend = (cpi->projected_frame_size - cpi->per_frame_bandwidth);
+
+        if (cpi->oxcf.number_of_layers > 1)
+            cpi->kf_overspend_bits += overspend;
+        else
+        {
+            cpi->kf_overspend_bits += overspend * 7 / 8;
+            cpi->gf_overspend_bits += overspend * 1 / 8;
+        }
+
+        /* Work out how much to try and recover per frame. */
+        cpi->kf_bitrate_adjustment = cpi->kf_overspend_bits
+                                     / estimate_keyframe_frequency(cpi);
+    }
+
+    cpi->frames_since_key = 0;
+    cpi->key_frame_count++;
+}
+
+
+void vp8_compute_frame_size_bounds(VP8_COMP *cpi, int *frame_under_shoot_limit, int *frame_over_shoot_limit)
+{
+    /* Set-up bounds on acceptable frame size: */
+    if (cpi->oxcf.fixed_q >= 0)
+    {
+        /* Fixed Q scenario: frame size never outranges target
+         * (there is no target!)
+         */
+        *frame_under_shoot_limit = 0;
+        *frame_over_shoot_limit  = INT_MAX;
+    }
+    else
+    {
+        if (cpi->common.frame_type == KEY_FRAME)
+        {
+            *frame_over_shoot_limit  = cpi->this_frame_target * 9 / 8;
+            *frame_under_shoot_limit = cpi->this_frame_target * 7 / 8;
+        }
+        else
+        {
+            if (cpi->oxcf.number_of_layers > 1 ||
+                cpi->common.refresh_alt_ref_frame ||
+                cpi->common.refresh_golden_frame)
+            {
+                *frame_over_shoot_limit  = cpi->this_frame_target * 9 / 8;
+                *frame_under_shoot_limit = cpi->this_frame_target * 7 / 8;
+            }
+            else
+            {
+                /* For CBR take buffer fullness into account */
+                if (cpi->oxcf.end_usage == USAGE_STREAM_FROM_SERVER)
+                {
+                    if (cpi->buffer_level >= ((cpi->oxcf.optimal_buffer_level + cpi->oxcf.maximum_buffer_size) >> 1))
+                    {
+                        /* Buffer is too full so relax overshoot and tighten
+                         * undershoot
+                         */
+                        *frame_over_shoot_limit  = cpi->this_frame_target * 12 / 8;
+                        *frame_under_shoot_limit = cpi->this_frame_target * 6 / 8;
+                    }
+                    else if (cpi->buffer_level <= (cpi->oxcf.optimal_buffer_level >> 1))
+                    {
+                        /* Buffer is too low so relax undershoot and tighten
+                         * overshoot
+                         */
+                        *frame_over_shoot_limit  = cpi->this_frame_target * 10 / 8;
+                        *frame_under_shoot_limit = cpi->this_frame_target * 4 / 8;
+                    }
+                    else
+                    {
+                        *frame_over_shoot_limit  = cpi->this_frame_target * 11 / 8;
+                        *frame_under_shoot_limit = cpi->this_frame_target * 5 / 8;
+                    }
+                }
+                /* VBR and CQ mode */
+                /* Note that tighter restrictions here can help quality
+                 * but hurt encode speed
+                 */
+                else
+                {
+                    /* Stron overshoot limit for constrained quality */
+                    if (cpi->oxcf.end_usage == USAGE_CONSTRAINED_QUALITY)
+                    {
+                        *frame_over_shoot_limit  = cpi->this_frame_target * 11 / 8;
+                        *frame_under_shoot_limit = cpi->this_frame_target * 2 / 8;
+                    }
+                    else
+                    {
+                        *frame_over_shoot_limit  = cpi->this_frame_target * 11 / 8;
+                        *frame_under_shoot_limit = cpi->this_frame_target * 5 / 8;
+                    }
+                }
+            }
+        }
+
+        /* For very small rate targets where the fractional adjustment
+         * (eg * 7/8) may be tiny make sure there is at least a minimum
+         * range.
+         */
+        *frame_over_shoot_limit += 200;
+        *frame_under_shoot_limit -= 200;
+        if ( *frame_under_shoot_limit < 0 )
+            *frame_under_shoot_limit = 0;
+
+    }
+}
+
+
+/* return of 0 means drop frame */
+int vp8_pick_frame_size(VP8_COMP *cpi)
+{
+    VP8_COMMON *cm = &cpi->common;
+
+    if (cm->frame_type == KEY_FRAME)
+        calc_iframe_target_size(cpi);
+    else
+    {
+        calc_pframe_target_size(cpi);
+
+        /* Check if we're dropping the frame: */
+        if (cpi->drop_frame)
+        {
+            cpi->drop_frame = 0;
+            return 0;
+        }
+    }
+    return 1;
+}
+// If this just encoded frame (mcomp/transform/quant, but before loopfilter and
+// pack_bitstream) has large overshoot, and was not being encoded close to the
+// max QP, then drop this frame and force next frame to be encoded at max QP.
+// Condition this on 1 pass CBR with screen content mode and frame dropper off.
+// TODO(marpan): Should do this exit condition during the encode_frame
+// (i.e., halfway during the encoding of the frame) to save cycles.
+int vp8_drop_encodedframe_overshoot(VP8_COMP *cpi, int Q) {
+  if (cpi->pass == 0 &&
+      cpi->oxcf.end_usage == USAGE_STREAM_FROM_SERVER &&
+      cpi->drop_frames_allowed == 0 &&
+      cpi->common.frame_type != KEY_FRAME) {
+    // Note: the "projected_frame_size" from encode_frame() only gives estimate
+    // of mode/motion vector rate (in non-rd mode): so below we only require
+    // that projected_frame_size is somewhat greater than per-frame-bandwidth,
+    // but add additional condition with high threshold on prediction residual.
+
+    // QP threshold: only allow dropping if we are not close to qp_max.
+    int thresh_qp = 3 * cpi->worst_quality >> 2;
+    // Rate threshold, in bytes.
+    int thresh_rate = 2 * (cpi->av_per_frame_bandwidth >> 3);
+    // Threshold for the average (over all macroblocks) of the pixel-sum
+    // residual error over 16x16 block. Should add QP dependence on threshold?
+    int thresh_pred_err_mb = (256 << 4);
+    int pred_err_mb = (int)(cpi->mb.prediction_error / cpi->common.MBs);
+    if (Q < thresh_qp &&
+        cpi->projected_frame_size > thresh_rate &&
+        pred_err_mb > thresh_pred_err_mb) {
+      // Drop this frame: advance frame counters, and set force_maxqp flag.
+      cpi->common.current_video_frame++;
+      cpi->frames_since_key++;
+      // Flag to indicate we will force next frame to be encoded at max QP.
+      cpi->force_maxqp = 1;
+      return 1;
+    } else {
+      cpi->force_maxqp = 0;
+      return 0;
+    }
+    cpi->force_maxqp = 0;
+    return 0;
+  }
+  cpi->force_maxqp = 0;
+  return 0;
+}