vp9_ratectrl.c

/*
 *  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 <assert.h>
#include <limits.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "vpx_mem/vpx_mem.h"

#include "vp9/common/vp9_alloccommon.h"
#include "vp9/common/vp9_common.h"
#include "vp9/common/vp9_entropymode.h"
#include "vp9/common/vp9_quant_common.h"
#include "vp9/common/vp9_seg_common.h"
#include "vp9/common/vp9_systemdependent.h"

#include "vp9/encoder/vp9_encodemv.h"
#include "vp9/encoder/vp9_ratectrl.h"

#define DEFAULT_KF_BOOST 2000
#define DEFAULT_GF_BOOST 2000

#define LIMIT_QRANGE_FOR_ALTREF_AND_KEY 1

#define MIN_BPB_FACTOR 0.005
#define MAX_BPB_FACTOR 50

// Bits Per MB at different Q (Multiplied by 512)
#define BPER_MB_NORMBITS    9

// Tables relating active max Q to active min Q
static int kf_low_motion_minq[QINDEX_RANGE];
static int kf_high_motion_minq[QINDEX_RANGE];
static int gf_low_motion_minq[QINDEX_RANGE];
static int gf_high_motion_minq[QINDEX_RANGE];
static int inter_minq[QINDEX_RANGE];
static int afq_low_motion_minq[QINDEX_RANGE];
static int afq_high_motion_minq[QINDEX_RANGE];
static int gf_high = 2000;
static int gf_low = 400;
static int kf_high = 5000;
static int kf_low = 400;

// Functions to compute the active minq lookup table entries based on a
// formulaic approach to facilitate easier adjustment of the Q tables.
// The formulae were derived from computing a 3rd order polynomial best
// fit to the original data (after plotting real maxq vs minq (not q index))
static int calculate_minq_index(double maxq,
                                double x3, double x2, double x1, double c) {
  int i;
  const double minqtarget = MIN(((x3 * maxq + x2) * maxq + x1) * maxq + c,
                                maxq);

  // Special case handling to deal with the step from q2.0
  // down to lossless mode represented by q 1.0.
  if (minqtarget <= 2.0)
    return 0;

  for (i = 0; i < QINDEX_RANGE; i++) {
    if (minqtarget <= vp9_convert_qindex_to_q(i))