xbmc/utils/BitstreamStats.cpp

   1 /*
   2  *  Copyright (C) 2005-2018 Team Kodi
   3  *  This file is part of Kodi - https://kodi.tv
   4  *
   5  *  SPDX-License-Identifier: GPL-2.0-or-later
   6  *  See LICENSES/README.md for more information.
   7  */
   8
   9 #include "BitstreamStats.h"
  10
  11 #include "utils/TimeUtils.h"
  12
  13 int64_t BitstreamStats::m_tmFreq;
  14
  15 BitstreamStats::BitstreamStats(unsigned int nEstimatedBitrate)
  16 {
  17   m_dBitrate = 0.0;
  18   m_dMaxBitrate = 0.0;
  19   m_dMinBitrate = -1.0;
  20
  21   m_nBitCount = 0;
  22   m_nEstimatedBitrate = nEstimatedBitrate;
  23   m_tmStart = 0LL;
  24
  25   if (m_tmFreq == 0LL)
  26     m_tmFreq = CurrentHostFrequency();
  27 }
  28
  29 void BitstreamStats::AddSampleBytes(unsigned int nBytes)
  30 {
  31   AddSampleBits(nBytes*8);
  32 }
  33
  34 void BitstreamStats::AddSampleBits(unsigned int nBits)
  35 {
  36   m_nBitCount += nBits;
  37   if (m_nBitCount >= m_nEstimatedBitrate)
  38     CalculateBitrate();
  39 }
  40
  41 void BitstreamStats::Start()
  42 {
  43   m_nBitCount = 0;
  44   m_tmStart = CurrentHostCounter();
  45 }
  46
  47 void BitstreamStats::CalculateBitrate()
  48 {
  49   int64_t tmNow;
  50   tmNow = CurrentHostCounter();
  51
  52   double elapsed = (double)(tmNow - m_tmStart) / (double)m_tmFreq;
  53   // only update once every 2 seconds
  54   if (elapsed >= 2)
  55   {
  56     m_dBitrate = (double)m_nBitCount / elapsed;
  57
  58     if (m_dBitrate > m_dMaxBitrate)
  59       m_dMaxBitrate = m_dBitrate;
  60
  61     if (m_dBitrate < m_dMinBitrate || m_dMinBitrate == -1)
  62       m_dMinBitrate = m_dBitrate;
  63
  64     Start();
  65   }
  66 }
  67
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  70