src/clock/clock_internal.c

   1 /*****************************************************************************
   2  * clock_internal.c: Clock internal functions
   3  *****************************************************************************
   4  * Copyright (C) 2018 VLC authors and VideoLAN
   5  *
   6  * Authors: Christophe Massiot <massiot@via.ecp.fr>
   7  *          Laurent Aimar < fenrir _AT_ videolan _DOT_ org >
   8  *
   9  * This program is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU Lesser General Public License as published by
  11  * the Free Software Foundation; either version 2.1 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17  * GNU Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public License
  20  * along with this program; if not, write to the Free Software Foundation,
  21  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 #ifdef HAVE_CONFIG_H
  25 # include "config.h"
  26 #endif
  27
  28 #include "clock_internal.h"
  29
  30 /*****************************************************************************
  31  * Long term average helpers
  32  *****************************************************************************/
  33 void AvgInit(average_t *avg, int range)
  34 {
  35     avg->range = range;
  36     AvgReset(avg);
  37 }
  38
  39 void AvgClean(average_t * avg)
  40 {
  41     VLC_UNUSED(avg);
  42 }
  43
  44 void AvgReset(average_t *avg)
  45 {
  46     avg->value = 0.0f;
  47     avg->count = 0;
  48 }
  49
  50 void AvgUpdate(average_t *avg, double value)
  51 {
  52     const int new_value_weight = 1;
  53     int average_weight;
  54     int divider;
  55     if (avg->count < avg->range)
  56     {
  57         average_weight = avg->count++;
  58         divider = avg->count;
  59     }
  60     else
  61     {
  62         average_weight = avg->range - 1;
  63         divider = avg->range;
  64     }
  65
  66     const double tmp = average_weight * avg->value + new_value_weight * value;
  67     avg->value = tmp / divider;
  68 }
  69
  70 double AvgGet(average_t *avg)
  71 {
  72     return avg->value;
  73 }
  74
  75 void AvgRescale(average_t *avg, int range)
  76 {
  77     const double tmp = avg->value * avg->range;
  78
  79     avg->range = range;
  80     avg->value = tmp / avg->range;
  81 }