interpretor/libsndfile-1.0.25/regtest/checksum.c

   1 /*
   2 **      Copyright (C) 2005-2011 Erik de Castro Lopo
   3 **
   4 **      This program is free software; you can redistribute it and/or modify
   5 **      it under the terms of the GNU General Public License as published by
   6 **      the Free Software Foundation; either version 2 of the License, or
   7 **      (at your option) any later version.
   8 **
   9 **      This program is distributed in the hope that it will be useful,
  10 **      but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 **      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 **      GNU General Public License for more details.
  13 **
  14 **      You should have received a copy of the GNU General Public License
  15 **      along with this program; if not, write to the Free Software
  16 **      Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  17 */
  18
  19 /*
  20 **      A simple checksum for short, int and float data.
  21 */
  22
  23 #include "sfconfig.h"
  24
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <math.h>
  29
  30 #include <sndfile.h>
  31
  32 #include "regtest.h"
  33
  34 #define BIG_PRIME               999983
  35
  36 #define ARRAY_LEN(x)    ((int) (sizeof (x)) / (sizeof ((x) [0])))
  37
  38 static int short_checksum (SNDFILE * file, int start) ;
  39 static int int_checksum (SNDFILE * file, int start) ;
  40 static int float_checksum (SNDFILE * file, int start) ;
  41
  42 int
  43 calc_checksum (SNDFILE * file, const SF_INFO * info)
  44 {       int start ;
  45
  46         /* Seed the checksum with data from the SF_INFO struct. */
  47         start = info->samplerate ;
  48         start = start * BIG_PRIME + info->channels ;
  49         start = start * BIG_PRIME + info->format ;
  50
  51         switch (info->format & SF_FORMAT_SUBMASK)
  52         {       case SF_FORMAT_FLOAT :
  53                 case SF_FORMAT_DOUBLE :
  54                         return float_checksum (file, start) ;
  55
  56                 case SF_FORMAT_PCM_24 :
  57                 case SF_FORMAT_PCM_32 :
  58                         return int_checksum (file, start) ;
  59
  60                 default :
  61                         return short_checksum (file, start) ;
  62                 } ;
  63
  64         return 0 ;
  65 } /* calc_checksum */
  66
  67 /*------------------------------------------------------------------------------
  68 */
  69
  70 static union
  71 {       short   s [1 << 16] ;
  72         int             i [1 << 15] ;
  73         float   f [1 << 15] ;
  74 } data ;
  75
  76 static int
  77 short_checksum (SNDFILE * file, int start)
  78 {       int k, count ;
  79
  80         do
  81         {       count = (int) sf_read_short (file, data.s, ARRAY_LEN (data.s)) ;
  82                 for (k = 0 ; k < count ; k++)
  83                         start = start * BIG_PRIME + data.s [k] ;
  84                 }
  85         while (count > 0) ;
  86
  87         return start ;
  88 } /* short_checksum */
  89
  90 static int
  91 int_checksum (SNDFILE * file, int start)
  92 {       int k, count ;
  93
  94         do
  95         {       count = (int) sf_read_int (file, data.i, ARRAY_LEN (data.i)) ;
  96                 for (k = 0 ; k < count ; k++)
  97                         start = start * BIG_PRIME + data.i [k] ;
  98                 }
  99         while (count > 0) ;
 100
 101         return start ;
 102 } /* int_checksum */
 103
 104 static int
 105 float_checksum (SNDFILE * file, int start)
 106 {       int k, count ;
 107
 108         do
 109         {       count = (int) sf_read_float (file, data.f, ARRAY_LEN (data.f)) ;
 110                 for (k = 0 ; k < count ; k++)
 111                         start = start * BIG_PRIME + lrintf (0x7FFFFFFF * data.f [k]) ;
 112                 }
 113         while (count > 0) ;
 114
 115         return start ;
 116 } /* float_checksum */
 117