cannam@85: /*
cannam@85: **	Copyright (C) 2005-2011 Erik de Castro Lopo
cannam@85: **
cannam@85: **	This program is free software; you can redistribute it and/or modify
cannam@85: **	it under the terms of the GNU General Public License as published by
cannam@85: **	the Free Software Foundation; either version 2 of the License, or
cannam@85: **	(at your option) any later version.
cannam@85: **
cannam@85: **	This program is distributed in the hope that it will be useful,
cannam@85: **	but WITHOUT ANY WARRANTY; without even the implied warranty of
cannam@85: **	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
cannam@85: **	GNU General Public License for more details.
cannam@85: **
cannam@85: **	You should have received a copy of the GNU General Public License
cannam@85: **	along with this program; if not, write to the Free Software
cannam@85: **	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
cannam@85: */
cannam@85: 
cannam@85: /*
cannam@85: **	A simple checksum for short, int and float data.
cannam@85: */
cannam@85: 
cannam@85: #include "sfconfig.h"
cannam@85: 
cannam@85: #include <stdio.h>
cannam@85: #include <stdlib.h>
cannam@85: #include <string.h>
cannam@85: #include <math.h>
cannam@85: 
cannam@85: #include <sndfile.h>
cannam@85: 
cannam@85: #include "regtest.h"
cannam@85: 
cannam@85: #define	BIG_PRIME		999983
cannam@85: 
cannam@85: #define	ARRAY_LEN(x)	((int) (sizeof (x)) / (sizeof ((x) [0])))
cannam@85: 
cannam@85: static int short_checksum (SNDFILE * file, int start) ;
cannam@85: static int int_checksum (SNDFILE * file, int start) ;
cannam@85: static int float_checksum (SNDFILE * file, int start) ;
cannam@85: 
cannam@85: int
cannam@85: calc_checksum (SNDFILE * file, const SF_INFO * info)
cannam@85: {	int start ;
cannam@85: 
cannam@85: 	/* Seed the checksum with data from the SF_INFO struct. */
cannam@85: 	start = info->samplerate ;
cannam@85: 	start = start * BIG_PRIME + info->channels ;
cannam@85: 	start = start * BIG_PRIME + info->format ;
cannam@85: 
cannam@85: 	switch (info->format & SF_FORMAT_SUBMASK)
cannam@85: 	{	case SF_FORMAT_FLOAT :
cannam@85: 		case SF_FORMAT_DOUBLE :
cannam@85: 			return float_checksum (file, start) ;
cannam@85: 
cannam@85: 		case SF_FORMAT_PCM_24 :
cannam@85: 		case SF_FORMAT_PCM_32 :
cannam@85: 			return int_checksum (file, start) ;
cannam@85: 
cannam@85: 		default :
cannam@85: 			return short_checksum (file, start) ;
cannam@85: 		} ;
cannam@85: 
cannam@85: 	return 0 ;
cannam@85: } /* calc_checksum */
cannam@85: 
cannam@85: /*------------------------------------------------------------------------------
cannam@85: */
cannam@85: 
cannam@85: static union
cannam@85: {	short	s [1 << 16] ;
cannam@85: 	int		i [1 << 15] ;
cannam@85: 	float	f [1 << 15] ;
cannam@85: } data ;
cannam@85: 
cannam@85: static int
cannam@85: short_checksum (SNDFILE * file, int start)
cannam@85: {	int k, count ;
cannam@85: 
cannam@85: 	do
cannam@85: 	{	count = (int) sf_read_short (file, data.s, ARRAY_LEN (data.s)) ;
cannam@85: 		for (k = 0 ; k < count ; k++)
cannam@85: 			start = start * BIG_PRIME + data.s [k] ;
cannam@85: 		}
cannam@85: 	while (count > 0) ;
cannam@85: 
cannam@85: 	return start ;
cannam@85: } /* short_checksum */
cannam@85: 
cannam@85: static int
cannam@85: int_checksum (SNDFILE * file, int start)
cannam@85: {	int k, count ;
cannam@85: 
cannam@85: 	do
cannam@85: 	{	count = (int) sf_read_int (file, data.i, ARRAY_LEN (data.i)) ;
cannam@85: 		for (k = 0 ; k < count ; k++)
cannam@85: 			start = start * BIG_PRIME + data.i [k] ;
cannam@85: 		}
cannam@85: 	while (count > 0) ;
cannam@85: 
cannam@85: 	return start ;
cannam@85: } /* int_checksum */
cannam@85: 
cannam@85: static int
cannam@85: float_checksum (SNDFILE * file, int start)
cannam@85: {	int k, count ;
cannam@85: 
cannam@85: 	do
cannam@85: 	{	count = (int) sf_read_float (file, data.f, ARRAY_LEN (data.f)) ;
cannam@85: 		for (k = 0 ; k < count ; k++)
cannam@85: 			start = start * BIG_PRIME + lrintf (0x7FFFFFFF * data.f [k]) ;
cannam@85: 		}
cannam@85: 	while (count > 0) ;
cannam@85: 
cannam@85: 	return start ;
cannam@85: } /* float_checksum */
cannam@85: