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