comparison src/libsndfile-1.0.25/tests/ulaw_test.c @ 0:c7265573341e

Import initial set of sources

+/*
+** Copyright (C) 1999-2011 Erik de Castro Lopo <[e-mail]>
+**
+** This program is free software; you can redistribute it and/or modify
+** it under the terms of the GNU General Public License as published by
+** the Free Software Foundation; either version 2 of the License, or
+** (at your option) any later version.
+**
+** This program is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+** GNU General Public License for more details.
+**
+** You should have received a copy of the GNU General Public License
+** along with this program; if not, write to the Free Software
+** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+*/
+
+#include "sfconfig.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#if HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+#include <sndfile.h>
+
+#include "utils.h"
+
+#define	BUFFER_SIZE		(65536)
+
+static unsigned char	ulaw_encode (int sample) ;
+static int				ulaw_decode (unsigned int ulawbyte) ;
+
+static	short			short_buffer [BUFFER_SIZE] ;
+static	unsigned char	ulaw_buffer [BUFFER_SIZE] ;
+
+int
+main (void)
+{	SNDFILE		*file ;
+	SF_INFO 	sfinfo ;
+	const char	*filename ;
+	int			k ;
+
+	print_test_name ("ulaw_test", "encoder") ;
+
+	filename = "test.raw" ;
+
+	sf_info_setup (&sfinfo, SF_FORMAT_RAW | SF_FORMAT_ULAW, 44100, 1) ;
+
+	if ((file = sf_open (filename, SFM_WRITE, &sfinfo)) == NULL)
+	{	printf ("sf_open_write failed with error : ") ;
+		fflush (stdout) ;
+		puts (sf_strerror (NULL)) ;
+		exit (1) ;
+		} ;
+
+	/* Generate a file containing all possible 16 bit sample values
+	** and write it to disk as ulaw encoded.frames.
+	*/
+
+	for (k = 0 ; k < 0x10000 ; k++)
+		short_buffer [k] = k & 0xFFFF ;
+
+	sf_write_short (file, short_buffer, BUFFER_SIZE) ;
+	sf_close (file) ;
+
+	/* Now open that file and compare the ulaw encoded sample values
+	** with what they should be.
+	*/
+
+	if ((file = sf_open (filename, SFM_READ, &sfinfo)) == NULL)
+	{	printf ("sf_open_write failed with error : ") ;
+		puts (sf_strerror (NULL)) ;
+		exit (1) ;
+		} ;
+
+	check_log_buffer_or_die (file, __LINE__) ;
+
+	if (sf_read_raw (file, ulaw_buffer, BUFFER_SIZE) != BUFFER_SIZE)
+	{	printf ("sf_read_raw : ") ;
+		puts (sf_strerror (file)) ;
+		exit (1) ;
+		} ;
+
+	for (k = 0 ; k < 0x10000 ; k++)
+		if (ulaw_encode (short_buffer [k]) != ulaw_buffer [k])
+		{	printf ("Encoder error : sample #%d (0x%02X should be 0x%02X)\n", k, ulaw_buffer [k], ulaw_encode (short_buffer [k])) ;
+			exit (1) ;
+			} ;
+
+	sf_close (file) ;
+
+	puts ("ok") ;
+
+	print_test_name ("ulaw_test", "decoder") ;
+
+	/* Now generate a file containing all possible 8 bit encoded
+	** sample values and write it to disk as ulaw encoded.frames.
+	*/
+
+	if (! (file = sf_open (filename, SFM_WRITE, &sfinfo)))
+	{	printf ("sf_open_write failed with error : ") ;
+		puts (sf_strerror (NULL)) ;
+		exit (1) ;
+		} ;
+
+	for (k = 0 ; k < 256 ; k++)
+		ulaw_buffer [k] = k & 0xFF ;
+
+	sf_write_raw (file, ulaw_buffer, 256) ;
+	sf_close (file) ;
+
+	/* Now open that file and compare the ulaw decoded sample values
+	** with what they should be.
+	*/
+
+	if (! (file = sf_open (filename, SFM_READ, &sfinfo)))
+	{	printf ("sf_open_write failed with error : ") ;
+		puts (sf_strerror (NULL)) ;
+		exit (1) ;
+		} ;
+
+	check_log_buffer_or_die (file, __LINE__) ;
+
+	if (sf_read_short (file, short_buffer, 256) != 256)
+	{	printf ("sf_read_short : ") ;
+		puts (sf_strerror (file)) ;
+		exit (1) ;
+		} ;
+
+
+	for (k = 0 ; k < 256 ; k++)
+		if (short_buffer [k] != ulaw_decode (ulaw_buffer [k]))
+		{	printf ("Decoder error : sample #%d (0x%04X should be 0x%04X)\n", k, short_buffer [k], ulaw_decode (ulaw_buffer [k])) ;
+			exit (1) ;
+			} ;
+
+	sf_close (file) ;
+
+	puts ("ok") ;
+
+	unlink (filename) ;
+
+	return 0 ;
+} /* main */
+
+
+/*=================================================================================
+**	The following routines came from the sox-12.15 (Sound eXcahcnge) distribution.
+**
+**	This code is not compiled into libsndfile. It is only used to test the
+**	libsndfile lookup tables for correctness.
+**
+**	I have included the original authors comments.
+*/
+
+/*
+** This routine converts from linear to ulaw.
+**
+** Craig Reese: IDA/Supercomputing Research Center
+** Joe Campbell: Department of Defense
+** 29 September 1989
+**
+** References:
+** 1) CCITT Recommendation G.711  (very difficult to follow)
+** 2) "A New Digital Technique for Implementation of Any
+**     Continuous PCM Companding Law," Villeret, Michel,
+**     et al. 1973 IEEE Int. Conf. on Communications, Vol 1,
+**     1973, pg. 11.12-11.17
+** 3) MIL-STD-188-113,"Interoperability and Performance Standards
+**     for Analog-to_Digital Conversion Techniques,"
+**     17 February 1987
+**
+** Input: Signed 16 bit linear sample
+** Output: 8 bit ulaw sample
+*/
+
+#define uBIAS 0x84		/* define the add-in bias for 16 bit.frames */
+#define uCLIP 32635
+
+static
+unsigned char ulaw_encode (int sample)
+{	static int exp_lut [256] =
+	{	0, 0, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3,
+		4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
+		5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
+		5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
+		6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
+		6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
+		6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
+		6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
+		7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+		7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+		7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+		7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+		7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+		7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+		7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+		7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7
+		} ;
+
+    int sign, exponent, mantissa ;
+    unsigned char ulawbyte ;
+
+    /* Get the sample into sign-magnitude. */
+    sign = (sample >> 8) & 0x80 ;					/* set aside the sign */
+    if ( sign != 0 )
+		sample = -sample ;							/* get magnitude */
+    if ( sample > uCLIP )
+		sample = uCLIP ;							/* clip the magnitude */
+
+    /* Convert from 16 bit linear to ulaw. */
+    sample = sample + uBIAS ;
+    exponent = exp_lut [( sample >> 7 ) & 0xFF] ;
+    mantissa = (sample >> ( exponent + 3 ) ) & 0x0F ;
+    ulawbyte = ~ (sign | ( exponent << 4 ) | mantissa) ;
+
+	return ulawbyte ;
+} /* ulaw_encode */
+
+
+/*
+** This routine converts from ulaw to 16 bit linear.
+**
+** Craig Reese: IDA/Supercomputing Research Center
+** 29 September 1989
+**
+** References:
+** 1) CCITT Recommendation G.711  (very difficult to follow)
+** 2) MIL-STD-188-113,"Interoperability and Performance Standards
+**     for Analog-to_Digital Conversion Techniques,"
+**     17 February 1987
+**
+** Input: 8 bit ulaw sample
+** Output: signed 16 bit linear sample
+*/
+
+static
+int ulaw_decode (unsigned int ulawbyte)
+{	static int exp_lut [8] = { 0, 132, 396, 924, 1980, 4092, 8316, 16764 } ;
+    int sign, exponent, mantissa, sample ;
+
+    ulawbyte = ~ ulawbyte ;
+    sign = (ulawbyte & 0x80) ;
+    exponent = (ulawbyte >> 4) & 0x07 ;
+    mantissa = ulawbyte & 0x0F ;
+    sample = exp_lut [exponent] + (mantissa << (exponent + 3)) ;
+    if (sign != 0)
+		sample = -sample ;
+
+    return sample ;
+} /* ulaw_decode */
+