annotate src/libsndfile-1.0.27/examples/make_sine.c @ 40:1df64224f5ac

Current libsndfile source

/*
** Copyright (C) 1999-2012 Erik de Castro Lopo <[e-mail]>
**
** All rights reserved.
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are
** met:
**
**     * Redistributions of source code must retain the above copyright
**       notice, this list of conditions and the following disclaimer.
**     * Redistributions in binary form must reproduce the above copyright
**       notice, this list of conditions and the following disclaimer in
**       the documentation and/or other materials provided with the
**       distribution.
**     * Neither the author nor the names of any contributors may be used
**       to endorse or promote products derived from this software without
**       specific prior written permission.
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
** TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
** PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
** CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
** EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
** PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
** OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
** WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
** OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
** ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#include	<stdio.h>
#include	<stdlib.h>
#include	<string.h>
#include	<math.h>

#include	<sndfile.h>

#ifndef		M_PI
#define		M_PI		3.14159265358979323846264338
#endif

#define		SAMPLE_RATE			44100
#define		SAMPLE_COUNT		(SAMPLE_RATE * 4)	/* 4 seconds */
#define		AMPLITUDE			(1.0 * 0x7F000000)
#define		LEFT_FREQ			(344.0 / SAMPLE_RATE)
#define		RIGHT_FREQ			(466.0 / SAMPLE_RATE)

int
main (void)
{	SNDFILE	*file ;
	SF_INFO	sfinfo ;
	int		k ;
	int	*buffer ;

	if (! (buffer = malloc (2 * SAMPLE_COUNT * sizeof (int))))
	{	printf ("Malloc failed.\n") ;
		exit (0) ;
		} ;

	memset (&sfinfo, 0, sizeof (sfinfo)) ;

	sfinfo.samplerate	= SAMPLE_RATE ;
	sfinfo.frames		= SAMPLE_COUNT ;
	sfinfo.channels		= 2 ;
	sfinfo.format		= (SF_FORMAT_WAV | SF_FORMAT_PCM_24) ;

	if (! (file = sf_open ("sine.wav", SFM_WRITE, &sfinfo)))
	{	printf ("Error : Not able to open output file.\n") ;
		free (buffer) ;
		return 1 ;
		} ;

	if (sfinfo.channels == 1)
	{	for (k = 0 ; k < SAMPLE_COUNT ; k++)
			buffer [k] = AMPLITUDE * sin (LEFT_FREQ * 2 * k * M_PI) ;
		}
	else if (sfinfo.channels == 2)
	{	for (k = 0 ; k < SAMPLE_COUNT ; k++)
		{	buffer [2 * k] = AMPLITUDE * sin (LEFT_FREQ * 2 * k * M_PI) ;
			buffer [2 * k + 1] = AMPLITUDE * sin (RIGHT_FREQ * 2 * k * M_PI) ;
			} ;
		}
	else
	{	printf ("makesine can only generate mono or stereo files.\n") ;
		exit (1) ;
		} ;

	if (sf_write_int (file, buffer, sfinfo.channels * SAMPLE_COUNT) !=
											sfinfo.channels * SAMPLE_COUNT)
		puts (sf_strerror (file)) ;

	sf_close (file) ;
	free (buffer) ;
	return 0 ;
} /* main */