/* volume.c - change the volume of a sound file
**
** Copyright (C) 1989 by Jef Poskanzer.
**
** Permission to use, copy, modify, and distribute this software and its
** documentation for any purpose and without fee is hereby granted, provided
** that the above copyright notice appear in all copies and that both that
** copyright notice and this permission notice appear in supporting
** documentation.  This software is provided "as is" without express or
** implied warranty.
*/

#include <stdio.h>
#include "libst.h"

#define MYBUFSIZ 256

main( argc, argv )
int argc;
char *argv[];
    {
    FILE *f;
    char mybuf[MYBUFSIZ];
    float scale;
    double atof();
    int c, lc;

    if ( argc < 2 || argc > 3 )
	{
	fprintf( stderr, "usage:  %s <factor> [<file>]\n", argv[0] );
	exit( 1 );
	}

    scale = atof( argv[1] );
    if ( scale == 0.0 )
	{
	fprintf( stderr, "%s: scale factor required\n", argv[0] );
	exit( 1 );
	}

    if ( argc == 2 )
	f = stdin;
    else if ( argc == 3 )
	{
	f = fopen( argv[2], "r" );
	if ( f == NULL )
	    {
	    perror( argv[2] );
	    exit( 1 );
	    }
	}
    setbuffer( stdout, mybuf, MYBUFSIZ );

    while ( (c = getc( f )) != EOF )
	{
	lc = st_ulaw_to_linear( c ) * scale;
	LINCLIP( lc );
	putchar( st_linear_to_ulaw( lc ) );
	}

    exit( 0 );
    }