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/* $OpenBSD: aparams.h,v 1.1 2008/05/23 07:15:46 ratchov Exp $ */
/*
* Copyright (c) 2008 Alexandre Ratchov <alex@caoua.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#ifndef APARAMS_H
#define APARAMS_H
#include <sys/param.h>
#define CHAN_MAX 16 /* max number of channels */
#define RATE_MIN 1 /* min sample rate */
#define RATE_MAX (1 << 30) /* max sample rate */
#define BITS_MAX 32 /* max bits per sample */
#if BYTE_ORDER == LITTLE_ENDIAN
#define NATIVE_LE 1
#elif BYTE_ORDER == BIG_ENDIAN
#define NATIVE_LE 0
#else
/* not defined */
#endif
/*
* encoding specification
*/
struct aparams {
unsigned bps; /* bytes per sample */
unsigned bits; /* actually used bits */
unsigned le; /* 1 if little endian, 0 if big endian */
unsigned sig; /* 1 if signed, 0 if unsigned */
unsigned msb; /* 1 if msb justified, 0 if lsb justified */
unsigned cmin, cmax; /* provided/consumed channels */
unsigned rate; /* frames per second */
};
/*
* Samples are numbers in the interval [-1, 1[, note that 1, the upper
* boundary is excluded. We represent them in 16-bit signed fixed point
* numbers, so that we can do all multiplications and divisions in
* 32-bit precision without having to deal with overflows.
*/
#define ADATA_SHIFT (8 * sizeof(short) - 1)
#define ADATA_UNIT (1 << ADATA_SHIFT)
#define ADATA_MAX (ADATA_UNIT - 1)
#define ADATA_MUL(x,y) (((x) * (y)) >> ADATA_SHIFT)
void aparams_init(struct aparams *, unsigned, unsigned, unsigned);
void aparams_print(struct aparams *);
void aparams_print2(struct aparams *, struct aparams *);
int aparams_eq(struct aparams *, struct aparams *);
unsigned aparams_bpf(struct aparams *);
#endif /* !defined(APARAMS_H) */
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