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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 1992-2003 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#ifndef _MULTIMEDIA_AUDIO_HDR_H
#define _MULTIMEDIA_AUDIO_HDR_H
#pragma ident "%Z%%M% %I% %E% SMI"
#ifdef __cplusplus
extern "C" {
#endif
/*
* Define an in-core audio data header.
*
* This is different that the on-disk file header.
* The fields defined here are preliminary at best.
*/
/*
* The audio header contains the following fields:
*
* endian Byte order of 16-bit or greater PCM,
* and possibly floating point data.
*
* sample_rate Number of samples per second (per channel).
*
* samples_per_unit This field describes the number of samples
* represented by each sample unit (which, by
* definition, are aligned on byte boundaries).
* Audio samples may be stored individually
* or, in the case of compressed formats
* (e.g., ADPCM), grouped in algorithm-
* specific ways. If the data is bit-packed,
* this field tells the number of samples
* needed to get to a byte boundary.
*
* bytes_per_unit Number of bytes stored for each sample unit
*
* channels Number of interleaved sample units.
* For any given time quantum, the set
* consisting of 'channels' sample units
* is called a sample frame. Seeks in
* the data should be aligned to the start
* of the nearest sample frame.
*
* encoding Data encoding format.
*
* data_size Number of bytes in the data.
* This value is advisory only, and may
* be set to the value AUDIO_UNKNOWN_SIZE
* if the data size is unknown (for
* instance, if the data is being
* recorded or generated and piped
* to another process).
*
* The first four values are used to compute the byte offset given a
* particular time, and vice versa. Specifically:
*
* seconds = offset / C
* offset = seconds * C
* where:
* C = (channels * bytes_per_unit * sample_rate) / samples_per_unit
*
*
*/
typedef struct {
unsigned sample_rate; /* samples per second */
unsigned samples_per_unit; /* samples per unit */
unsigned bytes_per_unit; /* bytes per sample unit */
unsigned channels; /* # of interleaved channels */
unsigned encoding; /* data encoding format */
unsigned endian; /* byte order */
unsigned data_size; /* length of data (optional) */
} Audio_hdr;
/*
* Define the possible encoding types.
* Note that the names that overlap the encodings in <sun/audioio.h>
* must have the same values.
*/
#define AUDIO_ENCODING_NONE (0) /* No encoding specified ... */
#define AUDIO_ENCODING_ULAW (1) /* ISDN u-law */
#define AUDIO_ENCODING_ALAW (2) /* ISDN A-law */
#define AUDIO_ENCODING_LINEAR (3) /* PCM 2's-complement (0-center) */
#define AUDIO_ENCODING_FLOAT (100) /* IEEE float (-1. <-> +1.) */
#define AUDIO_ENCODING_G721 (101) /* CCITT g.721 ADPCM */
#define AUDIO_ENCODING_G722 (102) /* CCITT g.722 ADPCM */
#define AUDIO_ENCODING_G723 (103) /* CCITT g.723 ADPCM */
#define AUDIO_ENCODING_DVI (104) /* DVI ADPCM */
/*
* Define the possible endian types.
*/
#define AUDIO_ENDIAN_BIG 0 /* SPARC, 68000, etc. */
#define AUDIO_ENDIAN_SMALL 1 /* Intel */
#define AUDIO_ENDIAN_UNKNOWN 2 /* Unknown endian */
/* Value used for indeterminate size (e.g., data passed through a pipe) */
#define AUDIO_UNKNOWN_SIZE ((unsigned)(~0))
/* Define conversion macros for integer<->floating-point conversions */
/* double to 8,16,32-bit linear */
#define audio_d2c(X) ((X) >= 1. ? 127 : (X) <= -1. ? -127 : \
(char)(rint((X) * 127.)))
#define audio_d2s(X) ((X) >= 1. ? 32767 : (X) <= -1. ? -32767 :\
(short)(rint((X) * 32767.)))
#define audio_d2l(X) ((X) >= 1. ? 2147483647 : (X) <= -1. ? \
-2147483647 : \
(long)(rint((X) * 2147483647.)))
/* 8,16,32-bit linear to double */
#define audio_c2d(X) (((unsigned char)(X)) == 0x80 ? -1. : \
((double)((char)(X))) / 127.)
#define audio_s2d(X) (((unsigned short)(X)) == 0x8000 ? -1. :\
((double)((short)(X))) / 32767.)
#define audio_l2d(X) (((unsigned long)(X)) == 0x80000000 ? -1. :\
((double)((long)(X))) / 2147483647.)
#ifdef __cplusplus
}
#endif
#endif /* !_MULTIMEDIA_AUDIO_HDR_H */
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