usr/src/cmd/audio/include/audio_hdr.h

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright 1992-2003 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 #ifndef _MULTIMEDIA_AUDIO_HDR_H
  28 #define _MULTIMEDIA_AUDIO_HDR_H
  29
  30 #pragma ident   "%Z%%M% %I%     %E% SMI"
  31
  32 #ifdef __cplusplus
  33 extern "C" {
  34 #endif
  35
  36 /*
  37  * Define an in-core audio data header.
  38  *
  39  * This is different that the on-disk file header.
  40  * The fields defined here are preliminary at best.
  41  */
  42
  43 /*
  44  * The audio header contains the following fields:
  45  *
  46  *      endian                  Byte order of 16-bit or greater PCM,
  47  *                                and possibly floating point data.
  48  *
  49  *      sample_rate             Number of samples per second (per channel).
  50  *
  51  *      samples_per_unit        This field describes the number of samples
  52  *                                represented by each sample unit (which, by
  53  *                                definition, are aligned on byte boundaries).
  54  *                                Audio samples may be stored individually
  55  *                                or, in the case of compressed formats
  56  *                                (e.g., ADPCM), grouped in algorithm-
  57  *                                specific ways.  If the data is bit-packed,
  58  *                                this field tells the number of samples
  59  *                                needed to get to a byte boundary.
  60  *
  61  *      bytes_per_unit          Number of bytes stored for each sample unit
  62  *
  63  *      channels                Number of interleaved sample units.
  64  *                                 For any given time quantum, the set
  65  *                                 consisting of 'channels' sample units
  66  *                                 is called a sample frame.  Seeks in
  67  *                                 the data should be aligned to the start
  68  *                                 of the nearest sample frame.
  69  *
  70  *      encoding                Data encoding format.
  71  *
  72  *      data_size               Number of bytes in the data.
  73  *                                 This value is advisory only, and may
  74  *                                 be set to the value AUDIO_UNKNOWN_SIZE
  75  *                                 if the data size is unknown (for
  76  *                                 instance, if the data is being
  77  *                                 recorded or generated and piped
  78  *                                 to another process).
  79  *
  80  * The first four values are used to compute the byte offset given a
  81  * particular time, and vice versa.  Specifically:
  82  *
  83  *      seconds = offset / C
  84  *      offset = seconds * C
  85  * where:
  86  *      C = (channels * bytes_per_unit * sample_rate) / samples_per_unit
  87  *
  88  *
  89  */
  90 typedef struct {
  91         unsigned        sample_rate;            /* samples per second */
  92         unsigned        samples_per_unit;       /* samples per unit */
  93         unsigned        bytes_per_unit;         /* bytes per sample unit */
  94         unsigned        channels;               /* # of interleaved channels */
  95         unsigned        encoding;               /* data encoding format */
  96         unsigned        endian;                 /* byte order */
  97         unsigned        data_size;              /* length of data (optional) */
  98 } Audio_hdr;
  99
 100 /*
 101  * Define the possible encoding types.
 102  * Note that the names that overlap the encodings in <sun/audioio.h>
 103  * must have the same values.
 104  */
 105 #define AUDIO_ENCODING_NONE     (0)     /* No encoding specified ... */
 106 #define AUDIO_ENCODING_ULAW     (1)     /* ISDN u-law */
 107 #define AUDIO_ENCODING_ALAW     (2)     /* ISDN A-law */
 108 #define AUDIO_ENCODING_LINEAR   (3)     /* PCM 2's-complement (0-center) */
 109 #define AUDIO_ENCODING_FLOAT    (100)   /* IEEE float (-1. <-> +1.) */
 110 #define AUDIO_ENCODING_G721     (101)   /* CCITT g.721 ADPCM */
 111 #define AUDIO_ENCODING_G722     (102)   /* CCITT g.722 ADPCM */
 112 #define AUDIO_ENCODING_G723     (103)   /* CCITT g.723 ADPCM */
 113 #define AUDIO_ENCODING_DVI      (104)   /* DVI ADPCM */
 114
 115 /*
 116  * Define the possible endian types.
 117  */
 118 #define AUDIO_ENDIAN_BIG 0      /* SPARC, 68000, etc. */
 119 #define AUDIO_ENDIAN_SMALL 1    /* Intel */
 120 #define AUDIO_ENDIAN_UNKNOWN 2  /* Unknown endian */
 121
 122 /* Value used for indeterminate size (e.g., data passed through a pipe) */
 123 #define AUDIO_UNKNOWN_SIZE      ((unsigned)(~0))
 124
 125
 126 /* Define conversion macros for integer<->floating-point conversions */
 127
 128 /* double to 8,16,32-bit linear */
 129 #define audio_d2c(X)            ((X) >= 1. ? 127 : (X) <= -1. ? -127 :  \
 130                                     (char)(rint((X) * 127.)))
 131 #define audio_d2s(X)            ((X) >= 1. ? 32767 : (X) <= -1. ? -32767 :\
 132                                     (short)(rint((X) * 32767.)))
 133 #define audio_d2l(X)            ((X) >= 1. ? 2147483647 : (X) <= -1. ?  \
 134                                     -2147483647 :                       \
 135                                     (long)(rint((X) * 2147483647.)))
 136
 137 /* 8,16,32-bit linear to double */
 138 #define audio_c2d(X)            (((unsigned char)(X)) == 0x80 ? -1. :   \
 139                                     ((double)((char)(X))) / 127.)
 140 #define audio_s2d(X)            (((unsigned short)(X)) == 0x8000 ? -1. :\
 141                                     ((double)((short)(X))) / 32767.)
 142 #define audio_l2d(X)            (((unsigned long)(X)) == 0x80000000 ? -1. :\
 143                                     ((double)((long)(X))) / 2147483647.)
 144
 145 #ifdef __cplusplus
 146 }
 147 #endif
 148
 149 #endif /* !_MULTIMEDIA_AUDIO_HDR_H */