xref: /netbsd/sys/dev/audio/alaw.c (revision 007c1f91)
1 /*	$NetBSD: alaw.c,v 1.4 2021/07/21 06:35:44 skrll Exp $	*/
2 
3 /*
4  * Copyright (C) 2018 Tetsuya Isaki. All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
20  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
21  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
22  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
23  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __KERNEL_RCSID(0, "$NetBSD: alaw.c,v 1.4 2021/07/21 06:35:44 skrll Exp $");
30 
31 #include <sys/param.h>
32 #include <sys/types.h>
33 #include <sys/systm.h>
34 #include <sys/device.h>
35 #include <dev/audio/audiovar.h>
36 #include <dev/audio/mulaw.h>
37 
38 static const uint16_t alaw_to_slinear16[256] = {
39 	0xea80, 0xeb80, 0xe880, 0xe980, 0xee80, 0xef80, 0xec80, 0xed80,
40 	0xe280, 0xe380, 0xe080, 0xe180, 0xe680, 0xe780, 0xe480, 0xe580,
41 	0xf540, 0xf5c0, 0xf440, 0xf4c0, 0xf740, 0xf7c0, 0xf640, 0xf6c0,
42 	0xf140, 0xf1c0, 0xf040, 0xf0c0, 0xf340, 0xf3c0, 0xf240, 0xf2c0,
43 	0xaa00, 0xae00, 0xa200, 0xa600, 0xba00, 0xbe00, 0xb200, 0xb600,
44 	0x8a00, 0x8e00, 0x8200, 0x8600, 0x9a00, 0x9e00, 0x9200, 0x9600,
45 	0xd500, 0xd700, 0xd100, 0xd300, 0xdd00, 0xdf00, 0xd900, 0xdb00,
46 	0xc500, 0xc700, 0xc100, 0xc300, 0xcd00, 0xcf00, 0xc900, 0xcb00,
47 	0xfea8, 0xfeb8, 0xfe88, 0xfe98, 0xfee8, 0xfef8, 0xfec8, 0xfed8,
48 	0xfe28, 0xfe38, 0xfe08, 0xfe18, 0xfe68, 0xfe78, 0xfe48, 0xfe58,
49 	0xffa8, 0xffb8, 0xff88, 0xff98, 0xffe8, 0xfff8, 0xffc8, 0xffd8,
50 	0xff28, 0xff38, 0xff08, 0xff18, 0xff68, 0xff78, 0xff48, 0xff58,
51 	0xfaa0, 0xfae0, 0xfa20, 0xfa60, 0xfba0, 0xfbe0, 0xfb20, 0xfb60,
52 	0xf8a0, 0xf8e0, 0xf820, 0xf860, 0xf9a0, 0xf9e0, 0xf920, 0xf960,
53 	0xfd50, 0xfd70, 0xfd10, 0xfd30, 0xfdd0, 0xfdf0, 0xfd90, 0xfdb0,
54 	0xfc50, 0xfc70, 0xfc10, 0xfc30, 0xfcd0, 0xfcf0, 0xfc90, 0xfcb0,
55 	0x1580, 0x1480, 0x1780, 0x1680, 0x1180, 0x1080, 0x1380, 0x1280,
56 	0x1d80, 0x1c80, 0x1f80, 0x1e80, 0x1980, 0x1880, 0x1b80, 0x1a80,
57 	0x0ac0, 0x0a40, 0x0bc0, 0x0b40, 0x08c0, 0x0840, 0x09c0, 0x0940,
58 	0x0ec0, 0x0e40, 0x0fc0, 0x0f40, 0x0cc0, 0x0c40, 0x0dc0, 0x0d40,
59 	0x5600, 0x5200, 0x5e00, 0x5a00, 0x4600, 0x4200, 0x4e00, 0x4a00,
60 	0x7600, 0x7200, 0x7e00, 0x7a00, 0x6600, 0x6200, 0x6e00, 0x6a00,
61 	0x2b00, 0x2900, 0x2f00, 0x2d00, 0x2300, 0x2100, 0x2700, 0x2500,
62 	0x3b00, 0x3900, 0x3f00, 0x3d00, 0x3300, 0x3100, 0x3700, 0x3500,
63 	0x0158, 0x0148, 0x0178, 0x0168, 0x0118, 0x0108, 0x0138, 0x0128,
64 	0x01d8, 0x01c8, 0x01f8, 0x01e8, 0x0198, 0x0188, 0x01b8, 0x01a8,
65 	0x0058, 0x0048, 0x0078, 0x0068, 0x0018, 0x0008, 0x0038, 0x0028,
66 	0x00d8, 0x00c8, 0x00f8, 0x00e8, 0x0098, 0x0088, 0x00b8, 0x00a8,
67 	0x0560, 0x0520, 0x05e0, 0x05a0, 0x0460, 0x0420, 0x04e0, 0x04a0,
68 	0x0760, 0x0720, 0x07e0, 0x07a0, 0x0660, 0x0620, 0x06e0, 0x06a0,
69 	0x02b0, 0x0290, 0x02f0, 0x02d0, 0x0230, 0x0210, 0x0270, 0x0250,
70 	0x03b0, 0x0390, 0x03f0, 0x03d0, 0x0330, 0x0310, 0x0370, 0x0350,
71 };
72 
73 static const uint8_t slinear8_to_alaw[256] = {
74 	0xd5, 0xc5, 0xf5, 0xfd, 0xe5, 0xe1, 0xed, 0xe9,
75 	0x95, 0x97, 0x91, 0x93, 0x9d, 0x9f, 0x99, 0x9b,
76 	0x85, 0x84, 0x87, 0x86, 0x81, 0x80, 0x83, 0x82,
77 	0x8d, 0x8c, 0x8f, 0x8e, 0x89, 0x88, 0x8b, 0x8a,
78 	0xb5, 0xb5, 0xb4, 0xb4, 0xb7, 0xb7, 0xb6, 0xb6,
79 	0xb1, 0xb1, 0xb0, 0xb0, 0xb3, 0xb3, 0xb2, 0xb2,
80 	0xbd, 0xbd, 0xbc, 0xbc, 0xbf, 0xbf, 0xbe, 0xbe,
81 	0xb9, 0xb9, 0xb8, 0xb8, 0xbb, 0xbb, 0xba, 0xba,
82 	0xa5, 0xa5, 0xa5, 0xa5, 0xa4, 0xa4, 0xa4, 0xa4,
83 	0xa7, 0xa7, 0xa7, 0xa7, 0xa6, 0xa6, 0xa6, 0xa6,
84 	0xa1, 0xa1, 0xa1, 0xa1, 0xa0, 0xa0, 0xa0, 0xa0,
85 	0xa3, 0xa3, 0xa3, 0xa3, 0xa2, 0xa2, 0xa2, 0xa2,
86 	0xad, 0xad, 0xad, 0xad, 0xac, 0xac, 0xac, 0xac,
87 	0xaf, 0xaf, 0xaf, 0xaf, 0xae, 0xae, 0xae, 0xae,
88 	0xa9, 0xa9, 0xa9, 0xa9, 0xa8, 0xa8, 0xa8, 0xa8,
89 	0xab, 0xab, 0xab, 0xab, 0xaa, 0xaa, 0xaa, 0xaa,
90 	0x2a, 0x2a, 0x2a, 0x2a, 0x2b, 0x2b, 0x2b, 0x2b,
91 	0x28, 0x28, 0x28, 0x28, 0x29, 0x29, 0x29, 0x29,
92 	0x2e, 0x2e, 0x2e, 0x2e, 0x2f, 0x2f, 0x2f, 0x2f,
93 	0x2c, 0x2c, 0x2c, 0x2c, 0x2d, 0x2d, 0x2d, 0x2d,
94 	0x22, 0x22, 0x22, 0x22, 0x23, 0x23, 0x23, 0x23,
95 	0x20, 0x20, 0x20, 0x20, 0x21, 0x21, 0x21, 0x21,
96 	0x26, 0x26, 0x26, 0x26, 0x27, 0x27, 0x27, 0x27,
97 	0x24, 0x24, 0x24, 0x24, 0x25, 0x25, 0x25, 0x25,
98 	0x3a, 0x3a, 0x3b, 0x3b, 0x38, 0x38, 0x39, 0x39,
99 	0x3e, 0x3e, 0x3f, 0x3f, 0x3c, 0x3c, 0x3d, 0x3d,
100 	0x32, 0x32, 0x33, 0x33, 0x30, 0x30, 0x31, 0x31,
101 	0x36, 0x36, 0x37, 0x37, 0x34, 0x34, 0x35, 0x35,
102 	0x0a, 0x0b, 0x08, 0x09, 0x0e, 0x0f, 0x0c, 0x0d,
103 	0x02, 0x03, 0x00, 0x01, 0x06, 0x07, 0x04, 0x05,
104 	0x1a, 0x18, 0x1e, 0x1c, 0x12, 0x10, 0x16, 0x14,
105 	0x6a, 0x6e, 0x62, 0x66, 0x7a, 0x72, 0x4a, 0x5a,
106 };
107 
108 /*
109  * audio_alaw_to_internal:
110  *	This filter performs conversion from A-law to internal format.
111  */
112 void
audio_alaw_to_internal(audio_filter_arg_t * arg)113 audio_alaw_to_internal(audio_filter_arg_t *arg)
114 {
115 	const uint8_t *s;
116 	aint_t *d;
117 	u_int sample_count;
118 	u_int i;
119 
120 	DIAGNOSTIC_filter_arg(arg);
121 	KASSERT(arg->srcfmt->encoding == AUDIO_ENCODING_ALAW);
122 	KASSERT(arg->srcfmt->stride == 8);
123 	KASSERT(arg->srcfmt->precision == 8);
124 	KASSERT(audio_format2_is_internal(arg->dstfmt));
125 	KASSERT(arg->srcfmt->channels == arg->dstfmt->channels);
126 
127 	s = arg->src;
128 	d = arg->dst;
129 	sample_count = arg->count * arg->srcfmt->channels;
130 
131 	for (i = 0; i < sample_count; i++) {
132 		aint_t val;
133 		val = alaw_to_slinear16[*s++];
134 		val <<= AUDIO_INTERNAL_BITS - 16;
135 		*d++ = val;
136 	}
137 }
138 
139 /*
140  * audio_internal_to_alaw:
141  *	This filter performs conversion from internal format to A-law.
142  */
143 void
audio_internal_to_alaw(audio_filter_arg_t * arg)144 audio_internal_to_alaw(audio_filter_arg_t *arg)
145 {
146 	const aint_t *s;
147 	uint8_t *d;
148 	u_int sample_count;
149 	u_int i;
150 
151 	DIAGNOSTIC_filter_arg(arg);
152 	KASSERT(arg->dstfmt->encoding == AUDIO_ENCODING_ALAW);
153 	KASSERT(arg->dstfmt->stride == 8);
154 	KASSERT(arg->dstfmt->precision == 8);
155 	KASSERT(audio_format2_is_internal(arg->srcfmt));
156 	KASSERT(arg->srcfmt->channels == arg->dstfmt->channels);
157 
158 	s = arg->src;
159 	d = arg->dst;
160 	sample_count = arg->count * arg->srcfmt->channels;
161 
162 	for (i = 0; i < sample_count; i++) {
163 		uint8_t val;
164 		val = (*s++) >> (AUDIO_INTERNAL_BITS - 8);
165 		*d++ = slinear8_to_alaw[val];
166 	}
167 }
168