Annotation of src/usr.bin/sndiod/dsp.h, Revision 1.10
1.10 ! ratchov 1: /* $OpenBSD: dsp.h,v 1.9 2021/01/12 15:46:53 naddy Exp $ */
1.1 ratchov 2: /*
3: * Copyright (c) 2012 Alexandre Ratchov <alex@caoua.org>
4: *
5: * Permission to use, copy, modify, and distribute this software for any
6: * purpose with or without fee is hereby granted, provided that the above
7: * copyright notice and this permission notice appear in all copies.
8: *
9: * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10: * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11: * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12: * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13: * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14: * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15: * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16: */
17: #ifndef DSP_H
18: #define DSP_H
19:
20: #include <sys/types.h>
21: #include "defs.h"
22:
23: /*
24: * Samples are numbers in the interval [-1, 1[, note that 1, the upper
25: * boundary is excluded. We represent them as signed fixed point numbers
26: * of ADATA_BITS. We also assume that 2^(ADATA_BITS - 1) fits in a int.
27: */
28: #ifndef ADATA_BITS
29: #define ADATA_BITS 16
30: #endif
31: #define ADATA_LE (BYTE_ORDER == LITTLE_ENDIAN)
32: #define ADATA_UNIT (1 << (ADATA_BITS - 1))
33:
34: #if ADATA_BITS == 16
35:
36: #define ADATA_MUL(x,y) (((int)(x) * (int)(y)) >> (ADATA_BITS - 1))
37:
38: typedef short adata_t;
39:
40: #elif ADATA_BITS == 24
41:
42: #define ADATA_MUL(x,y) \
43: ((int)(((long long)(x) * (long long)(y)) >> (ADATA_BITS - 1)))
44:
45: typedef int adata_t;
46:
47: #else
48: #error "only 16-bit and 24-bit precisions are supported"
49: #endif
50:
51: /*
1.8 ratchov 52: * The FIR is sampled and stored in a table of fixed-point numbers
53: * with 23 fractional bits. For convenience, we use the same fixed-point
54: * numbers to represent time and to walk through the table.
55: */
56: #define RESAMP_BITS 23
57: #define RESAMP_UNIT (1 << RESAMP_BITS)
58:
59: /*
60: * Filter window length (the time unit is RESAMP_UNIT)
61: */
62: #define RESAMP_LENGTH (8 * RESAMP_UNIT)
63:
64: /*
65: * Time between samples of the FIR (the time unit is RESAMP_UNIT)
66: */
67: #define RESAMP_STEP_BITS (RESAMP_BITS - 6)
68: #define RESAMP_STEP (1 << RESAMP_STEP_BITS)
69:
70: /*
71: * Maximum downsample/upsample ratio we support, must be a power of two.
72: * The ratio between the max and the min sample rates is 192kHz / 4kHz = 48,
73: * so we can use 64
74: */
75: #define RESAMP_RATIO 64
76:
77: /*
1.1 ratchov 78: * Maximum size of the encording string (the longest possible
79: * encoding is ``s24le3msb'').
80: */
81: #define ENCMAX 10
82:
83: /*
84: * Default bytes per sample for the given bits per sample.
85: */
86: #define APARAMS_BPS(bits) (((bits) <= 8) ? 1 : (((bits) <= 16) ? 2 : 4))
87:
88: struct aparams {
89: unsigned int bps; /* bytes per sample */
90: unsigned int bits; /* actually used bits */
1.5 ratchov 91: unsigned int le; /* 1 if little endian, else be */
1.1 ratchov 92: unsigned int sig; /* 1 if signed, 0 if unsigned */
1.5 ratchov 93: unsigned int msb; /* 1 if msb justified, else lsb */
1.1 ratchov 94: };
95:
96: struct resamp {
1.8 ratchov 97: #define RESAMP_NCTX (RESAMP_LENGTH / RESAMP_UNIT * RESAMP_RATIO)
1.1 ratchov 98: unsigned int ctx_start;
99: adata_t ctx[NCHAN_MAX * RESAMP_NCTX];
1.8 ratchov 100: int filt_cutoff, filt_step;
1.1 ratchov 101: unsigned int iblksz, oblksz;
102: int nch;
103: };
104:
105: struct conv {
106: int bfirst; /* bytes to skip at startup */
107: unsigned int bps; /* bytes per sample */
108: unsigned int shift; /* shift to get 32bit MSB */
1.5 ratchov 109: unsigned int bias; /* bias of unsigned samples */
1.1 ratchov 110: int bnext; /* to reach the next byte */
111: int snext; /* to reach the next sample */
112: int nch;
113: };
114:
115: struct cmap {
116: int istart;
117: int inext;
118: int onext;
119: int ostart;
120: int nch;
121: };
122:
123: #define MIDI_TO_ADATA(m) (aparams_ctltovol[m] << (ADATA_BITS - 16))
1.9 naddy 124: extern const int aparams_ctltovol[128];
1.1 ratchov 125:
126: void aparams_init(struct aparams *);
127: void aparams_log(struct aparams *);
128: int aparams_strtoenc(struct aparams *, char *);
129: int aparams_enctostr(struct aparams *, char *);
130: int aparams_native(struct aparams *);
131:
1.7 ratchov 132: void resamp_do(struct resamp *, adata_t *, adata_t *, int);
1.1 ratchov 133: void resamp_init(struct resamp *, unsigned int, unsigned int, int);
134: void enc_do(struct conv *, unsigned char *, unsigned char *, int);
135: void enc_sil_do(struct conv *, unsigned char *, int);
136: void enc_init(struct conv *, struct aparams *, int);
137: void dec_do(struct conv *, unsigned char *, unsigned char *, int);
138: void dec_init(struct conv *, struct aparams *, int);
139: void cmap_add(struct cmap *, void *, void *, int, int);
140: void cmap_copy(struct cmap *, void *, void *, int, int);
141: void cmap_init(struct cmap *, int, int, int, int, int, int, int, int);
142:
143: #endif /* !defined(DSP_H) */
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