Annotation of src/usr.bin/sndiod/dsp.h, Revision 1.11
1.11 ! ratchov 1: /* $OpenBSD: dsp.h,v 1.10 2021/05/25 08:06:12 ratchov 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: */
1.11 ! ratchov 28: #define ADATA_BITS 24
1.1 ratchov 29: #define ADATA_LE (BYTE_ORDER == LITTLE_ENDIAN)
30: #define ADATA_UNIT (1 << (ADATA_BITS - 1))
31:
32: #define ADATA_MUL(x,y) \
33: ((int)(((long long)(x) * (long long)(y)) >> (ADATA_BITS - 1)))
34:
35: typedef int adata_t;
36:
37: /*
1.8 ratchov 38: * The FIR is sampled and stored in a table of fixed-point numbers
39: * with 23 fractional bits. For convenience, we use the same fixed-point
40: * numbers to represent time and to walk through the table.
41: */
42: #define RESAMP_BITS 23
43: #define RESAMP_UNIT (1 << RESAMP_BITS)
44:
45: /*
46: * Filter window length (the time unit is RESAMP_UNIT)
47: */
48: #define RESAMP_LENGTH (8 * RESAMP_UNIT)
49:
50: /*
51: * Time between samples of the FIR (the time unit is RESAMP_UNIT)
52: */
53: #define RESAMP_STEP_BITS (RESAMP_BITS - 6)
54: #define RESAMP_STEP (1 << RESAMP_STEP_BITS)
55:
56: /*
57: * Maximum downsample/upsample ratio we support, must be a power of two.
58: * The ratio between the max and the min sample rates is 192kHz / 4kHz = 48,
59: * so we can use 64
60: */
61: #define RESAMP_RATIO 64
62:
63: /*
1.1 ratchov 64: * Maximum size of the encording string (the longest possible
65: * encoding is ``s24le3msb'').
66: */
67: #define ENCMAX 10
68:
69: /*
70: * Default bytes per sample for the given bits per sample.
71: */
72: #define APARAMS_BPS(bits) (((bits) <= 8) ? 1 : (((bits) <= 16) ? 2 : 4))
73:
74: struct aparams {
75: unsigned int bps; /* bytes per sample */
76: unsigned int bits; /* actually used bits */
1.5 ratchov 77: unsigned int le; /* 1 if little endian, else be */
1.1 ratchov 78: unsigned int sig; /* 1 if signed, 0 if unsigned */
1.5 ratchov 79: unsigned int msb; /* 1 if msb justified, else lsb */
1.1 ratchov 80: };
81:
82: struct resamp {
1.8 ratchov 83: #define RESAMP_NCTX (RESAMP_LENGTH / RESAMP_UNIT * RESAMP_RATIO)
1.1 ratchov 84: unsigned int ctx_start;
85: adata_t ctx[NCHAN_MAX * RESAMP_NCTX];
1.8 ratchov 86: int filt_cutoff, filt_step;
1.1 ratchov 87: unsigned int iblksz, oblksz;
88: int nch;
89: };
90:
91: struct conv {
92: int bfirst; /* bytes to skip at startup */
93: unsigned int bps; /* bytes per sample */
94: unsigned int shift; /* shift to get 32bit MSB */
1.5 ratchov 95: unsigned int bias; /* bias of unsigned samples */
1.1 ratchov 96: int bnext; /* to reach the next byte */
97: int snext; /* to reach the next sample */
98: int nch;
99: };
100:
101: struct cmap {
102: int istart;
103: int inext;
104: int onext;
105: int ostart;
106: int nch;
107: };
108:
109: #define MIDI_TO_ADATA(m) (aparams_ctltovol[m] << (ADATA_BITS - 16))
1.9 naddy 110: extern const int aparams_ctltovol[128];
1.1 ratchov 111:
112: void aparams_init(struct aparams *);
113: void aparams_log(struct aparams *);
114: int aparams_strtoenc(struct aparams *, char *);
115: int aparams_enctostr(struct aparams *, char *);
116: int aparams_native(struct aparams *);
117:
1.7 ratchov 118: void resamp_do(struct resamp *, adata_t *, adata_t *, int);
1.1 ratchov 119: void resamp_init(struct resamp *, unsigned int, unsigned int, int);
120: void enc_do(struct conv *, unsigned char *, unsigned char *, int);
121: void enc_sil_do(struct conv *, unsigned char *, int);
122: void enc_init(struct conv *, struct aparams *, int);
123: void dec_do(struct conv *, unsigned char *, unsigned char *, int);
124: void dec_init(struct conv *, struct aparams *, int);
125: void cmap_add(struct cmap *, void *, void *, int, int);
126: void cmap_copy(struct cmap *, void *, void *, int, int);
127: void cmap_init(struct cmap *, int, int, int, int, int, int, int, int);
128:
129: #endif /* !defined(DSP_H) */