Annotation of src/usr.bin/sndiod/dsp.h, Revision 1.13
1.13 ! ratchov 1: /* $OpenBSD: dsp.h,v 1.12 2022/12/26 19:16:03 jmc 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: /*
1.12 jmc 64: * Maximum size of the encoding string (the longest possible
1.1 ratchov 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;
1.13 ! ratchov 88: int diff;
1.1 ratchov 89: int nch;
90: };
91:
92: struct conv {
93: int bfirst; /* bytes to skip at startup */
94: unsigned int bps; /* bytes per sample */
95: unsigned int shift; /* shift to get 32bit MSB */
1.5 ratchov 96: unsigned int bias; /* bias of unsigned samples */
1.1 ratchov 97: int bnext; /* to reach the next byte */
98: int snext; /* to reach the next sample */
99: int nch;
100: };
101:
102: struct cmap {
103: int istart;
104: int inext;
105: int onext;
106: int ostart;
107: int nch;
108: };
109:
110: #define MIDI_TO_ADATA(m) (aparams_ctltovol[m] << (ADATA_BITS - 16))
1.9 naddy 111: extern const int aparams_ctltovol[128];
1.1 ratchov 112:
113: void aparams_init(struct aparams *);
114: void aparams_log(struct aparams *);
115: int aparams_strtoenc(struct aparams *, char *);
116: int aparams_enctostr(struct aparams *, char *);
117: int aparams_native(struct aparams *);
118:
1.13 ! ratchov 119: void resamp_getcnt(struct resamp *, int *, int *);
! 120: void resamp_do(struct resamp *, adata_t *, adata_t *, int, int);
1.1 ratchov 121: void resamp_init(struct resamp *, unsigned int, unsigned int, int);
122: void enc_do(struct conv *, unsigned char *, unsigned char *, int);
123: void enc_sil_do(struct conv *, unsigned char *, int);
124: void enc_init(struct conv *, struct aparams *, int);
125: void dec_do(struct conv *, unsigned char *, unsigned char *, int);
126: void dec_init(struct conv *, struct aparams *, int);
127: void cmap_add(struct cmap *, void *, void *, int, int);
128: void cmap_copy(struct cmap *, void *, void *, int, int);
129: void cmap_init(struct cmap *, int, int, int, int, int, int, int, int);
130:
131: #endif /* !defined(DSP_H) */
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