summaryrefslogtreecommitdiff
path: root/src/pcm_resample.h
blob: 24d17ff9ba18542efc14288d7076445081a6df36 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
/*
 * Copyright (C) 2003-2010 The Music Player Daemon Project
 * http://www.musicpd.org
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#ifndef MPD_PCM_RESAMPLE_H
#define MPD_PCM_RESAMPLE_H

#include "check.h"
#include "pcm_buffer.h"

#include <stdint.h>
#include <stddef.h>
#include <stdbool.h>

#ifdef HAVE_LIBSAMPLERATE
#include <samplerate.h>
#endif

/**
 * This object is statically allocated (within another struct), and
 * holds buffer allocations and the state for the resampler.
 */
struct pcm_resample_state {
#ifdef HAVE_LIBSAMPLERATE
	SRC_STATE *state;
	SRC_DATA data;

	struct pcm_buffer in, out;

	struct {
		unsigned src_rate;
		unsigned dest_rate;
		uint8_t channels;
	} prev;

	int error;
#endif

	struct pcm_buffer buffer;
};

/**
 * Initializes a pcm_resample_state object.
 */
void pcm_resample_init(struct pcm_resample_state *state);

/**
 * Deinitializes a pcm_resample_state object and frees allocated
 * memory.
 */
void pcm_resample_deinit(struct pcm_resample_state *state);

/**
 * Resamples 16 bit PCM data.
 *
 * @param state an initialized pcm_resample_state object
 * @param channels the number of channels
 * @param src_rate the source sample rate
 * @param src the source PCM buffer
 * @param src_size the size of #src in bytes
 * @param dest_rate the requested destination sample rate
 * @param dest_size_r returns the number of bytes of the destination buffer
 * @return the destination buffer
 */
const int16_t *
pcm_resample_16(struct pcm_resample_state *state,
		uint8_t channels,
		unsigned src_rate,
		const int16_t *src_buffer, size_t src_size,
		unsigned dest_rate, size_t *dest_size_r,
		GError **error_r);

/**
 * Resamples 32 bit PCM data.
 *
 * @param state an initialized pcm_resample_state object
 * @param channels the number of channels
 * @param src_rate the source sample rate
 * @param src the source PCM buffer
 * @param src_size the size of #src in bytes
 * @param dest_rate the requested destination sample rate
 * @param dest_size_r returns the number of bytes of the destination buffer
 * @return the destination buffer
 */
const int32_t *
pcm_resample_32(struct pcm_resample_state *state,
		uint8_t channels,
		unsigned src_rate,
		const int32_t *src_buffer, size_t src_size,
		unsigned dest_rate, size_t *dest_size_r,
		GError **error_r);

/**
 * Resamples 24 bit PCM data.
 *
 * @param state an initialized pcm_resample_state object
 * @param channels the number of channels
 * @param src_rate the source sample rate
 * @param src the source PCM buffer
 * @param src_size the size of #src in bytes
 * @param dest_rate the requested destination sample rate
 * @param dest_size_r returns the number of bytes of the destination buffer
 * @return the destination buffer
 */
static inline const int32_t *
pcm_resample_24(struct pcm_resample_state *state,
		uint8_t channels,
		unsigned src_rate,
		const int32_t *src_buffer, size_t src_size,
		unsigned dest_rate, size_t *dest_size_r,
		GError **error_r)
{
	/* reuse the 32 bit code - the resampler code doesn't care if
	   the upper 8 bits are actually used */
	return pcm_resample_32(state, channels,
			       src_rate, src_buffer, src_size,
			       dest_rate, dest_size_r, error_r);
}

#endif