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
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
|
/* ------------------------------------------------------------------
* Copyright (C) 2011 Martin Storsjo
* Copyright (C) 2017 Matthias P. Braendli
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
* express or implied.
* See the License for the specific language governing permissions
* and limitations under the License.
* -------------------------------------------------------------------
*/
#include "config.h"
#if HAVE_ALSA
#include "AlsaInput.h"
#include <cstdio>
#include <stdexcept>
#include <string>
#include <alsa/asoundlib.h>
#include <sys/time.h>
using namespace std;
AlsaInput::~AlsaInput()
{
// Ensures push() doesn't get blocked
m_queue.clear();
if (m_alsa_handle) {
snd_pcm_close(m_alsa_handle);
m_alsa_handle = nullptr;
}
}
static std::string alsa_strerror(int err)
{
string s(snd_strerror(err));
return s;
}
void AlsaInput::m_init_alsa()
{
int err;
snd_pcm_hw_params_t *hw_params;
fprintf(stderr, "Initialising ALSA...\n");
const int open_mode = 0;
if ((err = snd_pcm_open(&m_alsa_handle, m_alsa_dev.c_str(),
SND_PCM_STREAM_CAPTURE, open_mode)) < 0) {
throw runtime_error("cannot open audio device " +
m_alsa_dev + "(" + alsa_strerror(err) + ")");
}
if ((err = snd_pcm_hw_params_malloc(&hw_params)) < 0) {
throw runtime_error("cannot allocate hardware parameter structure (" +
alsa_strerror(err) + ")");
}
if ((err = snd_pcm_hw_params_any(m_alsa_handle, hw_params)) < 0) {
throw runtime_error("cannot initialize hardware parameter structure (" +
alsa_strerror(err) + ")");
}
if ((err = snd_pcm_hw_params_set_access(m_alsa_handle, hw_params,
SND_PCM_ACCESS_RW_INTERLEAVED)) < 0) {
throw runtime_error("cannot set access type (" + alsa_strerror(err) + ")");
}
if ((err = snd_pcm_hw_params_set_format(m_alsa_handle, hw_params,
SND_PCM_FORMAT_S16_LE)) < 0) {
throw runtime_error("cannot set sample format (" +
alsa_strerror(err) + ")");
}
if ((err = snd_pcm_hw_params_set_rate_near(m_alsa_handle,
hw_params, &m_rate, 0)) < 0) {
throw runtime_error("cannot set sample rate (" + alsa_strerror(err) + ")");
}
if ((err = snd_pcm_hw_params_set_channels(m_alsa_handle,
hw_params, m_channels)) < 0) {
throw runtime_error("cannot set channel count (" +
alsa_strerror(err) + ")");
}
if ((err = snd_pcm_hw_params(m_alsa_handle, hw_params)) < 0) {
throw runtime_error("cannot set parameters (" + alsa_strerror(err) + ")");
}
snd_pcm_hw_params_free (hw_params);
if ((err = snd_pcm_prepare(m_alsa_handle)) < 0) {
throw runtime_error("cannot prepare audio interface for use (" +
alsa_strerror(err) + ")");
}
fprintf(stderr, "ALSA init done.\n");
}
ssize_t AlsaInput::m_read(uint8_t* buf, snd_pcm_uframes_t length)
{
int err;
err = snd_pcm_readi(m_alsa_handle, buf, length);
if (err != (ssize_t)length) {
if (err < 0) {
fprintf (stderr, "read from audio interface failed (%s)\n",
snd_strerror(err));
}
else {
fprintf(stderr, "short alsa read: %d\n", err);
}
}
return err;
}
AlsaInputThreaded::~AlsaInputThreaded()
{
m_running = false;
// Ensures push() doesn't get blocked
m_queue.clear();
if (m_thread.joinable()) {
m_thread.join();
}
}
void AlsaInputThreaded::prepare()
{
if (m_fault) {
fprintf(stderr, "Cannot start alsa input. Fault detected previsouly!\n");
}
else {
m_init_alsa();
m_running = true;
m_thread = std::thread(&AlsaInputThreaded::process, this);
}
}
bool AlsaInputThreaded::read_source(size_t num_bytes)
{
// Reading done in separate thread, no normal termination condition possible
return true;
}
void AlsaInputThreaded::process()
{
uint8_t samplebuf[NUM_SAMPLES_PER_CALL * BYTES_PER_SAMPLE * m_channels];
while (m_running) {
ssize_t n = m_read(samplebuf, NUM_SAMPLES_PER_CALL);
if (n < 0) {
m_running = false;
m_fault = true;
break;
}
m_queue.push(samplebuf, BYTES_PER_SAMPLE*m_channels*n);
}
}
void AlsaInputDirect::prepare()
{
m_init_alsa();
}
bool AlsaInputDirect::read_source(size_t num_bytes)
{
const int bytes_per_frame = m_channels * BYTES_PER_SAMPLE;
assert(num_bytes % bytes_per_frame == 0);
const size_t num_frames = num_bytes / bytes_per_frame;
vector<uint8_t> buf(num_bytes);
ssize_t ret = m_read(buf.data(), num_frames);
if (ret > 0) {
m_queue.push(buf.data(), ret * bytes_per_frame);
}
return ret == (ssize_t)num_frames;
}
#endif // HAVE_ALSA
|
