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
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
|
/*
* Copyright (C) 2022 Javier S. Pedro
*
* 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.
*/
#define LOG_ENABLED 1
#define LOG_ENABLE_FLOW 1
#define LOG_GROUP LOG_GROUP_DEV_SB16
#include <VBox/err.h>
#include <VBox/log.h>
#include <alsa/asoundlib.h>
#include "pcmalsa.h"
PCMOutAlsa::PCMOutAlsa() : _pcm(NULL)
{
}
PCMOutAlsa::~PCMOutAlsa()
{
}
int PCMOutAlsa::open(const char *dev, unsigned int sampleRate, unsigned int channels)
{
int err;
err = snd_pcm_open(&_pcm, dev, SND_PCM_STREAM_PLAYBACK, 0);
if (err < 0) {
LogWarn(("ALSA playback open error: %s\n", snd_strerror(err)));
return VERR_AUDIO_STREAM_COULD_NOT_CREATE;
}
// TODO: Right now, setting a too large period size means we will not let the main
// thread run long enough to actually change notes/voices. Need some actual synchronization.
int periodSize = 10 /*msec*/;
int bufferSize = 100 /*msec*/;
err = setParams(sampleRate, channels, bufferSize * 1000 /*usec*/, periodSize * 1000);
if (err < 0) {
snd_pcm_close(_pcm);
_pcm = NULL;
return VERR_AUDIO_STREAM_COULD_NOT_CREATE;
}
return VINF_SUCCESS;
}
int PCMOutAlsa::close()
{
if (_pcm) {
snd_pcm_drain(_pcm);
snd_pcm_close(_pcm);
}
return VINF_SUCCESS;
}
ssize_t PCMOutAlsa::avail()
{
snd_pcm_sframes_t frames = snd_pcm_avail(_pcm);
if (frames < 0) {
LogWarn(("ALSA trying to recover from avail error: %s\n", snd_strerror(frames)));
frames = snd_pcm_recover(_pcm, frames, 0);
if (frames == 0) {
frames = snd_pcm_avail(_pcm);
}
}
if (frames < 0) {
LogWarn(("ALSA avail error: %s\n", snd_strerror(frames)));
return VERR_AUDIO_STREAM_NOT_READY;
}
return frames;
}
int PCMOutAlsa::wait()
{
int err = snd_pcm_wait(_pcm, -1);
if (err < 0) {
LogWarn(("ALSA trying to recover from wait error: %s\n", snd_strerror(err)));
err = snd_pcm_recover(_pcm, err, 0);
}
if (err < 0) {
LogWarn(("ALSA wait error: %s\n", snd_strerror(err)));
return VERR_AUDIO_STREAM_NOT_READY;
}
return VINF_SUCCESS;
}
ssize_t PCMOutAlsa::write(int16_t *buf, size_t n)
{
snd_pcm_sframes_t frames = snd_pcm_writei(_pcm, buf, n);
if (frames < 0) {
LogFlow(("ALSA trying to recover from error: %s\n", snd_strerror(frames)));
frames = snd_pcm_recover(_pcm, frames, 0);
}
if (frames < 0) {
LogWarn(("ALSA write error: %s\n", snd_strerror(frames)));
return VERR_AUDIO_STREAM_NOT_READY;
}
return frames;
}
int PCMOutAlsa::setParams(unsigned int sampleRate, unsigned int channels, unsigned int bufferTime, unsigned int periodTime)
{
snd_pcm_hw_params_t *hwparams;
snd_pcm_sw_params_t *swparams;
int err;
snd_pcm_hw_params_alloca(&hwparams);
snd_pcm_sw_params_alloca(&swparams);
/* choose all parameters */
err = snd_pcm_hw_params_any(_pcm, hwparams);
if (err < 0) {
LogWarnFunc(("Broken PCM configuration: no configurations available: %s", snd_strerror(err)));
return err;
}
/* set software resampling */
err = snd_pcm_hw_params_set_rate_resample(_pcm, hwparams, 1);
if (err < 0) {
LogWarnFunc(("Resampling setup failed: %s", snd_strerror(err)));
return err;
}
/* set the selected read/write format */
err = snd_pcm_hw_params_set_access(_pcm, hwparams, SND_PCM_ACCESS_RW_INTERLEAVED);
if (err < 0) {
LogWarnFunc(("Access type not available: %s", snd_strerror(err)));
return err;
}
/* set the sample format */
err = snd_pcm_hw_params_set_format(_pcm, hwparams, SND_PCM_FORMAT_S16);
if (err < 0) {
LogWarnFunc(("Sample format not available: %s", snd_strerror(err)));
return err;
}
/* set the count of channels */
err = snd_pcm_hw_params_set_channels(_pcm, hwparams, channels);
if (err < 0) {
LogWarnFunc(("Channels count (%i) not available: %s", channels, snd_strerror(err)));
return err;
}
/* set the stream rate */
unsigned int rrate = sampleRate;
err = snd_pcm_hw_params_set_rate_near(_pcm, hwparams, &rrate, 0);
if (err < 0) {
LogWarnFunc(("Rate %iHz not available for playback: %s", sampleRate, snd_strerror(err)));
return err;
}
if (rrate != sampleRate) {
LogWarnFunc(("Rate doesn't match (requested %iHz, get %iHz)", sampleRate, rrate));
return -EINVAL;
}
/* set the buffer time */
err = snd_pcm_hw_params_set_buffer_time_near(_pcm, hwparams, &bufferTime, NULL);
if (err < 0) {
LogWarnFunc(("Unable to set buffer time %u for playback: %s\n", bufferTime, snd_strerror(err)));
return err;
}
err = snd_pcm_hw_params_get_buffer_size(hwparams, &_bufferSize);
if (err < 0) {
printf("Unable to get buffer size for playback: %s\n", snd_strerror(err));
return err;
}
/* set the period time */
err = snd_pcm_hw_params_set_period_time_near(_pcm, hwparams, &periodTime, NULL);
if (err < 0) {
printf("Unable to set period time %u for playback: %s\n", periodTime, snd_strerror(err));
return err;
}
err = snd_pcm_hw_params_get_period_size(hwparams, &_periodSize, NULL);
if (err < 0) {
printf("Unable to get period size for playback: %s\n", snd_strerror(err));
return err;
}
/* write the parameters to device */
err = snd_pcm_hw_params(_pcm, hwparams);
if (err < 0) {
LogWarnFunc(("Unable to set hw params: %s", snd_strerror(err)));
return err;
}
LogFunc(("Using bufferSize=%lu periodSize=%lu\n", _bufferSize, _periodSize));
/* get the current swparams */
err = snd_pcm_sw_params_current(_pcm, swparams);
if (err < 0) {
LogWarnFunc(("Unable to determine current swparams: %s", snd_strerror(err)));
return err;
}
/* start the transfer when the buffer is almost full: */
/* (buffer_size / avail_min) * avail_min */
err = snd_pcm_sw_params_set_start_threshold(_pcm, swparams, (_bufferSize / _periodSize) * _periodSize);
if (err < 0) {
LogWarnFunc(("Unable to set start threshold mode: %s", snd_strerror(err)));
return err;
}
/* allow the transfer when at least period_size samples can be processed */
err = snd_pcm_sw_params_set_avail_min(_pcm, swparams, _periodSize);
if (err < 0) {
LogWarnFunc(("Unable to set avail min: %s", snd_strerror(err)));
return err;
}
/* write the parameters to the playback device */
err = snd_pcm_sw_params(_pcm, swparams);
if (err < 0) {
LogWarnFunc(("Unable to set sw params: %s", snd_strerror(err)));
return err;
}
return 0;
}
|
