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
|
/***************************************************************************
alsa.c - description
-------------------
begin : Sat Mar 01 2003
copyright : (C) 2002 by Pete Bernert
email : BlackDove@addcom.de
***************************************************************************/
/***************************************************************************
* *
* 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. See also the license.txt file for *
* additional informations. *
* *
***************************************************************************/
#include <stdio.h>
#include <string.h>
#define ALSA_PCM_NEW_HW_PARAMS_API
#define ALSA_PCM_NEW_SW_PARAMS_API
#include <alsa/asoundlib.h>
#include "out.h"
static snd_pcm_t *handle = NULL;
static snd_pcm_uframes_t buffer_size;
static void alsa_finish(void);
// SETUP SOUND
static int alsa_init(void)
{
snd_pcm_hw_params_t *hwparams;
snd_pcm_status_t *status;
snd_ctl_t *ctl_handle = NULL;
snd_ctl_card_info_t *info;
unsigned int pspeed;
int pchannels;
int format;
unsigned int buffer_time = 100000;
unsigned int period_time = buffer_time / 4;
const char *alsa_name = "default";
const char *name;
int retval = -1;
int err;
name = getenv("ALSA_NAME");
if (name != NULL)
alsa_name = name;
snd_ctl_card_info_alloca(&info);
if ((err = snd_ctl_open(&ctl_handle, alsa_name, 0)) < 0) {
printf("control open: %s\n", snd_strerror(err));
}
else if ((err = snd_ctl_card_info(ctl_handle, info)) < 0) {
printf("control info: %s\n", snd_strerror(err));
snd_ctl_card_info_clear(info);
}
if (ctl_handle != NULL)
snd_ctl_close(ctl_handle);
name = snd_ctl_card_info_get_name(info);
if (name != NULL) {
if (strcasecmp(name, "PulseAudio") == 0) {
// PulseAudio's ALSA emulation is known to be broken..
printf("alsa: refusing to run under PulseAudio's emulation\n");
return -1;
}
else {
printf("alsa: using '%s', set ALSA_NAME to change\n", name);
}
}
pchannels=2;
pspeed = 44100;
format = SND_PCM_FORMAT_S16;
if ((err = snd_pcm_open(&handle, alsa_name,
SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK)) < 0)
{
printf("Audio open error: %s\n", snd_strerror(err));
return -1;
}
if((err = snd_pcm_nonblock(handle, 0))<0)
{
printf("Can't set blocking moded: %s\n", snd_strerror(err));
goto out;
}
snd_pcm_hw_params_alloca(&hwparams);
if((err=snd_pcm_hw_params_any(handle, hwparams))<0)
{
printf("Broken configuration for this PCM: %s\n", snd_strerror(err));
goto out;
}
if((err=snd_pcm_hw_params_set_access(handle, hwparams, SND_PCM_ACCESS_RW_INTERLEAVED))<0)
{
printf("Access type not available: %s\n", snd_strerror(err));
goto out;
}
if((err=snd_pcm_hw_params_set_format(handle, hwparams, format))<0)
{
printf("Sample format not available: %s\n", snd_strerror(err));
goto out;
}
if((err=snd_pcm_hw_params_set_channels(handle, hwparams, pchannels))<0)
{
printf("Channels count not available: %s\n", snd_strerror(err));
goto out;
}
if((err=snd_pcm_hw_params_set_rate_near(handle, hwparams, &pspeed, 0))<0)
{
printf("Rate not available: %s\n", snd_strerror(err));
goto out;
}
if((err=snd_pcm_hw_params_set_buffer_time_near(handle, hwparams, &buffer_time, 0))<0)
{
printf("Buffer time error: %s\n", snd_strerror(err));
goto out;
}
if((err=snd_pcm_hw_params_set_period_time_near(handle, hwparams, &period_time, 0))<0)
{
printf("Period time error: %s\n", snd_strerror(err));
goto out;
}
if((err=snd_pcm_hw_params(handle, hwparams))<0)
{
printf("Unable to install hw params: %s\n", snd_strerror(err));
goto out;
}
snd_pcm_status_alloca(&status);
if((err=snd_pcm_status(handle, status))<0)
{
printf("Unable to get status: %s\n", snd_strerror(err));
goto out;
}
buffer_size = snd_pcm_status_get_avail(status);
retval = 0;
out:
if (retval != 0)
alsa_finish();
return retval;
}
// REMOVE SOUND
static void alsa_finish(void)
{
if(handle != NULL)
{
snd_pcm_drop(handle);
snd_pcm_close(handle);
handle = NULL;
}
}
static float alsa_capacity(void) {
int l;
if (handle == NULL) return 0;
if (buffer_size == 0) return 0;
l = snd_pcm_avail(handle);
if (l < 0) return 0;
return (float)l / buffer_size;
}
// GET BYTES BUFFERED
static int alsa_busy(void)
{
return alsa_capacity() < 0.5;
}
// FEED SOUND DATA
static void alsa_feed(void *pSound, int lBytes)
{
char sbuf[4096];
if (handle == NULL) return;
if (snd_pcm_state(handle) == SND_PCM_STATE_XRUN)
{
memset(sbuf, 0, sizeof(sbuf));
snd_pcm_prepare(handle);
snd_pcm_writei(handle, sbuf, sizeof(sbuf) / 4);
snd_pcm_writei(handle, sbuf, sizeof(sbuf) / 4);
snd_pcm_writei(handle, sbuf, sizeof(sbuf) / 4);
}
else
{
int l = snd_pcm_avail(handle);
if (l < lBytes / 4)
{
if (l == 0)
return;
lBytes = l * 4;
}
}
snd_pcm_writei(handle, pSound, lBytes / 4);
}
void out_register_alsa(struct out_driver *drv)
{
drv->name = "alsa";
drv->init = alsa_init;
drv->finish = alsa_finish;
drv->busy = alsa_busy;
drv->feed = alsa_feed;
drv->capacity = alsa_capacity;
}
|
