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
|
/*
* @(#) obuffer_linux.cc 1.3, last edit: 02 Mar 1995 18:38:05
* @(#) Copyright (C) 1993, 1994 Tobias Bading (bading@cs.tu-berlin.de)
* @(#) Berlin University of Technology
*
* LinuxObuffer class written by
* Louis P. Kruger (lpkruger@phoenix.princeton.edu)
*
* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/*
* Changes from version 1.1 to 1.2:
* - new LinuxObuffer class, which works with 16 bit soundcards
* like Gravis Ultrasound, SoundBlaster 16 or Pro Audio Spectrum 16,
* if attached to /dev/dsp
*/
// statics of class LinuxObuffer:
int LinuxObuffer::audio_fd = -1;
int LinuxObuffer::open_audio_device (void)
{
int fd;
if ((fd = open ("/dev/audio", O_WRONLY | O_NDELAY, 0)) < 0)
if (errno == EBUSY)
{
extern boil verbose_mode, wait_if_busy;
if (wait_if_busy)
{
if (verbose_mode)
cerr << "Dsp device is busy, waiting...\n";
if ((fd = open ("/dev/audio", O_WRONLY, 0)) < 0)
{
perror ("Can't open /dev/audio for writing");
exit (1);
}
if (verbose_mode)
cerr << "Starting playback...\n";
}
else
{
cerr << "Sorry, the dsp device is busy!\n";
exit (1);
}
}
else
{
perror ("Can't open /dev/audio for writing");
exit (1);
}
// turn NDELAY mode on, because write() must never block maplay:
int flags;
if ((flags = fcntl (fd, F_GETFL, 0)) < 0)
{
perror ("fcntl F_GETFL on /dev/audio failed");
exit (1);
}
flags |= O_NDELAY;
if (fcntl (fd, F_SETFL, flags) < 0)
{
perror ("fcntl F_SETFL on /dev/audio failed");
exit (1);
}
return fd;
}
LinuxObuffer::LinuxObuffer (uint32 number_of_channels, Header *header)
{
#ifdef DEBUG
if (!number_of_channels || number_of_channels > MAXCHANNELS)
{
cerr << "LinuxObuffer: 0 < number of channels < " << MAXCHANNELS << "!\n";
exit (1);
}
#endif
channels = number_of_channels;
for (int i = 0; i < number_of_channels; ++i)
bufferp[i] = buffer + i;
if (audio_fd < 0)
{
cerr << "Internal error, LinuxObuffer::audio_fd has to be initialized\n"
"by LinuxObuffer::class_suitable()!\n";
exit (1);
}
// configure the device:
int play_precision = 8;
int play_stereo = channels - 1;
int play_encoding = AFMT_MU_LAW;
// 486DX2's are too slow eh? fix the rate at 8 kHz
int play_sample_rate = 8000;
if(
ioctl(audio_fd, SNDCTL_DSP_SAMPLESIZE, &play_precision) == -1 ||
ioctl(audio_fd, SNDCTL_DSP_STEREO, &play_stereo) == -1 ||
ioctl(audio_fd, SNDCTL_DSP_SPEED, &play_sample_rate) == -1 ||
ioctl(audio_fd, SNDCTL_DSP_SETFMT, &play_encoding) == -1
)
{
perror ("configuration of /dev/audio failed");
exit (1);
}
}
LinuxObuffer::~LinuxObuffer (void)
{
close (audio_fd);
}
void LinuxObuffer::append (uint32 channel, int16 value)
{
#ifdef DEBUG
if (channel >= channels)
{
cerr << "illegal channelnumber in LinuxObuffer::append()!\n";
exit (1);
}
if (bufferp[channel] - buffer >= OBUFFERSIZE)
{
cerr << "buffer overflow!\n";
exit (1);
}
#endif
*bufferp[channel] = linear2ulaw[value >> 3];
bufferp[channel] += channels;
}
void LinuxObuffer::write_buffer (int)
{
int length = (int)((char *)bufferp[0] - (char *)buffer);
if (write (audio_fd, buffer, length) != length)
{
perror ("write to /dev/audio failed");
exit (1);
}
for (int i = 0; i < channels; ++i)
bufferp[i] = buffer + i;
}
boil LinuxObuffer::class_suitable (uint32 number_of_channels)
{
// open the dsp audio device:
audio_fd = open_audio_device ();
return True;
}
|
