2 Copyright (C) 1996-1997 Id Software, Inc.
4 This program is free software; you can redistribute it and/or
5 modify it under the terms of the GNU General Public License
6 as published by the Free Software Foundation; either version 2
7 of the License, or (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
13 See the GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
21 #include <sys/param.h>
22 #include <sys/audioio.h>
23 #include <sys/endian.h>
24 #include <sys/ioctl.h>
33 static const int tryrates[] = {44100, 22050, 11025, 8000};
35 static int audio_fd = -1;
36 static qboolean snd_inited = false;
38 // TODO: allocate them in SNDDMA_Init, with a size depending on
39 // the sound format (enough for 0.5 sec of sound for instance)
40 #define SND_BUFF_SIZE 65536
41 static qbyte dma_buffer [SND_BUFF_SIZE];
42 static qbyte writebuf [SND_BUFF_SIZE];
45 qboolean SNDDMA_Init (void)
51 memset ((void*)shm, 0, sizeof (*shm));
53 // Open the audio device
57 snddev = "/dev/sound";
59 audio_fd = open (snddev, O_WRONLY | O_NDELAY | O_NONBLOCK);
62 Con_Printf("Can't open the sound device (%s)\n", snddev);
66 // Look for an appropriate sound format
67 // TODO: we should also test mono/stereo and bits
68 // TODO: support "-sndspeed", "-sndbits", "-sndmono" and "-sndstereo"
69 shm->format.channels = 2;
70 shm->format.width = 2;
71 for (i = 0; i < sizeof (tryrates) / sizeof (tryrates[0]); i++)
73 shm->format.speed = tryrates[i];
75 AUDIO_INITINFO (&info);
76 info.play.sample_rate = shm->format.speed;
77 info.play.channels = shm->format.channels;
78 info.play.precision = shm->format.width * 8;
79 // We only handle sound cards of the same endianess than the CPU
80 #if BYTE_ORDER == BIG_ENDIAN
81 info.play.encoding = AUDIO_ENCODING_SLINEAR_BE;
83 info.play.encoding = AUDIO_ENCODING_SLINEAR_LE;
85 if (ioctl (audio_fd, AUDIO_SETINFO, &info) == 0)
88 if (i == sizeof (tryrates) / sizeof (tryrates[0]))
90 Con_Print("Can't select an appropriate sound output format\n");
95 // Print some information
96 Con_Printf("%d bit %s sound initialized (rate: %dHz)\n",
98 (info.play.channels == 2) ? "stereo" : "mono",
99 info.play.sample_rate);
101 shm->samples = sizeof (dma_buffer) / shm->format.width;
103 shm->buffer = dma_buffer;
109 int SNDDMA_GetDMAPos (void)
116 if (ioctl (audio_fd, AUDIO_GETINFO, &info) < 0)
118 Con_Print("Error: can't get audio info\n");
123 return ((info.play.samples * shm->format.channels) % shm->samples);
126 void SNDDMA_Shutdown (void)
140 Send sound to device if buffer isn't really the dma buffer
143 void SNDDMA_Submit (void)
147 static int wbufp = 0;
150 int stop = paintedtime;
155 if (paintedtime < wbufp)
158 bsize = shm->format.channels * shm->format.width;
159 bytes = (paintedtime - wbufp) * bsize;
164 if (bytes > sizeof (writebuf))
166 bytes = sizeof (writebuf);
167 stop = wbufp + bytes / bsize;
170 // Transfert the sound data from the circular dma_buffer to writebuf
171 // TODO: using 2 memcpys instead of this loop should be faster
173 idx = (wbufp*bsize) & (sizeof (dma_buffer) - 1);
174 for (b = bytes; b; b--)
176 *p++ = dma_buffer[idx];
177 idx = (idx + 1) & (sizeof (dma_buffer) - 1);
180 if (write (audio_fd, writebuf, bytes) < bytes)
181 Con_Print("audio can't keep up!\n");
186 void *S_LockBuffer (void)
191 void S_UnlockBuffer (void)