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1 | /* sound output via OSS */ |
2 | #include <stdio.h> |
3 | #include <sys/types.h> |
4 | #include <sys/stat.h> |
5 | #include <fcntl.h> |
6 | #include <sys/ioctl.h> |
7 | #include <sys/soundcard.h> |
8 | #include <unistd.h> |
9 | |
10 | #include "sndout_oss.h" |
11 | |
12 | static int sounddev = -1, mixerdev = -1; |
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13 | static int can_write_safe; |
14 | |
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15 | |
16 | int sndout_oss_init(void) |
17 | { |
18 | if (mixerdev >= 0) close(mixerdev); |
19 | mixerdev = open("/dev/mixer", O_RDWR); |
20 | if (mixerdev == -1) |
21 | { |
22 | perror("open(\"/dev/mixer\")"); |
23 | } |
24 | |
25 | return 0; |
26 | } |
27 | |
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28 | int sndout_oss_start(int rate, int frame_samples, int stereo) |
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29 | { |
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30 | static int s_oldrate = 0, s_old_fsamples = 0, s_oldstereo = 0; |
31 | int frag, bsize, bits, ret; |
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32 | |
33 | // if no settings change, we don't need to do anything, |
34 | // since audio is never stopped |
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35 | if (rate == s_oldrate && s_old_fsamples == frame_samples && s_oldstereo == stereo) |
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36 | return 0; |
37 | |
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38 | if (sounddev >= 0) { |
39 | ioctl(sounddev, SOUND_PCM_SYNC, 0); |
40 | close(sounddev); |
41 | } |
42 | |
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43 | sounddev = open("/dev/dsp", O_WRONLY|O_ASYNC); |
44 | if (sounddev == -1) |
45 | { |
46 | perror("open(\"/dev/dsp\")"); |
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47 | sounddev = open("/dev/dsp1", O_WRONLY|O_ASYNC); |
48 | if (sounddev == -1) { |
49 | perror("open(\"/dev/dsp1\")"); |
50 | return -1; |
51 | } |
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52 | } |
53 | |
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54 | // calculate buffer size. We one to fit 1 frame worth of sound data. |
55 | // Also ignore mono because both GP2X and Wiz mixes mono to stereo anyway. |
56 | bsize = frame_samples << 2; |
57 | |
58 | for (frag = 0; bsize; bsize >>= 1, frag++) |
59 | ; |
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60 | |
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61 | frag |= 16 << 16; // fragment count |
62 | ret = ioctl(sounddev, SNDCTL_DSP_SETFRAGMENT, &frag); |
63 | if (ret < 0) |
64 | perror("SNDCTL_DSP_SETFRAGMENT failed"); |
65 | |
66 | bits = 16; |
67 | ret = ioctl(sounddev, SNDCTL_DSP_STEREO, &stereo); |
68 | if (ret == 0) |
69 | ret = ioctl(sounddev, SNDCTL_DSP_SETFMT, &bits); |
70 | if (ret == 0) |
71 | ret = ioctl(sounddev, SNDCTL_DSP_SPEED, &rate); |
72 | if (ret < 0) |
73 | perror("failed to set audio format"); |
74 | |
75 | // not sure if this is still needed (avoiding driver bugs?) |
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76 | usleep(192*1024); |
77 | |
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78 | printf("sndout_oss_start: %d/%dbit/%s, %d buffers of %i bytes\n", |
79 | rate, bits, stereo ? "stereo" : "mono", frag >> 16, 1 << (frag & 0xffff)); |
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80 | |
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81 | s_oldrate = rate; s_old_fsamples = frame_samples; s_oldstereo = stereo; |
82 | can_write_safe = 0; |
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83 | return 0; |
84 | } |
85 | |
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86 | int sndout_oss_write(const void *buff, int len) |
87 | { |
88 | return write(sounddev, buff, len); |
89 | } |
90 | |
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91 | int sndout_oss_can_write(int bytes) |
92 | { |
93 | audio_buf_info bi; |
94 | int ret; |
95 | |
96 | #ifdef __GP2X__ |
97 | // note: SNDCTL_DSP_GETOSPACE crashes F100 kernel for some reason |
98 | // if called too early, so we work around here |
99 | if (can_write_safe++ < 8) |
100 | return 1; |
101 | #endif |
102 | ret = ioctl(sounddev, SNDCTL_DSP_GETOSPACE, &bi); |
103 | if (ret < 0) |
104 | return 1; |
105 | |
106 | // have enough bytes to write + 4 extra frags |
107 | return bi.bytes - bi.fragsize * 4 >= bytes ? 1 : 0; |
108 | } |
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109 | |
110 | void sndout_oss_sync(void) |
111 | { |
112 | ioctl(sounddev, SOUND_PCM_SYNC, 0); |
113 | } |
114 | |
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115 | void sndout_oss_setvol(int l, int r) |
116 | { |
117 | if (mixerdev < 0) return; |
118 | |
119 | l=l<0?0:l; l=l>255?255:l; r=r<0?0:r; r=r>255?255:r; |
120 | l<<=8; l|=r; |
121 | ioctl(mixerdev, SOUND_MIXER_WRITE_PCM, &l); /*SOUND_MIXER_WRITE_VOLUME*/ |
122 | } |
123 | |
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124 | void sndout_oss_exit(void) |
125 | { |
126 | if (sounddev >= 0) close(sounddev); sounddev = -1; |
127 | if (mixerdev >= 0) close(mixerdev); mixerdev = -1; |
128 | } |
129 | |