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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\")"); |
47 | return -1; |
48 | } |
49 | |
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50 | // calculate buffer size. We one to fit 1 frame worth of sound data. |
51 | // Also ignore mono because both GP2X and Wiz mixes mono to stereo anyway. |
52 | bsize = frame_samples << 2; |
53 | |
54 | for (frag = 0; bsize; bsize >>= 1, frag++) |
55 | ; |
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56 | |
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57 | frag |= 16 << 16; // fragment count |
58 | ret = ioctl(sounddev, SNDCTL_DSP_SETFRAGMENT, &frag); |
59 | if (ret < 0) |
60 | perror("SNDCTL_DSP_SETFRAGMENT failed"); |
61 | |
62 | bits = 16; |
63 | ret = ioctl(sounddev, SNDCTL_DSP_STEREO, &stereo); |
64 | if (ret == 0) |
65 | ret = ioctl(sounddev, SNDCTL_DSP_SETFMT, &bits); |
66 | if (ret == 0) |
67 | ret = ioctl(sounddev, SNDCTL_DSP_SPEED, &rate); |
68 | if (ret < 0) |
69 | perror("failed to set audio format"); |
70 | |
71 | // not sure if this is still needed (avoiding driver bugs?) |
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72 | usleep(192*1024); |
73 | |
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74 | printf("sndout_oss_start: %d/%dbit/%s, %d buffers of %i bytes\n", |
75 | rate, bits, stereo ? "stereo" : "mono", frag >> 16, 1 << (frag & 0xffff)); |
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76 | |
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77 | s_oldrate = rate; s_old_fsamples = frame_samples; s_oldstereo = stereo; |
78 | can_write_safe = 0; |
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79 | return 0; |
80 | } |
81 | |
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82 | int sndout_oss_write(const void *buff, int len) |
83 | { |
84 | return write(sounddev, buff, len); |
85 | } |
86 | |
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87 | int sndout_oss_can_write(int bytes) |
88 | { |
89 | audio_buf_info bi; |
90 | int ret; |
91 | |
92 | #ifdef __GP2X__ |
93 | // note: SNDCTL_DSP_GETOSPACE crashes F100 kernel for some reason |
94 | // if called too early, so we work around here |
95 | if (can_write_safe++ < 8) |
96 | return 1; |
97 | #endif |
98 | ret = ioctl(sounddev, SNDCTL_DSP_GETOSPACE, &bi); |
99 | if (ret < 0) |
100 | return 1; |
101 | |
102 | // have enough bytes to write + 4 extra frags |
103 | return bi.bytes - bi.fragsize * 4 >= bytes ? 1 : 0; |
104 | } |
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105 | |
106 | void sndout_oss_sync(void) |
107 | { |
108 | ioctl(sounddev, SOUND_PCM_SYNC, 0); |
109 | } |
110 | |
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111 | void sndout_oss_setvol(int l, int r) |
112 | { |
113 | if (mixerdev < 0) return; |
114 | |
115 | l=l<0?0:l; l=l>255?255:l; r=r<0?0:r; r=r>255?255:r; |
116 | l<<=8; l|=r; |
117 | ioctl(mixerdev, SOUND_MIXER_WRITE_PCM, &l); /*SOUND_MIXER_WRITE_VOLUME*/ |
118 | } |
119 | |
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120 | void sndout_oss_exit(void) |
121 | { |
122 | if (sounddev >= 0) close(sounddev); sounddev = -1; |
123 | if (mixerdev >= 0) close(mixerdev); mixerdev = -1; |
124 | } |
125 | |