| 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; |
| 13 | |
| 14 | int sndout_oss_init(void) |
| 15 | { |
| 16 | if (mixerdev >= 0) close(mixerdev); |
| 17 | mixerdev = open("/dev/mixer", O_RDWR); |
| 18 | if (mixerdev == -1) |
| 19 | { |
| 20 | perror("open(\"/dev/mixer\")"); |
| 21 | } |
| 22 | |
| 23 | return 0; |
| 24 | } |
| 25 | |
| 26 | |
| 27 | int sndout_oss_start(int rate, int bits, int stereo) |
| 28 | { |
| 29 | static int s_oldrate = 0, s_oldbits = 0, s_oldstereo = 0; |
| 30 | int frag = 0, bsize, buffers, ret; |
| 31 | |
| 32 | // if no settings change, we don't need to do anything, |
| 33 | // since audio is never stopped |
| 34 | if (rate == s_oldrate && s_oldbits == bits && s_oldstereo == stereo) |
| 35 | return 0; |
| 36 | |
| 37 | if (sounddev >= 0) close(sounddev); |
| 38 | sounddev = open("/dev/dsp", O_WRONLY|O_ASYNC); |
| 39 | if (sounddev == -1) |
| 40 | { |
| 41 | perror("open(\"/dev/dsp\")"); |
| 42 | return -1; |
| 43 | } |
| 44 | |
| 45 | // calculate buffer size |
| 46 | // this is tuned for GP2X |
| 47 | buffers = 16; |
| 48 | bsize = rate / 32; |
| 49 | if (rate > 22050) { bsize*=4; buffers*=2; } |
| 50 | while ((bsize>>=1)) frag++; |
| 51 | frag |= buffers<<16; // 16 buffers |
| 52 | ret = ioctl(sounddev, SNDCTL_DSP_SETFRAGMENT, &frag); |
| 53 | if (ret) perror("SNDCTL_DSP_SETFRAGMENT failed"); |
| 54 | |
| 55 | ret = ioctl(sounddev, SNDCTL_DSP_STEREO, &stereo); |
| 56 | ret |= ioctl(sounddev, SNDCTL_DSP_SETFMT, &bits); |
| 57 | ret |= ioctl(sounddev, SNDCTL_DSP_SPEED, &rate); |
| 58 | if (ret) printf("failed to set audio format\n"); |
| 59 | usleep(192*1024); |
| 60 | |
| 61 | printf("gp2x_set_sound: %i/%ibit/%s, %i buffers of %i bytes\n", |
| 62 | rate, bits, stereo?"stereo":"mono", frag>>16, 1<<(frag&0xffff)); |
| 63 | |
| 64 | s_oldrate = rate; s_oldbits = bits; s_oldstereo = stereo; |
| 65 | return 0; |
| 66 | } |
| 67 | |
| 68 | |
| 69 | int sndout_oss_write(const void *buff, int len) |
| 70 | { |
| 71 | return write(sounddev, buff, len); |
| 72 | } |
| 73 | |
| 74 | |
| 75 | void sndout_oss_sync(void) |
| 76 | { |
| 77 | ioctl(sounddev, SOUND_PCM_SYNC, 0); |
| 78 | } |
| 79 | |
| 80 | |
| 81 | void sndout_oss_setvol(int l, int r) |
| 82 | { |
| 83 | if (mixerdev < 0) return; |
| 84 | |
| 85 | l=l<0?0:l; l=l>255?255:l; r=r<0?0:r; r=r>255?255:r; |
| 86 | l<<=8; l|=r; |
| 87 | ioctl(mixerdev, SOUND_MIXER_WRITE_PCM, &l); /*SOUND_MIXER_WRITE_VOLUME*/ |
| 88 | } |
| 89 | |
| 90 | |
| 91 | void sndout_oss_exit(void) |
| 92 | { |
| 93 | if (sounddev >= 0) close(sounddev); sounddev = -1; |
| 94 | if (mixerdev >= 0) close(mixerdev); mixerdev = -1; |
| 95 | } |
| 96 | |