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- /* sound output via OSS */
- #include <stdio.h>
- #include <sys/types.h>
- #include <sys/stat.h>
- #include <fcntl.h>
- #include <sys/ioctl.h>
- #include <sys/soundcard.h>
- #include <unistd.h>
- #include "sndout_oss.h"
- static int sounddev = -1, mixerdev = -1;
- int sndout_oss_init(void)
- {
- if (mixerdev >= 0) close(mixerdev);
- mixerdev = open("/dev/mixer", O_RDWR);
- if (mixerdev == -1)
- {
- perror("open(\"/dev/mixer\")");
- }
- return 0;
- }
- int sndout_oss_start(int rate, int bits, int stereo)
- {
- static int s_oldrate = 0, s_oldbits = 0, s_oldstereo = 0;
- int frag = 0, bsize, buffers, ret;
- // if no settings change, we don't need to do anything,
- // since audio is never stopped
- if (rate == s_oldrate && s_oldbits == bits && s_oldstereo == stereo)
- return 0;
- if (sounddev >= 0) close(sounddev);
- sounddev = open("/dev/dsp", O_WRONLY|O_ASYNC);
- if (sounddev == -1)
- {
- perror("open(\"/dev/dsp\")");
- return -1;
- }
- // calculate buffer size
- // this is tuned for GP2X
- buffers = 16;
- bsize = rate / 32;
- if (rate > 22050) { bsize*=4; buffers*=2; }
- while ((bsize>>=1)) frag++;
- frag |= buffers<<16; // 16 buffers
- ret = ioctl(sounddev, SNDCTL_DSP_SETFRAGMENT, &frag);
- if (ret) perror("SNDCTL_DSP_SETFRAGMENT failed");
- ret = ioctl(sounddev, SNDCTL_DSP_STEREO, &stereo);
- ret |= ioctl(sounddev, SNDCTL_DSP_SETFMT, &bits);
- ret |= ioctl(sounddev, SNDCTL_DSP_SPEED, &rate);
- if (ret) printf("failed to set audio format\n");
- usleep(192*1024);
- printf("gp2x_set_sound: %i/%ibit/%s, %i buffers of %i bytes\n",
- rate, bits, stereo?"stereo":"mono", frag>>16, 1<<(frag&0xffff));
- s_oldrate = rate; s_oldbits = bits; s_oldstereo = stereo;
- return 0;
- }
- int sndout_oss_write(const void *buff, int len)
- {
- return write(sounddev, buff, len);
- }
- void sndout_oss_sync(void)
- {
- ioctl(sounddev, SOUND_PCM_SYNC, 0);
- }
- void sndout_oss_setvol(int l, int r)
- {
- if (mixerdev < 0) return;
- l=l<0?0:l; l=l>255?255:l; r=r<0?0:r; r=r>255?255:r;
- l<<=8; l|=r;
- ioctl(mixerdev, SOUND_MIXER_WRITE_PCM, &l); /*SOUND_MIXER_WRITE_VOLUME*/
- }
- void sndout_oss_exit(void)
- {
- if (sounddev >= 0) close(sounddev); sounddev = -1;
- if (mixerdev >= 0) close(mixerdev); mixerdev = -1;
- }
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