extracted OSS code to sndout_oss_*, BTN->PBTN, refactoring

[libpicofe.git] / linux / sndout_oss.c

diff --git a/linux/sndout_oss.c b/linux/sndout_oss.c
new file mode 100644 (file)
index 0000000..e2d0bde
--- /dev/null
+++ b/linux/sndout_oss.c
@@ -0,0 +1,96 @@
+/* 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;
+}
+