X-Git-Url: https://notaz.gp2x.de/cgi-bin/gitweb.cgi?a=blobdiff_plain;ds=inline;f=linux%2Fsndout_oss.c;fp=linux%2Fsndout_oss.c;h=e2d0bdeaa6fdcc417d5a45cf79412545332cc55b;hb=b3972d826fe31f82aa3382f80454e5d8ce895705;hp=0000000000000000000000000000000000000000;hpb=725d7f6c16b396ad3c7f98175cc20289c5241f3a;p=libpicofe.git

diff --git a/linux/sndout_oss.c b/linux/sndout_oss.c
new file mode 100644
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;
+}
+