support multiple sound drivers, add sdl

[libpicofe.git] / linux / sndout_oss.c

diff --git a/linux/sndout_oss.c b/linux/sndout_oss.c
index f74e706..c0b775a 100644 (file)
--- a/linux/sndout_oss.c
+++ b/linux/sndout_oss.c
@@ -1,3 +1,14 @@
+/*
+ * (C) Gražvydas "notaz" Ignotas, 2009-2010
+ *
+ * This work is licensed under the terms of any of these licenses
+ * (at your option):
+ *  - GNU GPL, version 2 or later.
+ *  - GNU LGPL, version 2.1 or later.
+ *  - MAME license.
+ * See the COPYING file in the top-level directory.
+ */
+
 /* sound output via OSS */
 #include <stdio.h>
 #include <sys/types.h>
@@ -9,9 +20,12 @@
 
 #include "sndout_oss.h"
 
+int sndout_oss_frag_frames = 1;
+
 static int sounddev = -1, mixerdev = -1;
 static int can_write_safe;
 
+#define FRAG_COUNT 4
 
 int sndout_oss_init(void)
 {
@@ -25,40 +39,48 @@ int sndout_oss_init(void)
        return 0;
 }
 
-int sndout_oss_start(int rate, int frame_samples, int stereo)
+void sndout_oss_stop(void)
+{
+       if (sounddev < 0)
+               return;
+
+       ioctl(sounddev, SOUND_PCM_SYNC, 0);
+       close(sounddev);
+       sounddev = -1;
+}
+
+int sndout_oss_start(int rate, int stereo)
 {
-       static int s_oldrate = 0, s_old_fsamples = 0, s_oldstereo = 0;
+       static int s_oldrate = 0, s_oldstereo = 0;
        int frag, bsize, bits, ret;
 
-       // if no settings change, we don't need to do anything,
-       // since audio is never stopped
-       if (rate == s_oldrate && s_old_fsamples == frame_samples && s_oldstereo == stereo)
+       // GP2X: if no settings change, we don't need to do anything,
+       // since audio is never stopped there
+       if (sounddev >= 0 && rate == s_oldrate && s_oldstereo == stereo)
                return 0;
 
-       if (sounddev >= 0) {
-               ioctl(sounddev, SOUND_PCM_SYNC, 0);
-               close(sounddev);
-       }
-
-       sounddev = open("/dev/dsp", O_WRONLY|O_ASYNC);
+       sndout_oss_stop();
+       sounddev = open("/dev/dsp", O_WRONLY);
        if (sounddev == -1)
        {
                perror("open(\"/dev/dsp\")");
-               sounddev = open("/dev/dsp1", O_WRONLY|O_ASYNC);
+               sounddev = open("/dev/dsp1", O_WRONLY);
                if (sounddev == -1) {
                        perror("open(\"/dev/dsp1\")");
                        return -1;
                }
        }
 
-       // calculate buffer size. We one to fit 1 frame worth of sound data.
-       // Also ignore mono because both GP2X and Wiz mixes mono to stereo anyway.
-       bsize = frame_samples << 2;
+       // try to fit sndout_oss_frag_frames (video) frames
+       // worth of sound data in OSS fragment
+       // ignore mono because it's unlikely to be used and
+       // both GP2X and Wiz mixes mono to stereo anyway.
+       bsize = (sndout_oss_frag_frames * rate / 50) * 4;
 
        for (frag = 0; bsize; bsize >>= 1, frag++)
                ;
 
-       frag |= 16 << 16;       // fragment count
+       frag |= FRAG_COUNT << 16;       // fragment count
        ret = ioctl(sounddev, SNDCTL_DSP_SETFRAGMENT, &frag);
        if (ret < 0)
                perror("SNDCTL_DSP_SETFRAGMENT failed");
@@ -72,13 +94,15 @@ int sndout_oss_start(int rate, int frame_samples, int stereo)
        if (ret < 0)
                perror("failed to set audio format");
 
+#ifdef __GP2X__
        // not sure if this is still needed (avoiding driver bugs?)
        usleep(192*1024);
+#endif
 
        printf("sndout_oss_start: %d/%dbit/%s, %d buffers of %i bytes\n",
                rate, bits, stereo ? "stereo" : "mono", frag >> 16, 1 << (frag & 0xffff));
 
-       s_oldrate = rate; s_old_fsamples = frame_samples; s_oldstereo = stereo;
+       s_oldrate = rate; s_oldstereo = stereo;
        can_write_safe = 0;
        return 0;
 }
@@ -88,6 +112,42 @@ int sndout_oss_write(const void *buff, int len)
        return write(sounddev, buff, len);
 }
 
+#include "../plat.h"
+
+/* not really non-blocking, just detects if blocking occurs
+ * and starts skipping writes in case it does. */
+int sndout_oss_write_nb(const void *buff, int len)
+{
+       static int lag_counter, skip_counter;
+       unsigned int t;
+       int ret;
+
+       if (lag_counter > 2) {
+               // skip writes if audio starts blocking
+               lag_counter = 0;
+               skip_counter = FRAG_COUNT;
+       }
+
+       if (skip_counter > 0) {
+               skip_counter--;
+               return len;
+       }
+
+       t = plat_get_ticks_ms();
+       ret = sndout_oss_write(buff, len);
+       t = plat_get_ticks_ms() - t;
+       if (t > 1) {
+               // this shouldn't really happen, most likely audio is out of sync
+               lag_counter++;
+               if (lag_counter > 2)
+                       printf("audio lag %u\n", t);
+       }
+       else
+               lag_counter = 0;
+
+       return ret;
+}
+
 int sndout_oss_can_write(int bytes)
 {
        audio_buf_info bi;
@@ -103,12 +163,13 @@ int sndout_oss_can_write(int bytes)
        if (ret < 0)
                return 1;
 
-       // have enough bytes to write + 4 extra frags
-       return bi.bytes - bi.fragsize * 4 >= bytes ? 1 : 0;
+       // have enough bytes to write + 1 frag
+       return bi.bytes - bi.fragsize >= bytes ? 1 : 0;
 }
 
-void sndout_oss_sync(void)
+void sndout_oss_wait(void)
 {
+       // FIXME?
        ioctl(sounddev, SOUND_PCM_SYNC, 0);
 }