X-Git-Url: https://notaz.gp2x.de/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=linux%2Fsndout_oss.c;h=0df17b272a7a91b797049871c473a0774459c02b;hb=20b143089cc395dbcd51cac516a9e36f4ab6f5ac;hp=f9cc6c23da30dd32f6de77350bc86b857c13d07b;hpb=f679add71bb8f7e6480cd5ab62e8b489454739a4;p=libpicofe.git

diff --git a/linux/sndout_oss.c b/linux/sndout_oss.c
index f9cc6c2..0df17b2 100644
--- 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>
@@ -98,6 +109,42 @@ 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;