Did some digging in the dxr3 em8300 kernel sources; turnes out that

the kernel driver ignores SETSCR commands when the difference is
smaller than 7200 (a very arbitrary value of 2 frames). Since my
favourite oss audio driver has a GAP_TOLERANCE of 5000, this resulted
in about a gazillion 'audio out: adjusting master clock' messages.
Now added an offset to simulate adjustments < 7200; as soon as the
offset goes over 7200 SETSCR is called and offset set to 0.

CVS patchset: 1288
CVS date: 2001/12/23 04:08:25

1 files changed, 18 insertions, 5 deletions

diff --git a/src/dxr3/dxr3_decoder.c b/src/dxr3/dxr3_decoder.c
index 023140bfb..f68c1f181 100644
--- a/src/dxr3/dxr3_decoder.c
+++ b/src/dxr3/dxr3_decoder.c
@@ -17,7 +17,7 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA
  *
- * $Id: dxr3_decoder.c,v 1.48 2001/12/23 02:36:54 hrm Exp $
+ * $Id: dxr3_decoder.c,v 1.49 2001/12/23 04:08:25 hrm Exp $
  *
  * dxr3 video and spu decoder plugin. Accepts the video and spu data
  * from XINE and sends it directly to the corresponding dxr3 devices.
@@ -174,6 +174,7 @@ typedef struct dxr3scr_s {
 	scr_plugin_t scr;
 	int fd_control;
 	int priority;
+	int offset; /* a little offset < 7200 */
 } dxr3scr_t;
 
 static int dxr3scr_get_priority (scr_plugin_t *scr) {
@@ -246,9 +247,18 @@ static int dxr3scr_set_speed (scr_plugin_t *scr, int speed) {
 */
 static void dxr3scr_adjust (scr_plugin_t *scr, uint32_t vpts) {
 	dxr3scr_t *self = (dxr3scr_t*) scr;
-	vpts >>= 1;
-	if (ioctl(self->fd_control, EM8300_IOCTL_SCR_SET, &vpts))
-		printf("dxr3scr: adjust failed (%s)\n", strerror(errno));
+	uint32_t cpts;
+	if (ioctl(self->fd_control, EM8300_IOCTL_SCR_GET, &cpts))
+		printf("dxr3scr: adjust get failed (%s)\n", strerror(errno));
+	cpts <<= 1;
+	self->offset = (vpts - (cpts + self->offset));
+	/* kernel driver ignores diffs < 7200 */
+	if (self->offset < -7200 || self->offset > 7200) {
+		vpts >>= 1;
+		if (ioctl(self->fd_control, EM8300_IOCTL_SCR_SET, &vpts))
+			printf("dxr3scr: adjust set failed (%s)\n", strerror(errno));
+		self->offset = 0;
+	}
 }
 
 /* *** dxr3scr_start ***
@@ -260,6 +270,7 @@ static void dxr3scr_start (scr_plugin_t *scr, uint32_t start_vpts) {
 	dxr3scr_t *self = (dxr3scr_t*) scr;
 	start_vpts >>= 1;
 
+	self->offset = 0;
 	if (ioctl(self->fd_control, EM8300_IOCTL_SCR_SET, &start_vpts))
 		printf("dxr3scr: start failed (%s)\n", strerror(errno));
 	/* mis-use start_vpts */
@@ -280,7 +291,7 @@ static uint32_t dxr3scr_get_current (scr_plugin_t *scr) {
 	if (ioctl(self->fd_control, EM8300_IOCTL_SCR_GET, &pts))
 		printf("dxr3scr: get current failed (%s)\n", strerror(errno));
 
-	return pts << 1;
+	return (pts << 1) + self->offset;
 }
 
 
@@ -300,6 +311,8 @@ static scr_plugin_t* dxr3scr_init (dxr3_decoder_t *dxr3) {
 	self->scr.start             = dxr3scr_start;
 	self->scr.get_current       = dxr3scr_get_current;
 
+	self->offset = 0;
+
 	if ((self->fd_control = open (devname, O_WRONLY)) < 0) {
 		printf("dxr3scr: Failed to open control device %s (%s)\n",
 		 devname, strerror(errno));