diff --git a/pipewire-jack b/pipewire-jack
index 796278b20..a52ad27a1 160000
--- a/pipewire-jack
+++ b/pipewire-jack
@@ -1 +1 @@
-Subproject commit 796278b207e686403638d1c850ce01fa0a0fee48
+Subproject commit a52ad27a169ffd6abb4090e1d77385bd879a1d43
diff --git a/spa/include/spa/node/io.h b/spa/include/spa/node/io.h
index 3e7f1b77a..116c30ea6 100644
--- a/spa/include/spa/node/io.h
+++ b/spa/include/spa/node/io.h
@@ -136,20 +136,20 @@ struct spa_io_segment_video {
 };
 
 /**
- * A segment converts a raw clock time to a segment (stream) position.
+ * A segment converts a running time to a segment (stream) position.
  *
- * The segment position is valid when the current clock position is between
+ * The segment position is valid when the current running time is between
  * start and start + duration. The position is then
  * calculated as:
  *
- *   (start - clock.position) * rate + position;
+ *   (running time - start) * rate + position;
  *
- * Support for looping is done by specifying a non-zero duration. When the
- * clock reaches start + duration, duration is added to start and the
- * loop repeats.
+ * Support for looping is done by specifying the LOOPING flags with a
+ * non-zero duration. When the running time reaches start + duration,
+ * duration is added to start and the loop repeats.
  *
- * Care has to be taken when the clock.duration extends past the
- * start + duration from the segment; the user should correctly
+ * Care has to be taken when the running time + clock.duration extends
+ * past the start + duration from the segment; the user should correctly
  * wrap around and partially repeat the loop in the current cycle.
  *
  * Extra information can be placed in the segment by setting the valid flags
@@ -162,15 +162,16 @@ struct spa_io_segment {
 #define SPA_IO_SEGMENT_VALID_BAR	(1<<1)
 #define SPA_IO_SEGMENT_VALID_VIDEO	(1<<2)
 	uint32_t valid;				/**< indicates what fields are valid below */
-	uint64_t start;				/**< position against clock position when this
+	uint64_t start;				/**< value of running time when this
 						  *  info is active. Can be in the future for
 						  *  pending changes. It does not have to be in
 						  *  exact multiples of the clock duration. */
-	uint64_t duration;			/**< duration when this info becomes invalid. If
-						  *  the duration is 0, this segment extends to the
-						  *  next segment. If the segment becomes invalid and
-						  *  the looping flag is set, the segment is repeats. */
-	uint64_t position;			/**< The position when the clock == start. */
+	uint64_t duration;			/**< duration when this info becomes invalid expressed
+						  *  in running time. If the duration is 0, this
+						  *  segment extends to the next segment. If the
+						  *  segment becomes invalid and the looping flag is
+						  *  set, the segment repeats. */
+	uint64_t position;			/**< The position when the running time == start. */
 	double rate;				/**< overal rate of the graph, can be negative for
 						  *  backwards time reporting. */
 
@@ -202,6 +203,11 @@ enum spa_io_position_state {
 struct spa_io_position {
 	struct spa_io_clock clock;		/**< clock position of driver, always valid and
 						  *  read only */
+	int64_t offset;				/**< an offset to subtract from the clock position
+						  *  to get a running time. This is the time that
+						  *  the state has been in the RUNNING state and the
+						  *  time that should be used to compare the segment
+						  *  start values against. */
 	uint32_t state;				/**< one of enum spa_io_position_state */
 
 	uint32_t n_segments;			/**< number of segments */
diff --git a/src/pipewire/node.c b/src/pipewire/node.c
index 9d96110df..46968feba 100644
--- a/src/pipewire/node.c
+++ b/src/pipewire/node.c
@@ -963,6 +963,7 @@ struct pw_node *pw_node_new(struct pw_core *core,
 
 	this->rt.activation->position.clock.rate = SPA_FRACTION(1, 48000);
 	this->rt.activation->position.clock.duration = DEFAULT_QUANTUM;
+	this->rt.activation->position.offset = INT64_MIN;
 	this->rt.activation->position.n_segments = 1;
 	this->rt.activation->position.segments[0].flags = 0;
 	this->rt.activation->position.segments[0].valid = SPA_IO_SEGMENT_VALID_POSITION;
@@ -1174,6 +1175,9 @@ static void update_position(struct pw_node *node)
 	uint32_t seq1, seq2, change_mask;
 	enum spa_io_position_state state;
 
+	if (a->position.offset == INT64_MIN)
+		a->position.offset = a->position.clock.position;
+
 	seq1 = SEQ_READ(&a->pending.seq);
 	change_mask = a->pending.change_mask;
 	state = a->pending.state;
@@ -1207,6 +1211,8 @@ static void update_position(struct pw_node *node)
 		seg->duration = segment.duration;
 		seg->position = segment.position;
 		seg->rate = segment.rate;
+		if (seg->start == 0)
+			seg->start = a->position.clock.position - a->position.offset;
 	}
 	if (change_mask & PW_NODE_ACTIVATION_UPDATE_STATE) {
 		switch (state) {
@@ -1219,11 +1225,9 @@ static void update_position(struct pw_node *node)
 			break;
 		}
 	}
-	if (seg->start == 0)
-		seg->start = a->position.clock.position;
 
 	if (a->position.state == SPA_IO_POSITION_STATE_STOPPED)
-		seg->start += a->position.clock.duration;
+		a->position.offset += a->position.clock.duration;
 }
 
 static int node_ready(void *data, int status)
diff --git a/src/pipewire/private.h b/src/pipewire/private.h
index 42dbd88e6..0583437bd 100644
--- a/src/pipewire/private.h
+++ b/src/pipewire/private.h
@@ -381,8 +381,10 @@ struct pw_node_activation {
 #define PW_NODE_ACTIVATION_UPDATE_STATE		(1<<0)
 #define PW_NODE_ACTIVATION_UPDATE_SEGMENT	(1<<1)
 #define PW_NODE_ACTIVATION_UPDATE_REPOSITION	(1<<2)
+#define PW_NODE_ACTIVATION_UPDATE_FLUSH		(1<<3)	/* flush out current segments and immediately
+							 * start the new one */
 		uint32_t change_mask;
-		enum spa_io_position_state state;
+		enum spa_io_position_state state;	/* when change_mask & PW_NODE_ACTIVATION_UPDATE_STATE */
 		struct spa_io_segment segment;		/* update for the extra segment info
 							 * fields. When REPOSITION update, the segment
 							 * position field will contain the desired