spa: add some latency helpers

Add more fields to the latency object.
Add methods to create, parse and process latency info.

src/pipewire/impl-link.c

@@ -637,6 +637,8 @@ static void input_remove(struct pw_impl_link *this, struct pw_impl_port *port)
 	spa_list_remove(&this->input_link);
 	pw_impl_port_emit_link_removed(this->input, this);
 
+	pw_impl_port_recalc_latency(this->input);
+
 	if ((res = pw_impl_port_use_buffers(port, mix, 0, NULL, 0)) < 0) {
 		pw_log_warn(NAME" %p: port %p clear error %s", this, port, spa_strerror(res));
 	}
@@ -657,6 +659,8 @@ static void output_remove(struct pw_impl_link *this, struct pw_impl_port *port)
 	spa_list_remove(&this->output_link);
 	pw_impl_port_emit_link_removed(this->output, this);
 
+	pw_impl_port_recalc_latency(this->output);
+
 	/* we don't clear output buffers when the link goes away. They will get
 	 * cleared when the node goes to suspend */
 	pw_impl_port_release_mix(port, mix);
@@ -932,17 +936,6 @@ static bool pw_impl_node_can_reach(struct pw_impl_node *output, struct pw_impl_n
 	return false;
 }
 
-static void recalculate_latencies(struct impl *impl)
-{
-	struct pw_impl_link *this = &impl->this;
-	/* from output port we get capture latency and propagate this
-	 * on the input port */
-	pw_impl_port_recalc_latency(this->output);
-	/* from input port we get playback latency and propagate that
-	 * on the output port */
-	pw_impl_port_recalc_latency(this->input);
-}
-
 static void try_link_controls(struct impl *impl, struct pw_impl_port *output, struct pw_impl_port *input)
 {
 	struct pw_control *cin, *cout;
@@ -1156,10 +1149,11 @@ struct pw_impl_link *pw_context_create_link(struct pw_context *context,
 	pw_impl_port_emit_link_added(output, this);
 	pw_impl_port_emit_link_added(input, this);
 
-	recalculate_latencies(impl);
-
 	try_link_controls(impl, output, input);
 
+	pw_impl_port_recalc_latency(this->output);
+	pw_impl_port_recalc_latency(this->input);
+
 	pw_impl_node_emit_peer_added(impl->onode, impl->inode);
 
 	return this;

src/pipewire/impl-port.c

@@ -25,6 +25,7 @@
 #include <string.h>
 #include <stdlib.h>
 #include <errno.h>
+#include <float.h>
 
 #include <spa/pod/parser.h>
 #include <spa/param/audio/format-utils.h>
@@ -355,24 +356,23 @@ static int process_latency_param(void *data, int seq,
 		uint32_t id, uint32_t index, uint32_t next, struct spa_pod *param)
 {
 	struct pw_impl_port *this = data;
-	uint32_t direction;
-	struct pw_port_latency latency;
+	struct spa_latency_info latency;
 
 	if (id != SPA_PARAM_Latency)
 		return -EINVAL;
 
-	if (spa_pod_parse_object(param,
-			SPA_TYPE_OBJECT_ParamLatency, NULL,
-			SPA_PARAM_LATENCY_direction,SPA_POD_Id(&direction),
-			SPA_PARAM_LATENCY_quantum,SPA_POD_Float(&latency.quantum),
-			SPA_PARAM_LATENCY_min,  SPA_POD_Int(&latency.min),
-			SPA_PARAM_LATENCY_max,  SPA_POD_Int(&latency.max)) < 0)
+	if (spa_latency_parse(param, &latency) < 0)
 		return 0;
-	if (direction != this->direction)
+	if (latency.direction != this->direction)
 		return 0;
-	pw_log_info("got latency %f %d %d", latency.quantum, latency.min, latency.max);
 
-	this->latency[direction] = latency;
+	pw_log_info("port %p: got %s latency %f-%f %d-%d %"PRIu64"-%"PRIu64, this,
+			pw_direction_as_string(this->direction),
+			latency.min_quantum, latency.max_quantum,
+			latency.min_rate, latency.max_rate,
+			latency.min_ns, latency.max_ns);
+
+	this->latency[this->direction] = latency;
 	return 0;
 }
 
@@ -515,6 +515,9 @@ struct pw_impl_port *pw_context_create_port(
 
 	pw_map_init(&this->mix_port_map, 64, 64);
 
+	this->latency[SPA_DIRECTION_INPUT] = SPA_LATENCY_INFO(SPA_DIRECTION_INPUT);
+	this->latency[SPA_DIRECTION_OUTPUT] = SPA_LATENCY_INFO(SPA_DIRECTION_OUTPUT);
+
 	if (info)
 		update_info(this, info);
 
@@ -1288,55 +1291,66 @@ int pw_impl_port_for_each_link(struct pw_impl_port *port,
 	return res;
 }
 
-static void port_set_latency(struct pw_impl_port *port, struct pw_port_latency *latency)
+static void port_set_latency(struct pw_impl_port *port, struct spa_latency_info *latency)
 {
-	struct pw_port_latency *current = &port->latency[port->direction];
+	struct spa_latency_info *current = &port->latency[latency->direction];
 	struct spa_pod *param;
 	struct spa_pod_builder b = { 0 };
 	uint8_t buffer[1024];
 
-	if (current->quantum == latency->quantum &&
-	    current->min == latency->min &&
-	    current->max == latency->max)
+	if (spa_latency_info_compare(current, latency) == 0)
 		return;
 
 	*current = *latency;
-	pw_log_info("port set latency %d %d %f", latency->min, latency->max, latency->quantum);
+	pw_log_info("port %p: set %s latency %f-%f %d-%d %"PRIu64"-%"PRIu64, port,
+			pw_direction_as_string(latency->direction),
+			latency->min_quantum, latency->max_quantum,
+			latency->min_rate, latency->max_rate,
+			latency->min_ns, latency->max_ns);
 
 	spa_pod_builder_init(&b, buffer, sizeof(buffer));
-	param = spa_pod_builder_add_object(&b,
-			SPA_TYPE_OBJECT_ParamLatency, SPA_PARAM_Latency,
-			SPA_PARAM_LATENCY_direction, SPA_POD_Id(port->direction),
-			SPA_PARAM_LATENCY_quantum, SPA_POD_Float(latency->quantum),
-			SPA_PARAM_LATENCY_min, SPA_POD_Int(latency->min),
-			SPA_PARAM_LATENCY_max, SPA_POD_Int(latency->max));
-
+	param = spa_latency_build(&b, SPA_PARAM_Latency, latency);
 	pw_impl_port_set_param(port, SPA_PARAM_Latency, 0, param);
 }
 
 int pw_impl_port_recalc_latency(struct pw_impl_port *port)
 {
 	struct pw_impl_link *l;
-	struct pw_port_latency latency = { .quantum = 0.0f, .min = UINT32_MAX, .max = 0 };
+	struct spa_latency_info latency;
 	struct pw_impl_port *other;
 
+	latency = SPA_LATENCY_INFO(SPA_DIRECTION_REVERSE(port->direction));
+	latency.min_quantum = FLT_MAX;
+	latency.min_rate = INT32_MAX;
+	latency.min_ns = INT64_MAX;
+
 	if (port->direction == PW_DIRECTION_OUTPUT) {
 		spa_list_for_each(l, &port->links, output_link) {
 			other = l->input;
-			latency.quantum = SPA_MAX(latency.quantum, other->latency[other->direction].quantum);
-			latency.min = SPA_MIN(latency.min, other->latency[other->direction].min);
-			latency.max = SPA_MAX(latency.max, other->latency[other->direction].max);
+			spa_latency_info_combine(&latency, &other->latency[other->direction]);
+			pw_log_info("port %p: peer %p: latency %f-%f %d-%d %"PRIu64"-%"PRIu64,
+					port, other,
+					latency.min_quantum, latency.max_quantum,
+					latency.min_rate, latency.max_rate,
+					latency.min_ns, latency.max_ns);
 		}
 	} else {
 		spa_list_for_each(l, &port->links, input_link) {
-			other = l->input;
-			latency.quantum = SPA_MAX(latency.quantum, other->latency[other->direction].quantum);
-			latency.min = SPA_MIN(latency.min, other->latency[other->direction].min);
-			latency.max = SPA_MAX(latency.max, other->latency[other->direction].max);
+			other = l->output;
+			spa_latency_info_combine(&latency, &other->latency[other->direction]);
+			pw_log_info("port %p: peer %p: latency %f-%f %d-%d %"PRIu64"-%"PRIu64,
+					port, other,
+					latency.min_quantum, latency.max_quantum,
+					latency.min_rate, latency.max_rate,
+					latency.min_ns, latency.max_ns);
 		}
 	}
-	if (latency.min == UINT32_MAX)
-		latency.min = 0;
+	if (latency.min_quantum == FLT_MAX)
+		latency.min_quantum = 0.0f;
+	if (latency.min_rate == INT32_MAX)
+		latency.min_rate = 0U;
+	if (latency.min_ns == INT64_MAX)
+		latency.min_ns = 0UL;
 
 	port_set_latency(port, &latency);
 	return 0;

src/pipewire/private.h

@@ -36,6 +36,7 @@ extern "C" {
 
 #include <spa/support/plugin.h>
 #include <spa/pod/builder.h>
+#include <spa/param/latency-utils.h>
 #include <spa/utils/result.h>
 #include <spa/utils/type-info.h>
 
@@ -686,12 +687,6 @@ struct pw_impl_node {
         void *user_data;                /**< extra user data */
 };
 
-struct pw_port_latency {
-	float quantum;		/** quantum multiplier */
-	uint32_t min;		/** min of all peers */
-	uint32_t max;		/** max of all peers */
-};
-
 struct pw_impl_port_mix {
 	struct spa_list link;
 	struct spa_list rt_link;
@@ -796,7 +791,7 @@ struct pw_impl_port {
 	} rt;					/**< data only accessed from the data thread */
 	unsigned int added:1;
 
-	struct pw_port_latency latency[2];	/**< latencies */
+	struct spa_latency_info latency[2];	/**< latencies */
 
 	void *owner_data;		/**< extra owner data */
 	void *user_data;                /**< extra user data */

src/tools/pw-cat.c

@@ -45,6 +45,7 @@
 #include <spa/utils/string.h>
 #include <spa/utils/json.h>
 #include <spa/debug/types.h>
+#include <spa/debug/pod.h>
 
 #include <pipewire/pipewire.h>
 #include <pipewire/i18n.h>
@@ -835,13 +836,15 @@ on_io_changed(void *userdata, uint32_t id, void *data, uint32_t size)
 }
 
 static void
-on_param_changed(void *userdata, uint32_t id, const struct spa_pod *format)
+on_param_changed(void *userdata, uint32_t id, const struct spa_pod *param)
 {
 	struct data *data = userdata;
 
-	if (data->verbose)
-		printf("stream param change: id=%"PRIu32"\n",
-				id);
+	if (data->verbose) {
+		printf("stream param change: id=%"PRIu32"\n", id);
+		if (param != NULL)
+			spa_debug_pod(0, NULL, param);
+	}
 }
 
 static void on_process(void *userdata)