Some sinks and sources do not have ports associated with them, such as a null
sink. Nonetheless sources and sinks with no ports can be used for sound
input/output with an associated latency, for example by capturing output from
a null sink and directing over a network, which is how some implementations of
network audio streaming protocols interact with PulseAudio.
To keep graphics in sync with audio in these cases, the application/plugin must
be able to report the latency due to network transport/buffering to PulseAudio
and have it included in the total latency for that source or sink.
Previously, only the latency offset of a whole port could be set.
You could call pa_sink_set_latency_offset(), but the value you passed in would
be overwritten on change to a new port - that value was really just a cached
value of the port's latency offset. So those variables and functions have since
(in the previous commit) been renamed pa_sink_set_port_latency_offset() etc, to
distinguish them from the ones introduced in this commit.
This patch adds set_sink_latency_offset() and set_source_latency offset(),
and the corresponding members of the sink and source structs.
It also adds corresponding hooks PA_CORE_HOOK_SINK_LATENCY_OFFSET_CHANGED
and PA_CORE_HOOK_SOURCE_LATENCY_OFFSET_CHANGED.
The total latency reported by a source or sink now includes both the port
latency offset (if any) as well as the source or sink's own latency offset.
---
src/pulsecore/core.h | 2 ++
src/pulsecore/sink.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
src/pulsecore/sink.h | 13 ++++++++++++-
src/pulsecore/source.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
src/pulsecore/source.h | 13 ++++++++++++-
5 files changed, 120 insertions(+), 2 deletions(-)
diff --git a/src/pulsecore/core.h b/src/pulsecore/core.h
index aefc1eb..864863f 100644
--- a/src/pulsecore/core.h
+++ b/src/pulsecore/core.h
@@ -125,6 +125,8 @@ typedef enum pa_core_hook {
PA_CORE_HOOK_CARD_PROFILE_AVAILABLE_CHANGED,
PA_CORE_HOOK_PORT_AVAILABLE_CHANGED,
PA_CORE_HOOK_PORT_LATENCY_OFFSET_CHANGED,
+ PA_CORE_HOOK_SINK_LATENCY_OFFSET_CHANGED,
+ PA_CORE_HOOK_SOURCE_LATENCY_OFFSET_CHANGED,
PA_CORE_HOOK_DEFAULT_SINK_CHANGED,
PA_CORE_HOOK_DEFAULT_SOURCE_CHANGED,
PA_CORE_HOOK_MODULE_NEW,
diff --git a/src/pulsecore/sink.c b/src/pulsecore/sink.c
index 86656f6..f7b5183 100644
--- a/src/pulsecore/sink.c
+++ b/src/pulsecore/sink.c
@@ -120,6 +120,11 @@ void pa_sink_new_data_set_volume(pa_sink_new_data *data, const pa_cvolume *volum
data->volume = *volume;
}
+void pa_sink_new_data_set_latency_offset(pa_sink_new_data *data, int64_t latency_offset) {
+ pa_assert(data);
+ data->latency_offset = latency_offset;
+}
+
void pa_sink_new_data_set_muted(pa_sink_new_data *data, bool mute) {
pa_assert(data);
@@ -314,6 +319,11 @@ pa_sink* pa_sink_new(
else
s->port_latency_offset = 0;
+ if (data->latency_offset)
+ s->latency_offset = data->latency_offset;
+ else
+ s->latency_offset = 0;
+
s->save_volume = data->save_volume;
s->save_muted = data->save_muted;
@@ -346,6 +356,7 @@ pa_sink* pa_sink_new(
s->thread_info.volume_change_safety_margin = core->deferred_volume_safety_margin_usec;
s->thread_info.volume_change_extra_delay = core->deferred_volume_extra_delay_usec;
s->thread_info.port_latency_offset = s->port_latency_offset;
+ s->thread_info.latency_offset = s->latency_offset;
/* FIXME: This should probably be moved to pa_sink_put() */
pa_assert_se(pa_idxset_put(core->sinks, s, &s->index) >= 0);
@@ -1505,6 +1516,8 @@ pa_usec_t pa_sink_get_latency(pa_sink *s) {
pa_assert_se(pa_asyncmsgq_send(s->asyncmsgq, PA_MSGOBJECT(s), PA_SINK_MESSAGE_GET_LATENCY, &usec, 0, NULL) == 0);
+ /* Total latency offset is the sum of the port latency offset and the sink latency offset */
+
/* usec is unsigned, so check that the offset can be added to usec without
* underflowing. */
if (-s->port_latency_offset <= (int64_t) usec)
@@ -1512,6 +1525,12 @@ pa_usec_t pa_sink_get_latency(pa_sink *s) {
else
usec = 0;
+ /* Similarly checking for underflow */
+ if (-s->latency_offset <= (int64_t) usec)
+ usec += s->latency_offset;
+ else
+ usec = 0;
+
return usec;
}
@@ -1539,6 +1558,8 @@ pa_usec_t pa_sink_get_latency_within_thread(pa_sink *s) {
if (o->process_msg(o, PA_SINK_MESSAGE_GET_LATENCY, &usec, 0, NULL) < 0)
return -1;
+ /* Total latency offset is the sum of the port latency offset and the sink latency offset */
+
/* usec is unsigned, so check that the offset can be added to usec without
* underflowing. */
if (-s->thread_info.port_latency_offset <= (int64_t) usec)
@@ -1546,6 +1567,12 @@ pa_usec_t pa_sink_get_latency_within_thread(pa_sink *s) {
else
usec = 0;
+ /* Similarly checking for underflow */
+ if (-s->thread_info.latency_offset <= (int64_t) usec)
+ usec += s->thread_info.latency_offset;
+ else
+ usec = 0;
+
return usec;
}
@@ -2892,6 +2919,10 @@ int pa_sink_process_msg(pa_msgobject *o, int code, void *userdata, int64_t offse
s->thread_info.port_latency_offset = offset;
return 0;
+ case PA_SINK_MESSAGE_SET_LATENCY_OFFSET:
+ s->thread_info.latency_offset = offset;
+ return 0;
+
case PA_SINK_MESSAGE_GET_LATENCY:
case PA_SINK_MESSAGE_MAX:
;
@@ -3300,6 +3331,22 @@ void pa_sink_set_port_latency_offset(pa_sink *s, int64_t offset) {
}
/* Called from main context */
+void pa_sink_set_latency_offset(pa_sink *s, int64_t offset) {
+ pa_sink_assert_ref(s);
+ pa_assert_ctl_context();
+
+ s->latency_offset = offset;
+
+ if (PA_SINK_IS_LINKED(s->state))
+ pa_assert_se(pa_asyncmsgq_send(s->asyncmsgq, PA_MSGOBJECT(s), PA_SINK_MESSAGE_SET_LATENCY_OFFSET, NULL, offset, NULL) == 0);
+ else
+ s->thread_info.latency_offset = offset;
+
+ pa_subscription_post(s->core, PA_SUBSCRIPTION_EVENT_SINK|PA_SUBSCRIPTION_EVENT_CHANGE, s->index);
+ pa_hook_fire(&s->core->hooks[PA_CORE_HOOK_SINK_LATENCY_OFFSET_CHANGED], s);
+}
+
+/* Called from main context */
size_t pa_sink_get_max_rewind(pa_sink *s) {
size_t r;
pa_assert_ctl_context();
diff --git a/src/pulsecore/sink.h b/src/pulsecore/sink.h
index 06a8ee9..a7fa96f 100644
--- a/src/pulsecore/sink.h
+++ b/src/pulsecore/sink.h
@@ -111,9 +111,13 @@ struct pa_sink {
pa_device_port *active_port;
pa_atomic_t mixer_dirty;
- /* The latency offset is inherited from the currently active port */
+ /* This latency offset is inherited from the currently active port */
int64_t port_latency_offset;
+ /* This latency offset is specific to the sink and will be summed with the above to give
+ * the total latency offset */
+ int64_t latency_offset;
+
unsigned priority;
bool set_mute_in_progress;
@@ -284,6 +288,9 @@ struct pa_sink {
/* This latency offset is a direct copy from s->port_latency_offset */
int64_t port_latency_offset;
+ /* This latency offset is a direct copy from s->latency_offset */
+ int64_t latency_offset;
+
/* Delayed volume change events are queued here. The events
* are stored in expiration order. The one expiring next is in
* the head of the list. */
@@ -332,6 +339,7 @@ typedef enum pa_sink_message {
PA_SINK_MESSAGE_SET_PORT,
PA_SINK_MESSAGE_UPDATE_VOLUME_AND_MUTE,
PA_SINK_MESSAGE_SET_PORT_LATENCY_OFFSET,
+ PA_SINK_MESSAGE_SET_LATENCY_OFFSET,
PA_SINK_MESSAGE_MAX
} pa_sink_message_t;
@@ -351,6 +359,7 @@ typedef struct pa_sink_new_data {
pa_sample_spec sample_spec;
pa_channel_map channel_map;
uint32_t alternate_sample_rate;
+ int64_t latency_offset;
pa_cvolume volume;
bool muted:1;
@@ -373,6 +382,7 @@ void pa_sink_new_data_set_sample_spec(pa_sink_new_data *data, const pa_sample_sp
void pa_sink_new_data_set_channel_map(pa_sink_new_data *data, const pa_channel_map *map);
void pa_sink_new_data_set_alternate_sample_rate(pa_sink_new_data *data, const uint32_t alternate_sample_rate);
void pa_sink_new_data_set_volume(pa_sink_new_data *data, const pa_cvolume *volume);
+void pa_sink_new_data_set_latency_offset(pa_sink_new_data *data, int64_t latency_offset);
void pa_sink_new_data_set_muted(pa_sink_new_data *data, bool mute);
void pa_sink_new_data_set_port(pa_sink_new_data *data, const char *port);
void pa_sink_new_data_done(pa_sink_new_data *data);
@@ -418,6 +428,7 @@ unsigned pa_device_init_priority(pa_proplist *p);
int pa_sink_update_rate(pa_sink *s, uint32_t rate, bool passthrough);
void pa_sink_set_port_latency_offset(pa_sink *s, int64_t offset);
+void pa_sink_set_latency_offset(pa_sink *s, int64_t offset);
/* The returned value is supposed to be in the time domain of the sound card! */
pa_usec_t pa_sink_get_latency(pa_sink *s);
diff --git a/src/pulsecore/source.c b/src/pulsecore/source.c
index da64e6b..21bb4f8 100644
--- a/src/pulsecore/source.c
+++ b/src/pulsecore/source.c
@@ -111,6 +111,11 @@ void pa_source_new_data_set_volume(pa_source_new_data *data, const pa_cvolume *v
data->volume = *volume;
}
+void pa_source_new_data_set_latency_offset(pa_source_new_data *data, int64_t latency_offset) {
+ pa_assert(data);
+ data->latency_offset = latency_offset;
+}
+
void pa_source_new_data_set_muted(pa_source_new_data *data, bool mute) {
pa_assert(data);
@@ -302,6 +307,11 @@ pa_source* pa_source_new(
else
s->port_latency_offset = 0;
+ if (data->latency_offset)
+ s->latency_offset = data->latency_offset;
+ else
+ s->latency_offset = 0;
+
s->save_volume = data->save_volume;
s->save_muted = data->save_muted;
@@ -331,6 +341,7 @@ pa_source* pa_source_new(
s->thread_info.volume_change_safety_margin = core->deferred_volume_safety_margin_usec;
s->thread_info.volume_change_extra_delay = core->deferred_volume_extra_delay_usec;
s->thread_info.port_latency_offset = s->port_latency_offset;
+ s->thread_info.latency_offset = s->latency_offset;
/* FIXME: This should probably be moved to pa_source_put() */
pa_assert_se(pa_idxset_put(core->sources, s, &s->index) >= 0);
@@ -1096,6 +1107,8 @@ pa_usec_t pa_source_get_latency(pa_source *s) {
pa_assert_se(pa_asyncmsgq_send(s->asyncmsgq, PA_MSGOBJECT(s), PA_SOURCE_MESSAGE_GET_LATENCY, &usec, 0, NULL) == 0);
+ /* Total latency offset is the sum of the port latency offset and the sink latency offset */
+
/* usec is unsigned, so check that the offset can be added to usec without
* underflowing. */
if (-s->port_latency_offset <= (int64_t) usec)
@@ -1103,6 +1116,12 @@ pa_usec_t pa_source_get_latency(pa_source *s) {
else
usec = 0;
+ /* Similarly checking for underflow */
+ if (-s->latency_offset <= (int64_t) usec)
+ usec += s->latency_offset;
+ else
+ usec = 0;
+
return usec;
}
@@ -1130,6 +1149,8 @@ pa_usec_t pa_source_get_latency_within_thread(pa_source *s) {
if (o->process_msg(o, PA_SOURCE_MESSAGE_GET_LATENCY, &usec, 0, NULL) < 0)
return -1;
+ /* Total latency offset is the sum of the port latency offset and the sink latency offset */
+
/* usec is unsigned, so check that the offset can be added to usec without
* underflowing. */
if (-s->thread_info.port_latency_offset <= (int64_t) usec)
@@ -1137,6 +1158,12 @@ pa_usec_t pa_source_get_latency_within_thread(pa_source *s) {
else
usec = 0;
+ /* Similarly checking for underflow */
+ if (-s->thread_info.latency_offset <= (int64_t) usec)
+ usec += s->thread_info.latency_offset;
+ else
+ usec = 0;
+
return usec;
}
@@ -2243,6 +2270,10 @@ int pa_source_process_msg(pa_msgobject *object, int code, void *userdata, int64_
s->thread_info.port_latency_offset = offset;
return 0;
+ case PA_SOURCE_MESSAGE_SET_LATENCY_OFFSET:
+ s->thread_info.latency_offset = offset;
+ return 0;
+
case PA_SOURCE_MESSAGE_MAX:
;
}
@@ -2579,6 +2610,22 @@ void pa_source_set_port_latency_offset(pa_source *s, int64_t offset) {
}
/* Called from main thread */
+void pa_source_set_latency_offset(pa_source *s, int64_t offset) {
+ pa_source_assert_ref(s);
+ pa_assert_ctl_context();
+
+ s->latency_offset = offset;
+
+ if (PA_SOURCE_IS_LINKED(s->state))
+ pa_assert_se(pa_asyncmsgq_send(s->asyncmsgq, PA_MSGOBJECT(s), PA_SOURCE_MESSAGE_SET_LATENCY_OFFSET, NULL, offset, NULL) == 0);
+ else
+ s->thread_info.latency_offset = offset;
+
+ pa_subscription_post(s->core, PA_SUBSCRIPTION_EVENT_SOURCE|PA_SUBSCRIPTION_EVENT_CHANGE, s->index);
+ pa_hook_fire(&s->core->hooks[PA_CORE_HOOK_SOURCE_LATENCY_OFFSET_CHANGED], s);
+}
+
+/* Called from main thread */
size_t pa_source_get_max_rewind(pa_source *s) {
size_t r;
pa_assert_ctl_context();
diff --git a/src/pulsecore/source.h b/src/pulsecore/source.h
index 31cd158..42819c2 100644
--- a/src/pulsecore/source.h
+++ b/src/pulsecore/source.h
@@ -112,9 +112,13 @@ struct pa_source {
pa_device_port *active_port;
pa_atomic_t mixer_dirty;
- /* The latency offset is inherited from the currently active port */
+ /* This latency offset is inherited from the currently active port */
int64_t port_latency_offset;
+ /* This latency offset is specific to the sink and will be summed with the above to give
+ * the total latency offset */
+ int64_t latency_offset;
+
unsigned priority;
bool set_mute_in_progress;
@@ -226,6 +230,9 @@ struct pa_source {
/* This latency offset is a direct copy from s->port_latency_offset */
int64_t port_latency_offset;
+ /* This latency offset is a direct copy from s->latency_offset */
+ int64_t latency_offset;
+
/* Delayed volume change events are queued here. The events
* are stored in expiration order. The one expiring next is in
* the head of the list. */
@@ -270,6 +277,7 @@ typedef enum pa_source_message {
PA_SOURCE_MESSAGE_SET_PORT,
PA_SOURCE_MESSAGE_UPDATE_VOLUME_AND_MUTE,
PA_SOURCE_MESSAGE_SET_PORT_LATENCY_OFFSET,
+ PA_SOURCE_MESSAGE_SET_LATENCY_OFFSET,
PA_SOURCE_MESSAGE_MAX
} pa_source_message_t;
@@ -289,6 +297,7 @@ typedef struct pa_source_new_data {
pa_sample_spec sample_spec;
pa_channel_map channel_map;
uint32_t alternate_sample_rate;
+ int64_t latency_offset;
pa_cvolume volume;
bool muted:1;
@@ -311,6 +320,7 @@ void pa_source_new_data_set_sample_spec(pa_source_new_data *data, const pa_sampl
void pa_source_new_data_set_channel_map(pa_source_new_data *data, const pa_channel_map *map);
void pa_source_new_data_set_alternate_sample_rate(pa_source_new_data *data, const uint32_t alternate_sample_rate);
void pa_source_new_data_set_volume(pa_source_new_data *data, const pa_cvolume *volume);
+void pa_source_new_data_set_latency_offset(pa_source_new_data *data, int64_t latency_offset);
void pa_source_new_data_set_muted(pa_source_new_data *data, bool mute);
void pa_source_new_data_set_port(pa_source_new_data *data, const char *port);
void pa_source_new_data_done(pa_source_new_data *data);
@@ -351,6 +361,7 @@ void pa_source_update_flags(pa_source *s, pa_source_flags_t mask, pa_source_flag
/*** May be called by everyone, from main context */
void pa_source_set_port_latency_offset(pa_source *s, int64_t offset);
+void pa_source_set_latency_offset(pa_source *s, int64_t offset);
/* The returned value is supposed to be in the time domain of the sound card! */
pa_usec_t pa_source_get_latency(pa_source *s);
--
2.5.0
