core: add a seperate fixed_latency field for sinks/sources with fixed latency

src/pulsecore/cli-text.c

@@ -288,7 +288,11 @@ char *pa_sink_list_to_string(pa_core *c) {
                     (double) pa_sink_get_requested_latency(sink) / (double) PA_USEC_PER_MSEC,
                     (double) min_latency / PA_USEC_PER_MSEC,
                     (double) max_latency / PA_USEC_PER_MSEC);
-        }
+        } else
+            pa_strbuf_printf(
+                    s,
+                    "\tfixed latency: %0.2f ms\n",
+                    (double) pa_sink_get_requested_latency(sink) / PA_USEC_PER_MSEC);
 
         if (sink->card)
             pa_strbuf_printf(s, "\tcard: %u <%s>\n", sink->card->index, sink->card->name);
@@ -382,7 +386,11 @@ char *pa_source_list_to_string(pa_core *c) {
                     (double) pa_source_get_requested_latency(source) / PA_USEC_PER_MSEC,
                     (double) min_latency / PA_USEC_PER_MSEC,
                     (double) max_latency / PA_USEC_PER_MSEC);
-        }
+        } else
+            pa_strbuf_printf(
+                    s,
+                    "\tfixed latency: %0.2f ms\n",
+                    (double) pa_source_get_requested_latency(source) / PA_USEC_PER_MSEC);
 
         if (source->monitor_of)
             pa_strbuf_printf(s, "\tmonitor_of: %u\n", source->monitor_of->index);

src/pulsecore/sink-input.c

@@ -824,6 +824,9 @@ void pa_sink_input_update_max_request(pa_sink_input *i, size_t nbytes  /* in the
 pa_usec_t pa_sink_input_set_requested_latency_within_thread(pa_sink_input *i, pa_usec_t usec) {
     pa_sink_input_assert_ref(i);
 
+    if (!(i->sink->flags & PA_SINK_DYNAMIC_LATENCY))
+        usec = i->sink->fixed_latency;
+
     if (usec != (pa_usec_t) -1)
         usec =  PA_CLAMP(usec, i->sink->thread_info.min_latency, i->sink->thread_info.max_latency);
 
@@ -835,8 +838,6 @@ pa_usec_t pa_sink_input_set_requested_latency_within_thread(pa_sink_input *i, pa
 
 /* Called from main context */
 pa_usec_t pa_sink_input_set_requested_latency(pa_sink_input *i, pa_usec_t usec) {
-    pa_usec_t min_latency, max_latency;
-
     pa_sink_input_assert_ref(i);
 
     if (PA_SINK_INPUT_IS_LINKED(i->state) && i->sink) {
@@ -848,11 +849,15 @@ pa_usec_t pa_sink_input_set_requested_latency(pa_sink_input *i, pa_usec_t usec)
      * we have to touch the thread info data directly */
 
     if (i->sink) {
-        pa_sink_get_latency_range(i->sink, &min_latency, &max_latency);
+        if (!(i->sink->flags & PA_SINK_DYNAMIC_LATENCY))
+            usec = i->sink->fixed_latency;
 
-        if (usec != (pa_usec_t) -1)
+        if (usec != (pa_usec_t) -1) {
+            pa_usec_t min_latency, max_latency;
+            pa_sink_get_latency_range(i->sink, &min_latency, &max_latency);
             usec =  PA_CLAMP(usec, min_latency, max_latency);
         }
+    }
 
     i->thread_info.requested_sink_latency = usec;
 

src/pulsecore/sink.c

@@ -50,6 +50,7 @@
 #define MIX_BUFFER_LENGTH (PA_PAGE_SIZE)
 #define ABSOLUTE_MIN_LATENCY (500)
 #define ABSOLUTE_MAX_LATENCY (10*PA_USEC_PER_SEC)
+#define DEFAULT_FIXED_LATENCY (250*PA_USEC_PER_MSEC)
 
 static PA_DEFINE_CHECK_TYPE(pa_sink, pa_msgobject);
 
@@ -208,6 +209,8 @@ pa_sink* pa_sink_new(
     s->muted = data->muted;
     s->refresh_volume = s->refresh_muted = FALSE;
 
+    s->fixed_latency = flags & PA_SINK_DYNAMIC_LATENCY ? 0 : DEFAULT_FIXED_LATENCY;
+
     reset_callbacks(s);
     s->userdata = NULL;
 
@@ -363,8 +366,13 @@ void pa_sink_put(pa_sink* s) {
     if (s->flags & PA_SINK_LATENCY)
         s->monitor_source->flags |= PA_SOURCE_LATENCY;
 
-    if (s->flags & PA_SINK_DYNAMIC_LATENCY)
+    if (s->flags & PA_SINK_DYNAMIC_LATENCY) {
         s->monitor_source->flags |= PA_SOURCE_DYNAMIC_LATENCY;
+        s->fixed_latency = 0;
+    } else if (s->fixed_latency <= 0)
+        s->fixed_latency = DEFAULT_FIXED_LATENCY;
+
+    s->monitor_source->fixed_latency = s->fixed_latency;
 
     pa_assert_se(sink_set_state(s, PA_SINK_IDLE) == 0);
 
@@ -1824,6 +1832,9 @@ pa_usec_t pa_sink_get_requested_latency_within_thread(pa_sink *s) {
 
     pa_sink_assert_ref(s);
 
+    if (!(s->flags & PA_SINK_DYNAMIC_LATENCY))
+        return PA_CLAMP(s->fixed_latency, s->thread_info.min_latency, s->thread_info.max_latency);
+
     if (s->thread_info.requested_latency_valid)
         return s->thread_info.requested_latency;
 
@@ -1839,13 +1850,8 @@ pa_usec_t pa_sink_get_requested_latency_within_thread(pa_sink *s) {
         (result == (pa_usec_t) -1 || result > monitor_latency))
         result = monitor_latency;
 
-    if (result != (pa_usec_t) -1) {
+    if (result != (pa_usec_t) -1)
-        if (result > s->thread_info.max_latency)
+        result = PA_CLAMP(result, s->thread_info.min_latency, s->thread_info.max_latency);
-            result = s->thread_info.max_latency;
-
-        if (result < s->thread_info.min_latency)
-            result = s->thread_info.min_latency;
-    }
 
     s->thread_info.requested_latency = result;
     s->thread_info.requested_latency_valid = TRUE;
@@ -1934,6 +1940,9 @@ void pa_sink_invalidate_requested_latency(pa_sink *s) {
 
     pa_sink_assert_ref(s);
 
+    if (!(s->flags & PA_SINK_DYNAMIC_LATENCY))
+        return;
+
     s->thread_info.requested_latency_valid = FALSE;
 
     if (PA_SINK_IS_LINKED(s->thread_info.state)) {

src/pulsecore/sink.h

@@ -86,6 +86,8 @@ struct pa_sink {
 
     pa_memchunk silence;
 
+    pa_usec_t fixed_latency; /* for sinks with PA_SINK_DYNAMIC_LATENCY this is 0 */
+
     /* Called when the main loop requests a state change. Called from
      * main loop context. If returns -1 the state change will be
      * inhibited */

src/pulsecore/source-output.c

@@ -520,6 +520,9 @@ void pa_source_output_update_max_rewind(pa_source_output *o, size_t nbytes  /* i
 pa_usec_t pa_source_output_set_requested_latency_within_thread(pa_source_output *o, pa_usec_t usec) {
     pa_source_output_assert_ref(o);
 
+    if (!(o->source->flags & PA_SOURCE_DYNAMIC_LATENCY))
+        usec = o->source->fixed_latency;
+
     if (usec != (pa_usec_t) -1)
         usec = PA_CLAMP(usec, o->source->thread_info.min_latency, o->source->thread_info.max_latency);
 
@@ -531,8 +534,6 @@ pa_usec_t pa_source_output_set_requested_latency_within_thread(pa_source_output
 
 /* Called from main context */
 pa_usec_t pa_source_output_set_requested_latency(pa_source_output *o, pa_usec_t usec) {
-    pa_usec_t min_latency, max_latency;
-
     pa_source_output_assert_ref(o);
 
     if (PA_SOURCE_OUTPUT_IS_LINKED(o->state) && o->source) {
@@ -544,11 +545,15 @@ pa_usec_t pa_source_output_set_requested_latency(pa_source_output *o, pa_usec_t
      * have to touch the thread info data directly */
 
     if (o->source) {
-        pa_source_get_latency_range(o->source, &min_latency, &max_latency);
+        if (!(o->source->flags & PA_SOURCE_DYNAMIC_LATENCY))
+            usec = o->source->fixed_latency;
 
-        if (usec != (pa_usec_t) -1)
+        if (usec != (pa_usec_t) -1) {
+            pa_usec_t min_latency, max_latency;
+            pa_source_get_latency_range(o->source, &min_latency, &max_latency);
             usec = PA_CLAMP(usec, min_latency, max_latency);
         }
+    }
 
     o->thread_info.requested_source_latency = usec;
 

src/pulsecore/source.c

@@ -43,6 +43,7 @@
 
 #define ABSOLUTE_MIN_LATENCY (500)
 #define ABSOLUTE_MAX_LATENCY (10*PA_USEC_PER_SEC)
+#define DEFAULT_FIXED_LATENCY (250*PA_USEC_PER_MSEC)
 
 static PA_DEFINE_CHECK_TYPE(pa_source, pa_msgobject);
 
@@ -199,6 +200,8 @@ pa_source* pa_source_new(
     s->muted = data->muted;
     s->refresh_volume = s->refresh_muted = FALSE;
 
+    s->fixed_latency = flags & PA_SOURCE_DYNAMIC_LATENCY ? 0 : DEFAULT_FIXED_LATENCY;
+
     reset_callbacks(s);
     s->userdata = NULL;
 
@@ -303,8 +306,7 @@ void pa_source_put(pa_source *s) {
     /* The following fields must be initialized properly when calling _put() */
     pa_assert(s->asyncmsgq);
     pa_assert(s->rtpoll);
-    pa_assert(!s->thread_info.min_latency || !s->thread_info.max_latency ||
+    pa_assert(s->thread_info.min_latency <= s->thread_info.max_latency);
-              s->thread_info.min_latency <= s->thread_info.max_latency);
 
     if (!(s->flags & PA_SOURCE_HW_VOLUME_CTRL)) {
         s->flags |= PA_SOURCE_DECIBEL_VOLUME;
@@ -316,6 +318,11 @@ void pa_source_put(pa_source *s) {
     if (s->flags & PA_SOURCE_DECIBEL_VOLUME)
         s->n_volume_steps = PA_VOLUME_NORM+1;
 
+    if (s->flags & PA_SOURCE_DYNAMIC_LATENCY)
+        s->fixed_latency = 0;
+    else if (s->fixed_latency <= 0)
+        s->fixed_latency = DEFAULT_FIXED_LATENCY;
+
     pa_assert_se(source_set_state(s, PA_SOURCE_IDLE) == 0);
 
     pa_subscription_post(s->core, PA_SUBSCRIPTION_EVENT_SOURCE | PA_SUBSCRIPTION_EVENT_NEW, s->index);
@@ -1096,6 +1103,9 @@ pa_usec_t pa_source_get_requested_latency_within_thread(pa_source *s) {
 
     pa_source_assert_ref(s);
 
+    if (!(s->flags & PA_SOURCE_DYNAMIC_LATENCY))
+        return PA_CLAMP(s->fixed_latency, s->thread_info.min_latency, s->thread_info.max_latency);
+
     if (s->thread_info.requested_latency_valid)
         return s->thread_info.requested_latency;
 
@@ -1105,13 +1115,8 @@ pa_usec_t pa_source_get_requested_latency_within_thread(pa_source *s) {
             (result == (pa_usec_t) -1 || result > o->thread_info.requested_source_latency))
             result = o->thread_info.requested_source_latency;
 
-    if (result != (pa_usec_t) -1) {
+    if (result != (pa_usec_t) -1)
-        if (s->thread_info.max_latency > 0 && result > s->thread_info.max_latency)
+        result = PA_CLAMP(result, s->thread_info.min_latency, s->thread_info.max_latency);
-            result = s->thread_info.max_latency;
-
-        if (s->thread_info.min_latency > 0 && result < s->thread_info.min_latency)
-            result = s->thread_info.min_latency;
-    }
 
     s->thread_info.requested_latency = result;
     s->thread_info.requested_latency_valid = TRUE;
@@ -1121,7 +1126,7 @@ pa_usec_t pa_source_get_requested_latency_within_thread(pa_source *s) {
 
 /* Called from main thread */
 pa_usec_t pa_source_get_requested_latency(pa_source *s) {
-    pa_usec_t usec;
+    pa_usec_t usec = 0;
 
     pa_source_assert_ref(s);
     pa_assert(PA_SOURCE_IS_LINKED(s->state));
@@ -1169,6 +1174,9 @@ void pa_source_invalidate_requested_latency(pa_source *s) {
 
     pa_source_assert_ref(s);
 
+    if (!(s->flags & PA_SOURCE_DYNAMIC_LATENCY))
+        return;
+
     s->thread_info.requested_latency_valid = FALSE;
 
     if (PA_SOURCE_IS_LINKED(s->thread_info.state)) {

src/pulsecore/source.h

@@ -87,6 +87,8 @@ struct pa_source {
 
     pa_memchunk silence;
 
+    pa_usec_t fixed_latency; /* for sources with PA_SOURCE_DYNAMIC_LATENCY this is 0 */
+
     /* Called when the main loop requests a state change. Called from
      * main loop context. If returns -1 the state change will be
      * inhibited */