[PATCH v2] rtp-send: Add "allow_suspending_on_idle" module argument

[tanu.kaskinen@xxxxxxxxxxxxxxx (Tanu Kaskinen)]

Some people want module-rtp-send to send silence when the sink that is
monitored goes idle, and some people want module-rtp-send to pause the
RTP stream to avoid unnecessary bandwidth consumption.
---
 src/modules/rtp/module-rtp-send.c | 63 ++++++++++++++++++++++++++++++++++++++-
 1 file changed, 62 insertions(+), 1 deletion(-)

diff --git a/src/modules/rtp/module-rtp-send.c b/src/modules/rtp/module-rtp-send.c
index 454e781..a2bc395 100644
--- a/src/modules/rtp/module-rtp-send.c
+++ b/src/modules/rtp/module-rtp-send.c
@@ -68,7 +68,8 @@ PA_MODULE_USAGE(
         "port=<port number> "
         "mtu=<maximum transfer unit> "
         "loop=<loopback to local host?> "
-        "ttl=<ttl value>"
+        "ttl=<ttl value> "
+        "allow_suspending_on_idle=<always|never|only_with_monitor_sources>"
 );
 
 #define DEFAULT_PORT 46000
@@ -92,9 +93,16 @@ static const char* const valid_modargs[] = {
     "mtu" ,
     "loop",
     "ttl",
+    "allow_suspending_on_idle",
     NULL
 };
 
+enum allow_suspending_on_idle {
+    ALLOW_SUSPENDING_ON_IDLE_ALWAYS,
+    ALLOW_SUSPENDING_ON_IDLE_NEVER,
+    ALLOW_SUSPENDING_ON_IDLE_ONLY_WITH_MONITOR_SOURCES
+};
+
 struct userdata {
     pa_module *module;
 
@@ -106,6 +114,8 @@ struct userdata {
     size_t mtu;
 
     pa_time_event *sap_event;
+
+    enum allow_suspending_on_idle allow_suspending_on_idle;
 };
 
 /* Called from I/O thread context */
@@ -139,6 +149,39 @@ static void source_output_push_cb(pa_source_output *o, const pa_memchunk *chunk)
     pa_rtp_send(&u->rtp_context, u->mtu, u->memblockq);
 }
 
+static pa_source_output_flags_t get_dont_inhibit_auto_suspend_flag(pa_source *source,
+                                                                   enum allow_suspending_on_idle allow_suspending_on_idle) {
+    pa_assert(source);
+
+    switch (allow_suspending_on_idle) {
+        case ALLOW_SUSPENDING_ON_IDLE_ALWAYS:
+            return PA_SOURCE_OUTPUT_DONT_INHIBIT_AUTO_SUSPEND;
+
+        case ALLOW_SUSPENDING_ON_IDLE_NEVER:
+            return 0;
+
+        case ALLOW_SUSPENDING_ON_IDLE_ONLY_WITH_MONITOR_SOURCES:
+            return source->monitor_of ? PA_SOURCE_OUTPUT_DONT_INHIBIT_AUTO_SUSPEND : 0;
+    }
+
+    pa_assert_not_reached();
+}
+
+/* Called from the main thread. */
+static void source_output_moving_cb(pa_source_output *o, pa_source *dest) {
+    struct userdata *u;
+
+    pa_assert(o);
+
+    u = o->userdata;
+
+    if (!dest)
+        return;
+
+    o->flags &= ~PA_SOURCE_OUTPUT_DONT_INHIBIT_AUTO_SUSPEND;
+    o->flags |= get_dont_inhibit_auto_suspend_flag(dest, u->allow_suspending_on_idle);
+}
+
 /* Called from main context */
 static void source_output_kill_cb(pa_source_output* o) {
     struct userdata *u;
@@ -188,6 +231,8 @@ int pa__init(pa_module*m) {
     socklen_t k;
     char hn[128], *n;
     bool loop = false;
+    enum allow_suspending_on_idle allow_suspending_on_idle = ALLOW_SUSPENDING_ON_IDLE_ONLY_WITH_MONITOR_SOURCES;
+    const char *allow_suspending_on_idle_str;
     pa_source_output_new_data data;
 
     pa_assert(m);
@@ -207,6 +252,19 @@ int pa__init(pa_module*m) {
         goto fail;
     }
 
+    if ((allow_suspending_on_idle_str = pa_modargs_get_value(ma, "allow_suspending_on_idle", NULL))) {
+        if (pa_streq(allow_suspending_on_idle_str, "always"))
+            allow_suspending_on_idle = ALLOW_SUSPENDING_ON_IDLE_ALWAYS;
+        else if (pa_streq(allow_suspending_on_idle_str, "never"))
+            allow_suspending_on_idle = ALLOW_SUSPENDING_ON_IDLE_NEVER;
+        else if (pa_streq(allow_suspending_on_idle_str, "only_with_monitor_sources"))
+            allow_suspending_on_idle = ALLOW_SUSPENDING_ON_IDLE_ONLY_WITH_MONITOR_SOURCES;
+        else {
+            pa_log("Failed to parse \"allow_suspending_on_idle\" parameter.");
+            goto fail;
+        }
+    }
+
     ss = s->sample_spec;
     pa_rtp_sample_spec_fixup(&ss);
     cm = s->channel_map;
@@ -377,6 +435,7 @@ int pa__init(pa_module*m) {
     pa_source_output_new_data_set_source(&data, s, false);
     pa_source_output_new_data_set_sample_spec(&data, &ss);
     pa_source_output_new_data_set_channel_map(&data, &cm);
+    data.flags |= get_dont_inhibit_auto_suspend_flag(s, allow_suspending_on_idle);
 
     pa_source_output_new(&o, m->core, &data);
     pa_source_output_new_data_done(&data);
@@ -388,6 +447,7 @@ int pa__init(pa_module*m) {
 
     o->parent.process_msg = source_output_process_msg;
     o->push = source_output_push_cb;
+    o->moving = source_output_moving_cb;
     o->kill = source_output_kill_cb;
 
     pa_log_info("Configured source latency of %llu ms.",
@@ -440,6 +500,7 @@ int pa__init(pa_module*m) {
     pa_sap_send(&u->sap_context, 0);
 
     u->sap_event = pa_core_rttime_new(m->core, pa_rtclock_now() + SAP_INTERVAL, sap_event_cb, u);
+    u->allow_suspending_on_idle = allow_suspending_on_idle;
 
     pa_source_output_put(u->source_output);
 
-- 
1.8.3.1