[pulseaudio-discuss] [PATCH] echo-cancel: Don't skip canceller when sink is inactive

[arun at accosted.net]

From: Arun Raghavan <git at arunraghavan.net>

This forces the canceller engine to be invoked even if playback is not
currently active. We need to do this for cases where the engine provides
additional processing that is independent of playback, such as noise
suppression and AGC.
---
 src/modules/echo-cancel/module-echo-cancel.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/src/modules/echo-cancel/module-echo-cancel.c b/src/modules/echo-cancel/module-echo-cancel.c
index cd539a4..484281f 100644
--- a/src/modules/echo-cancel/module-echo-cancel.c
+++ b/src/modules/echo-cancel/module-echo-cancel.c
@@ -794,7 +794,7 @@ static void do_push_drift_comp(struct userdata *u) {
 
 /* This one's simpler than the drift compensation case -- we just iterate over
  * the capture buffer, and pass the canceller blocksize bytes of playback and
- * capture data.
+ * capture data. If playback is currently inactive, we just push silence.
  *
  * Called from source I/O thread context. */
 static void do_push(struct userdata *u) {
@@ -880,12 +880,6 @@ static void source_output_push_cb(pa_source_output *o, const pa_memchunk *chunk)
         return;
     }
 
-    if (PA_UNLIKELY(u->source->thread_info.state != PA_SOURCE_RUNNING ||
-                    u->sink->thread_info.state != PA_SINK_RUNNING)) {
-        pa_source_post(u->source, chunk);
-        return;
-    }
-
     /* handle queued messages, do any message sending of our own */
     while (pa_asyncmsgq_process_one(u->asyncmsgq) > 0)
         ;
@@ -942,8 +936,8 @@ static void source_output_push_cb(pa_source_output *o, const pa_memchunk *chunk)
         u->sink_skip -= to_skip;
     }
 
-    /* process and push out samples */
-    if (u->ec->params.drift_compensation)
+    /* process and push out samples, do drift compensation only if the sink is actually running */
+    if (u->ec->params.drift_compensation && u->sink->thread_info.state == PA_SINK_RUNNING)
         do_push_drift_comp(u);
     else
         do_push(u);
-- 
2.5.0