[pulseaudio-discuss] [PATCH 7/7] tunnel-new: Increase latency on underflow/overflow

[Pierre Ossman]

We need to adapt to communication latencies between us and the next
server. Do this the simplest way possible by increasing the minimum
latency whenever we've hit an underflow/overflow.

Signed-off-by: Pierre Ossman <ossman at cendio.se>
---
 src/modules/module-tunnel-sink-new.c   | 16 ++++++++++++++++
 src/modules/module-tunnel-source-new.c | 15 +++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/src/modules/module-tunnel-sink-new.c
b/src/modules/module-tunnel-sink-new.c index ebaa7f3..78c01cc 100644
--- a/src/modules/module-tunnel-sink-new.c
+++ b/src/modules/module-tunnel-sink-new.c
@@ -62,6 +62,7 @@ PA_MODULE_USAGE(
 /* FIXME: Default latency to use until we have proper rewind support.
  *        Probably best to keep this in sync with
DEFAULT_FIXED_LATENCY. */ #define DEFAULT_LATENCY_USEC
(250*PA_USEC_PER_MSEC) +#define LATENCY_INC_MAX_STEP_USEC
(10*PA_USEC_PER_MSEC) #define TUNNEL_THREAD_FAILED_MAINLOOP 1
 
 static void stream_state_cb(pa_stream *stream, void *userdata);
@@ -307,7 +308,22 @@ static void stream_moved_callback(pa_stream
*stream, void *userdata) { 
 /* called when the server experiences an underrun of our buffer */
 static void stream_underflow_callback(pa_stream *stream, void
*userdata) {
+    pa_usec_t old_min_latency, new_min_latency;
+    struct userdata *u = userdata;
+    pa_assert(u);
+
     pa_log_info("Server signalled buffer underrun.");
+
+    old_min_latency = u->sink->thread_info.min_latency;
+    new_min_latency = PA_MIN(old_min_latency * 2, old_min_latency +
LATENCY_INC_MAX_STEP_USEC);
+    new_min_latency = PA_MIN(new_min_latency,
u->sink->thread_info.max_latency); +
+    if (old_min_latency != new_min_latency) {
+        pa_log_info("Increasing minimal latency to %0.2f ms",
+                    (double) new_min_latency / PA_USEC_PER_MSEC);
+
+        pa_sink_set_latency_range_within_thread(u->sink,
new_min_latency, u->sink->thread_info.max_latency);
+    }
 }
 
 /* called when the server experiences an overrun of our buffer */
diff --git a/src/modules/module-tunnel-source-new.c
b/src/modules/module-tunnel-source-new.c index e46dda2..99149c3 100644
--- a/src/modules/module-tunnel-source-new.c
+++ b/src/modules/module-tunnel-source-new.c
@@ -59,6 +59,7 @@ PA_MODULE_USAGE(
         "cookie=<cookie file path>"
         );
 
+#define LATENCY_INC_MAX_STEP_USEC (10*PA_USEC_PER_MSEC)
 #define TUNNEL_THREAD_FAILED_MAINLOOP 1
 
 static void stream_state_cb(pa_stream *stream, void *userdata);
@@ -176,6 +177,7 @@ static void read_new_samples(struct userdata *u) {
             pa_memblock_unref_fixed(memchunk.memblock);
         } else {
             size_t bytes_to_generate = nbytes;
+            pa_usec_t old_min_latency, new_min_latency;
 
             /* we have a hole. generate silence */
             memchunk = u->source->silence;
@@ -190,6 +192,19 @@ static void read_new_samples(struct userdata *u) {
             }
 
             pa_memblock_unref(memchunk.memblock);
+
+            /* there is no overflow callback so we're just going to
have
+             * to assume that a hole means an overflow occured */
+            old_min_latency = u->source->thread_info.min_latency;
+            new_min_latency = PA_MIN(old_min_latency * 2,
old_min_latency + LATENCY_INC_MAX_STEP_USEC);
+            new_min_latency = PA_MIN(new_min_latency,
u->source->thread_info.max_latency); +
+            if (old_min_latency != new_min_latency) {
+                pa_log_info("Increasing minimal latency to %0.2f ms",
+                            (double) new_min_latency /
PA_USEC_PER_MSEC); +
+                pa_source_set_latency_range_within_thread(u->source,
new_min_latency, u->source->thread_info.max_latency);
+            }
         }
 
         pa_stream_drop(u->stream);
-- 
2.5.5