Use pacing info in ProbeBitrateEstimator to validate probe results.

webrtc/modules/congestion_controller/probe_bitrate_estimator.cc

Index: webrtc/modules/congestion_controller/probe_bitrate_estimator.cc
diff --git a/webrtc/modules/congestion_controller/probe_bitrate_estimator.cc b/webrtc/modules/congestion_controller/probe_bitrate_estimator.cc
index 0a48a2ee3883621a494341b2202bda27fd25835d..0ffb9e8cdc85532ad705839d800cc4b7bbdc6ea9 100644
--- a/webrtc/modules/congestion_controller/probe_bitrate_estimator.cc
+++ b/webrtc/modules/congestion_controller/probe_bitrate_estimator.cc
@@ -17,7 +17,10 @@
 
 namespace {
 // The minumum number of probes we need for a valid cluster.

[Sergey Ulanov, 2017/03/08 22:12:20]

Update this comment (e.g. "Portion of successful probes in a cluster for a valid
probe.")?

[philipel, 2017/03/09 11:47:41]

Done.

-constexpr int kMinNumProbesValidCluster = 4;
+constexpr float kMinReceivedProbesRatio = 4.0 / 5.0;

[Sergey Ulanov, 2017/03/08 22:12:20]

0.8?

[philipel, 2017/03/09 11:47:41]

Changed to int instead.

+
+// The minumum number of bytes we need for a valid cluster.

[Sergey Ulanov, 2017/03/08 22:12:20]

rephrase this comment as well please. It's a ratio, not number of bytes.

[philipel, 2017/03/09 11:47:41]

Done.

+constexpr float kMinReceivedBytesRatio = 4.0 / 5.0;
 
 // The maximum (receive rate)/(send rate) ratio for a valid estimate.
 constexpr float kValidRatio = 2.0f;
@@ -63,7 +66,15 @@ int ProbeBitrateEstimator::HandleProbeAndEstimateBitrate(
   cluster->size_total += payload_size_bits;
   cluster->num_probes += 1;
 
-  if (cluster->num_probes < kMinNumProbesValidCluster)
+  RTC_DCHECK_GT(packet_info.pacing_info.probe_cluster_min_probes, 0);
+  RTC_DCHECK_GT(packet_info.pacing_info.probe_cluster_min_bytes, 0);
+
+  int min_probes =
+      static_cast<int>(packet_info.pacing_info.probe_cluster_min_probes *

[terelius, 2017/03/08 15:55:11]

This might not be rounded correctly. kMinReceivedProbesRatio is not exactly
representable as a float.

[Sergey Ulanov, 2017/03/08 22:12:20]

maybe use integer percentage value (4/5 = 80%)? Then this calculation can be
done without float.

[philipel, 2017/03/09 11:47:41]

True, switched to int as Sergey suggested.

[philipel, 2017/03/09 11:47:41]

Good idea, implemented!

+                       kMinReceivedProbesRatio);
+  int min_bytes = static_cast<int>(

[terelius, 2017/03/08 15:55:11]

This might not be rounded correctly. kMinReceivedBytesRatio is not exactly
representable as a float.

+      packet_info.pacing_info.probe_cluster_min_bytes * kMinReceivedBytesRatio);
+  if (cluster->num_probes < min_probes || cluster->size_total < min_bytes * 8)
     return -1;
 
   float send_interval_ms = cluster->last_send_ms - cluster->first_send_ms;