X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=nageru%2Fmixer.cpp;h=ce8a73237fd4a838ee85ca0c307663d6e3c9edda;hb=0f5b8fd8420a450f5994d5f535fdce84dbb10093;hp=01f6abede373918a723629b9ccc0d379cd6911bc;hpb=30c0b7ebd9954339486f1286b82df4776e1bc9b4;p=nageru

diff --git a/nageru/mixer.cpp b/nageru/mixer.cpp
index 01f6abe..ce8a732 100644
--- a/nageru/mixer.cpp
+++ b/nageru/mixer.cpp
@@ -234,6 +234,16 @@ void JitterHistory::unregister_metrics(const vector<pair<string, string>> &label
 
 void JitterHistory::frame_arrived(steady_clock::time_point now, int64_t frame_duration, size_t dropped_frames)
 {
+	if (frame_duration != last_duration) {
+		// If the frame rate changed, the input clock is also going to change,
+		// so our historical data doesn't make much sense anymore.
+		// Also, format changes typically introduce blips that are not representative
+		// of the typical frame stream. (We make the assumption that format changes
+		// don't happen all the time in regular use; if they did, we should probably
+		// rather keep the history so that we take jitter they may introduce into account.)
+		clear();
+		last_duration = frame_duration;
+	}
 	if (expected_timestamp > steady_clock::time_point::min()) {
 		expected_timestamp += dropped_frames * nanoseconds(frame_duration * 1000000000 / TIMEBASE);
 		double jitter_seconds = fabs(duration<double>(expected_timestamp - now).count());
@@ -277,7 +287,7 @@ void QueueLengthPolicy::unregister_metrics(const vector<pair<string, string>> &l
 }
 
 void QueueLengthPolicy::update_policy(steady_clock::time_point now,
-                                      steady_clock::time_point expected_next_frame,
+                                      steady_clock::time_point expected_next_input_frame,
                                       int64_t input_frame_duration,
                                       int64_t master_frame_duration,
                                       double max_input_card_jitter_seconds,
@@ -288,7 +298,7 @@ void QueueLengthPolicy::update_policy(steady_clock::time_point now,
 
 	// Figure out when we can expect the next frame for this card, assuming
 	// worst-case jitter (ie., the frame is maximally late).
-	double seconds_until_next_frame = max(duration<double>(expected_next_frame - now).count() + max_input_card_jitter_seconds, 0.0);
+	double seconds_until_next_frame = max(duration<double>(expected_next_input_frame - now).count() + max_input_card_jitter_seconds, 0.0);
 
 	// How many times are the master card expected to tick in that time?
 	// We assume the master clock has worst-case jitter but not any rate