Fix a thread race on the jitter history, potentially leading to crashes.

diff --git a/mixer.cpp b/mixer.cpp
index 31277f1cd87af1bf2e03a67a1f169dcdf8f8c03a..9c07dc5002b09c6d9cf6b99648e889c0c9b93b37 100644 (file)
--- a/mixer.cpp
+++ b/mixer.cpp
@@ -738,11 +738,6 @@ void Mixer::bm_frame(unsigned card_index, uint16_t timecode,
 
        card->last_timecode = timecode;
 
-       // Calculate jitter for this card here. We do it on arrival so that we
-       // make sure every frame counts, even the dropped ones -- and it will also
-       // make sure the jitter number is as recent as possible, should it change.
-       card->jitter_history.frame_arrived(video_frame.received_timestamp, frame_length, dropped_frames);
-
        PBOFrameAllocator::Userdata *userdata = (PBOFrameAllocator::Userdata *)video_frame.userdata;
 
        size_t cbcr_width, cbcr_height, cbcr_offset, y_offset;
@@ -786,8 +781,9 @@ void Mixer::bm_frame(unsigned card_index, uint16_t timecode,
                        new_frame.dropped_frames = dropped_frames;
                        new_frame.received_timestamp = video_frame.received_timestamp;
                        card->new_frames.push_back(move(new_frame));
-                       card->new_frames_changed.notify_all();
+                       card->jitter_history.frame_arrived(video_frame.received_timestamp, frame_length, dropped_frames);
                }
+               card->new_frames_changed.notify_all();
                return;
        }
 
@@ -911,8 +907,9 @@ void Mixer::bm_frame(unsigned card_index, uint16_t timecode,
                        new_frame.dropped_frames = dropped_frames;
                        new_frame.received_timestamp = video_frame.received_timestamp;  // Ignore the audio timestamp.
                        card->new_frames.push_back(move(new_frame));
-                       card->new_frames_changed.notify_all();
+                       card->jitter_history.frame_arrived(video_frame.received_timestamp, frame_length, dropped_frames);
                }
+               card->new_frames_changed.notify_all();
        }
 }