...

A first subscriber issue

Before WCS build 5.2.1760 RTSP streams may start to play with a huge delay for the first subscriber. This was due to key frames missing caused by subscriber thread starting after publisher thread. Since build 5.2.1760 the behavior was changed: publisher thread starts after subscriber thread. This may be reverted if necessary by the following parameter

agent_use_subscriber_listener=false

Stream timestamp fix

In some RTSP streams a frame timestamps may be in wrong order, for example two subsequent frames may have the same timestamp. Such stream may not be displayed or periodically display a gray square while playing via WebRTC. Since build 5.2.1794 the following parameter is availbel to fix a broken timestamps

jitter_buffer_attempt_to_correct_broken_timestamp=true

In this case RTSP capturing client log may contain a messages as follows

Non-monotonous timestamp in input stream; previous: 453424, current: 453424; changing to 453425. This may result in incorrect timestamps in the output

and the problem stream should play normally.

Known issues

...

streams_synchronization=camera1/-21800;camera2/2079600704

Solution: in build before 5.2.1775 increase synchronization buffers for audio and video tracks

audio_incoming_buffer_size=100
video_incoming_buffer_size=100

since build 5.2.1775 increase force synchronization timeout for audio and video tracks

video_force_sync_timeout=1000
audio_force_sync_timeout=1000