Question / Help OBS Streaming and Recording choppy, but no indication during stream.

[lynch_se]

Hi!

As the headline says.... I had a live-stream with OBS with one camera with SDI thru a BlackMagic Recorder ( the little gray box) and a HDMI source from a computer.
Everything has worked perfectly for about a year or so with no problems. But this last time things went bad. No indication in OBS about dropping frames or anything. All that was visible was a very high CPU-load, about 97%. But as nothing else screamed that things where going badly I didn't think much of it, until it was all over. We had had some complaints from viewers that saw the choppy steam. But they thought it was a "internet"-thing. So did I, until I watched the recorded file. That was just as choppy.

Both the stream and the recorded file was in the same bad condition. But the sound was perfect. And the movie-files we played during the live-stream turned out okay without choppiness. We had to re-record everything offline again to have a recorded file. And this time things worked.

So my question to all of you is: What could have caused this?

I have attached the log file for that day.
Our live-stream started at: 19:50
The highlight is: 20:27:43.910: Video stopped, number of skipped frames due to encoding lag: 25468/56328 (45.2%)

Thanks in advance!

 

[Narcogen]

11:01:31.712: YUV mode: 709/Full

Change that to 709/Partial. You're increasing load and decreasing quality.

https://obsproject.com/forum/resour...t-color-range-settings-guide-test-charts.442/

At one point in this session, you went from slight, occasional CPU overload to absolute nightmare:

17:07:06.664: Video stopped, number of skipped frames due to encoding lag: 4/412 (1.0%)
20:27:43.910: Video stopped, number of skipped frames due to encoding lag: 25468/56328 (45.2%)

You are using your CPU to encode. If it goes and stays much about 80% utilization, you're likely to lose some frames. If it gets above 95% utilization, you are going to have what you have here-- dropped almost half the frames.

Turn on the Status display row at the bottom of the main window, or open the Stats pane. It will warn you if this happens.

Logfile doesn't tell me why this happened, but in the minutes leading up to this session start, OBS started and stopped the Decklink capture multiple times, and audio buffering increased, which is often a symptom of CPU overload.

The BlackMagic device capture method is generally for Decklink cards. (That's why the logfile calls it "decklink".) Most of the rest of their hardware line is intended to be added as Video Capture sources. Have you tried that?