Question / Help Jerky/jumpy video when recording Silverlight tennis stream (720p)

[delpetra]

I have a bit of a weird/unique question!

I use OBS to record tennis matches from BT Sport, as they use the Silverlight player and hence I cannot capture the video directly. I change the resolution on an external display to 1280x720, and load the 720p stream fullscreen, then use OBS window capture to record this window.

I'm using the settings from this post, but with 25fps (as I'm pretty sure the stream is 25fps) and crf=15. I have a quad core Intel i5-3470S CPU.

Sometimes the video I record gets a bit jerky/jumpy, as shown in these clips: https://www.youtube.com/watch?v=BzPE9CBkG7Y
I don't think this is due to my internet connection as I have fibre optic (70Mb down, 20Mb up) and if I watch the stream at the same time on my monitor it is not jerky/jumpy.

I've tried decreasing (and increasing) the crf number, however this doesn't appear to fix this. I struggle to say for sure whether low crf numbers actually fix it as any reduction in this jerky/jumpy effect may just be a placebo. Either way, using values below 10 drastically increases file size so I don't think that's the solution.

Two log files from the two most recent recordings I've done are attached (the clips in that YouTube video are from these recordings). I've removed the bits from the test recordings I was doing.

Any suggestions are greatly welcomed!

 

[Boildown]

Encode statistics look very good:

19:57:52: Video Encoding: x264
19:57:52: fps: 25
19:57:52: width: 1280, height: 720
19:57:52: preset: veryfast
19:57:52: profile: main
19:57:52: keyint: 50
19:57:52: CBR: no
19:57:52: CFR: yes
19:57:52: max bitrate: 1000
19:57:52: buffer size: 0
19:57:52: quality: 17
19:57:52: ------------------------------------------
05:57:48: Total frames encoded: 899886, total frames duplicated: 138 (0.02%)
05:57:48: Number of frames skipped due to encoder lag: 13 (0.00%)
05:57:48: Total frames rendered: 899880, number of late frames: 10 (0.00%) (it's okay for some frames to be late)

You could crank up the preset to Faster if you wanted, maybe Fast. But that won't solve the main problem. Seeing how its not your computer lagging, I'd suspect either a source issue or an FPS mis-match. Are you sure the video isn't choppy when it arrives at your computer? Can you determine the framerate of the incoming video to verify its actually 25fps (perhaps with FRAPS)?

 

[delpetra]

Encode statistics look very good:



You could crank up the preset to Faster if you wanted, maybe Fast. But that won't solve the main problem. Seeing how its not your computer lagging, I'd suspect either a source issue or an FPS mis-match. Are you sure the video isn't choppy when it arrives at your computer? Can you determine the framerate of the incoming video to verify its actually 25fps (perhaps with FRAPS)?

Thanks for the reply. I've tried installing fraps but no matter what hotkeys I choose, it doesn't seem to want to give me an FPS overlay. Can't find anything online that fixes this.
Next time they broadcast some tennis I'll try recording in 20fps, as I remember seeing a post on the BT forums suggesting that was the actual framerate of the stream. Although, if that is the cause of the problem, wouldn't that cause this jerky/jumpy effect throughout the whole of the recording?

 

[Boildown]

Although, if that is the cause of the problem, wouldn't that cause this jerky/jumpy effect throughout the whole of the recording?

Yes actually. So if that's not the case, I'd suspect the source is actually sending you jerky video. Or something else that we haven't thought of. But it looks like OBS is running great. How about a different browser? Are you hardwired or using wifi?

 

[delpetra]

Yes actually. So if that's not the case, I'd suspect the source is actually sending you jerky video. Or something else that we haven't thought of. But it looks like OBS is running great. How about a different browser? Are you hardwired or using wifi?

Managed to get FRAPS working, but it just shows the framerate as 60fps. Guessing that's because that's the refresh rate of my monitor?

Tried recording in 20 and 24fps but neither look right at all.

I'm connected to the internet via an ethernet cable. And I often record overnight, so the only thing my computer is doing is recording (I close background apps like Dropbox and Google Drive).

I know there have been lots of complaints about BT Sport's livestreaming but I find it very pleasant to watch live! If I'm watching the livestream at the same time on the monitor it looks fine.

Since updating to Windows 10 I've been using Firefox instead of IE (as now Chrome have dropped support for Silverlight), but tried switching back to IE. I thought I'd fixed the problem, but once I recorded another full length match I noticed it again. Here's a video showing the recording transitioning from good (before the ad break) to bad: https://www.youtube.com/watch?v=JOI4E0OTQJs Attached is a log file for that recording.

Thanks so much for your help so far!

 

[Boildown]

How about recording at 60fps? Your monitor framerate? The OBS logs don't show any problems that I can see. You can also change the Profile to High if you want, no reason to have it on Main.

 

[delpetra]

How about recording at 60fps? Your monitor framerate? The OBS logs don't show any problems that I can see. You can also change the Profile to High if you want, no reason to have it on Main.

Will try that next time there's tennis on (find it hard to notice the effect with other sports haha!) and let you know. Have changed that too. Thanks!