MKV Capture Yields Graphical Anomalies

myk.robinson

myk.robinson

New Member
Not quite sure how to explain this, but I'll try. I run a YouTube channel called Let's Talk About REAPER. For my show, I film myself with my Sony Alpha camera and simultaneously record my screen and voiceover using OBS, and I edit later in Davinci Resolve.

Historically I've had no issue but I recently started capturing from OBS to . mkv instead of .MP4 , I think perhaps because of the warning in OBS about not being able to recover in case something crashed.

Davinci Resolve can accept the .mkv file without the need to remux first, but I'm noticing that there are strange glitches when there is faster motion onscreen.

I thought maybe it was something to do with Resolve initially, but if I play the .mkv directly in VLC, I see the same thing. This issue does not happen when OBS captures to .MP4

What can I do to avoid these glitches? To see an example, feel free to check out the video I posted on my channel today, just spot check to any place where I am moving things around onscreen, and it looks as if things are warping instead of moving naturally.

If there is further information you may need from me like settings or something, please advise what you might need in order to better advise.

Here's the log


Thanks for your time.
 
Instead of your current settings, switch to simple output mode, indistinguishable recording quality, nvenc recording encoder, mkv recording format.
 
Harold said:
Instead of your current settings, switch to simple output mode, indistinguishable recording quality, nvenc recording encoder, mkv recording format.
Click to expand...
Hey, Harold.

I'm not really able to run simple output mode, as I need separated audio tracks. If I am playing any audio in REAPER, i need that to be separated from my speaking mic so I can process them individually in post.

I did use the log analyzer and changed the color range to partial. I also have changed from VBR to CBR, wonder if the bitrate was causing some of the issue. I will test a bit later in the day (time for work) and see if any of that helps.

Thanks
 
If you intend to postprocess your video, neither VBR nor CBR are useful rate controls. These are made for directly streaming to keep the bitrate within bounds. For postprocessing, your raw material should contain the best quality, even during high motion, so switch to a quality based rate control such as CQP. Use a CQ value of about 18-20 (lower values give higher quality).

Just changing between mp4 and mkv should not result in any quality change, because you're only changing the container format, but not the actual encoded video data stored within. If you still witness it while using the same encoding parameters, your postprocessing software does handle these container formats differently.
 
Additionally, when you use the CQP rate control, you're able to change the nvenc preset to quality instead of max quality to greatly reduce load on the video card at the cost of slightly larger recordings.
 
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