Ministraitor
New Member
Running OBS 19.0.3 on Ubuntu 17.04, dist-upgrade'd this morning - issue still there.
My process to capture video is to first process the raw video from the capture card using ffmpeg, then send the result to a v4l2-loopback device. Both OBS and a backup ffmpeg process then use the video stream read from this loopback device (device doesn't allow concurrent readers, v4l2-loopback does). When I look at the video in OBS, there's a horizontal block in the bottom-right corner that is bright green which does not appear in the ffmpeg video. That block is 2 pixels high and at a guess I would say 40 pixels wide but haven't measured that.
See this video for a display of the problem: https://www.youtube.com/watch?v=2Zb-3_46YIc
Youtube's rechewing at times seems to discolor the block, in the original I get from the box it's a solid green throughout.
This process I perform on 2 video streams which appear in the same scene in OBS. While the streams are of very different dimensions (1440x810 and 480x854) they both have this seemingly exact same size block in the bottom-right corner.
When I look at properties of the video inputs, the green is visible there as well. When I read straight from my capture cards (either Magewell Pro-SDI or their USB offering) the image doesn't show this problem, but the source is now its unfiltered 1920x1080 so that might account for something.
Feeding into the loopback device with this command (/dev/${1} is my capture card, video0 the loopback device):
ffmpeg -r 50 -y -nostats -f v4l2 -i "/dev/${1}" -vf "hqdn3d=6:6:20:20,scale=w=854:h=480,format=pix_fmts=yuv420p,transpose=dir=clock" -f v4l2 -r 50 /dev/video0
The larger stream doesn't get denoised or transposed, and of course the scaling values differ.
I did not have this problem when I was on the older version that installed on Ubuntu 16.04 LTS.
I'm currently working around the issue by cropping the bottom 2 pixels from the image using a Transform.
The logs aren't showing any problems and it would appear that according to OBS everything's just fine.
My process to capture video is to first process the raw video from the capture card using ffmpeg, then send the result to a v4l2-loopback device. Both OBS and a backup ffmpeg process then use the video stream read from this loopback device (device doesn't allow concurrent readers, v4l2-loopback does). When I look at the video in OBS, there's a horizontal block in the bottom-right corner that is bright green which does not appear in the ffmpeg video. That block is 2 pixels high and at a guess I would say 40 pixels wide but haven't measured that.
See this video for a display of the problem: https://www.youtube.com/watch?v=2Zb-3_46YIc
Youtube's rechewing at times seems to discolor the block, in the original I get from the box it's a solid green throughout.
This process I perform on 2 video streams which appear in the same scene in OBS. While the streams are of very different dimensions (1440x810 and 480x854) they both have this seemingly exact same size block in the bottom-right corner.
When I look at properties of the video inputs, the green is visible there as well. When I read straight from my capture cards (either Magewell Pro-SDI or their USB offering) the image doesn't show this problem, but the source is now its unfiltered 1920x1080 so that might account for something.
Feeding into the loopback device with this command (/dev/${1} is my capture card, video0 the loopback device):
ffmpeg -r 50 -y -nostats -f v4l2 -i "/dev/${1}" -vf "hqdn3d=6:6:20:20,scale=w=854:h=480,format=pix_fmts=yuv420p,transpose=dir=clock" -f v4l2 -r 50 /dev/video0
The larger stream doesn't get denoised or transposed, and of course the scaling values differ.
I did not have this problem when I was on the older version that installed on Ubuntu 16.04 LTS.
I'm currently working around the issue by cropping the bottom 2 pixels from the image using a Transform.
The logs aren't showing any problems and it would appear that according to OBS everything's just fine.