Question / Help White lines on certain .PNGs?

[Hamburghini]

Hello there! Before I begin I just want to applaud the devs on their fantastic and amazingly-still-free product, I know you guys have put in a lot of hard work to get it to where it is now and wish you only the best of success for the future. With that being said, however, I do feel it is necessary to bring issues to light so further improvements can be implemented.

Therefore, I wanted to bring up and possibly find a solution to this issue I'm having. When placing a .PNG file into a scene, I've noticed that sometimes it will have these strange white lines attached. Now, you may be thinking, "Well, they're probably just white lines on the image itself that you forgot about!" However, this is not the case as I've gone back into Adobe PS multiple times to see if this was so and it is most certainly not.

I've also noticed that, when moving it around, the thickness of the white lines will vary, and if you position it just right, they will no longer appear. While this may sound like a solution, it is not, considering I cannot have it placed wherever I want in the scene without these possibly appearing.

So, I come to you, OBS Forums, in hopes that you guys understand what I'm talking about and know of a possible solution for this issue as it has been driving me mad the past few weeks. I've linked a screenshot/gif of what I'm experiencing and the original .PNG file down below as well as attached the log file. Thank you!

GIF/PIC

ORIGINAL PIC

 

[Suslik V]

I see nothing... O_o

Well, there is more interesting thing... Import in OBS Studio this picture: http://www.4p8.com/eric.brasseur/gamma-1.0-or-2.2.png
I disagree with some thoughts of the info (EDIT: or info) author, but can you test the image on your system?

Set it's size to 256x128 via Transform>Edit Trancform...>Size (twice reduce)
Write video file with OBS Studio (or you may preview scene, fullscreen projector), and play it. Say, what you see?

I see that my scaling software 'sucks' ^_^


Edit: just in case, my log-file https://gist.github.com/ef016e116e44fc6a2366

 

[Hamburghini]

Thank you, I will try this tomorrow as I am currently away from my computer and will update this post with my results.

 

[sam686]

Try loading my "testalpha1.png" that contains a message, hidden away with transparency. loading into OBS-mp and making it bigger will show a message.

The problem shows up when having a white transparent pixel right next to a black opaque/visible pixel, showing up as a gray semi-transparent between image's pixels after resizing in OBS-mp.

 

[Suslik V]

Try loading my "testalpha1.png" that contains a message, hidden away with transparency. loading into OBS-mp and making it bigger will show a message.

The problem shows up when having a white transparent pixel right next to a black opaque/visible pixel, showing up as a gray semi-transparent between image's pixels after resizing in OBS-mp.

I see the message. This is hardware and driver dependent test, I think (maybe I'm wrong, don't know, correct me please). But Video>Base (Canvas) Resolution and Video>Output (Scaled) Resolution defined for previous test ('sucks' message) gives the same result, while your image doesn't display any messages on my system.

OK, modified tests:

first

1. Import in OBS Studio this picture: http://www.4p8.com/eric.brasseur/gamma-1.0-or-2.2.png
2. set Video>Base (Canvas) Resolution: 512x256
3. set Video>Output (Scaled) Resolution: 256x128
4. Write video file with OBS Studio
5. Play recorded video file (100% size. Yes, very small image)
   
6. Say, what you see?

second

1. Import in OBS Studio this picture: https://obsproject.com/forum/attachments/testalpha1-png.13853/
2. set Video>Base (Canvas) Resolution: 128x16
3. set Video>Output (Scaled) Resolution: 256x32 (or 64x8)
4. Write video file with OBS Studio
   
5. Play recorded video file (100% size. Yes, very small image)
6. Say, what you see?

 

[Jack0r]

I just tried the original topic creators picture. While the preview in OBS Studio shows small white lines around the poke balls, neither the recording nor the fullscreen projector preview show them. Its probably a result of the scaling algorithm of the preview I would guess, but that is something we would have to ask Jim of course.

 

[Hamburghini]

I just tried the original topic creators picture. While the preview in OBS Studio shows small white lines around the poke balls, neither the recording nor the fullscreen projector preview show them. Its probably a result of the scaling algorithm of the preview I would guess, but that is something we would have to ask Jim of course.

That does make sense, but I can still notice it in my VODS, unfortunately: https://www.twitch.tv/hamburghini/v/53290670. If you find out about an answer to this, please let me know! Thank you very much!

 

[Hamburghini]

I see the message. This is hardware and driver dependent test, I think (maybe I'm wrong, don't know, correct me please). But Video>Base (Canvas) Resolution and Video>Output (Scaled) Resolution defined for previous test ('sucks' message) gives the same result, while your image doesn't display any messages on my system.

OK, modified tests:

first

1. Import in OBS Studio this picture: http://www.4p8.com/eric.brasseur/gamma-1.0-or-2.2.png
2. set Video>Base (Canvas) Resolution: 512x256
3. set Video>Output (Scaled) Resolution: 256x128
4. Write video file with OBS Studio
5. Play recorded video file (100% size. Yes, very small image)
   
6. Say, what you see?

second

1. Import in OBS Studio this picture: https://obsproject.com/forum/attachments/testalpha1-png.13853/
2. set Video>Base (Canvas) Resolution: 128x16
3. set Video>Output (Scaled) Resolution: 256x32 (or 64x8)
4. Write video file with OBS Studio
   
5. Play recorded video file (100% size. Yes, very small image)
6. Say, what you see?

Trying this out now, will update this reply with my findings in a moment!

UPDATE: Test 1 Results / Test 2 Results

What's interesting is that in the Preview for Test 2 I could read the words, yet they are not present in the video.

So, what exactly does this indicate and how can I possibly resolve it?

 

[sam686]

How OBS-mp preview appear to work is it actually re-draws all sources at window resolution, ignoring base resolution. I wonder how a tiny base resolution of 16x12 is somehow super sharp no pixelation preview from downsizing an image/video? This wasn't the case with the old OBS which uses base resolution for preview.

As long as not resizing the 1280x720 image with a base resolution of 1280x720, it should be fine for stream/record even though the preview might be wrong in OBS-mp.

EDIT: Found a workaround, resize OBS-mp window so the preview resolution is exactly the same as base resolution.

 

[Suslik V]

modified tests v3, for more clear result (no sub-sampled chroma but still YUV output):

first

1. Import in OBS Studio this picture: http://www.ericbrasseur.org/gamma-1.0-or-2.2.png (EDIT: or https://www.imagemagick.org/Usage/images/gamma_rules.png if previous link is broken)
2. set Settings>Video>Base (Canvas) Resolution: 512x256
3. set Settings>Video>Output (Scaled) Resolution: 256x128
4. set Settings>Advanced>Color Format: I444
5. set Settings>Output>Recording tab>Rate Control: CRF
6. set Settings>Output>Recording tab>CRF: 0
   
7. Write video file with OBS Studio
8. Play recorded video file (100% size. Yes, very small image)
9. Say, what you see?

second

1. Import in OBS Studio this picture: https://obsproject.com/forum/attachments/testalpha1-png.13853/
2. set Video>Base (Canvas) Resolution: 128x16
3. set Video>Output (Scaled) Resolution: 256x32 (or 64x8)
4. set Settings>Advanced>Color Format: I444
5. set Settings>Output>Recording tab>Rate Control: CRF
   
6. set Settings>Output>Recording tab>CRF: 0
   
7. Write video file with OBS Studio
8. Play recorded video file (100% size. Yes, very small image)
9. Say, what you see?