Rendering Mixed Resolution Clips

[Paul33]

Shooting with a mobile phone with different resolution max for front and back camera leaves me with a mixture of clips, mostly 4K for the front camera and a few 1080HD clips from the back "selfie" camera.

When I render my final video using 4K settings, what is happening to the 1080HD clips ? The end result looks okay but is it causing deterioration for the HD clips even if I can't really see it ?

Equally, is there anything I should do with the HD clips to mix them in better ?

[pvreditor]

If you render mixed resolution clips (4K & HD) into a 4K file, the encoder will "upscale" the HD material to 4K. There should be no degradation, but the HD clips won't look quite as sharp as 4K clips. That's to be expected, since HD clips have 1/4 the resolution of 4K clips.

[Paul33]

Thanks for that. I figured that was the case but nice to hear it confirmed !

[dontgetsuspicious]

If you render mixed resolution clips (4K & HD) into a 4K file, the encoder will "upscale" the HD material to 4K. There should be no degradation, but the HD clips won't look quite as sharp as 4K clips. That's to be expected, since HD clips have 1/4 the resolution of 4K clips.

Do not expect this but thanks anyway.

[tletter]

... the encoder will "upscale" the HD material to 4K. There should be no degradation, but the HD clips won't look quite as sharp as 4K clips.

There will be degradation since for a 1080p image to be transformed into a 4K image, it needs to gain over 6 million pixels through the upscaling process (at which point, it will become a 4K image). Upscaling relies on a process called interpolation, which is really just a glorified guessing game. Since interpolation isn’t magic, there will be an evident difference between the upscaled 1080p image and true, native 4K content.

The end result looks okay

Why the concern if you're happy with the result?

tletter
https://www.youtube.com/user/tletter

[pvreditor]

If you render mixed resolution clips (4K & HD) into a 4K file, the encoder will "upscale" the HD material to 4K. There should be no degradation, but the HD clips won't look quite as sharp as 4K clips. That's to be expected, since HD clips have 1/4 the resolution of 4K clips.

Do not expect this but thanks anyway.

I've produced hundreds of 4K videos and have been happy with the way editing software (including VideoStudio) handled rendering 1080p into 4K. But I realize that the mileage of others may vary.

[pvreditor]

I just uploaded a video to YouTube, and it happens to be a tutorial on how to do simple on-screen titles with VideoStudio. The intro/outro shots of me are in 4K, and all the screen-grabbed shots of VideoStudio are HD (1920 x 1080). The whole video was rendered in 4K. I think it came out looking good, and the screen-grabbed stuff is certainly clear enough to show what I need to show. Here's a link: https://youtu.be/2f9NrF_skh0

[Paul33]

The end result looks okay

Why the concern if you're happy with the result?

tletter

Probably more curiosity and understanding than concern but my being "happy with the result" doesn't necessarily mean that its the best result I can get. Always happy to learn from you folks !