More and more cameras shoot in 4K nowadays, even the low-end consumer models and smartphones are no longer limited to HD resolution. Almost 3 years ago YouTube added a support for 4K videos and Vimeo followed 1,5 years later.
The videos uploaded to YouTube or Vimeo in 4K resolution look beautiful. Even when we watch 4K videos on 1080p screens they are downscaled and all the details are not lost due to compression.
It’s pretty clear that if there is the possibility to upload 4K video, we should do that. It will certainly look better.
But there’s another question that might be asked here… We know that the codec used for video compression decreases the quality and there is always a loss in details when uploading a video to one of the mentioned websites.
What if we have 1080p video?
Can we upscale it to 4K before uploading?
Let’s have a look at the below examples. I used a short excerpt shot on my BlackMagic Pocket Cinema Camera in 1080p natively. I created 3 versions of the video and uploaded to Vimeo and YouTube:
- 2160p 50mbps vimeo | youtube (1080p upscaled to 4K)
- 1080p 10bmps vimeo | youtube (default bitrate)
- 1080p 50mbps vimeo | youtube (increased bitrate)
Because the 4K video was rendered using 50bmps bitrate I wanted to see if there is any difference between 10bmps and 50mpbs of the 1080p video.
Here’s 100% crop of the face details (click to zoom in):
The difference between 1080p in both YouTube and Vimeo is very small. Both services compress the image quite a bit and we can see a lot of artifacts in the background. Increasing the bitrate doesn’t change anything – the video is re-encoded on the server anyway so there is no point in uploading a bigger file.
The last column with the 4K clips looks way better than 1080p versions. Let’s have a closer look.
Below is the comparison of 1080p clip and 4K clip both played at 1080p at youtube:
We can clearly see that even for playback at 1080p the difference in quality and sharpness is huge. This is true for both Vimeo and YouTube.
Here’s the difference between Vimeo and YouTube in 4K:
As expected, Vimeo holds much more details compared to YouTube. Have a look at the eyes and cheeks skin texture, the difference is significant.
Personally, from now on I will upscale any video to 4K before uploading without hesitation. The sharpness, quality and lack of artifacts is really worth it.
In case you were wondering how to upscale your video quickly here is my solution for After Effects and Premiere Pro. I prefer the first one (looks a bit better) but the second one is pretty good too.
How to upscale 1080p video to 4K
The first step is to change the resolution of the current comp from 1080p to 4K. Go to the Composition settings and type in the new resolution 3840×2160:
Then find in the effects explorer a plugin called Detail-preserving Upscale and drag it on top of your clip:
You will see two buttons in the plugin settings – click the first one and After Effects will scale the footage to fill the frame which should result in 200% zoom for 1080p clip.
I added also a little bit of unsharp mask on top of that to enhance the details even more.
Optionally you could add some film grain on top to add a little bit of organic texture. But be careful with that as h.264 codec might treat the grain as noise and blur it out which looks really bad.
To upscale our video to 4K in Premiere Pro we have to change the sequence settings. Use the settings below:
Then select the clip on the timeline and go to the Video Effects tab:
In the Motion section, set the scale to 200%. I also added Unsharp Mask effect on top of that to enhance the details and sharpen the clip after upscaling it.
The videos in 4K resolution have different bitrate threshold on YouTube and Vimeo servers than 1080p ones. This means that when we get the 1080p video and upscale it to 4K it will be less compressed than the original file in native resolution.
If you want your 1080p videos to look best upscale them to 4K before uploading. Additional processing time and the increased file size is well worth it.
Also published on Medium.