I recently uploaded a 4K/60p 3D video to Youtube. Unfortunately, when I played it on my TV using the Youtube app on the Roku box, it displays as 1280×720/60p. Why did Youtube degrade to 720p? We answer that question below.
A 1280 x 720 3D stream becomes two 640×720 clips – one for the left eye and one for the right eye which looks fuzzy. At 1920 x 1080, a 3D side by side format video retains 960 x 1080 for each eye, which is much greater resolution.
Bottom line – 3D videos should primarily be uploaded as 30p videos, even if originally shot in 60p if they are intended for viewing on Youtube television apps.
My TV, like most vintage TVs that support 3D, does not support 60 frames per second except in 720p mode.
In fact, all 60p videos on Youtube are downgraded to 720p when playing on the Roku Youtube app.
The same video, when uploaded at 30p displays correctly as 1920×1080/30p and is not downgraded.
What this means
If you are a weirdo like me and shooting 3D video, do not upload any 3D video in 60p because it will be downgraded by TV-based viewing apps not to 1080/30p but to 720/60p. This is because TV’s that support 3D are, almost exclusively, from the 3D hey day era of about 2011 to 2013, after which manufacturers began to discontinue their 3D TVs. TVs of that age only supported 30p and did not support 60.
Youtube had a choice to degrade the video from 60p to 30p, or to retain 60 frames per second – they chose the later and degraded the resolution to 1280 x 720/60p, unfortunately.
If you intend for your 3D video to be viewed on 3D TVs, you will want to upload videos as 30p, even if you originally shot them in a 60p format.
Videos uploaded in 60p will play correctly TVs that support 60p and on most 3D computer monitors. If your target is a 3D TV, you will want to upload only a 30p version. But if your target is 3D computer monitors, you can upload 60p clips.