All posts by Bartosz Barlowski

Carmack (Oculus CTO) talks about 360 video challanges.

360 video Samsung Gear VR
John Carmack holds a Samsung Gear VR Headset

“People that are resolution-picky will probably prefer monoscopic videos, which can have twice the resolution of stereo videos. The stereo effect may not be worth anything to you if you can’t get past the blurring.

Here are some notes about video quality that I circulated internally at Oculus:
The hardware decoder on the Samsung devices can handle a lot of bit rate; I think we have successfully played back up to 80 Mb/s, but the largest image stream it can decode is 4096×2048 at 30 fps. For a monoscopic panorama that is roughly the resolution that we render synthetic game content at (but game content is 60 fps), but less than half the optimal resolution for display on the 2560×1440 displays.
There are two limits in play here — the Google video framework in Android has an (arbitrary, as for as I can tell) limit of 2048 lines high on an image, and the decoding hardware has a limit of about 240 Mpixels/s which can be flexibly divided between image size and frame rate. The optimal video stream for the current hardware would be about 6000×3000 at 60 fps in stereo, or 2160 Mpixels/s. A factor of nine over what we have now. When we get 4k displays, that will double again.

The videos we play back now are, in my opinion, “good enough”, but it is clearly still a point that is arguable. One of the super-picky and critical artists we work with kept telling me that our 4k x 2k panoramic photos just didn’t look good, but when I developed the “overlay plane” technology that allowed us to directly sample 1536×1536 cube maps (roughly equal to 6000×3000 equirectangular panoramas) without double-distorting for VR, he finally said “Yeah, that looks good”. He still hates the quality on our panoramic videos. All of the still images in the 360 photos VR app are processed for this resolution, but they don’t necessarily have an optimal content pipeline and compression settings for peak quality.
I want to be able to demonstrate video at this peak quality level, and I think it is going to be important in the coming years, but it isn’t clear what the user experience would be for acquiring and viewing these massive datasets, so this is not the priority of the day.”


source: reddit