Tsahi Levent-Levi (owner of Bloggic Me and WebRTC courses) explains why pushing raw resolution is problematic for WebRTC CPU optimization. He walks through a back-of-the-envelope calculation: 4K (3840×2160) yields ~8 million pixels per frame, ×60fps ≈ 0.5 billion pixels per second per direction (≈1 billion for encode+decode), not counting 2–3 bytes per pixel for RGB—showing that raw resolution scaling is CPU-expensive and not a practical path to higher video quality in real-time communications.
Chapters
Hi, my name is Sahil Lewandlevi. I'm the owner of Bloggic Me and WebRTC courses and I'm here to break down real time communications so you don't have to. I want to go and explain why we have an issue around CPU optimization. Let's talk about quality for a second. If we think about quality, the best video quality that we can achieve today probably or likely would be 4K at 60fps. That would be 4K resolution with 60 frames per second. You've got TVs that do that today, so why not have that in your video conferencing using WebRTC? Let's do the calculation. When look at 4k. 4k is actually 3840 pixels on the width on 2160 pixels on the height. That would be the number of pixels per frame that we're going to need to process. That means encode and decode. If this is a one on one call, not even going to group calls here. If we multiply these two, we've got about 8 million pixels, give or take that we need to process per frame on encoding, 8 million pixels on decoding, 8 million pixels. Now how many pixels are these going to be per second? Let's multiply it by 60 and what we reach is around half a billion pixels per second that we need to process in each direction. So about a billion pixels per second. And now I haven't even gotten into the RGB part that each pixel is two or three bytes and all of the other complexities that we have. So if we want to reach high quality by saying, well, the higher the resolution, the higher the quality, then we're in big trouble. So this is likely not the way to optimize media quality for the CPU of the device. Go and follow me at Blogic me. Thank you.
