A short conversational video discussing whether higher video bitrate improves quality. Speakers note that higher bitrate generally helps but with diminishing returns, describe a historical WebRTC/VP8 behavior where VGA was encoded at ~1.7 Mbps despite lower needed bitrates, and recommend choosing resolution and bitrate based on objectives (participant count, importance of a feed) to avoid wasting CPU, memory, and network.
Here's a nice question. Is higher video bitrate better for quality.
In general? I would say yes, but the answer is, of course it's a little more complicated than that because you can just spend so many bits on encoding. But there is a diminishing return of investment there. So at some point you're like, okay, we're increasing the bitrate by 20, 20% but getting a 2% increase in quality.
Yes. I think the most interesting or the most common example that I have for this was in the early days of webertc. I don't even know what it does today. But if you had VGA resolution coming out of the camera and there was as much bitrate as you want in the world, WebRTC would still use 1.7Mbps to encode VGA resolutions with VP8, where the only reason is why they'll do that when 800 kilobits can produce the exact same results or an approximation that is good enough for everyone.
Yes, yes. That behavior is still there, by the way.
Okay, good. Good to know that they didn't change the letters there.
Yes, yes, but I mean, you can get 720p with VP8 at 800 to 1200 kilobits per second and it's okay. Yep, but okay, as we see, we have higher bitrate for vga than for 720p. And the thing.
Yes, I think when you start thinking about video and bit rates and quality, don't always think that if you send more it's going to be better because in order to send more, I need to invest more cpu, more memory, and more network resources. So I would start with asking what exactly do I need? What is my objective? So if the screen resolution is low, I would use lower resolution and then lower bitrates. If there are many participants that are going to be displayed on the same screen, I would likely go for lower resolutions and again, lower bit rates. If that video that I'm sending is not that important in the context of that specific session, I am going to lower the bitrate. So I hope that in this session that we're actually recording using WebRTC, our own videos are not sent at 1080p quality or 4K quality when we're not taking the full area of the screen itself. That would be wasteful.
Yes.
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