Now that's some data Carmack's not going to like ;-)
> The debug stats in the top corner showed that he was using 60-80KB/sec of bandwidth while playing. He explained that each frame was being sent down over the internet from a co-lo center.
I'm wondering what kind of miracle makes a video game display streamable at that speed with any form of acceptable quality (not even talking about 1080p@60Hz), especially given the following:
> The codec in the prototype was nothing more than a series of JPEG images sent at 15-60+ frames per second.
A single acceptably lossy typical JPEG game shot at 1080p is north of 600~800kB, while even one at 720p (typical of a '08 laptop) come up being 150~300kB. Below that you start to get noticeable artifacts.
Even if the game engine/platform knows what has been updated and only send deltas of sort (again taking the series of JPEG images case), you still have to account for the worst case, that is basically the whole screen changes at once, sixty times per second.
And indeed, in the Steam video, you can see throughput data at the top: when nothing's moving the value is as expected very low, but you immediately notice the peak at 9Mbps when the L4D video ends[0], with typical values during the video at 4~6Mbps, which is much more inline with a 1080p stream.
Even the fading Source logo produces a 2.5Mbps stream (which produces very small diff areas), at 85% quality. There seems to be some cap at 48Mbps.
You can also see various timings, and the adaptative compression kicking in on the 9Mbps section, where you can read:
There seems to be another timing value at the beginning, with an "encryption" label, hovering at 9ms.
BTW, what's with the monotonically increasing with time stream = ${p}% value? That makes it look like a streamed video, not an interactive one. Not being suspicious but it felt weird.
Comments
Now that's some data Carmack's not going to like ;-)
> The debug stats in the top corner showed that he was using 60-80KB/sec of bandwidth while playing. He explained that each frame was being sent down over the internet from a co-lo center.
I'm wondering what kind of miracle makes a video game display streamable at that speed with any form of acceptable quality (not even talking about 1080p@60Hz), especially given the following:
> The codec in the prototype was nothing more than a series of JPEG images sent at 15-60+ frames per second.
A single acceptably lossy typical JPEG game shot at 1080p is north of 600~800kB, while even one at 720p (typical of a '08 laptop) come up being 150~300kB. Below that you start to get noticeable artifacts.
Even if the game engine/platform knows what has been updated and only send deltas of sort (again taking the series of JPEG images case), you still have to account for the worst case, that is basically the whole screen changes at once, sixty times per second.
And indeed, in the Steam video, you can see throughput data at the top: when nothing's moving the value is as expected very low, but you immediately notice the peak at 9Mbps when the L4D video ends[0], with typical values during the video at 4~6Mbps, which is much more inline with a 1080p stream. Even the fading Source logo produces a 2.5Mbps stream (which produces very small diff areas), at 85% quality. There seems to be some cap at 48Mbps.
You can also see various timings, and the adaptative compression kicking in on the 9Mbps section, where you can read:
There seems to be another timing value at the beginning, with an "encryption" label, hovering at 9ms.BTW, what's with the monotonically increasing with time stream = ${p}% value? That makes it look like a streamed video, not an interactive one. Not being suspicious but it felt weird.
[0]: https://www.youtube.com/watch?v=FRtBuP2-_pA&feature=play...