Thanks Doug.
I recall the 600D card write speed is 50% less than the 70D. Not sure about the 60D.
The variable fps is not working with the 70D ML presently for h264 video.
So if the 70D supports faster cpu & bus, it may very well reach 50% faster fps for 1080p than the 600D (i.e. up to 70 fps???).
I think the line of 70D investigation, has to be to use existing IPB compression chip.
Clearly IPB bit rates are less CPU than All-I. So if the existing pipe-line can handle All-I at 720p / 60 fps,
then when we switch to IPB some of the cpu and pipeline is not used/free. I seem to recall IPB is about 1/3 the data as All-I.
So the cpu power & pipeline has some untapped capacity in IPB.
The question becomes in 720p IPB compression, how can we trick the camera into using 1080p?
Or the converse question in 1080p IPB compression, how can we trick the camera into going 60fps?
There is some potential here.
The HDR 60fps video correction for fast motion, to be honest sounds like a rats nest.
I wonder if you shift each frame by 1/120th of a second, alternately (shift ahead, shift behind) then
use HDR frame processing, followed by PPro stabilizer correction, if it would generate a sharp 30 fps picture?
Considering how slow HDR processing for in camera stills, this post processing would always be in post for video.