Before submit this suggestion to the dev team, i would to know if it's already possible to find and navigate the keyframes of the original imported video? Instead of frame by frame.
For example, an AVC video encoded with a keyframe every 5 seconds, keept these frames as references (and at the maximum quality) and between them, each frame is predicted, "interpolated", so calculated.
It seems Vegas converts and includes all frames in timeline as "hard" frames. Or something like that.
I want the original keyframes can be keept and reachable in the timeline, like it's the case in MPC-HC.
I started to comment on this (twice), but on re-reading whydat's 2 posts, I am really at a loss as to what the OP is getting at. Is it that the OP expects that keyframes used in an already rendered video event to be available on VP's TL (or any other NLE's TL for that matter) for further modification? If that is the case, then 'no'. Similarly, VFX used in an already rendered video event can't be called upon again. To adjust VFX, it's necessary to go back to the original pre-rendered source and adjust there and then render again.
The comparison to MPC-HC is not exactly equal. MPC is a media player which does not, AFAIK, render. Vegas Pro is an NLE - an editor.
The real goal why i asked that, is the difficult the hardware decoder have to play a loop which doesn't start and end on keyframes of the media, and finish to freeze Vegas after a few playing.
Maybe an issue from decoder, maybe an issue from driver, maybe an issue from Vegas, maybe an issue due to keyframing not considered.
Very imaginative, but nonlinear editors, in order to work, must unpack each non-I frame to raw bits, and express them as hard frames on the timeline.
Frame-based and stream-based processing are as different as night and day, the latter being for temporal acquisition, transmission, and media players, which Vegas is not. I doubt we will see stream-based editing in our lifetimes. The logistics are daunting, as the distance between I-frames can be 300-400 frames.