This is what I see there

http://peter-ftp.co.uk/screenshots/20181202483011318.jpg

And?????
They cannot add themselves, but you did it (or someone else).
On track 3 you did something with trackmotion and placed at least one keyframe.
On track 4 you used the FX's Deform, Color Curves and Trackmotion all with at least one keyframe.

Yes I use the three FXs
- deform for a tiny bit of geometric correction on the camera
- colour curves for removing some haze
- track motion to tilt the image 1.8 degrees CW and then zoom in a few % to take out the empty corners
I never added any key frames.

I have just added the Deform FX to an unused track and this is what I get

I have now finished this edit and it is the last for a while.

Oddly enough Vegas 16 froze totally (not even a cursor shape changing) but instead of terminating it with the OS I just left it and when I came back half an hour later it was running fine. I don't think I remember the last time I have seen a crashed windoze app recover by itself!

j-v can you think of any way that extra keyframe could have been added as a side effect?

That point in the project is where the source video was broken into two files. The camera I use (Sony X3000) seems to write about 90GB and then it starts a new file. So I load both into the media list, and then drag/drop them onto the timeline.

Do you think these spurious keyframes could affect the velocity feature?

I can do more tests once this job has rendered (overnight now, and probably I will re-do it once after that, tomorrow) because I have spent several hours on it today and don't want to break it :) V16 is clearly not as solid as the previous versions. I am pretty sure some of the cases do generate a speedup but (a) don't show the 10 markers (or sometimes any markers) and (b) the speedup is not 10x but around 6x.

Those key frames appear to not do anything, in that they all start at 00:00:00.

I certainly didn't create them, and they can' be deleted, saying they are a part of the said FX.

One thing I recall is that the current batch of v16 projects started by importing a .veg file which was ex v14.

Does anyone from Magic read this forum? I would be happy to have a go at producing a small set of files which show the problem.

Those key frames appear to not do anything, in that they all start at 00:00:00.

I certainly didn't create them, and they can' be deleted, saying they are a part of the said FX.

One thing I recall is that the current batch of v16 projects started by importing a .veg file which was ex v14.

Have you done any track motion in that track or pan/crop in an event? If so and if you had the “sync to cursor” enabled, a keyframe will be generated whenever you make a change to the settings in the fx window.

I use track motion on the video track, to get a 1.8 degree rotation and a slight zoom. This was mentioned here
https://www.vegascreativesoftware.info/us/forum/bizzare-gradual-shift-in-the-video--113935/#ca704169
and this explanation posted there. Yes that could have been the source of the keyframe.

However this particular thread is concerned with the velocity profile feature not working in certain circumstances. Do you think the two are related?

I have now finished this project (last video here https://vimeo.com/304099022) (you have to copy/paste that URL for it to work; clicking doesn't work) and have again tried the velocity profile.

This time, none of the tick marks are displayed.

However, an examination of the playback shows that the zoom worked to some extent. A 10x ("1000%") speedup produces a roughly 6x speedup, and the rest of the event is padded with material from the original mp4 file (but which was cut out from the timeline!).

Obviously a 10x speedup produces a poor result most of the time (because a 50fps video results in a 5fps video i.e. likely very jumpy) but that isn't the point.

Unfortunately I can't put the project on dropbox etc because the whole size of it is about 100GB, of which 99% is the one mp4 file.

I could try to produce a smaller version but it doesn't look like vegas or anyone else is interested.

Although there are members of the Vegas support team who I'm sure participate in this community forum, if you want their attention on your problem you should start a support ticket request directly with Magix Support.

I'm interested in your problem, but do not have the same problem so it doesn't effect me. And, I have somewhat lost track of all the testing and results you have posted. I think it still may have something to do with your NET framework version install, but that may be a rabbit hole. You should be some where in around ver 4 of NET Framework Advanced. I could be totally wrong, but I think the tick marks are part of the animation engine and the animation can be screwed up without the proper NET Framework. Anyone with more knowledge than I, please correct me if I am wrong.

If you can replicate your issue with a smaller project and source file, say maybe in the 1-3 gb range, others here may be interested in downloading it and work with you. I'm on a limited monthly data allotment and wouldn't be able to help unless you get your sample down to 1 gb.

I can control whether the markers appear or not, simply by replacing the main mp4 video file (which has now been chopped up) with another one, or even with the original same one.

So it doesn't appear to be an OS GDI or similar issue.

Tonight I will try transferring the whole project to a Dell XPS13 laptop (QC i7) which also has v16 on it and I will see if it does the same thing. That runs win10, whereas my main machine is win7-64.

On the Dell XPS13 win10 laptop, I see the same behaviour. No markers shown and some velocity profile is applied but not 10x.

well.....what can I say! the Vegas feature works for me with my source, lucky me!

The Dell XPS13 also needs GPU disabled, to render... I posted that in the Issues thread. V14 worked ok on the same laptop with default settings...

I realize this was a couple of years ago @peterh337 but after looking through the posts and trying to put together what I could of the numerous follow-up tests replies. If I'm understanding correctly, there are times in various situations where the velocity envelopes works properly in providing you 10x speed up or 1000% and there are other times where it won't work and gives you around 27% (or what I'd guess 25%) speed up which is evident because of the black arrow marker that identifies when a clip restarts. As in, it should have at least 9 of those markers for being sped up 10x but you only get 1 black marker, depending on what version you use, what PC or laptop you use, or any other variable that doesn't seem to help identify what causes you to be able to use it or not be able to use it correctly, right?

From what I've noted, there were a number of things checked and resetting default settings for Vegas did not resolve the issue, and while I've noticed you've come to believe it's media property dependent, but what I haven't seen mentioned yet was how your project video settings were set up or your global project property settings (which is what I would've hoped the preferences reset would've addressed). Specifically, whether or not resampling was enabled or not and whether or not you have smart resampling enabled.

Resampling can be applied to a particular bit of media that's already been cut up and only appled to the one segment or it can be applied to the original track and after making any trims or splits, will continue to apply the same settings to those segments. This would explain why when you deleted all the tracks, it won't work

 I have deleted all the tracks on the project except the one with the mp4, done a save as, exited, restarted v16, and it still doesn't work.

and

Any portion of that mp4, it doesn't work on. Even if I cut off everything except a clean part of it; it doesn't work on that part. 

Then when you reloaded it, it's hypothetically possible that you either didn't make the same changes to the media properties yet or your project settings were not applied to it that may have effected it, which would explain why it works without restarting Vegas.

But if I reload that mp4, via drag/drop from the media list on top left, it works on it even without restarting vegas.

My speculation is based on the premise that resampling is something you don't want enabled if you have the existing frames (or let's refer to it as the data) needed to slow down or speed up a clip because it was captured within the camera itself. However in post, you'd want it enabled if say you're slowing down a clip that was shot at 30FPS and need it to replay at a speed equivalent to it being played at 15 FPS and need those in-between frames to be software generated. Or, when you're speeding up a clip, in your case 50FPS and you want the playback to appear smooth by compressing those 50 frames into 5 frames at a playback rate of 30 FPS for example.

The variations of when it would work and when it would work could be affected by whether or not you're allowing the imported media to set the project video settings or not. This might explain why it's so hard to pinpoint what is affecting it as this choice pops up by default upon import of your first media file that goes on the timeline can be quickly prevented from future pop ups with a simple tick and I imagine easily forgotten or disregard in the midst of habitually hitting ok or cancel.

Though I don't know if it's the actual verdict or not, it's something worth observing to see if it's the culprit. There's also a setting in Preferences under External Control & Automation that allows you to set the priorities for New video envelopes to be Linear, Fast, Smooth, etc. that could possible have an effect. Anyhow, I hope that helps even if it is too late to have any effect on that particular project of yours.

Many thanks for your input :)

I am still "here" and still doing the same sort of projects, sporadically.

My last video is this: https://vimeo.com/470500052

The problem I have found is rather more basic: speeding up doesn't work if there are multiple tracks and especially (obviously) if there is audio. I tried to speed up some of the Alps footage (after say 11:30) and then some of the departure footage, but really the only way would be to render it, then cut the bits you want to speed up and just do those, and re-render. Obviously any audio will be messed up.

I also tried Respeedr 1.0 which came with some version of Vegas, and that works rather better than the functions in Vegas but it (obviously) dumps the audio track.

All speed ups I tried produced a very jumpy result; no idea how to fix that.

This incidentally means that it is better to shoot in 4K, edit in 4K, and render only the finished job to HD.