I forgot that was there! I tried it with same results. Guess it is what it is. Thanks.

"Guess it is what it is.

I just tried the same with 1440x1080-60i AVCHD video (rendered to 1440x1080-60i) and the herky-jerky motion seemed to start at the point of reversal. Don't have much (any) time now but here it looks like "interlacing artifacts".

Vegas has had a bug, which gets fixed and then seems to come back in later releases, where it doesn't get the field order correct when video is reversed. There are dozens of posts about this over the years. Here is one of many:

Reversed m2t clip has reversed field order

In my post in that thread I link to another thread where I provided a workaround that seemed to work in Vegas 5. If that doesn't work, cut the event at the exact point where the video starts to play backwards (and cut later on if the video starts to play forwards again). Right click on the event that now has only backwards motion and change the field order from upper to lower (or vice versa).

Be sure to set a deinterlace method to other than "none", else you will end up with the field order reversed.

In order to reverse a video, Vegas must not only reverse the frame order but also the field order. It reverses field order by deinterlacing and estimating the missing lines in each double rate frame. With deinterlace method set to "none", Vegas assumes that the video is progressive and therefore doesn't have to do the above processing.

I've probably spent more time this summer working on pure concepts and other people's bugs than editing.

I find the underlying reasons for the problem in this post very disturbing.

One of the projects I did this summer was associated with the best (or least bad) ways to resize interlaced video. Since it's summer, sometimes I would just like to edit some video of my granddaughter in Vegas and move on.

I'm going to come clean: I failed the test for rocket science. Consequently, it's unlikely I'm ever going to be able to anticipate or understand all the little quirks that Vegas seems to have dealing with interlaced video. As a face-saving move, even a dummy like myself was able to reverse a segment of video using a progressive source,
a ten-minute task including upload.

Even though I've spent much more time and effort trying to get a smooth reversed scene within Vegas Pro, I am ashamed of the output. I wouldn't even show it to my family and friends. Ever the optimist, in spite of the evidence, there's always the 64 bit Yadif plugin.

It's summer. I'll get to it.

No wait! It's fall already.

Well, after a PM from JD I did a little testing. I'm not sure if this will help, but I did discover a few things.

First, I didn't find any evidence of the field reversal bug, so hopefully that isn't the cause of the OP's "choppiness." I took an HDV clip, put it on the timeline in both Vegas 7 and Vegas 10, added a velocity envelope and then ran the clip forward and then dragged the velocity envelope so that, after a few frames of slow down and speed up, the clip was playing at "full speed" backwards. I rendered using both the NTSC DV Widescreen template (so I could test re-sizing) and also the HDV m2t template. I put the resulting renders on a timeline and then served them out into an AVISynth script that lets me view each video field separately. If there is any field reversal, the reversal will immediately become apparent because of the "back and forth" motion you get when viewing individual fields that have been reversed.

I observed no field reversal.

However, in doing this, I did notice that the individual fields of the reversed video looked "blended" and soft. I then went back to my original Vegas timeline, duplicated the event that had the forward-the-backward velocity envelope, and then lined up the duplicate to try to put a reverse frame directly below the same frame played in the forward direction.

This is when I had an "ah-ha" moment: I couldn't line up the two frames, because the reversed frames were different! In other words, none of the forward frames had any exact counterparts in the reversed video, even though both were playing at 100% of the original speed.

So, I asked myself: "Why?"

My answer -- which I think is correct -- is because if you use a velocity envelope to transition from forwards to backwards, you will almost certainly not arrive at the minus 100% (full-speed backwards) point at exactly a frame boundary. As a result, Vegas's "smart resample" will create a new frame of video by blending adjacent frames. This will make the video look soft. Perhaps this could be described as "choppy."

The solution is to disable resample for the event that you have reversed. Once I did that, I got reverse video that was perfect resolution. Of course the slow motion during the transition became choppy because with resample diabled, Vegas creates slow motion by simply duplicating frames.

So, if that solves either the OP's problem or John's problem, then it is not a Vegas bug, although I'll admit it isn't a very obvious thing that most people would look for.

If this doesn't fix the problem, then maybe someone could post 1-3 seconds of reversed video that is "choppy" and also post the VEG file used to create it. I'd be happy to take a look and see if I can come up with additional ideas.

I have just tried a few clips varying from 30 seconds up to 2 minutes using 'right click - reverse' and each time play back was smooth, with no noticeable softening of the preview image. The clips were all HD down converterd to SD from camera in capturing. Each had quite a good amount of movement in the subject matter. Smart resample was on throughout these tests.

The specs for my machine are probqably quite underwhelming compared to many I see here, and using XP still. I am using VP10e and have not seen a'bug' in the reverse, so far.

I know this doesn't advance your problem but I thought it may help to see the problem may be elsewhere rather than specificially with VP.