MPEG Streamclip Repeats Frame Every 5th Frame

[willard]

When using MPEG Streamclip to export VOB segments to MOV, I get a repeated frame every fourth or so frame in the end MOV result. When viewing the VOB in the MPEG Streamclip window beforehand I got no such repeated frame. NOTE: This happens only with VOBs that came from trendy-movie DVDs; no such repetition with documentary videos, cheaper independent flicks, home videos, and Energizer Bunny propaganda shorts.

Weird: I have been using OpenShiiva for these trendy conversions (to MP4) and it works each time. However this application does not seem to like LESS-trendy files! It sometimes gives me frame problems with these files, which is the kind of opposite of the problem I've been having with Streamclip.

I thought for sure I could conquer this problem by experimenting with settings. Four wasted months later I have no confidence regarding anything where my brain is concerned and I think I've run out of settings.

[Case]

That sounds exactly like what would happen in a NTSC Film (23.976 fps) to NTSC (29.97 fps) conversion. You may have smoother results if you force the MOV framerate to 23.976 fps.

[willard]

That's a good idea, but my laziness comes into play. With bigger problems I'm more likely to jump in and fix everything; with problems that are 99% fixed the end result with me is an effortlessly-produced and imperfect file. Also, when I mess with frame rates myself I tend to lose a frame here and there.

The thing that bugs me is that my roommate has the same problem with MPEG Streamclip, so it's probably something I can find an answer to eventually ... provided someone out there who has experienced it is like me and not like her, a misplaced-in-time punk rocker who sees technical challenges as one more reason to hate life and overuse the F word.

[terryj]

That's a good idea, but my laziness comes into play. With bigger problems I'm more likely to jump in and fix everything; with problems that are 99% fixed the end result with me is an effortlessly-produced and imperfect file. Also, when I mess with frame rates myself I tend to lose a frame here and there.

You might want to ge a handle on that....

Seriously though, Case's suggestion will work for you,
and maybe if you read it to your roommate, she could get
it accomplished for the both of you...? I mean, it's not that
hard to set the conversion rate, step back, and let MpegStreamclip
do it's job....or is it...?

[Case]

When I used MPEG Streamclip's Export to QuickTime, I noticed the empty framerate box. From the Guide: "If you leave this field empty, the frame rate will be the same as the original movie's frame rate (shown in the "Stream Info" window)."
Problem is, a 23.976 fps clip with 3:2 pulldown (like a film DVD) will show as 29.97 in the Stream Info, thus the MOV conversion will be to 29.97, creating duplicate frames in the process.
So next time, fill in 23.976 in the Export framerate box, when dealing with film source. Unless you need the MOV to be 29.97 fps.

[willard]

Thanks very much, both of you.

So I was mistaken in asssuming that whenever you designate a frame rate you'll have problems? Maybe I need to think about this and let it sink in, but ... because of a few past experiences and a limited understanding of math I was convinced that whenever you avoided telling an application "just gimme every single frame and don't argue," in other words, whenever you designated a frame rate and hoped that the real world turned out to be as precise as the "fake" one in theoretical mathematics, eventually things wouldn't match up anymore.

When I've exported image sequences using QT (before I knew you could leave the frame rate blank!) ... even when I got the frame rate right it wasn't long before a frame or two were completely missing.

I could be wrong, but not knowing for sure and designating a frame rate might mean untold years of "frame loss paranoia." To be certain I was practicing a safe method and losing nothing to the frame gremlins would mean waiting until my death; sometimes in life you need only one counterexample of the other guy's theory to feel safe, then again, sometimes you need an entire life without counterexamples of yours.