Deleting duplicate frames

[abc-123]

I have this mpeg...

...which looks like this when I run it through biterate viewer...

... but the video stutters horribly when played. The audio is in sync though. I'm trying to find a way to make the motion more fluid.
I opened it in virtualdub and checked out each frame one by one. It showed me 4 identical frames where there should be just one. Looks like this:

Then I opened it in tmpgenc and used the inverse telecine filter. That shows me 1 interlaced frame followed by 7 identical frames where there should be one. Looks like this:


I have 2 full length movies that have the exact same problem. Can anyone suggest how to fix this and get rid of all the extra frames?

I'd prefer to have a non-interlaced mpeg1 at 29.97 fps when finished.

[junkmalle]

It looks like you have a 7.5 fps video that was converted to 29.97 fps by repeating every frame four times.

Removing duplicate frames will not make it run smoother. After frame reduction, if you play each frame for for 1/7.5 second it will have the same running time but will be just as choppy. If you display each frame for 1/29.97 second it will play four times faster.

In all likelyhood someone converted a normal 29.97 fps video to a 7.5 fps AVI file to reduce the size. Then later someone else converted that 7.5 fps AVI file back to 29.97 fps for VCD.

[abc-123]

Ok.....

The movies are mostly visual with little dialogue so I don't care *that* much if the resulting speed is different. As long as the audio and video is in sync and my dvd player can play it of course. (It's a no-name cheap one that plays xvcd's just fine.)

I could always mess around and maybe remove some of the duplicates rather than all.... it would certainly look less choppy than it is now, that's for sure. I'd mess with it untill I found a comfortable compromise between choppiness and speed.

But how does one remove the extra frames?
And can you speed up sound so that it sounds like you've got your finger on the fast forward button? (Yes, I realize people will sound like chipmunks, but I don't really care.)


Oh btw, does anyone know what 'constrained param. flag' in biterate viewer means?

[manono]

Hi-

I guess you didn't understand what junkmalle said. I think he's right-on in his analysis. Someone removed 75% of the frames, if it was originally 30fps, and 69% of the frames, if it was originally 24fps. Those frames are missing and gone forever. Even if you remove all the duplicate frames, it'll play just as choppy. Even if you remove them and speed it up to 29.97fps to play on your DVD player, it'll still be just as choppy, plus everything will play superfast and very unnatural. Plus, if you do that, and speed up the audio to match, it'll sound way worse than simple chipmunk talk or helium talk. It'll sound completely absurd, and will probably be unintelligible.

As for removing the duplicate frames, it's easy enough, but you'll have to reencode. Then, unless you speed it up, it won't play on your DVD player. If you want to make a 7.5fps AVI, you could do that, but MPEG-1/2 will require 29.97fps output.

I say either leave it alone, or send it to the Recycle Bin.

[junkmalle]

Deleting duplicate frames is easy. Open your file in VirtualDubMod. Select Video -> Frame Rate.

In the top section of the dialog (source rate adjustment) select "change to [119.88] frames per second.

In the middle section (frame rate conversion) select "Decimate by [4]".

Select you output codec and encode (or frameserve to your MPEG encoder). That will remove 3 of every 4 frames and increase the playback speed by a factor of 4 to restore the 29.97 fps of the original. You'll have to use an audio editor like CoolEditPro or GoldWave to speed up the audio by four fold to match the video. Then multiplex the new audio with the video.

The result will playback very smoothly at 29.97 frames per second. But the video will often be to fast to tell what's going on and the audio will be unintelligible.