Joining Mpegs help please [Archive]

SDVideoDude

10th March 2003, 06:31

Originally posted by JonRead
I use AVI/MPEG/RM joiner, it works for me.....

http://www.boilsoft.com

To paraphrase an old classic, is it a "good" joiner or a "bad" joiner? :p

As a "newbie.1" I know there are issues with syncing the audio and video, so I'm not sure if this is possible or not. What I'm looking for is what I'd call a "smart" joiner. A "dumb" or non-smart joiner would just stitch the together, tail to head, sort of like a copy and append file operation.

Maybe a better term would be "semi-smart". A good basic "stitcher" would need to check the stream headers in both (all) files to be sure the format of the AVI/MPEG (gasp RM) files match. It's probably more complex than that and I'd love to hear a detailed explanation of anyone either has one or knows of a site/FAQ/guide that goes into what's needed to join parts/clips together.

My concept of a "smart" stitcher would be this. If I understand this correctly (probably not ;) ) there could be at least these cases to deal with, assuming the files pass the check for exact A&V format
matching:

[list=1]
The end of clip A has a slight overlap with the start of clip B
Accounting for things like keyframes, proper GOP structures, etc, clip A ends at the end of the A&V streams for frame n, and clip B starts at frame n+1
There is no "perfect" seam or any overlap between clip A and clip B, i.e. frames are missing.
[/list=1]

That's probably a gross simplification.

A very cool stitching program could find the overlapping frames or the n and n+1 case and piece them together such that the resulting output file would appear to be seamless.

I think it's way more complicated than that, so I'm not sure if such a tool exists, without getting into expensive editing programs.

If it's not possible to automate the process so that the seam is close to as invisible as possible, another alternative seems like it would be pretty cool. Showing three windows where left is clip A, right is clip B and center window is a composite of the last frame of clip A and the first frame of clip B.

I think overlaying the frames from the seam, and then allowing the user to change the frames at the seam point from both clips might be a way to more easily/correctly manually identify the proper seam between the clips.

Along with the video frames, maybe a smaller below each could show some representation of the audio for that frame, to allow the user to "eyeball" the audio as well. Maybe independently. LOL. Clicking on the visual represenation of the audio could give the user different "audio views" for matching.

With clips that overlap a few seconds or so, I've tried "manually" joining two clips by trying to find the overlap or the best join point and trimming clip A, but I don't have much luck either finding the right frame or matching the audio. A lot of times, the differences between the frames is so small, it's very hard to visually find the right frame without seeing them either side by side or superimposed.

I'm probably hallucinating right? :D

There's so much to learn, and it seems fairly complex. But I'm learning more and more every week. Forums like this and the various guides some very generous people have written, really help with the process. Sometime maybe I too can say, "I are an exspurt". :D

By now, the people that really know how digital media works are probably rolling on the floor, laughing uncontrollably and pointing fingers at me, between gasps. :o Maybe that good laugh can be my way of a very, very small repayment for sharing your time and wisdom? :cool:

Thanks,
Mark