Chop off end of video no re-encode, stream copy?

[OgreVorbis]

Is there some way using VirtualDub or other software that I can just chop off the end of an AVI capture file? It's completely uncompressed, so it should be able to just truncate the file. Instead, Vdub just copies the whole video to a new file the same way it would be if I made millions of edits. Direct stream copy is the same way.
If this isn't possible, then I might try to write my own program to do it. Just enter how many seconds to cut off, it finds the closest keyframe, then cuts the file short.
See, all my tapes are random lengths for some reason. I thought there were specific defined tape lengths, but some start rewinding right at 30 mins, others 50 mins, 60 mins, 80 mins, 90. I don't understand, but point is I can't just set my virtualdub to limit file size or time or something. It seems like I can only stop it manually at the end and if I'm not there, it overshoots.

[themaster1]

Stream copy mode should do it unless its an exotic codec

[Hushpower]

Quote:

Is there some way using VirtualDub or other software that I can just chop off the end of an AVI capture file?

Of course. You haven't described exactly what process you have used so far, but all you need to do is set the In marker (left-pointing black arrow below the timeline at the start of the section you want to remove, then set the Out marker at the end of the section. The timeline between the two markers will turn blue. Hitting DEL will remove that blue section.

Then just do a Save As, using Direct Stream Copy.

Conversely, if you want to keep only the blue section, use Edit>Crop to selection.

[OgreVorbis]

Quote:

Originally Posted by Hushpower

Of course. You haven't described exactly what process you have used so far, but all you need to do is set the In marker (left-pointing black arrow below the timeline at the start of the section you want to remove, then set the Out marker at the end of the section. The timeline between the two markers will turn blue. Hitting DEL will remove that blue section.

Then just do a Save As, using Direct Stream Copy.

Conversely, if you want to keep only the blue section, use Edit>Crop to selection.

Thanks, but I do already understand that.

Here's the specifics: I don't have a ton of disk space (500GB drive with not much free). I'm using an old PC with an AGP port for the AiW capture card. I also have random length tapes and can't sit there just waiting for the end to manually stop capturing. It still takes like 30 minutes just to save a stream copy with only the end chopped off. I just want to delete the end of the file INSIDE the current file w/o making a copy.
Being a programmer, I know that windows has the built in code function SetEndOfFile() which is an operation that should be completed in a second.

Alternatively, if it's not possible, then is there some way to get VirtualDub to detect when the player has hit the end of the tape and auto stop capture? If it can do this, that solves the problem too.

[lordsmurf]

Quote:

Originally Posted by OgreVorbis

Is there some way using VirtualDub or other software that I can just chop off the end of an AVI capture file?

Yep.

clip, snip
- You can either select and delete unwanted, all deselected for the same.
- Or select the wanted.

Video > Stream Copy mode
File > Save As

No filters, nothing else.

Quote:

If this isn't possible, then I might try to write my own program to do it.

Honestly, this would be welcome.

There are a lot of formats that need this treatment. Not just the lossless AVIs, but H.264/5, MPEG-1/2, and ProRes422. Some formats need the first/final GOP re-encodes, but most are key keyframe cuts. What we have now is old, spread out, buggy. A central single tool would be awesome. I'm sure that a lot of us would even be willing to donate a few bucks, much like Hybrid.

Some is non-obvious, as you see here with VirtualDub selection/deseleaction.

Quote:

Originally Posted by OgreVorbis

It still takes like 30 minutes just to save a stream copy

SSD.
I've gone to the expense and trouble of upgrading my capture systems. It's not a simple PC build, lots of settings, special formatting, etc. And some special hardware, such as dual boot hardware. (You cannot software dual boot for this. It will degrade and crash.)

Quote:

Being a programmer,

Oh yeah? Do you want to tackle a VirtualDub capture mode re-write?

Quote:

Alternatively, if it's not possible, then is there some way to get VirtualDub to detect when the player has hit the end of the tape and auto stop capture?

Nope. But see above. I'd like to re-fit VirtualDub, but my coding chops are beyond rusty.

There is way to preset the length of the capture. If it's an SP tape, then you can set it for 2:10 (because it's never 2:00, always more). In seconds. It's in the menu in capture mode, same menu as timing settings, but I forgot name offhand. Not at my capture systems today.

[latreche34]

Most software that I've used make a new edited copy of the original file even if it doesn't re-encode the video, Chopping off a part of a video within the same file without making a new file sounds like an odd approach that is not needed by 99.99% of people since getting an extra storage is not a problem for those 99.99%, Good luck.

[OgreVorbis]

Quote:

Originally Posted by lordsmurf

Yep.
Video > Stream Copy mode
File > Save As

See that's the thing. Save AS. Not just Save.
I think I know why they didn't give vdub a save function. The files are too huge to shift the bits around in. Much easier to just write a new file. However, that overlooks how easy it is to save to the same file if you are just cutting the end off.

Quote:

SSD.
I've gone to the expense and trouble of upgrading my capture systems. It's not a simple PC build, lots of settings, special formatting, etc. And some special hardware, such as dual boot hardware. (You cannot software dual boot for this. It will degrade and crash.)

Yeah, well this comp does have one SATA1 port free. It's just gratuitous to solve a software problem with bigger hardware.

Quote:

Oh yeah? Do you want to tackle a VirtualDub capture mode re-write?

Well, not the whole thing. What's wrong with that part of it?

Quote:

Nope. But see above. I'd like to re-fit VirtualDub, but my coding chops are beyond rusty.

There is way to preset the length of the capture. If it's an SP tape, then you can set it for 2:10 (because it's never 2:00, always more). In seconds. It's in the menu in capture mode, same menu as timing settings, but I forgot name offhand. Not at my capture systems today.

I think I saw that option a while back when I was exploring the menus. It might help me a bit. Thing is, I've got some tapes that I expect to be 1 or 2 hours long, and they are only 30 mins. So there's twice as much wasted space. Now I go and edit out all the blank captured stuff at the end, Save As... Now I have used 3x the space for no reason. I can go back and delete later, sure, but it's still annoying. Vdub needs to be able to detect the end of a tape.

[OgreVorbis]

It would be so nice if vdub was like this:

Menu items:
1. Learn when to stop capture
2. Use default end detection
3. [ ] Enable smart stop capture

1. This saves an image file of the rewind/stop screen. On future tapes, if #3 is enabled, it will then use this still frame with a little fuzzy logic to compare with the current frame and stops capturing.

2. This will simply detect an 80-90% black screen or blue screen (for X seconds) cause most VCRs look like that at the end of the tape. This should work most of the time without needing #1.

3. Enable/disable the function. (automatically stop capturing at end of tape)