VirtualDub Gone Wild?

[solarblast]

I have a fairly simple task for VDub to perform. I captured a 54 minute avi file from my DV8 camera via Vegas, 10G. About 15 minutes of the middle needed to be removed, so I took it into Vdub. I deleted the 15 minutes and then used File->Save as AVI. It seems determined to produce something far beyond 10G. What's happening? It seems like it's going to take 90 minutes to make the new avi. I selected the full length with the markers, 0 to 71946 frames. I stopped it after it produced 18G and had gotten about 1/3 or less of the way through the file.

[redwudz]

Did you select a codec? If not, it will be a huge RGB file by default. You would generally want the same codec as the original, but that depends of what you want your output format to be.

[guns1inger]

If you are just cutting, use Direct Stream Copy mode so it just writes the unchanged data as it existed in the first place.

Why not use Vegas ?

[solarblast]

Direct stream copy? Ah, I see under Video that it's a choice. I'll try it. I think I'm going to write that down. I suspect I used it once before.

Is there a way in Vegas to paste two avi files together and write the result as avi? Actually, I'm pretty sure there is, but I've never figured out how to match the parameters with the input file. I just have a personal preference to whittle down avi files when they are somewhat bulked up by stuff I can't use.

A friend told me that VDub has the ability to do some motion stablization. Is that true?

Thanks for the tip. I'll try direct stream shortly.

[redwudz]

There is a 'Deshaker' filter: http://www.compression.ru/video/deshaker/index_en.html

And one guide: http://dvformat.digitalmedianet.com/articles/viewarticle.jsp?id=28849

[guns1inger]

Vegas is a fully featured editor - adding and cutting avi files is bread and butter. Why else would you have it ? If you only use it to capture from your DV camera then you may as well uninstall it and get all the disc space back. WinDV will do the same job and is a lot smaller.

[solarblast]

I certainly use it for a lot more than capture; however, when I've shot video that contains material that is of little use like the 15 minute segment, then I do not want it even in the avi file. The camera was pointing at the ground for 15 minutes. As I edit the file, I'd rather not have to contend with the segment, and not even waste space on my HD. If there's a way to simply use Vegas to remove the segment AND produce a shortened avi file of the same format, I'd like to know how to do that (in the sense of the VDub direct stream copy). I would prefer to do it in Vegas than VDub.

[guns1inger]

I can't believe you use Vegas for more than capture if you cannot do even the most basic of edits.

Put the video on the timeline. Drage the cursor to the start of the segment you want to remove. Hit the S (split) key once. Move the cursor to the end of the segment you want to remove. Hit the S key again. Click on the segment you want to delete, and hit Del (delete). If you have ripple editing on, the two halves will join up automagically. If not, drag the second half back top the first. Finally, click on File -> Render and select DV avi and whatever format your file is (NTSC/PAL 4:3/16:9). If you have done nothing else to your video, Vegas will save the video in the same way the virtualdub does in Direct Stream Copy mode.

[solarblast]

Yes, I know how to edit the timeline. My previous experience with cutting out a segment suggests that the final avi file ends up bloated, i.e., bigger than the original avi file. I may be mistaken, but a year ago I mentioned this on this forum, and a number of respondents said to use VDub or possibly another utility. I'll try it again as you mentioned and see what the results are.

[guns1inger]

The output size comes down to the bitrate and codec you are using. The best option, wherever possible, is to avoid re-encoding. This means using a lossless codec, or using the same codec as the source and an editor that is smart enough to realise nothing has changed. For DV format source, Vegas is smart enough to understand that if the video hasn't been changed, it can be written as is. If you are getting a larger file size you are using the wrong codec, regardless of the software.

[tmh]

OK, he captures the 54 min. Dv footage. Then if he puts the clip into timeline and edits out the part he doesn't want, then saves the movie as a dv file, then he can go back and delete the original 54 min. clip I guess. Seems to me VDub is easier for this also in de=irect stream copy mode.

I THINK the point isn't how to get rid of the bad footage in the movie, it's how to get rid of it completely so it isn't hogging memory. If one just uses it in the timeline then edits for a final movie, the original clip is still on the harddrive.

[solarblast]

You've got it. Getting rid of useless space, but not necessarily in memory. For the post part, I think the avi file is sitting on the HD, and Vegas probably has a 'map' of the lay out with pointers into the HD. For example, the third minute of video of video can be found on track 900 of the HD, and the 20th minute may begin on track 3555. When Vegas needs to operate on the 20th minute, it goes directly to track 3555 and scoops up whatever it needs to display beginning there. Probably some chunk of the avi file resides in memory for quick access. I just don't need to waste disk space for video I have no interest in using*.

Later today I'll be trying out the Vegas angle explained above to see if I can really produce a direct copy avi without bloating it. At the moment, VDub did just fine, and I'm editing the results.

* In this case, the footage has some value. Even though I had the camera on while it was hanging downward photographing the floor, there is value to it. The audio is an interesting discussion I was having with my guide on some technical matters. There is some salvageable video too, but it's really not the aim of my video to go into those details. So in this case, I'm really not going to save disk space, since I saved that segment to a different avi file. Most of the time, I just cut such stuff out and put it in the Recycle bin.

[guns1inger]

OK, he captures the 54 min. Dv footage. Then if he puts the clip into timeline and edits out the part he doesn't want, then saves the movie as a dv file, then he can go back and delete the original 54 min. clip I guess. Seems to me VDub is easier for this also in de=irect stream copy mode.

I THINK the point isn't how to get rid of the bad footage in the movie, it's how to get rid of it completely so it isn't hogging memory. If one just uses it in the timeline then edits for a final movie, the original clip is still on the harddrive.

It doesn't matter what method is used, at some point, until he deletes the original file, he has two versions hanging around.

A smarter approach would be to use Vegas to create an EDL and just capture the parts he wants, and not even transfer the sections he doesn't. Makes for simpler trimming.

[solarblast]

OK, I ran a test on an avi file 6.54G. I cut it in two and Rendered the first half as AVI with a template of NTSC DV, apparently the default. I then closed Vegas and tried the opposite half. If I add the two lengths together, the total is 6.59G. I'm pretty sure I did not make the cut precisely where I did the first time, but I would say I'd accept that no substantial change occurred.

However, there's no doubt in my mind that when I tried this 10 or months ago, something went wrong and the addition above was not even close. Why I do not know. Nevertheless, it is good to know that Vegas is capable of producing a proper file when individual pieces are sliced out of it.

End of story for me.