Problems re-using VirtualDub

[djdust]

Hi all

A year ago I did some work using VirtualDub to edit some video files of mine that were recorded with my simple mobile camera. All I did was put a simple Fade-In / Fade-Out at the beginning and end of the files using the FadeFX filter and the first thing I did was learn to set the Video > "Smart Processing" and also Video > "Full Processing Mode" so that only the bits of video needing work would be re-encoded.

A year on, I'm trying to do the exact same thing again, except this time it's not playing ball. VirtualDub is just re-encoding the *entire* file and it's driving me mad as I don't understand why it's doing it. I'm definitely setting the "Smart Rendering" option but am ending up with files a third of the original size.

Can anyone help at all?

cheers

[jagabo]

Are you using the same compression codec as the source video?

[djdust]

Yes. When I load the file into VirtualDub, it's showing up as "Xvid MPEG-4 Codec (XVID)". I'm choosing the same as output...

[jagabo]

I just tried an Xvid AVI with two instances of FadeFX, one to fade in at the start, one to fade out at the end. It looks like VirtualDub doesn't know that the FadeFX filters only effect certain frames (in this case at the start and end of the video). You have to enable the Blend option for each filter in the filter list and use the Curve Editor to limit the filters to the effected segments. Then Smart Editing works.

[djdust]

Thanks Jagabo, it's *almost* working now, except for some reason it won't let me do both the start and end fades together. If I attempt to do both, the second fade just gets left out.... Can you get it working ok at your end..?

[jagabo]

I did both start and end fades when I tested. The end fade was a little tricky. The frame numbers in the Curve Editor went beyond the number of frames in the video. Be sure you set the blending for the correct frames.

[djdust]

Getting another problem as well now..

I'm finding that if I create a version of a file with a fade-in, it works fine when playing it back thru a media player. However, when putting the file into VirtualDub again, it gets a horrible juddering effect during the duration of the fade-in which shows up on any additional work I do on the file. Any idea why it's doing this?

I swear this all worked fine a year ago...

[jagabo]

I'm finding that if I create a version of a file with a fade-in, it works fine when playing it back thru a media player. However, when putting the file into VirtualDub again, it gets a horrible juddering effect during the duration of the fade-in which shows up on any additional work I do on the file. Any idea why it's doing this?

Just a guess: Try changing the state of the Packed Bitstream setting.

[djdust]

Forgive my ignorance, can you tell me where this is in VirtualDub?

[jagabo]

It's in the Xvid settings. Along with Profile, Level, etc. At the main Xvid dialog press the More... button to the right of Profile @ Level.

[djdust]

cheers, found it and unticked it - still getting the awful juddering effect though..

[jagabo]

So the reencoded part is juddery but not the rest of the video? Or vice versa? Or both are juddery?

And you said only in VirtualDub? Do you mean while previewing the video? Or while stepping through frames with the arrow keys?

By the way, the test video I reencoded didn't have any problems anywhere.

[poisondeathray]

what version of vdub?

[djdust]

So the reencoded part is juddery but not the rest of the video? Or vice versa? Or both are juddery?

Just the re-encoded bit. The rest is fine.

And you said only in VirtualDub? Do you mean while previewing the video? Or while stepping through frames with the arrow keys?

While previewing the video. I thought it might be the software being a bit jerky but the output is juddery too...

what version of vdub?

The latest - 1.9.11

[jagabo]

If you step through the video frame by frame (use the right arrow key on the keyboard) are there missing or duplicate frames? If not, I wouldn't worry about it since it doesn't effect playback in media players.

[DarrellS]

You need to use the fill filter instead of the FadeFX filter to be able to fade in and out in different places in the clip. You can add as many fades as you want.

Gif #1 shows fade in from black at beginning and fade out to black at end.

Gif #2 shows a scene fade in to black and fade out from black.

[DarrellS]

EDIT: Choose Video > Compression > Full Processing Mode > Codec used in original file > Smart Render > Audio > Direct Stream Copy > File > Save As AVI.

Some filters are not made to run in Blend mode so you end up encoding the whole file. That is why it is better to use the Fill filter for fade to black (or any other color). Also if you use the curve editor and fail to get the outside points all the way down to the line then you'll end up encoding the whole file since the Smart Render sees the Curve being the length of the whole file.

[jagabo]

if you use the curve editor and fail to get the outside points all the way down to the line then you'll end up encoding the whole file since the Smart Render sees the Curve being the length of the whole file.

That's a good point.