Novice: VirtualDub cropping & window sizes

[terrypin]

Hope this is the appropriate forum?

I'm a novice in this video area. I am learning VirtualDub 1.6, and have just been trying my first crop. But on clicking the Cropping button from the Filters window, the resultant window was larger than my 1024 x 768 screen! So it seems impossible to make the adjustments.

After experimenting into the small hours last night I don't think I properly understand some basics about VirtualDub windows. For example, what is the default size that VD opens at? Can that be changed? If the image is smaller than the VD window, what is the second image that I see partially to its right? Is that the next frame or what? Will images in VD always be shown at their actual size, regardless of how you resize the VD window?

Any advice would be appreciated please.

--
Terry, West Sussex, UK

[guns1inger]

Vdub opens with two visible windows. Left in the input, essentially the avi you have just loaded, and the right is the output, showing the effect of any filters you may ave applied.

Right-click on either of these to change the 100% size of the viewport, and the aspect ratio (handy when checking 16:9 avisynth files). This can be done independently.

Changing the size or aspect ratio of these windows has no effect on the video itself, it is purely visual.

Output is generally where the action is, so if you are running at a lower resolution, try reducing the input window to 50% to give you more room for the output window to display.

[jagabo]

Output is generally where the action is, so if you are running at a lower resolution, try reducing the input window to 50% to give you more room for the output window to display.

Or use "Options -> Swap input/output panes" to reverse the position of the windows.

[terrypin]

Thanks both.

Despite normally r-clicking anything in sight, I obviously missed that facility in VirtualDub and greatly welcome learning about it. For one thing, it solves the problem I'd encountered in being unable to crop a large image, as I couldn't reach the buttons! (BTW, I saw nothing about r-clicking in Help; am I missing some basic documentation?)

Several points still confuse me though:

1. In Options, the following 3 toggles don't appear to make any difference to my display, either via the menu or using their shortcut keys:
- Display Input Video
- Display Output Video
- Display Decompressed Output
What are they meant to do please?

2. With a file loaded and my first crop finished, I see the input window on the left and the output on the right, as you describe. But clicking either of the play buttons (marked I and O) runs only the input.

3. However, I have occasionally seen the right hand video running, and I think this was after I'd moved the position marker running across the whole window. Basically, I don't know the rules here at all!

4. What does 'dub in progress' mean? Is it simply 'video is playing'?

--
Terry, West Sussex, UK

[guns1inger]

1 & 2 Appear to be bugs with the latest VdubMod. They certainly worked in the previous version. To be honest, I hadn't noticed because I really only use vdub to preview AVS files to check the AR, so the input windoa is really all I watch.

3. See previous points about it being buggy.

4. Pretty much.

[terrypin]

Thanks. At least those are not just down to my ignorance then!

--
Terry, West Sussex, UK

[guns1inger]

Or we both have missed something

[jagabo]

Despite normally r-clicking anything in sight, I obviously missed that facility in VirtualDub and greatly welcome learning about it. For one thing, it solves the problem I'd encountered in being unable to crop a large image, as I couldn't reach the buttons! (BTW, I saw nothing about r-clicking in Help; am I missing some basic documentation?)

Programmers are rarely interested in writing documentation.

1. In Options, the following 3 toggles don't appear to make any difference to my display, either via the menu or using their shortcut keys:
- Display Input Video
- Display Output Video
- Display Decompressed Output
What are they meant to do please?

All three work for me in VirtualDub, VirtualDubMPEG2, and VirtualDubMod.

Display Input video enables displaying of the source (before any filtering) video in the input pane. If you disable this the input pane will remain blank as you scroll through the video, play the video, or when encoding.

Display Output Video enables displaying of the output pane (post filtering). If you disable this the output pane will remain empty as you scroll through the video, play the video, or when encoding.

Display Decompressed Output instructs the output pane to display the decomrpessed output while saving to a file. Each frame, as it's saved to the output file, is read back from the output file, decompressed and displayed. Use a codec like Xvid, set the bitrate really low, and Save as AVI. You'll see the really bad looking encoded/decoded result in the output pane. This only works if you have Display Output Video enabled.

2. With a file loaded and my first crop finished, I see the input window on the left and the output on the right, as you describe. But clicking either of the play buttons (marked I and O) runs only the input.

The I button only plays the input video, so only the input frame is drawn. The O button plays both the input and output (filtered) video. If you didn't see the output video playing it's probably because you disabled the output pane while playing with #1.

3. However, I have occasionally seen the right hand video running, and I think this was after I'd moved the position marker running across the whole window. Basically, I don't know the rules here at all!

See #1 and #2.

4. What does 'dub in progress' mean? Is it simply 'video is playing'?

It the title bar? It says that whenever you play or save a video. Note that closing the little status window by pressing the close-window button in the top right corner doesn't stop VirtualDub's encoding and file saving. It simply closes the status window.