How can I modify the first frame of an AVI file?

[jsevinsk]

I have a cheap PMP that will play my DivX/AVI files on its small LCD screen. When selecting a video to play, you can't choose the video by name. You have to choose it by thumbnail. It uses the first frame of AVI file as the thumbnail, and unfortunately, all my AVI movies start with a black screen. Is there some tool I can download that will let me alter the first frame of the AVI file and change it to whatver I want?

[Cornucopia]

Neat idea, don't know of an app that'll do that automatically (although it should be possible).

Try this instead:

1. Load file up on Vdub (assuming you have the codecs already). Set to DirectStreamCopy(A+V, but audio set to none temporarily). Scan to point you want to use as thumbnail. Select In and Out (so it's just 1 frame).
2. Save as AVI. Close File.
3. Now, open Thumb.AVI and then append original AVI to the end of it (also DirectStreamCopy).
4. Save as Original+Thumb.AVI

Done.

Scott

[jsevinsk]

What's the proper way to remove the audio? I must be doing something wrong because I'm not familiar with that tool. First I selected Streams --> Stream List, which showed me that there was one audio streem. I pressed the Disable button, then saved the one-frame-long AVI file. However, when I loaded that file and tried to append the original, I got an error that says the segment has a different number of streams. If I save the one frame with the audio stream, the whole process works, but then I get a short random piece of audio at the beginning of the movie.

Ideas?

[Cornucopia]

You've got the wrong application:

VirtualdubMOD has [Streams|StreamsList], Virtualdub DOESN'T. It has [Audio | NoAudio/SourceAudio(aka from AVI)/WAVaudio]. You would set it to NoAudio.
--or--
If it says it only wants to do same-stream joins, you create a 1/29.97th of a second (=1frame or 33.3667 milliseconds) length of Digital Silence (all Zeroes). Most WAV editors can do this easily. Use that in Vdub along with your Thumbnail clip. Selection [Audio|WAVaudio]. Then append the original. If it acts goofy about the 2nd section also needing WAVaudio, do a WAV export from Vdub ahead of time and use it instead of its internal during the join.

Scott

[jsevinsk]

OK, now that I have downloaded the right tool...

It seems like I can't just grab any one frame that I want and save it. What I end up saving is a piece of video from the last key frame up until my end point. Is there any way around this problem?

[Cornucopia]

It's a "problem" for you, but it's actually the way all those things work...

Remember I said "DirectStreamCopy", so that means it's not being decoded/converted to RGB, etc. The video stream packets are getting sent straight out with the same structure.
Also, you've got a DivX file, so that means it's using MPEG4-type compression with I-B-P frames. Remember, they're not being Decoded...
Since MPEG4-type compression works with GOP's (not just frames), to copy WITHOUT DECODING requires copying a whole GOP.

Workaround:

Remember I originally thought about "saving an Image Sequence (BMP)"? Well, that's what you should do here.
It'll probably save the whole GOP, but that's only ~15 pictures. You just sift through to find the one you want and encode that to an I-Frame-Only DivX-compressed video file (1 frame long).

Then continue with the rest of my suggestion.

Scott