HuffYUV 2.1.1 codec gives larger filesize than original AVI?

[lnong]

Here's what happened:

Using VirtualVCR w/ HuffYUV 2.1.1 codec, I captured a 45-min video (video only, no audio) from an analog source, and got a 15GB AVI file. Then I used VirtualDubMOD to cut off about 300 unwanted frames from both ends of the video, as well as about 200 consecutive frames in the middle. When I did "Save As", the "Uncompressed RGB" compression method was preselected. I changed the selection to "HuffYUV 2.1.1". After waiting for 1.5 hrs while VirtualDub did its 2-pass encoding, I ended up with a 21GB AVI (which is 6GB larger than the original AVI). How can this be explained?

Actually, I was pondering whether I should choose "Uncompressed RGB" or "HuffYUV 2.1.1". First I thought that if I choose the HuffYUY method, then my original AVI (which was compressed with HuffYUV 2.1.1 during capture) would be further compressed which would result in more quality loss. In this case, choosing "Uncompressed RGB" is better because the HuffYUY compression scheme in the original file is preserved in the final AVI. However, I then thought that maybe VirtualDub does it differently. When it loads the original AVI, the file is decompressed for editing. Then when selecting "Huffy 2.1.1" compression during "Save As", it will re-encode the edited AVI using the same existing compression method as in the original AVI. This seems more logical and that was why I selected "HuffYUV 2.1.1".

But due to this larger resultant file now, I'm kinda lost again. Can someone please explain?

[Safesurfer]

What you should have done is choose "Direct stream copy", instead of "Full processing." If all you are doing is trimming bits out, you don't need to process (unless you added any filters.)

[Nelson37]

Agree with safesurfer.

BUT - I am not aware of any "2-pass encoding" using Huffy, SFAIK this is not possible. Something is wrong here.

[Cornucopia]

What you're forgetting is that HUFFYUV is "Lossless" compression (usually). You could conceiveably compress-uncompress & edit-recompress-uncompress and add fx-recompress-uncompress and add titles-recompress and it shouldn't degrade the picture any more than the orignal capture quality. There are exceptions (framesize adj, color averaging, etc), but it should hold up nonetheless.

Yes, you should use "Direct Stream copy"

Check your orig & your mod files with Gspot or similar. It could be that the codec chosen wasn't what you thought it was.

Or,
did you accidentally include audio in the modded file? You said the original had none and that would account for some size change.

Scott

[Steen4]

You are not the first to wonder about this. Follow this link for information:

https://www.videohelp.com/forum/viewtopic.php?t=239875&highlight=

This should help...

[lnong]

Thanks for your help guys. I used "Direct Stream Copy" and I didnt have to choose the compression method. Yeah, the filesize is a bit smaller than the original now, which is expected after deleting those 400+ frames.