AVI file size increase after editing in VirtualDub

[wickedlemon]

Hi

I captured a 22 minute AVI at 720 x 576 PAL using huffy codec. Comes in at about 8Gb.

When I apply a fade to black filter at the end and save (again using huffy) the file size goes up to 16Gb.

Does anyone have any suggestions as to what (wrong) setting would account for the difference?

The same program is saving the original capture and the filtered video, so I can't see where the variation is coming from.

Thanks

[Yirkin]

Are you doing a direct stream copy for the audio? If not then maybe it is uncompressing it in your new file?

Howard

[wickedlemon]

I'm not doing direct stream copy.

Correct me if I'm wrong, but a fader filter wouldn't work in direct stream copy mode? I tried this setting and it didn't seem to work for me.

[bugster]

AFAIK, when you use virtualdub like this, you have to set up the compression method and parameters to be used during the save. So you must set video to full processing and compression to huffy with the same settings as before. Are you doing this or are you not touching the compression, in which case it is probably defaulting to 'none', i.e, RAW AVI.

[Craig Tucker]

If you were saving as a raw avi vdub should have given you a warning that the file you were about to save had no compression and would be very large.

[bugster]

If you were saving as a raw avi vdub should have given you a warning that the file you were about to save had no compression and would be very large.

Hmmm, true, though these warnings could have been turned off at sometime.

Craig, I don't use huffy, I was only doing a bit of educated guesswork. Would the file size doubling like has been described possibly explain huffy to raw avi conversion, or is huffy more efficient than this?

[pijetro]

It probably wants to do a raw colourspace conversion. Go to Video>compression, and see what setting is defaulted....The fade would be good if you frameserved your video, but since you've made a change in the .AVI, you're telling Vdub to save a duplicate .AVI with the fade included, at uncompressed settings.....

[Yirkin]

Oh I see. Didn't realize that a fade to black filter was audio related. I hope you figure it out.

Howard

[wickedlemon]

Gone into Video compression options and made sure Compression is set to Huffy and not Uncompressed before saving and still get big file. I don't understand how it works ok when I save initially after capture, but not after making changes.

[bugster]

Oh I see. Didn't realize that a fade to black filter was audio related. I hope you figure it out.

Howard

Good point, but I doubt uncompressed audio would increase the file size from 8 to 16Gb.

wickedlemon, if your final requirement is to encode to mpeg, why not frameserve from vdub instead of saving out a new Avi, as pijetro sugests.