converting Huffuv AVI to Lagarith AVI

[abbymat]

I converted some AVIs encoded with Huffyuv to Lagarith using Virtualdub hoping the file size would decrease BUT suprisingly they have increased ! Any idea why ?

thanks

[Soopafresh]

The colorspace. Try saving in Lagarith, but go to Lagarith settings and save in YUV colorspace.

[jagabo]

Use Fast Recompress mode in VirtualDub. This will keep VirtualDub from converting YUY2 to RGB before sending it to Lagarith. Make sure that HuffYUV is set up to output YUY2 (make sure "always suggest RGB format for output" isn't checked).

[abbymat]

Thanks, I'll try out the suggestions.

One other question, I have Null Frames present in the Huffyuv AVI, so should I set "Enable Null Frames" in the Lagarith options when converting ?

[jagabo]

The null frame setting shouldn't matter as far as conversion is concerned. But some conversion/editing programs can't handle null frames. So be sure whatever software you plan to use in the future can handle them. Null frames (used where a frame is exactly the same as the previous frame) are very rare in real world video. About the only place you will see identical frames is computer generated video.

[abbymat]

I did with the settings you suggested, its better now - filesize is not increasing as before but decreases slightly.

an 80 Gb Huffyuv file is now 79 Gb on conversion to Lagarith - about 1.5% compression. Should I not get about 10-30% compression at least ?!!

[jagabo]

Lagarith usually does get more compression than HuffYUV -- in the 10 to 30 percent range you've heard. But not always. Are you sure you used Fast Recompress in VirtualDub?

[abbymat]

Yes, when I used Full Processing the 80gb increased to 100gb. After you told me, I used Fast Recompress and its now 79gb, a very slight compression. Is there any oter settings on Virtualdub that can increase compression further ?

[guns1inger]

Not hugely. While Lagarith can get more compression that Huffuy, conditions have to be right, and if your video doesn't meet the right conditions, for whatever reasons, the difference can be less and even minimal.

Given that lossless compression is usually used for intermediate files, and won't be around for long, saving a few GB here and there seems not worth the effort you are expending.

I would be spending more time on the project that spawned the video, than on trying to squeeze a little more compression out of a lossless codec.