[nbwriter]

Dear Contributors,

Thanks to Dvder for generously posting his work. This is what it's all about

bicubic enlargement from 512 to 720

Upscaling resolution to 720p will not garner any advantages in the output file due to the simple reason you're asking your software to stretch each pixel. What will happen is that your film will look washed-out (a saturation problem) and ghosting may occur (the pixel stretching problem: basically shadows and outlines are enlarged).

Although it goes against logic, a better route here is to reduce 720p content to 512p - so you obtain a high def output file. (Each pixel is being more tightly packed into each frame, a trick professional graphics artists use all the time).

You can easily see how this "reduction technique" works if you have a HD jpeg at 3000px x 3000px and reduce it to 1500 x 1500, you finish up with a picture that has super-definition on your screen!

DivX 6 plugin in VirtualDub for re-coding...

Hmm.. I'm not sure who gave you this nugget of advice, but DivX always performed poorly on Microsoft Windows PCs. This is wholey to do with Microsoft's myopic coding (in their OS) supporting only "the chosen few" codecs that the company preferred: MPEG4, MPEG2, WMV.

Pro coders like YIFY go for MPEG4 using the MP4 container, although I prefer MPEG4 avi coz AVI can be further optimized, once you know what you're doing...

Resetting, or changing keyframe intervals in an AVI file will probably lead to MORE jitter (sync issues) since these are pre-set at the encoding stage. Straight re-encoding into MPEG4 from a source file will just avoid that altogether.

I'm intrigued by the suggestion of altering the file header information. Presumably that'd be via a hex editior?

Going to the hex level on video files is not advisable, rather a simple tool called DivFix will repair missing or corrupt header information in source files, outputting a file that has less errors. (Its a depreciated tool, but many a pro-coder swears by it).

I estimated 25 fps, at 720x540 with 32 bit colour depth should still leave a whole heap of spare cycles on a 3.4 GHz processor

I have my doubts, if I've understood you correctly, you were re-processing every single frame of a source file using DivX Plugin and VirtualDub.. On Core4 it will thrash through all the pixels per frame like a combine harvester on jet fuel... I just hope you have a high-spec cooling fan fitted over your CPU!

No processing filter I tried (unless I went for a cartoon-like effect) would eliminate the shifting subtle pysychedelic green and purple tones from the allegedly white bed sheet

Ahh...I see.... You probably took the route here of a filter in VirtualDub, right? From my experience, if you wish for "crisper" whites in videos consider (the much simpler factors) of contrast or/and gamma levels- these can be finely adjusted in Videopad (for example). Videopad isnt a pro-level editor, but it does the job...

Final thoughts:

Reviewing "Lisa Phillips - Leigh Nearly Naked", I reckon you had minor contrast, gamma and color saturation issues in Scene 1. But the saturation issue isnt there in later scenes, so well done. Ghosting and jitter have been avoided, I suspect, due to the high quality source files you were working with. Full marks, too, for going with MP3 audio at 192 Kbps, that's how the pros do it! (Lovely crisp audio with MP3 every time)

Kind Regards NB