Weird issues....help a Divx newbie.

[Macros746]

Hello all, I'm relatively new to the whole Divx scene being a hardcore VCD/SVCD boy. But, recently, I decided I was being stupid and closeminded. So I downloaded Gordian Knot and encoded my first movie with Divx 4.11. It turned out very nicely (I followed the guide exactly except I didn't do the compression test) Then I uninstalled Divx 4.11 using the add/remove menu and even deleted the reg entry just to be sure. Then I installed Gordonian knot again without Divx 4.11 and installed Divx 5 pro. Then, on my second movie I ran into some weird issues. Firstly, the compression test doesn't work....it seems to be trying to access divx 4.11.... Finally, when I encoded Count of Monte Cristo the file ended up being over 4 gigs! When I selected 1 CD. Don't know what I'm doing wrong. Is there some special way to uninstall Gordian Knot before reinstalling it? HELP. By the way, I'm really having fun playing with Divx.....it's a lot of fun :D

Macros

[manono]

Hi-

First make sure that DivX5 actually got installed (maybe a reboot is necessary). Open VDub, and go Video-Compression and make sure it's listed among the Video Codecs. If it's not there, then reinstall it.

As for uninstalling GKnot, open GKnot and go Options-Delete Registry Keys and then just Delete the program and start over again. That frequently fixes a lot of problems.

[Macros746]

Thanks for the input/....I'll try that right away. Now another quick question....I notice in the two movies I've successfully encoded that there are comblike marks in movement scenes (it looks very much like interlacing) Is this normal and unavoidable in Divx?

Macros

[manono]

Hi-

It's normal (well, semi-normal), and it's avoidable. You didn't say whether you were PAL or NTSC. But assuming you're NTSC, you might try making your .d2v with No Field Operation and putting on IVTC in GKnot.

Have you read the guides? You said you did, but you missed some basic information. When you made your .d2v in DVD2AVI, the information it gave you should have told you whether you could Force Film or use IVTC (with the FILM percentage figure it gives you when done). Also, I do recommend doing the Compression Test to help you in choosing the correct resolution and file size for your movie. Good Luck.

[Macros746]

Thanks for all the help everyone. I uninstalled, reinstalled, and now all seems to be working rather well. Just a few questions now. The horizontal lines thing. You said it is avoidable...is it merely a bitrate issue? Or is there more to it? I always want to know all the details on these things. When Harry met Sally was largely 'combfree' but there were a few points during motion scenes and scene shifts (during every scene shift you can see those lines for the merest of a split second...normal?)

Thanks again,
Macros

[jggimi]

The horizontal-lines that you see now and again are interlace artifacts. You are seeing them because of a procedural error you are making when you encode.

Somehow, you are not properly converting the video from what's good for TV to what's good for a PC.

NTSC TVs have interlaced displays. Every second, an NTSC TV displays 59.94 fields. Two of these fields make up a complete frame -- a single image. 59.94 / 2 = 29.97, the framerate of NTSC.

Using the 480 vertical lines of a 720x480 DVD as an example, the first field contains lines 1,3,5,7...475, 477, 479. The second field contains lines 2,4,6,8...476, 478, 480. This type of signal is called "Interlaced."

PC monitors are not interlaced displays, instead, they are progressive, and are designed to show complete frames. Interlaced frames look awful on them -- horizontal bars, ghost images.

Unfortunately, video from NTSC DVDs will contain either interlaced video -- if the origin was a video camera -- or will contain data that *looks* interlaced, if the origin was film. With video source, the frames must be de-interlaced.

With film source, an understanding of how 35mm film gets turned into an NTSC video stream is required.

The process of getting from 24fps film to 29.97 video is called Telecining. It adds ~6 frames per second, by combining fields from adjacent frames. If you were to examine Telecined content frame-by-frame -- and sometimes you have to -- you'll see progressive frames interspersed with what look like interlaced frames. The process of removing those extra frames and reassembling fields in the proper order is called Inverse Telecining, or IVTC. The resulting content will have a framerate of 23.976, pretty close to the original film's 24 fps.

With the Gordian Knot encoding suite, the default method of IVTC is done in the DVD2AVI step, using a feature called "Force FILM." The resulting .d2v project file will point to properly reassembled, progressive frames, and will already be converted to 23.976fps. But sometimes, Force FILM cannot be used. It usually depends on the DVD production company, and the choices they make. Sometimes, the content will determine it, especially for content which is a hybrid of film and video. Then, the IVTC must be done during the encoding step, with software that analyzes every frame. In Gordian Knot, you do this, only if needed, by selecting "IVTC" in the Save&Encode window.

The guide recommends using "Force FILM" to IVTC whenever the preview results in a Progressive/FILM content of 95% or greater. Note that in order to do a proper preview, "Force FILM" must be turned off.

[stanky]

That's the best I've seen that explained. It all just came together for me. Thanks for making all those funny words mean something to me ;)

Cheers,
Stanky