Can you force frames in CCE like you can in TMPGEnc?

[Kiddfrost]

Hi,

I am reducing the size of ripped DVD so I can fit it on to a DVD-R. When using CCE the output is jerky as soon as there in any movement in the picture. When using TMPGEnc I get the same problem. If I force the I frames when using TMPGEnc the film comes out just fine. I was wondering is there an equivalent setting in CCE to force the I frames as I would prefer to use CCE. The movie I am encoding is NTSC 29.97 fps, 4:3.

Thanks

[adam]

I'm not sure how additional I frames can affect jerkiness and I'm not quite sure what you mean buy forcing I frames. I assume you mean putting an I frame at every scene change, and if so CCE does this by default. To turn it off you would look in the GOP section and check restrict auto I frame insertion.

Since you say you are encoding in ntsc and your source is dvd, that leads me to believe that this may be a field order problem, which means you are really not frameserving as you should be.

Nearly all ntsc dvds store the film progressively at 23.976fps and use pulldown flags to telecine the film to 29.97fps as it plays. This increases quality by %20 because you have %20 less frames to encode, and there is no reason why you shouldn't use the same techique in your dvd's, or Svcds and vcds for that matter.

I assume you are using dvd2avi to process your vobs. If so then preview it and let it get past the credits. If it says film or %95 or higher film then enable forced film in the video tab. This will export 23.976fps material to your encoder. When you are done encoding in CCE run the m2v file through pulldown.exe to add the pulldown flags. Now any dvd authoring software will accept this file as 29.97fps, and it will playback at that speed, but you will have much better quality and it will eliminate any possible interlacing problems.

Now the reason I even bothered to bring this is up is because by not using forced film and by frameserving at 29.97fps, your material is now interlaced. In order to encode interlaced footage you must specify the correct field order otherwise the playback will be very jerky. By instead using forced film you are only dealing with progressive frames so you cannot possibly run into field order problems.

If for some reason you cannot use forced film, ex: hybrid, pure ntsc etc..., or your source is 29.97fps and not coming from a dvd, well then you need to select the right field order in the video tab in cce. This post is getting rather long so if you want to know how to determine field order just do a forum search. It shouldn't be too hard to find.

[Kiddfrost]

Thank you very much for the detailed reply, I have certainly learned a few things from it. To give a little more detail, I used dvd2avi to process the vobs without using force film. It reported 29.97fps and NTSC(not film or a %age). In bitrate viewer, 29.97fps, interlaced, frame, field and top field first was reported. From what you said (if I understand correctly) I am presuming this is a hybrid or pure NTSC movie. I have tried upper and lower field in the video tab but it made no difference. I also tried all the other settings in the video tab except half vertical and horizontal resolutions. When I said force the I frames, I used IFOEdit to create a TMPGEnc text file template with all the I frames in it and then imported it into TMPGEnc and everything worked fine. I have also tried force film in dvd2avi and pulldown when encoding with CCE but the movie came out even jerkier. I have no idea what is going on here, I've even formatted the drive and re-installed everything to no avail.

[adam]

Ok your doing it right. Unfortunately this is just one of the very rare dvds that is pure ntsc, what dvd is this by the way? My first suggestion is to attempt an inverse telecine, but this is really more for quality. This removes the added fields bringing your video from 29.97fps back down to 23.976fps. First turn off forced film in dvd2avi. TMPGenc has an IVTC option in its filters or you can use an IVTC filter in your frameserve script if you use CCE, but it will only work if your source is actually telecined, but if its from a dvd chances are it is. I recommend getting decomb and using it to IVTC. Again, the reason I bring this up is because I still think it might be a field order problem, and by getting the source back to progressive frames you will effectively sidestep the issue, and gain considerable quality to boot.

Personally I always IVTC when possible, and have rarely run into any field order problems as a result, but I have heard that CCE has a bug with field order setting. Apparantly regardless of which field order you set it still uses the default, so if your field order happens to be, say Bottom field first, then theres no way to keep it interlaced in CCE without jerky movement.

So the answer is to reverse the field order in your source. You can do this in dvd2avi in the same spot where you choose forced film.

Also something that I should have thought of before...if you still have one of these mpg's that you encoded that was jerky you can try to reverse the field order without having to re-encode it. Use pulldown.exe. You may want to pick up the gui if you are unfamiliar with this function.

Hopefully this is just a field order problem, because not only is it easy to correct but it is a non-issue with the majority of ntsc dvds.

[Kiddfrost]

Hi,

I'll try reversing the field order first using dvd2avi and if that doesn't work I'll read up on how to use IVTC and give that a go. The movie I'm trying to backup is an American made educational film which was brought from Switzerland and given to me as a present. I'll let you know how I get on.
Thanks for the help!

[Kiddfrost]

You were absolutely bang on the button,,, field order problem or what! I reversed the field in dvd2avi and it worked a treat. The strange thing is that in TMPGEnc I did get the same problem whether upper or lower field was set as in cce so I don't know where the cause of the problem came from. I also tried it in DVD2SVCD by directing it to my vobs, changing the bitrate and editing the script file deleting the simple rezize line and it worked without a problem. Anyway all is sorted and I know the place to go the next time I run into a brick wall,,,,,,,Thanks again!!!