CCE + zoom = shakiness

[chobo321321]

I have been doing some tests between Tmpgenc 2.5, and CCE SP 2.67. I noticed that if I use my DVD players zoom feature (2x, 4x) the image encoded by CCE will appear a bit shaky(a small bit of flickering up and down) throughout the whole image. When I encoded with Tmpgenc there was no shakiness, or flickering.

My source file or encoding is an Anime-DVD rip, so I'm assuming it's progressive, and therefore field order has no bearing on it at all. The source also has a framerate of 23.97, which I used as my encode setting, and then later had to use a program called pulldown to do a inverse 2:3 pulldown. For tmpgenc the setting is in the program, but I chose a 3:2 pulldown instead. Would this make any difference?

Does anyone know what may cause this? I really like CCE because it's so fast, and the image quality is better. Any help is appreciated.

[adam]

Well if its an anime source then it would most likely be interlaced, in which case you are encoding wrong in both programs, so who knows exactly why one happened to work out and the other didn't.

You need to actually check your sources before encoding. If you follow the DVD ripping guides on this site it shows you how. Preview the DVD in DVD2avi. If it shows FILM or something like 95% FILM, then your source is progressive. You can safetly enable the forced film option and treat your source as 23.976fps progressive. If dvd2avi reports anything else then your source is 29.97fps interlaced and you have to treat it as such.

Assuming your source is in fact progressive 23.976fps, and you correctly used the forced film option in DVD2AVI, my guess is that maybe you have CCE setup incorrectly. Make sure and set it to progressive on the video tab. Having it set to interlaced would certainly make it shaky.

Also make sure that the line offset number is set to 0. I don't know why having this checked would make the playback jerky, but it would unnecessary crop the first scan line, so just do it to be safe.

In pulldown.exe I would also set the prog_seq option to interlaced and the prog_frames option to progressive. This is how ALL NTSCfilm DVDs must be encoded.

[chobo321321]

Well if its an anime source then it would most likely be interlaced

I have read many guides stating that DVD-rips, are progressive, while TV capture, and DV camcorders are interlaced (very confusing) . I'll try those pulldown settings. Also I use avisynth and CCE for encoding I don't use DVD2AVI becuause it never works when I just try an AVI with just a video stream. Thanks for the help, i'll try to find those sources that said anime is usually progressive, and post them up.

[chobo321321]

I forgot to add that my source files are usually OGM, or MKV, and I extract the video to AVI, so I'm not sure how I can tell whether the source is progressive, or interlace.

[chobo321321]

I guess I'm just going to have to use trial, and error. There are just way too many conflicting ideas, and opinions about what is progressive, and interlaced, and some are even both...

[chobo321321]

I forgot mention that when I load up my files in dvd-lab the ones that were down in tmpgenc display 3:2 pulldown, and the ones in CCE with pulldown.exe display 2:3 pulldown. Does this make any difference?

[adam]

DVDs can be progressive or interlaced, and most theatrically released films are stored using progressive frames. Anime are the exception. Most anime DVDs are interlaced, and a hybrid form at that. This is due to the convoluted distribution system used. The DVDs are usually produced in one region and then re-encoded for release in another. There are entire sites like this dedicated to the IVTC'ing of just anime's...they are typically the biggest encoding challenge available. Since you posted this in the DVD to DVDR thread I assumed your source was a DVD, but apparantly its an avi file using some codec. So, its almost surely progressive. An AVI certainly can be interlaced, but since whoever encoded this probably chose avi because it was intended to be played on a pc...which requires progressive playback. So either this DVD was progressive NTSCfilm, or it was deinterlaced during the conversion. If the latter is the case, then there is no guarantee that the motion will be smooth with any encoder.

DVD2AVI can only open mpeg2. I only recommended it because it is the standard procedure for ripping an NTSC DVD. For an avi source, it cannot be used.

Since your source is almost surely progressive, just double check to make sure that it is in fact 23.976fps and not 29.97fps. Load it in something like VirtualDub and hit file/file information.

3:2 and 2:3 aren't the same thing, but in effect there's really no difference. They both repeat fields in the pattern, they just start on different fields. It shouldn't have any effect on how the video actually plays or looks.

Go ahead and try my suggestion for pulldown.exe. When dealing with progressive footage, where field order can't screw things up, shakiness problems are usually caused by incorrect flags set in the stream. If you encode progressively you must ensure that the prog_frames setting is enabled. You'd do this by setting the encoder to progressive. Whether you did it or not, pulldown.exe can set this. As for prog_sequence, the DVD specifications require that it ALWAYS be set to interlaced, so I'd go ahead and set this option in pulldown.exe as well.

I can certainly understand wanting to eliminate every anomoly in an encode, but is there a particular reason that you are concerned about this shakiness during zooms? Are you actually watching these movies zoomed in? Why?

[chobo321321]

Thanks so much for your help adam! The avi is was done using xvid codex 4, and it appears to be progressive. I just watched the whole encode on TV, and I was wrong, the flickering is evident in the tmpgenc encode as well. I just used zoom to see if the flickering was more noticable, but it's the same as with zoom off.

The reason this is an annoying problem is because the source files aspect ratio is 16:9 which means it has a letterbox on my TV because it's 4:3, and where the picture ends and the letterbox starts there is flickering on the top and bottom parts. It's not too noticable, but once you know it's there it's pretty bad .

I'm also trying to get my encodes as near perfect as I can, and learn as much about encoding anime, so I can write a guide on it and save people a lot of trouble

[adam]

Is the flickering only occuring on where the top of the picture meets the letterboxing, and not on the bottom? If so then I'm positive your flags are set incorrectly. This is exactly what happens when you encode using progressive frames but set the prog_frames flag to interlaced.

I've even seen a number of commercial DVDs which have done this. Check out R1 releases of Signs or Gladiator. Get up real close and you will see that where the top scan line meets the letterboxing, it jumps up and down every second or so. I checked, and the flags are set wrong.

[chobo321321]

Thanks for your quick response. I just checked and it happens on both the top and bottom near the letterboxing (where it meets).

[chobo321321]

I encoded another few epsiodes, and burned them to DVD using an offset of 0, and I used your settings for pulldown. When I look close at the TV I notice that the flickering is more noticable when a light color meets the letterboxing(where it meets the top, and bottom letterboxing). It is not noticable if it's a dark blue, or black.

[chobo321321]

I just found some info, and wanted to see if you think this would be the cause of the flickering.

he crop boxes allow you to exclude an area of the input image to conserve active bits. For instance, if your source is a full screen (4:3) image that shows a widescreen picture (16:9), you have black bars on the top and bottom. Doesn?t make much sense having all that space converted to part of the film, does it? Not only does it take time (and precious bits), you?re also likely to get a flickering effect in the finished film file. Enter the number of pixels you wish ffmpegx to ignore in the T(op), B(ottom), L(eft) and R(ight) boxes (T and B being the more common of the two). Again, if you?re not quite sure you?ve entered the correct values, do a short test run before you do the entire thing. (Not implemented for ?VCD MPEG-1? or MPEG-2.)

My source file is an 640-360 (SVCD with letterboxing), so it's really a 4:3 aspect ration containing a 16:9 image. When I encode it also encodes the letterboxing wasting pixels on black bars. If I remove the letterboxing before encoding how would it look on a 4:3 tv? Would the program create it's on letterboxing?

Sorry to keep bothering you.