Field order vs. inferior media

[Tom Lewandowski]

I'm a DVD-Video newbie here, though I've been producing SVCD's for a while and understand the basic concepts of what I'm doing. DVD seems to be a whole different ball-game, however. I've been lurking on this site, soaking in the vast amount of information offered! Excellent site!

I use TMPEnc for encoding my AVI's and have always wondered about field order. From what I understand, hardware capture cards set the field order during capture -- and I would assume, that's consistent for each capture. That is, it doesn't start with field "A" for one capture, then field "B" for another capture session. My Asus V7700 (and the Asus website) doesn't provide any information about field order during capture.

Up until now, I've trusted TMPEnc to "guess" correctly at the field order and process appropriately. (I've just read the thread on '100% accuratecy of determining field order with TMPEnc' and this will be helpful.)

But my problem is as follows:

After encoding the AVI (about a 25-minute video) with TMPEnc, loading the movie into Movie Factory 3, burning to a DVD+RW, and viewing it on my two DVD standalone players -- the results are the same -- I get that infamous "jerky playback about 10-minutes into the 25-minute movie. The first 10-minutes play perfectly! (The action is fast throughout the whole video.) It's VERY characteristic of a field order problem.

Question:
So I guess I'm wondering...if it IS an incorrect field order problem, wouldn't the WHOLE video be affected? My thoughts were in the direction that maybe the pack of DVD+RW discs have a bad spot (bad lot), but I don't have enough experience with DVD recording (err...problems) to know. I guess I want to try to prevent...as best I can...burning coasters when I burn the final DVD-R's.

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Having had burn problems with Ulead's older Movie Factory 2 software, I also tried using MF2/3 simply for creating the VIDEO_TS folders, then use Nero 6 to burn the DVD+RW disc. Exact same results.

Sony DRU510-A
Fuji DVD+RW 4x media

[fmctm1sw]

I once complained about jerky left to right movement on my tv. I found it was caused primarily by telecined material. If you have a movie, I'd look into IVTC. To check for correct field order I recommend AVIsynth.

[bottle-necked]

Welcome to the forum Tom Lewandowski.....

My ATI MMC captures in Field Order A. When I capture in Ulead VideoStudio I must set the program to capture in Field Order B. If I import files i've captured with my ATI MMC program Ulead reports these as being Field Order B. So I now know as long as Ulead reports my video files as Field Order B they will play on my TV when actually they are Field Order A files. ???? Don't ask me why.... lol When I take an AVI file to TMPGEnc I make sure to set it so I get a Field Order A file out.

A while back I did a few simple tests to find out this information. I captured short clips with these programs, gave them all distinguishing names, then created a DVD-RW so I could view them on my TV and settop box. I learned very quickly which field order I needed and what was going on with Ulead. You may want to do this also. It will save you a lot of grief later on. I wrote my findings down in my notebook for reference. I'm old and can't remember things for long. haha

If you are using the proper field order and have jerky sceens in the middle of the file makes me think the original video has a problem. I have created files like that before and it was due, I beleive, to either a falty source like a VCR tape, or too high CPU load or program activity. I was never able to repair any of them to my satifaction.

A field order problem will either show itself from the beginning of the file all the way through, or it will show itself in panning or motion shots. (You can probably still see it in slow action shots but it might not be so noticable.) My experience has shown that when capturing MPEG2 in the wrong field order the file will show it all the time. When encoding from AVI with the wrong order it will only show it in pans or motion shots, but it will still be 'all the way through'. When video suddenly, and for no apparent reason, becomes jerky then I have found it's the video at fault. lol

Bad RW? Ok, burn a full disk movie on it and watch the results of known good video and look for the bad section. That should prove it. But I don't think it's the disk. lol But as usualy I might be wrong.

Good luck.

[Tom Lewandowski]

Thanks, bottle-necked. I know you're right...the only way I'm going to know for sure is by experimenting with complete videos.

What I'm doing -- just to get my feet wet into DVD recording -- is capturing from a Hi8 video that I recorded from satellite, of "Finding Nemo". The source tape is quite good. (I know, it'll end up being a lot cheaper for me just to buy the darn commercial DVD from the store.) But I thought this would be a good way to learn and experiment before I started transfering other videotapes (VHS and Hi8) to DVD. Other than the 'jitters', the transfer results are excellent.

Thanks for the help and the welcome!

[bottle-necked]

Ok, try an experiment using standard sizes and bitrates of several short clips, author and burn them to dvd and test them on your tv.

1. mpeg1 CBR 1.15Mbps 352x240 48k 16 Stereo 224kbps
2. mpeg1 CBR 1.85Mbps 352x240 48k 16 Stereo 224kbps
3. mpeg2 VBR 4.0Mbps 352x480 " " " 256kbps
4. mpeg2 VBR 6.0Mbps 720x480 " " " 256kbps
5. mpeg2 VBR 8.0Mbps " " " " 256kbps

Capture a few short clips in both field orders and author these to dvd. This little experiment will tell you a lot.

Also, visit LordSmurf's Site. He has a lot of good information there you will find interesting. Guaranteed.

Best of luck!!!!!

[Tom Lewandowski]

Just a followup...

I did as you suggested, and after several hours of encoding and testing, I found that the problem with my jittering video was indeed the field order. Supposedly, the Asus V7700 ALWAYS captures field "B" first, yet TMPEnc was often reporting that field "A" was captured first. Using the "How to be certain of field order with TMPEnc..." method, I verified each captured AVI before encoding, and set TMPEnc field order according to what I saw -- not according to what TMPEnc reported. Now, the same DVD+RW discs I used previously -- play perfectly all the way through! (I did this with the same 25-minute clip...just to be sure enough time had elapsed.)

So, apparently improper field order can be demonstrated at various points in a video, and not necessary, EVERYwhere. Or, maybe with some captures, it can be practically unnoticeable in some fast-paced areas, and more noticeable in others. And perhaps, it's something that's capture-device-dependant. In any event, I'm excited that's it's working properly.

Thanks for all the help!

[bottle-necked]