Frame Jitters

RCF_DV_Guru wrote on 6/8/2003, 9:33 PM
I have rendered some analog video footage and played it back as the MPEG2 files on my PC, no problem. Then I made the DVD files and played them back on my PC, ok again. BUT when I Make the DVD and play it on my DVD player I have odd Video footage that has the Jitters, looks like it is skipping frames. Not every clip, but odd ones?
As I said, the files play back ok Prior to being burnt. But why not after?
Thanks
Wayne

Comments

markwill wrote on 6/9/2003, 6:17 AM
Do the problematic portions have motion ie:dancing ?
aussiemick wrote on 6/9/2003, 8:54 PM
Experienced exactly the same problem, but when played on a different set top player the video was ok! Pioneer said the problem probably lay in the bit rate. Encoded at alower bit rate and the video was ok on the original player. Test it on a DVD-RW at various bit rates and see if improves.
RCF_DV_Guru wrote on 6/10/2003, 7:31 AM
Yes some do contain motion, but the problem is also visible with motionless sections.
RCF_DV_Guru wrote on 6/10/2003, 7:48 AM
Thanks but can you recommend a bit rate to try?
RCF_DV_Guru wrote on 6/13/2003, 9:54 AM
For anyone that is interested, I believe I have solved the problem. I have rendered a sample of media that had the jitters with different field orders and have found that on playback the media was fine once I changed the field order from Upper Field First to Lower Field First it worked fine. So now all I have to do is change all the media.
This problem came about from capturing analoge media through 2 different methods, a pinnacle card(same software) and a canapus box(Useing Sonic Foundry Vegas - "Legendary" Software). Anyhow at the end of the day I wound up with 2 sets of media in the same project that rendered and burnt just fine as VCD or SVCD(MPEG1) but not DVD(MPEG2) and they both had different field orders.
Thanks for your advice mick, but it made no difference.
regards
johnmeyer wrote on 6/13/2003, 8:25 PM
Yes. Anytime anyone speaks about "jittery" "juddery" or "jerky" movement, changing the field order is the first thing to try. Gald it cleared things up.
BillyBoy wrote on 6/13/2003, 10:09 PM
DV is ALWAYS lower field first. Period.
RCF_DV_Guru wrote on 6/14/2003, 1:44 AM
Wish i knew that a while ago... Maybe i should read the manual again! :)
johnmeyer wrote on 6/18/2003, 8:54 AM
Actually, DV is NOT always bottom field first. If you capture analog video through the Radeon 8500DV using any DV encoder (e.g., Mainconcept), the 8500DV software will encode TOP field first.

If you capture DV through the 1394 port, then it is always bottom field first.
JonErik wrote on 10/7/2003, 2:01 PM
My source material is upper field first (mmv), why can I not render this to lower field first and burn to DVD? Shouldn't Vegas then change the field order or is it not possible? I set the source filed order to upper.

Anyways if I set the render as field order also to upper, it played back amazingly better on my Phillips 612 DVD player. Can I assume this to be valid for all players?

Also, why does WinDVD play it back the same way no matter what field order I render it to?

Best Regards

Jon Erik
vonhosen wrote on 10/7/2003, 3:48 PM
Why do you want Vegas to render your project to MPEG as lower field first ?
What benefit are you hoping to get from that instead of upper field first ?

It shouldn't matter a great deal whether you render your footage out to MPEG as upper field first or lower first. The important factor is that the encoder is told the correct field order of the source it is to encode.
I think most MPEG-2 encoders like to render the MPEG for DVD out as upper field first by default but like I say it shouldn't matter a great deal.

As for WinDVD playing it back the same no matter what.
Are you talking about playback via WinDVD on your computer or using WinDVD to display out to a TV ?
Because your computer monitor isn't going to worry about field order much as it is displaying progressively not interlaced like a TV set. That's why field order problems do not show themselves readily on a computer monitor but are easily visible on an interlaced TV set.
FrameScale wrote on 1/4/2004, 6:45 PM
I'm having the same problem. It only happens with DVDA, so I know my encoding is correct.

So how exactly am I to change the field order? A lot of my video is already encoded and ready to roll. I'd rather not re-encode anything. Everything I import into DVDA gives the jitters -- more like stutters, about every 12th frame, even DV's (AVI's) imported directly from my video camera.

I think DVDA is just bugged.
farss wrote on 1/4/2004, 10:05 PM
In general all DV is lower field first, the encoder should be told the same thing. I can assure you this is not being caused by DVDA, in effect DVDA does NOTHING to the video, it muxes already encoded streams together and that's it.

On what are you seeing these "stutters", during preview on DVDA?
If so it's just that the preview on DVDA is none too good at full scale.
If it's playing the DVD on a STB I'd start be suspecting the DVD player, maybe the bitrate is too high for it.

Hard to really know without more detailed explaination.
FrameScale wrote on 1/6/2004, 6:12 AM
I've narrowed it down to the Main Concept MPEG codecs, installed with Vegas. My other machine does not have these codecs and plays and encodes MPEGs just fine. Using a utility called GSpot lets me view a MPEG file and see what my systems use to decode.

Computer A:
MainConcept MPEG Splitter > DVD Express Decoder (comes with DirectDVD) > Overlay Mixer (Windows XP) > Video Renderer (Windows XP)

Result: video plays choppy, my MPEG encoders crash, Vegas Architech produces stuttery DVD's

Computer B:
Same except the Splitter is MPEG-2 Splitter (Windows XP)

Result: perfect video

So any ideas on what I do about this, and if there's a chance to get Vegas to work properly? Main Concepts web site doesn't have anything on their codecs -- they just sell standalone software.
FrameScale wrote on 1/7/2004, 4:42 PM
To add, there is some compat issues with DVD Express Decoder (comes with DirectDVD) and Main Concept. I got rid of DVD Express Decoder and now no jitters.