Problem with Jerky Motion in Final Video
 

Sorry if this has been covered before but i've had a good look and can't find any posts relating to this specific problem.

The problem is when i output my final video and view it on my HD TV (Sony Bravia KDL-32D3000) the footage often looks jerky whenever there is motion in the video. So for example, if someone walks across the screen (with the camera stationary) then they don't move smoothly across the screen but instead 'jerk' backwards and forwards slightly at certain points. Or if i do a pan it looks jerky instead of nice and smooth as it did in the original footage (i.e with my camera connected directly to the TV via HDMI). Its not unwatchable but it definitely doesn't look good! In certain slow motion shots in the edit it looks really bad but then others look perfectly smooth. I'm thinking it must be some kind of frame rate issue but i can't see where i'm going wrong.

Here is my workflow:

Camera - Sony XR500E (European version)
Editing Software - Premiere CS4
Authoring Tool - Encore CS4

- I'm shooting on the XR500 in FH recording mode (1920x1080/50i).
- I import the m2ts files onto my PC using the picture motion browser software.
- I then convert the files using Neoscene (settings: Quality - medium, Output frame format - maintain source frame format) to AVIs
- I then import the AVIs into a sequence (settings: AVCHD 1080i25 (50i)) in Premiere and do the edit
- I export the sequence in Adobe Media encoder (settings: MPEG2, HDTV 1080i 25 High Quality)
- Write the file to a blu-ray disc in Encore
- Watch the blu-ray disc on my PS3 through the Sony TV and get the jerkiness described above (i get the same problem if i watch the mpg file on my PC monitor)

I also get the same problem if i send the timeline to encore and write it out as a standard DVD (both on my HD TV and an SD TV that i tried).

Can anyone spot anything i'm doing wrong? Thanks in advance for any help - this is driving me mad!

Cheers
Jamie

"- I then convert the files using Neoscene (settings: Quality - medium, Output frame format - maintain source frame format) to AVIs
- I then import the AVIs into a sequence (settings: AVCHD 1080i25 (50i)) in Premiere and do the edit"

If the above is correct, it looks like you are using the wrong sequence setting in Premiere.
If you have converted your AVCHD source files to Cineform HD .avi, then you need to edit those .avi clips on, and export from, a 1080 50i Cineform .avi sequence preset, not an AVCHD preset.
This could account for all of your problems.

Thanks for the reply Robert.

I tried setting up a new sequence preset in Premiere using the following instructions:

Cineform Tech Blog premiere pro

In my case, i used 25 frames per second, 1920x1080, square pixels (1.0) and "Upper Field First" for the Fields setting. I then copied my edit from the AVCHD preset that i used previously into my new 'cineform' preset, sent the sequence to encore and wrote out a DVD. I am still getting the jerky motion that i described before.

Its strange - its not constant, sometimes its perfectly smooth (especially in a few slow motion effects that i did) but the majority of the time any motion in the video is very jerky. Am i doing anything wrong setting up the cineform .avi sequence preset?

It's hard to know what's going on.
What I would do is a test run of a handful of original CFHD.avi clips (not copied from an existing sequence) on a new Cineform preset sequence timeline. Trim them a bit, throw in some crossfades, etc., export to BR file and from Encore burn a test BD & see what you get. I use rewritable BDs for this sort of thing- very cost effective.
If the test BD looks good on HDTV (which it should), then all is working properly.
This might also imply some difficulty in getting your existing AVCHD sequence project into the proper format and looking as it should.
Good luck

Thanks for the post Robert. Sorry for the delay in replying - have been away from my PC for the last week. I was just about to go through my whole workflow and post screen grab of all my settings. I'm starting to think however that it may be a problem with my cineform AVI files.

Below are the settings i used in Neo Scene to convert the .m2ts files from my XR500E.

http://www.dvinfo.net/forum/attachme...i_settings.jpg

I've just gone back and checked the original cineform avi files that i converted with these settings (i.e. 'maintain source frame format') - when i play them in windows media player they look very 'flickery' as if it is flicking between frames or something. When i convert the original file again changing the 'Output frame format' option to 'Deinterlace' or 'Convert to 24p' the resulting files look much smoother in windows media.

Do you think this is the source of the 'judder' problem in my final video? Should i de-interlace the m2ts files in Neo Scene before i edit in Premiere?

I have no experience with Neoscene, only with Prospect HD.
You need to check and see if Neoscene offers the 1920x1080 format. Originally Neoscene was a product for HDV use and as such only offered 1440x1080 resolution. If Neoscene is actually converting your 1920 AVCHD to 1440 1.3 par CF.avi, then you need to use those specs for your CF sequence in Premiere. And, I might add, the final image quality wil not be as good as if you had been able to maintain 1920 rez throughout the workflow.
Deinterlacing, or changing frame rate to 24 should not be necessary, or a factor affecting your final result. Previewing high data rate interlaced footage (like CF.avi) on a natively progressive system like a computer can cause some motion artifacts that are simply "previewing artifacts" and are not a reflection of the quality and integrity of your footage files.
Again, I would suggest a test along these lines:
1) Convert a handfull of AVCHD clips to 50i CF.avi.
2) Check and be sure what the actual converted avi framesize and par are- 1920 par 1.0, or (what I suspect) 1440 1.3 par.
3) in PPro open a Cineform preset sequence with exactly the correct parameters for your footage
4) put the clips on the timeline sequence, trim them, add some transitions, black video, etc. and export the sequence to AME, transcode to a Blu Ray codec
5) Import the BR file to Encore, author a simple BR Disk project
6) Burn the BD and play it on a BR player to a HDTV.
It should look perfect. If it does, then you know what workflow to follow going forward.
This is the true test.
Viewing even perfect HD footage on computer with various players, or within PPro is always subject to artifact from many possible causes- which don't even matter- all that matters is how the final product for distribution looks. In this case, an actual Blu Ray disk.
I also advise taking accurate notes when exploring a workflow, and attach them to the resulting media for future reference- so you can know exactly what you did, and what the end product looked like.
It always seems like a big detour from the task at hand, but (compared to working in DV) this stuff is quite complex and very unforgiving. A single wrong setting will do you in.
Once you get it right, type it up, file it , and you are home free.

Robert, thanks for the detailed reply.

I've checked the neoscene specs (at http://www.cineform.com/neoscene/features.php) and it does appear to support full 1920x1080 format files. When i import the cineform avi files into a project in premiere, i checked their size by right clicking on them and selecting 'Properties' - i've attached the results for the cineform avi files and the raw .m2ts. Assuming i can trust premiere's interpretation of the files then the cineform files have retained the 1920x1080 size.

To follow your suggestion, i created a new sequence with the settings in the attached image. When i put the .m2ts file on the timeline i don't get a red bar above the file which i assume means that the sequence settings match the file properties. When i put the cineform avi on a yellow bar appears above it, which from what i understand is what you'd expect to see. I trimmed the files, added a few transitions then sent the timeline to a standard dvd encore project and burned it to a standard dvd (i'm waiting for some new blank blu rays to get delivered!) using the automatic settings.

When i watch the dvd through my Sony LCD HD TV, the .m2ts files look perfect - nice smooth motion, no problems at all. Then when the cineform avi files play i get the jerky motion. So it definitely seems to be something about the cineform files that is causing the problem. But from the checks i've performed there doesn't seem to be any difference in the size, frame rate or field order of the 2 files.

There must be some difference in the files that is causing the 'jerky' motion problem with the cineform files though. Is there anything else that i can check/try?

A couple of observations:
Cineform HD interlaced .avi to DVD is a tricker animal than going to Blu Ray.
Excellent Blu Ray is a straight shot from CFHD timeline> export to AME BR codec> burn to BD
My workflow for the best 60i DVD is 1920x1080 60i CF.avi> export to a Cineform SD 720x480 60i CF.avi> transcode to m2v from the SD "master" .avi file
If the HD CF.avi is progressive, then you can skip the step of exporting to a SD CF .avi, and just like with Blu Ray, it's a straight shot to export from CFHD 30p .avi to DVD m2v> burn to DVD.
Take your handfull of AVCHD clips and have Neoscene deinterlace them as CFHD 30p (25p) .avi, put them on a PPro CF 1920 25p sequence> export to AME m2v>burn DVD and see if that looks as it should.
If it does, then you know you have an issue with the AME downscaling of your HD interlaced footage (a known issue with AME and CFHD 60i), and you'll need to make the CFSD .avi intermediate file, and code to DVD from that.
I tend to maintain my acquisition parameters throughout the workflow- if I shoot AVCHD 60i, I will remain in 60i until a change is necessary- ex: web delivery (30p). If I shoot 30p I will stay there until the end- ex: BR 1920 60i.
However, there are many who will routinely deinterlace 60i acquired footage on ingest, and use a 30p workflow throughout. Cineform HD Link does a great job (much better than PPro/AME) of deinterlacing the 60i AVCHD to 30p CFHD.avi.
Bottom line, you need to explore all of these alternatives and decide what works best and looks best to you.