DV and DVD playback motion artifact on TV (NOT on PC playback)

drtelemark wrote on 8/26/2002, 6:13 PM

I have just converted a bunch of videos to MPEG2 format and burned to DVD (by the way, the Pioneer A04 is a great deal). One problem has come up when viewing the files on my DVD player on TV in that with some sections of video, when there is lateral motion, there appear about 6 horizontal areas that are evenly spaced on the screen where the video shimmers and appear wavy within each section. When the motion stops, the distortion disappears. Playback on the PC is totally fine.

I did not resample the original captured video (I usually do for slow motion), nor have I reduced interlaced flicker.

Thanks for the help in advance.

Comments

vonhosen wrote on 8/26/2002, 6:32 PM

The symptoms you are describing sound like field order problem. With incorrect field order it would show up as jittery during motion when viewed on TV but not on computer monitor.

Check you haven't inadvertently changed the field order for your project/render.

As a general rule the field order of your captured footage is going to be dependant on the capture device. With DV this is Lower field first but with analog it will depend on the device itself so check capture device documentation.

SonyDennis wrote on 8/27/2002, 8:51 AM

I agree. In fact, sometimes field interpretation issues can grow from scanline sized artifacts to big blocks, when interlaced footage is marked as "(none) progressive" and vertical scaling is applied, the interlaced scanlines moiré with the scale factor, producing some really horrible artifacts. I used to see this a lot from the old version of Sound Forge (before it handled deinterlacing) when it was used for streaming output from interlaced sources.
///d@

drtelemark wrote on 8/28/2002, 12:01 PM

Both the capture and render were done with lower field order first. Shouldn't that prevent the problem?

SonyDennis wrote on 8/28/2002, 5:04 PM

Yes, so maybe it's not an interlace problem. I'd have to see the artifact to conjecture more.
///d@

John_Cline wrote on 8/28/2002, 7:50 PM

While the DV source footage is indeed "lower field first", you must render the MPEG2 output to be upper field first.

John

BillyBoy wrote on 8/28/2002, 10:22 PM

This curious John, why do you think so? I've burned many DVD's and have not changed field order and have no problems at all using the default lower field first setting.

John_Cline wrote on 8/29/2002, 4:20 AM

DV video is a lower field first format, DVD is an upper field first format. Some MPEG2 encoders will do the translation automatically. I assume that yours does this as you haven't had to make the adjustment manually.

John

doboyd wrote on 8/29/2002, 5:55 AM

I too have expereinced the same effect when converting to SVCD (PAL) using the MC encoder in Vegas. TMPG does not do this, nor CCE. It is only visible with motion or panning. My DV clips are interlaced, and if the field order is reversed then the whole video is horribly jumpy with any motion, so I don't understand changing the field order in the MPEG2 encode. I encode in TMPG with lower field first. My camera can also record progressive footage, and this is not a problem, only the interlaced "normal" video. I don't resample or reduce interlace flicker,and all settings are as per default templates, interlaced, lower field 1st. I have tried encoding as progressive, but this just blurs any motion. I tried getting an answer on the forum before, but with no luck. I would really like to use the encoder in Vegas and would hope to get a DVD burner by Christmas, but at present I am resigned to using TMPG and rendering to an intermediate DV file.

John_Cline wrote on 8/29/2002, 8:45 AM

Earlier versions of TMPGENC used to scan the DV file to determine the field order, but now it just assumes that it is lower-field-first. The fact is that TMPGENC either assumes or, in the case of interlaced files other than DV format, asks what the field order is of the SOURCE file, if it happens to be DV or it determines that the SOURCE file is lower-field-first, it's smart enough to automatically swap the field order to upper-field-first when it encodes to MPEG2.

I've never used the MainConcept MPEG2 encoder in VV, so I have no idea how it handles it.

John

doboyd wrote on 8/29/2002, 6:27 PM

So, apart from field order issues, does anyone have any idea about the original problem?? The horizontal banding?? Sonic Dennis?? I would like to use the MC encoder, but on interlaced files its not possible.

SonyDennis wrote on 8/30/2002, 10:34 AM

I'd have to see the artifact to conjecture more.

Could you email a still showing the problem? If you email to drdropout@sonicfoundry.com, have him forward it to me and include a note referencing this thread. Include the .veg file if possible and tell us what settings you are rendering to.

///d@

northerner wrote on 10/24/2002, 12:24 PM

Is there a solution to the originally posted problem?

"viewing the files on my DVD player on TV in that with some sections of video, when there is lateral motion, there appear about 6 horizontal areas that are evenly spaced on the screen where the video shimmers and appear wavy within each section. When the motion stops, the distortion disappears. Playback on the PC is totally fine."

I have the same symptoms and would like to resolve it as well.

PDB wrote on 10/25/2002, 4:54 AM

Ok, just to make life a little more confusing...

What encoder and settings are you using to create the mpeg2 files? Does your DVD authoring app re-encode the files? I had a similar problem when I used sonic MyDVD authoring prog which used to re-encode all files: any movement in the vid would result in horizontal lines/distortion. I now use Dazzle DVD complete which doesnt re-encode (if mpeg2 file is compliant) and there you go...no more distortion... The choice of media is also relevant... I have tried sony, HP, and Memorex and only had probs with memorex (freezing, loss of menu, jitters etc...)

BTW, I now used Mainconcept encoder in VV with deafault settings and the quality as far as I'm concerned is outstanding (albeit for home vids; not pro use) and less hassle than encoding in AVI to then re-encode to MPEG2 with TMPEG etc...

Hope this has not caused more confusion: I think they are relevant issues...

JohnI wrote on 10/25/2002, 12:53 PM

I have spent hours chasing a problem that sounds stunningly similar to the one first described - Wavy line on verticals during movement which do not appear on the computer display that look awful on a TV display. I tried every combination of field order to no avail.

So what was it? In my case I found the "Track Motion" but at the left side was coloured (activated) - whereas most of the others were greyed (not in use). I had no intention to use Track motion on that track and in fact could not see any affect of it on the screen. However once I disabled and cleared it to grey the problem magically disappeared, I hope this helps those of you who have complained of similar.

John I

northerner wrote on 10/25/2002, 10:28 PM

I'm not doing any track motion. All I have to do to get the problem to show up is pan the camera horizontally for a few seconds, capture the video with Vegas, and use the Mpeg2 SVCD template to encode it.
The VV project is opened as NTSC DV (lower fields first) and encoded MainConcept Mpeg2 (lower fields first). The blurry lines show up every time on TV (not computer monitor).

If I take the same AVI and then use TMPGEnc to encode it (lower fields first), the output on TV is clean. I'd rather use the MC though, since its less messing around.

owlsroost wrote on 10/26/2002, 5:56 AM

For encoding to SVCD, see http://www.sonicfoundry.com/forums/ShowMessage.asp?MessageID=110318&Replies=6&Page=2 and http://www.sonicfoundry.com/forums/ShowMessage.asp?ForumID=4&MessageID=106772

Tony

owlsroost wrote on 10/26/2002, 6:05 AM

By the way, encoding from a PAL DV avi file in TMPGEnc (which it correctly detects is lower field first), it generates an MPEG file with the 'field top first' flag set to zero (as checked with Bitrate Viewer) i.e. a lower field first MPEG file.

Just tried it with TMPGEnc 2.57 to check.

Tony

northerner wrote on 10/26/2002, 8:40 PM

Thanks for pointing me in the right direction owlsroost. All I needed was the "stretch video to fill output frame size" enabled. That cleaned up all of the horizontal blur lines.