Tmpegnc - SVCD - "jumpy video"

[dc91gt]

Last couple of rips i've done I've been having a problem with the mpeg2
I get from Tmpengc...

Large portions of the movie the video gets really jumpy, almost like if you encoded a file for too high a bit rate for your player - but it's evident viewing the file on the PC as well (powerdvd, or windvd). Kind of a flicker to the video.

the encodes I'm doing are pretty straight forward:

smartripper
dvd2avi
Tmpengc plus 2.58x

Tmpengc settings:

2-Pass VBR, min: 1900 avg: 2350 max: 2500 (fits on 2 cd's if under 90 minutes) 480x336, full screen, keep aspect ratio (both were 16:9's).

I've seen this now with the last two encodes I've done: 40 days/nights and Scorpion king.

Anyone else seen this problem?

thanks,
-d

[DJRumpy]

I ran into something simular, when I upgraded my video drivers, which in turn upgraded my capture drivers. This also happens on your standalone?

[bugster]

There are 2 common causes of jumpy/jerky video that I am aware of. The first is a framerate mismatch between source and destination formats (perhaps you need to select/unselect 'force film' in DVD2AVI). The other is interlacing field order. Maybe these two DVD's are interlaced whereas the others have been progressive. Try changing the field order from A first to B first (or vice versa).

Not sure if any of this is right but its got to be worth looking into,. right?

[poopyhead]

field order shouldn't show up on the computer monitor because the monitor displays both fields at once...however, the TV shows the fields one-after-the-other, so field order problems would show up on TV...

however, i'm thinking that the source DVD has NTSC video type. to verify this, when using dvd2avi, load the vob files and preview by pressing f5 and look at the info box that appears. it should tell you the video type (FILM or NTSC) and frame type (interlaced or progressive). look at the movie for awhile and take note of both the video and frame type. my best bet is that the movie is NTSC (or some higher percentage of NTSC, i've had 10% NTSC, 90% FILM give me jumpiness)....also, the frame type will probably be interlaced.

if this is the case, you need to turn OFF force film in dvd2avi...in tmpgenc, you can do either of two things

1) IVTC
or
2) make your output video 29.97 fps + interlaced (not 3:2 pulldown)

[DJRumpy]

Hmm. I didn't read this carefully enough. These are DVD rips. I would think that if he ripped and kept the 29.97 framerate, and encoded using the 3:2 pulldown option in TMPGenc, that the change from the framerate flags would be immediately obvious on any part of the film, and not during the high motion scenes.

Does anyone know what happens when you add 3:2 flags to a 29.97fps MPEG? Will TMPGenc actually IVTC the material back to 23.976, and add the flags, or does it just add the flags to the MPEG?

[poopyhead]

Hmm. I didn't read this carefully enough. These are DVD rips. I would think that if he ripped and kept the 29.97 framerate, and encoded using the 3:2 pulldown option in TMPGenc, that the change from the framerate flags would be immediately obvious on any part of the film, and not during the high motion scenes.

Does anyone know what happens when you add 3:2 flags to a 29.97fps MPEG? Will TMPGenc actually IVTC the material back to 23.976, and add the flags, or does it just add the flags to the MPEG?

i don't think you can really encode at both 29.97 fps + 3:2 pulldown. the point of the 3:2 pulldown is for a video encoded at 23.976 fps to play as 29.97 fps. if the video was already encoded at 29.97 fps to begin with, 3:2 pulldown is not needed.

as for IVTC, tmpgenc prolly IVTC the 29.97 fps back to 23.976 fps and then uses the 3:2 pulldown to make the video 29.97 fps on playback

[Digifreak]

One more thing to consider that causes jumpy video on some players is setting the output to 16:9. Many players (including all Apex I have tried) are not able to properly play back 16:9 DAR flag encoded (S)VCD and will jitter.

[dc91gt]

Interesting replies guys, I've got some stuff to look at.

I can say this... two rips done prior, the source DVD was 4:3 - both those play back and encoded flawlessly.

However, the last two I did, which exhibited the problem, were both source: 16:9, however, I don' recall if dv2avi was set to force film, I'll have to re-grab then and check. I did however in my encoding, left the source as 16:9, but set my encode video settings to 4:3, adjusted the resolution to 448x336 to keep the aspect ratio proper and set full screen w/keep aspect.

So if the source is NTSC video - then I don't want 3:2 right? and if it's 23x FPS film, I want 3:2? I'm unfamilar with what 3:2 pull down does? I guess its a ratio to adjust the delta between 23 and 29 fps?

thanks
-d

[wulf109]

I gave up on DVD2AVi a long time ago because of these problems which seem to get worse if you increase the frame size you encode at in Tmpeg. My solution has been to stop using DVD2AVI and encode the vob's directly in Tmpeg.

[Digifreak]

Never use resolution to determine display aspect ratio, use DAR flags in the encoded video (4:3 or 16:9). Most software players recognize DAR flags, only Windows Media Player (without additional codec) does not. If you are encoding 16:9 to watch on 4:3 television, set source 16:9 and output 4:3 and TMPGEnc will encode in black bars to keep the video aspect of the 16:9 to display correctly on 4:3 television. Yes, with 23 fps use 3:2 pulldown and with interlaced NTSC do not, 3:2 pulldown flags the video to inserts extra frames to compensate for the different frame rates. To determine interlaced/film or 4:3/16:9 on source you must let DVD2AVI preview for a while because the beginning intros to a lot of movies is interlaced. The best way to determine interlaced or not as well as source aspect is to open a VOB with bitrate viewer.
http://www.tecoltd.com/bitratev.htm
Open the 2nd or later VOB to make sure you are past the interlaced section at the beginning of a movie.

[dc91gt]

Digifreak ---

So if I'm doing an SVCD encode...

source is 16:9

I set the source in tmpengc to 16:9 (which I do)
Set the video to "full screen - retain aspect ratio"
And leave the SVCD resolution at 480x480?

The last one is my question. I seem to recall doing that and the video
aspect ratio wasn't correct. Hence why I've been doing all of the above,
cept setting the resolution to 448x336 so the video looks correct and not stretch. I could have recalled this wrong. Let me know.

-d

[DJRumpy]

Poopyhead (poopyhead? ), I know what the 3:2 flags are for, and how they are used. I'm wondering if it's possible to try and add them to a 29.97 fps MPEG. The option is selectable in TMPGenc no matter what template your using, meaning it could be inadvertantly checked, when someone is not using a FILM source. I've never tried it, and certainly wouldn't want it as an end result, but someone may have ended up there by mistake.

The thread about the DAR flags is interesting though. If the standalone does have a problem with 16:9 DARS on a SVCD, then use PULLDOWN.EXE to switch the flag. Shouldn't take more than a minute or two to change it, re-burn, and verify.

[Digifreak]

dc, the settings you give are correct for a 16:9 movie on a 4:3 television as long as you set output to 4:3 with "Video/Video stream setting/Aspect ratio/4:3 display". Suggest leaving your resolution to 480x480 though this is not absolutely necessary. If this resolution did not display properly on your PC it was probably because you viewed it on Window Media Player (WMP) which does not recognize DAR flags and displays resloution pixels as square. This would play as a square screen on WMP. These settings will absolutely display properly on your standalone with a 4:3 TV. I've found the best way to verify aspect ratios is with the spinning globe on Universal Studios movies, even slight distortion in the globe is obvious.

As for DJRumpy, I've tried to fix jumpy 16:9 encoded video to 4:3 using the aspect command from pulldown.exe by demuxing video and processing with the aspect command from pulldown but never got it to display back to 4:3. I ended up reencoding to 4:3 and it played fine. If you have had success with pulldown to change DAR flags I would like to know specifically how you did it and the exact command line for pulldown as you used it.

[DJRumpy]

Digi, I use the GUI for pulldown.

Just tell it not to add any flags. Check off only the checkbox to change the DAR, and go. Works like a charm.

http://guiguy.wminds.com/downloads/pulldownbatchfe