Having some "Jumpy" video while watching some DVD'

[Sominex24]

OK,


Here is the setup I am using:

Transfer the videos FROM MiniDV via firewire cable.

Use Ulead DVD Workshop 2 as the software to transfer and store the video

Convert the video to MPG using TMPGE

Use Ulead DVD Workshop 2 again to author and burn the movies. Here are the results he is getting---


Here is what my friend sent me:



I forgot to tell you about my DVD experiments. I played the first home
DVD that you made for me on three different DVD players and noted the
results. I concentrated on some of the scenes that were the most
'jumpy'. I noticed that the scenes that have problems are ones that
have lots of motion. Not so much motion within the video, but when the
camera pans around or moves a lot is when the video seems to flicker.
When I tried it on two different DVD players, they did the same thing in
the same places. The one player was a little better than the other, but
they were pretty close. Then I played the same section on a computer
with a DVD drive. On the computer, in the places where the video
flickered, instead of skipping fames, it seemed to slow down to get all
of the frames in. Here is what I think is happening ...

When a scene does not have much motion in it, everything is fine and all
three DVD players play it the same. When there is a lot of motion in a
shot, or more importantly, when a larger portion of the screen changes
from one frame to another, the math required to decode is much more
intense and time consuming. It's like the first two DVD players are
overwhelmed with the amount of decoding that needs to be done, so they
just skip frames as needed to keep up the pace. The DVD playback on the
computer is just as overwhelmed, but instead of skipping frames, it just
slows down in order to get every video frame displayed. You can
actually hear it slow down in the audio. I would imagine that on a
computer that is really fast, like yours, there is no flickering at all
cause it has enough horsepower to decode everything.

That tells me that all of the video information is really on the DVD,
but it's just too complex for the DVD players. Can we try an
experiment? The scene that seems to be the worst is the swimming
lessons at the very beginning. The camera pans around a lot and makes
the video real jumpy. Can you take a short section of that scene and
try different mpeg coding options to see if it makes a difference? I'll
bet that if you actually decrease the quality and/or frame rate, that it
makes it better cause the DVD player doesn't have to work as hard. Let
me know if we can try this. Thanks.




Any ideas? Could it be the settings I am using in TMPGE?


Are there any stadard or common things in the conversion process that can cause this "flickering" or "speeding up of video"? (even if only for a few seconds at a time?

[lucasgric]

What is the output bitrate of your video?

The maximum standard bitrate for a DVD-Video is 10'08 Mbps, including the audio and the video streams. If the bitrate is less than 10'08 the DVD should not jump on any player.

I've not used Ulead DVD Workshop, but most of DVD authoring programs advice you if the max bitrate is reached.

In TMPGenc, be sure the parameter "VBV buffer size" is set to the standard value: 224 or 0 (automatic; TMPGenc internally will set it to 224). Check the medium video bitrate and the audio bitrate not to overcome 10'08 Mbps.

I hope this can help you. Excuse my english.

[winifreid]

I suspect it has to do with Field order. In TmpGenc it can be either Bottom first (B) or top first (a). There are some ways of determinig wihich it should be, but I think the easiest way is to just try both with a short action sequence and see which works. It is also possible that your bitrate is to low for your resolution.

[Sominex24]

I suspect it has to do with Field order. In TmpGenc it can be either Bottom first (B) or top first (a). There are some ways of determinig wihich it should be, but I think the easiest way is to just try both with a short action sequence and see which works. It is also possible that your bitrate is to low for your resolution.

OK,

I really need to just get educated more on the whole process of what AVI video is, why and how it gets compressed, through what techniques and software this is done, all the way to the burning stage.


I need some good reading material to just get me more educated


Any advice??



Are there good informational reading sources on this web site?

[lordsmurf]

www.digitalFAQ.com capture guides can give you a primer on digital video

[DVD_Ripper]

"Jumpiness" sounds like there were frames lost during the transfer from your DV to computer.

Are you really seeing pixelation ... where, during fast motion, you are seeing pixels forming around the fast moving objects that 'comes and goes'

[Sominex24]

"Jumpiness" sounds like there were frames lost during the transfer from your DV to computer.

Are you really seeing pixelation ... where, during fast motion, you are seeing pixels forming around the fast moving objects that 'comes and goes'

Hard to put into words Ripper-

Some of the scenes where the camera is moving around, the images on the screen get a bit "jumpy" and blurring

I would quite call it pixelation


---


I can not get virtuadub to work with my firewire card as of yet-

I tried doing capturing the video DIRECT to MPG, but I could see a LOT if pixelation


Let me ask you guys this....

If the problems are NOT occuring during the capture process, when could this be occuring?

Am I skimping on the TMPGE conversion too much?


I have a P3 2.8 (Prescott Core) Hyper Threading

1 GB of dual channel RAM

and I am working on a 160 GB HD with about 70 GB free space left


Am I doing something wrong in the conversion process?

I would LOVE to capture RIGHT TO MPG, but it just looks so pixelated at points

[guns1inger]

I think the likely culprits have already been mentioned in the posts above. You just need to work through them to find the actual cause. So far, the following have been suggested;

1. Droppped frames during capture. The easiest way to test for this is to view the DV on your PC before encoding. If it all looks smooth, chances are this is not the cause. Use DVIO or WINDV to capture some footage. They will tell you if frames are being dropped.

2. Interlace flicker. MiniDV is lower (bottom) field first in most cases. Make sure you have this set correctly.

3. Too high/Too low on th bit rate. Too low and you'll get pixelation, too high and players will struggle to keep up, causing jumpiness/slow down/crashing. Use a software player that shows bit rates on-screen during playback to see what is happening. Try freeze frame through some of these troublesome scenes to see how much pixelisation this really is.

From the description from your friend, I believe the most likely culprit is spiking bit rates going over the allowable top-end. The problem appears to happen mostly in panning scenes. In a pan, almost every pixel changes every frame. This is the least ideal scenario for mpeg conversion, and will use the highest bit rates if encoding with VBR. If the encoder is going to spike, this is where it will do it. You could try bringing the high rate down, or going to CBR instead. However both of these could result in lower overall quality.

Finally, I know not everyone agrees with me, but I have had issues using TMPGEnc on DV footage, especially in scenes with a lot of movement. I suffer interlacing issues that I don't see using the MainConcept encoder. I no longer use TMPGEnc for DV sourced footage.