What is causing noise?

[tarrickb]

When i convert DV footage to MPEG-2 preserving the interlace, i see noise around moving objects that remain visable once burned and viewed on an LCD TV (not as visable on CRT).
The source is great quality, so I'm really disapointed about seeing this noise. Do you think i need to use filters, or is there something else i can try.

On a related point, the noise largely disappears when i choose to deinterlace using Sony Vegas...but as mentioned 100000000 times on this forum, i know de-interlacing isn't the best option.

[BJ_M]

most LCD TV displays are not the best test of interlaced (or much else) media ...

dont read to much into it until you have viewed the stuff on a better display ..

even most HD doesnt look to hot on MOST LCD TVs

[tarrickb]

Well, the DVD i'm creating is mostly going to be viewed on LCDs so is it suggested that i de-interlace?

[BJ_M]

not going to help a whole lot as you will also lose quality ..

best bet is the highest quality you can get with the source .

low light level dv is almost unwatchable on lcd

reduce sharpness ..

sometimes even adding a small amount of blur (.01) can help

[tarrickb]

Well...to tell you the truth, when i apply the "reduce interlace flicker" switch in Vegas, I don't notice a reduction in quality...i just notice the video being not as sharp (blurrier) and it doesn't have any noise.

[BJ_M]

same as adding blur

[tarrickb]

So do you think this is an OK option??? I've been on the fence about this issue for a while.

My pros for de-interlacing are:
1. Not sure if all the viewers of this DVD will be watching on TVs, and know for a fact that the vast majority will probably use WMP to view the DVD and wonder what is wrong with it (they will see interlace lines)
2. Don't see too much of a degration of quality, and it removes noise!

Pros for interlace:
1. Very sharp, good motion video.

What do you all think???

[BJ_M]

"reduce interlace flicker" is not deinterlacing in vegas

[tarrickb]

really????????????????

wow i thought it was becasue it completly removes the interlace lines. So do you recommend this?

[BJ_M]

You can get smooth, but slightly blurry video.
If you want crystal sharp slow motion, you can right-click on the video event that has been slowed down or shows noise or edges, select “Properties,” and then click on the “Disable Resample” setting. This will tell Vegas to simply play back the original frames, but at a much slower rate. The effect is identical to what you get when you slow down a movie projector. As you make the playback slower and slower, you begin to see just a series of still images, one after another. Each frame is exactly as sharp as the original, but it gets very “jerky” as the motion is slowed.
There has been much discussion of other settings, such as supersampling, best mode rendering, and setting project properties to “interpolate frames” instead of “blend fields.” These don’t make the motion look any smoother. If you find that your slow motion exhibits flicker, you can enabling the Video Bus track (in the View menu), adding a Motion Blur envelope, and setting it to somewhere between 2-4. You can also try right-clicking on the event, select Properties, and click on reduce interlace flicker. Don’t do either of these things if you don’t have to, because they both can slightly degrade the video’s crispness, and Motion Blur substantially increases rendering time.

Reduce interlace flicker
(video only)

This switch can be useful in cases where the source material didn't originate as video and contains extremely high spatial or temporal frequencies.

When you watch the rendered (interlaced) output on video of this sort of media, you may see flickering or crawling edges if this switch is not applied

Enable this switch when using imported images that were not created using a video camera (such as photographs) or when using generated media or text.

Resample
(video only)


Select a radio button to determine how video frames will be resampled when the frame rate of a media file is lower than the project’s frame rate. This can occur either when the event has a velocity envelope or when the frame rate of the original media is different than the Frame rate setting on the Video tab of the Project Properties dialog.

With resampling, the intervening frames are interpolated from the source frames, much like a crossfade effect between the original frames. This may solve some interlacing problems and other jittery output problems.

Smart resample


Resampling occurs only when an event's calculated frame rate does not match the project frame rate and the project frame rate is 24 fps or greater.

The calculated frame rate takes into account any changes made to event speed with velocity envelope, playback rate, and undersample rate.

Force resample
The event is always resampled, regardless of its frame rate or the output frame rate.

Disable resample
No resampling will occur.

[BJ_M]

in other words -- Reduce interlace flicker doesnt remove interlace lines, it is a low pass filter

[tarrickb]

interesting...thanks!

so i guess this is ok to use then to combat the noise?

[BJ_M]

sure -- just be aware it will "soften" the image somewhat (great for text on screen though)

[edDV]

I see compromise here. Keep interlaced for DVD. Carefully deinterlace for WMV.

If stop motion detail is required (e.g. sports), toss a field and live with half vertical resolution. If not, other deinterlace techniques will look awful in stop motion but will blur out at 1x.

There is no rule that TV viewers and streaming viewers have to look at the same file.

[tarrickb]

Yea...I'm no doubt sticking with interlaced, have made up my mind in that regard.