Small gridlines on sony vegas pro 8 ????

[holeepassion]

I suddenly see all these lines, not very clear but on close look, they could be quite annoying on LCD. I wonder what causes this ??? Too much processing or something else ?

I did not see this in my earlier video editing, only recent ones so not quite sure why ??? Any ideas how to get rid of them ??? They are almost constant, like overlayed on top of the video rather ????

I could probably using gaussian blur to get rid of background, but on the subject, that might cause a bit of issue !!!

Thank you

[jagabo]

Post a sample image. But it sounds like interlacing or macroblocks from too low a bitrate in the source.

[holeepassion]

No, they are not the same. Or it could be a variation. I believe my source was recorded in the highest setting possible which was 30fps, 640 x 480, not a HD but pretty great result. Previously, I haven't seen it. I am wondering could this be due to contrast adjustment ??? It seems to make it appear more I guess ???

Here is the screen dump ... it can look pretty annoying although it is not too obvious. Hope it is something due to post processing. I did reedit the video file before but it was saved using uncompressed avi files. Others seem to be ok. Just in the last two video clips, I noticed this. If you could pinpoint, that would be great. Otherwise, I might have to post process them including noise reduction, sharpening from the start which could take a while as I have to do it for each individual short clip of the videos I processed.

Thank you for your response so far.

[guns1inger]

They look like compression artifacts or artifacts introduced by filtering, although they could also be introduce post encoding by a playback filter.

What is your source format ?
What do you encode it to ?
What settings do you use ?
What filters have you applied at any point in the process ?
That image is obviously not 640 x 480, so are these artifacts visible when played back at the native resolution ?

[jagabo]

I have seen some players do that on playback -- so it may not be a problem with the video itself. If you post a short sample of the video I'll take a look at it.

[edDV]

We aren't looking at video there are we. This is some computer video player trying to anti-alias a low resolution playback cheat. Those pixels are huge.

[holeepassion]

They look like compression artifacts or artifacts introduced by filtering, although they could also be introduce post encoding by a playback filter.

What is your source format ?
What do you encode it to ?
What settings do you use ?
What filters have you applied at any point in the process ?
That image is obviously not 640 x 480, so are these artifacts visible when played back at the native resolution ?

Kool. Source is high quality 640 x 480. Now, the rendered result is 720 x 480 uncompressed. I used the high quality, uncompressed video. What filters ? you mean the video effects ??? I did some noise reduction using external party neat image. Then I did some contrast adjustment. I did some color balance. Some unsharp mask and a little sharpening. That's it.

Thanks

[holeepassion]

I have seen some players do that on playback -- so it may not be a problem with the video itself. If you post a short sample of the video I'll take a look at it.

Kool. I spend like all night rending that five minutes clip so I hope so. I would post some when I managed to get some short sample. What sort of resolution you want ??? I did try to get a lot shorter video and it still gave me the gridlines. I checked my previous video clips, nothing of this sort happening.

Thanks for your kind assistance.

[holeepassion]

We aren't looking at video there are we. This is some computer video player trying to anti-alias a low resolution playback cheat. Those pixels are huge.

Thanks for your reply. I hope so. I was thinking it could be due to its very high resolution, and size of around 9 gigs for the 5 minutes. But I did tried a much shorter version so I think it is not due to size. I guess maybe I could try to burn to DVD and check it on TV instead

It seems to be what you said but am a little confused with different video clips versus others. Could be due to artifacts from filters as previously mentioned also. But the gridlines seem to be on top of the videos not within it so ... fingers crossed nothing major where I have to redo the post processing.

Thanks again for the reply.

[edDV]

When you view on a computer monitor the raster is first deinterlaced if interlace, then scaled to the open window. The scaling causes much of what you see. Hardware scaling from the display card can help if the card is good.

Some players inverse telecine 480i/1080i as do some display cards. Others don't and cause all sorts of artifacts from 24p source.

[jagabo]

The size of the grid in the posted image is 22x22 pixels. Given the size of the frame and the fact that the video was 480 lines tall, the size of the grid is 16x16 pixels in the video before scaling for display. That could indicate a problem with the video (breaking the frame down into 16x16 pixels blocks is common in video processing) or an error caused by scaling the video during playback. Without seeing a sample of the video we can't tell you which. A second or so of the 640x480 video should be enough.