This is something I have recently noticed, and I need to know if it is unique to my system or whether I am doing something fundamentally wrong.

 In my last wedding film, I used a white colour clip placed beneath tracks of video for various effects,and it worked fine. What I did notice however is that when viewed in the master viewer or played out on a computer screen, there is a white border around the overlyiing video clip as if the colour clip is larger than the source video.. It's not visible on a TV and I understand the reasons for this, but the question is should the colour clip not be tha same size as the video?  I have done nothing to re -size any of the original video which has come from several camera sources and was imported via EZ capture, PAL DV 25fps SD.

I realise of course that I could apply a 2d filter to each clip, but do I really need to?

The main reason for asking is that I am preparing a piece for boradcast at a charity event in 4 weeks time, and it may be via computer/projector.

Thanks

Dave

A television set does not display the full picture that is broadcast.  There is a slight cropping that takes place and the amount varies from set to set or manufacturer to manufacturer.  For this reason, there is a "safe" zone for your picture content.  This is represented by the rectangle you see when you first open the Title Deko.  Staying within that safe zone with your content guarantees that it will not be cut off/cropped when viewed.  The TDK zone is very conservative and you can create title content slightly outside the boundary shown with little fear of it not showing.  However, when filming events it is best to be on the conservativve side and keep the objects of interest in the center of the field of view or at least leave an edge of noncritical content around the edge of the field of view.

 In a word, the white edge you see in the preview screen is still there but the tv set crops it off.  I am providing this info for others who may not be aware of this quirk of television sets. 

I have been concerned in the past about the 'underscanned' [i.e. full frame] picture displaying itself in the wrong environment - such as a DVD being played back with conflicting DVD player/TV aspect ratio settings. With incorrect user settings, it is possible for the viewer to see the full frame underscanned on his TV, which is designed to overscan [i.e. zoom the picture in a few percent]. Depending on what resizing effects have been applied from scene to scene in Liquid, the viewer watching in full underscanned frame may still spot the unsightly jagged line present at the top of the normal picture and black unsused space at either side [which in your case seems to be containing your colour clip, which is always full framed by default].

I raised this issue in this thread:-

http://forums.pinnaclesys.com/forums/thread/225771.aspx

So for DVD playback, you could ignore any uneven framing in the 'underscanned' area [TVs playing with overscan], but run the risk of the unsightly edges becoming visible with incorrect user aspect ratio settings, or DVD playback via computer. For computer playback, switch underscan on in the Liquid timeline viewer and make those frame edges your guide as to what will be seen.

As many films these days are desirable to be seen both on DVD/TV and computer, to comfortably accomodate both of these at once I would suggest either zooming in your video picture to ensure it fills the screen throughout in underscan mode [resulting in slight loss of quality, and perhaps messing with your original desired camera framing somewhat], or better, making two slightly different edits - for TV, crop the top and bottom of your video just in the underscanned area [meaning the normal overscanned TV picture is unaffected, but if seen underscanned there will be a neat black border rather than any broken pixel lines/protruding video layers], and for computer playback, perhaps just take away a few lines of pixels to neaten up the underscanned picture as you desire* [or just use the version with the full underscanned frame tidied up for TV].

*I have ingested firewire miniDV footage into Liquid from many different camera sources at 4:3, 16:9 aspect ratios, and always have to consider the broken top line of pixels as well as the black side bars visible in underscan. I have always assumed this is indeed what I should be seeing in full frame, though I have never heard anyone else talk about these artifacts specifically.

Thanks for the replies. I do understand the under/overscan scenario, I'm just curious to know why the colour clips are larger than the source video, and visible at the edges on a computer when placed behind video.

Dave

Because the color clips are the full size of the inlay window inside Liquid and the source video is 1440X1080 (for HDV).

Tim

dheron did say he was using PAL SD. I have tried using a 4:3 clip and 16:9 and putting a colour clip underneath and cannot get any colour border to show.

I have viewed this in underscan and full screen on my LCD monitor.

Perhaps dheron can post a screenshot to show what he is seeing?

"Because the color clips are the full size of the inlay window inside Liquid"

What size is that?  I suspected there might be a diference in the sizes of the assets involved, but I thought Liquid automatically made everything the same size.

"dheron did say he was using PAL SD. I have tried using a 4:3 clip and 16:9 and putting a colour clip underneath and cannot get any colour border to show. I have viewed this in underscan and full screen on my LCD monitor"

This is interesting - are you saying that when you view captured footage in underscan, there are absolutely no blank unused spaces around the picture? The underscanned picture fills the entire screen, like your colour clip?

When I view ingested footage captured by various cameras in both 4:3 and 16:9 in underscan mode, I always have small blank borders running up the left and right of the picture, plus a 'broken line' of pixels running along the top [the likes of which I have also seen in television news broadcasts].

I will post a screenshot example when I can - would be good to hear what is the expected normal presentation in Liquid of an underscanned picture in respect of this.

What I should have said that I could not see the colour clip (which for this test I had made orange) outside the video clip, which I thought dheron meant.

If I select underscan, then there is a border around the video area, but not the colour of the created clip underneath, if that makes sense.

Yes - the underscanned video picture is displaying the colour clip underneath, which fills the entire frame in underscan by default.

Therefore it must be the rule that to create a video for computer playback, the editor must apply either cropping or zooming to tidy up the full frame overscanned picture since that is what will be displayed.

Otherwise there are borders either side, and the broken top line I have mentioned.

Unless someone thinks this is not how ingested footage should look in underscan?

I am editing 16x9 for web video and have noticed a black line above and below the video. These lines exist after the rendering completes. If I zoom in, the lines disappear... until the render completes. Then no matter how far I zoom in (CPU or GPU editor), the lines return as soon as the rendering completes.

 Perhaps this is a similar issue...