Best solution for overscan problem

[hkmak]

Hello, I have this overscan problem when watching my DVD-R home video on TV. Anyone have the best solution to overcome this? Should I resize the video (make it smaller) and add it border or just crop it (sacrifice the outbound image)? What is the best solution?

[lusid]

Overscan is by design. It's normal to lose 5% to 10% of the edge of the footage to overscan. Broadcasters take this into account durring filming and post production, so that nothing critical lands outside the safe zone.

Some tv's might let you adjust the amount of overscan, most don't. You could shrink the footage into the center 90% of the display, which is safe on most tvs, or the center 80% which is same on almost all of them. Then add a border, but it's best to just plan around it when you're filming your home videos to begin with.

[hkmak]

lusid,

Thanks for your advice. May I ask what software to use to shrink the original AVI video? Do I need to add in border to fix it back to original size before I encode it using TMpgenc?

[lusid]

Adding a border would be a good idea, but it is possible to have tmpgenc do that for you.

As for resizing, if your source is interlaced then you should deinterlace before resizing or use an interlace aware resizing filter. Otherwise the results won't be pretty. If your working with avi footage, use virtualdub. You should be able to do all the processing in virtualdub and frameserve it out to tmpgenc.

[hkmak]

Sorry to bother you again lusid, tmpgenc can do border add in? How? If not, which software can? My AVI is capture from my DV cam, is it interlaced or non-interlace?

[Anonymous65]

The camcorder should have a safe area square on the viewfinder so you know what to expect when viewing the video on a TV set. If not, always shoot looser than it looks like in the view finder. All professional cameras (like TV studio models) have this safe area square to guide the camera person to what will actually bee seen by the public. Until we all watch TV with a LCD monitor, we will always have to deal with overscan of the TV set. I would not mess with borders or cropping, nobody does this. Shoot your video with a 10% overscan in mind like the pro.
The video from your camcorder is most likely interlaced, that is the standard for NTSC and PAL video.

[adam]

I agree with skittelsen that overscanning should be taken into account when filming but I strongly disagree about not cropping out the part of the picture that will not be displayed. There is no point wasting bitrate on picture that you will never see and I for one definitely do crop out and add borders over this portion of the picture. Actually I know lots of people who do also.

The amount of overscanning differs from tv to tv, and to determine the actual amount your tv crops you would need to run some tests, but almost all tv's crop at least 12 pixels. You can safely crop these pixels and add black borders and believe it or not it really does make a pretty significant impact on your video quality since you are saving 12 pixels on all sides for every single frame in your film. That really does add up faster than you would think.

If you are using avisynth to frameserve you can use FitCD to create an avs script that takes overscanning into account.

[adam]

Sorry to bother you again lusid, tmpgenc can do border add in? How? If not, which software can? My AVI is capture from my DV cam, is it interlaced or non-interlace?

In the advanced tab double click on the clip frame filter. To add borders check the mask button for whatever side you want, ex: left, right, top, or bottom.

So to add borders over the top check top mask and keep hitting the plus arrow in the Top box.

[Big_Jit]

If you download the sample VCD from this site it has some stills that will play on your DVD player that will let you know exaltly how to resize/offset the video by pixels and percentage...

http://www.vcdhelp.com/vcd.htm

[Nelson37]

I agree with Adam, I get significant improvement by cropping to 672x448 on capture, resizing to 336x448, and using AddBorder(8,16,8,16) with AVIsynth. The black borders are invisible on my TV.