How to test for overscan?

[lubczyk]

Ok, I have a Toshiba DLP 50HM66 HDTV. I also have a PS3. I would like to test for the exact amound of overscan that I have.

This is the current script I use for overscan compenation:


LoadPlugin("F:\PS3 Encoding\Program Files\AviSynth 2.5\plugins\vsfilter.dll")
LoadPlugin("F:\PS3 Encoding\Program Files\AviSynth 2.5\plugins\directshowsource.dll")

directshowsource("[SS-Eclipse] Clannad - 19 (1024x576 h264) [94EF58DF].mkv", fps=23.976, convertfps=true, audio=false) #replace with appropriate source filter...

textsub("subs.ass") #could be srt, ass, ssa, etc...

addborders (16,16,16,16)

I will increase addborders to see just how far overscan extends. Is it possible to change the color of addborders to lets say Yellow or Red? That would make it easier to test for the exact amound of overscan that I have to compensate for.

[hanfrunz]

Hi,

you should build yourself a testpattern. like this:


___
1 ___
2 ___
3 ___
4


put a pattern like this to all 4 sides of the picture. Render a short clip an look how much pixels are cropped on each side.

hanfrunz

[J_Darnley]

If you had read the docs you would have seen:
AddBorders (clip, int left, int top, int right, int bottom, int "color")

The color parameter is optional (added in v2.07), default=0 <black>, and is specified as an RGB value regardless of whether the clip format is RGB or YUV based. Color presets can be found in the file colors_rgb.avsi, which should be present in your plugin folder. See here (file:///C:/Program%20Files/AviSynth%202.5/Docs/english/syntax.htm#Colors) for more information on specifying colors.

[2Bdecided]

You can download the 16:9 Guide Graphic from here:
http://www.bbc.co.uk/commissioning/tvbranding/picturesize.shtml
It labels all the pixels. Unfortunately, it's square pixel, and resizing it to 720x576 will mean the pixel numbers aren't correct - but it's a start!

Cheers,
David.

[2Bdecided]

PAL 16:9 -- 64:45 || PAL 4:3 -- 64:60 || NTSC 16:9 -- 64:54 || NTSC 4:3 -- 64:72

I still think that's a "brave" thing to put in your .sig. You should at least mention that you're assuming 720 pixels define the aspect ratio, which is against the ITU specs and against all standard video sampling frequencies (i.e. multiples of 13.5MHz).

http://forum.doom9.org/showthread.php?t=132378

Cheers,
David.

[lubczyk]

Hi,

you should build yourself a testpattern. like this:


___
1 ___
2 ___
3 ___
4


put a pattern like this to all 4 sides of the picture. Render a short clip an look how much pixels are cropped on each side.

hanfrunz


Would you mind taking me step by step? I have no idea how to do such a thing in avisynth

[J_Darnley]

I still think that's a "brave" thing to put in your .sig. You should at least mention that you're assuming 720 pixels define the aspect ratio, which is against the ITU specs and against all standard video sampling frequencies (i.e. multiples of 13.5MHz).

http://forum.doom9.org/showthread.php?t=132378

Cheers,
David.

I did have a whole rant typed but then I decided I would not de-rail the thread. Basically, I don't care about analogue relics. People who do, should know that my sig is not accurate. People who dont, either really don't or don't know of the problem but if they think they might, they should read up before they commit to anything. But just to be safe and please you, I might put a small warning.

If you really want to discuss, you can PM me.

Would you mind taking me step by step? I have no idea how to do such a thing in avisynth

AddBorders(2,2,2,2, colour)
AddBorders(2,2,2,2, colour)
...
AddBorders(2,2,2,2, colour)
Wasn't that hard. Repeat for desired border sizes. Replace colour with desired colour(s). Size two borders required for YV12 colourspace. If you want size one, then you will need to convert to an RGB colour space and then use black and white borders or the colours will be lost when converted back to YV12.

[lubczyk]

I did have a whole rant typed but then I decided I would not de-rail the thread. Basically, I don't care about analogue relics. People who do, should know that my sig is not accurate. People who dont, either really don't or don't know of the problem but if they think they might, they should read up before they commit to anything. But just to be safe and please you, I might put a small warning.

If you really want to discuss, you can PM me.



AddBorders(2,2,2,2, colour)
AddBorders(2,2,2,2, colour)
...
AddBorders(2,2,2,2, colour)
Wasn't that hard. Repeat for desired border sizes. Replace colour with desired colour(s). Size two borders required for YV12 colourspace. If you want size one, then you will need to convert to an RGB colour space and then use black and white borders or the colours will be lost when converted back to YV12.


_____________


Thanks. I thought you were referring to something else, but now I see I was on the right track.

[mahsah]

("[SS-Eclipse] Clannad - 19 (1024x576 h264) [94EF58DF].mkv

Interesting name for your "backup" there.

[Comatose]

You guys don't have to go nazi every single time, jeez.

[lubczyk]

Interesting name for your "backup" there.

It's not a backup, it's a test clip.

It's easier to tell how much is cut off with animation.

Once I can get the overscan of my tv, I can apply to my all my live-action movies.

[2Bdecided]

I did have a whole rant typed but then I decided I would not de-rail the thread.Let's take it here then...
http://forum.doom9.org/showthread.php?t=132378