How to get correct aspect ratio values for comfig.xml?

[owilsky]

Hi,

I still have an old 4:3 CRT TV but none of NextPVR's aspect rations show the correct image for me.
I understand that I can create my own aspect ratio in config.xml and I understand what the four values mean.

Code:

[B]<AspectRatioMode name="4:3" ratio="-0.17, 0, 1.17, 0" />[/B]

I am using a 4:3 TV, using DVB-S (SD), my Recordings and DVDs have either 4:3 or 16:9 format. I want the faces of the persons display correct, not horizontally or vertically streched/distorted.

But how do I get the values I need, trial and error? Or are there any tricks for that?

Best regards,
Oliver

[johnsonx42]

Your format isn't quite correct there. For 4:3 content in a 16:9 format on a 4:3 display, you'll want

Code:

<AspectRatioMode name="LetterBox">-0.17,-0.02,1.17,1.02</AspectRatioMode>"

Think of the numbers as a percentage (or scaling factor). The numbers I gave mean put the upper left corner of the video frame 17% outside the left edge of the screen (0.0), and 2% above the top of the screen (the latter to cut off VBI data that often displays on older analog shows re-broadcast in digital); then put the lower right corner 17% past the right edge of the screen (the right edge is 1.0), and 2% below the bottom edge of the screen (again because I find some older shows have "imperfect" lower edges, and I want edge-to-edge beauty).

[owilsky]

Thanks. But 17% lost at the left and the right edge is too much for me.
What I wanted to know is how did you get to the values? Why 0.17? Trial and error or some higher maths?

[sub]

0,0,1,1 is top,left,right,bottom. This is fullscreen. ie 0,0 is top left. 1,1 is bottom right. From that you have to use maths to work it out based on the aspect ratio of your screen.