PDA

View Full Version : Screenshot Size


xb2iris
2008-08-13, 21:10
How does one edit the size of a screenshot when xbmc capsures a screenshot...

Mine currently takes low res 720x576 pictures, but is this value customisable, because I have I use 720p resolutions at present!

Thanks for the help!

kraqh3d
2008-08-13, 21:17
that doesnt sound right. i would think it would take a copy of the current "viewport" size which should match the screeen resolution.

Jezz_X
2008-08-14, 02:39
indeed 720x576 is PAL resolution XBMC takes the screenshot at whatever it is runnign in on linux for me it takes them at 1360x768 because thats what I run in

KidKiwi
2008-08-14, 05:25
Not wanting to HJ the thread - and not specifically a Linux question, but taking a screenshot produces a 720x576 PAL pixel image. If this was a capture of a 16x9 movie, then the image is squashed horizontally. Is there a formula?? to return it to the correct aspect ratio? I know I can stretch one side in an image editor - but how much should I stretch it - to what pixel size. I've usually done this by eye, but surely there must be a correct sizing method? Thx

kraqh3d
2008-08-14, 05:37
im running the win32 build in 720p 16:9 (which is 1280x720 resolution) and i took a few screenshots. all of them are in that resolution. while playing a 16:9 movie, its an exact capture of the frame.

if you're getting screenshots in 720x576, then i can only assume thats the resolution you are running xbmc in. (standard PAL as Jezz_X said.)

jmarshall
2008-08-14, 05:43
The actual pixel ratios are specified in guilib/GraphicContext.cpp, but the what the video is using is whatever you set it up to use in screen calibration.

The values for those that care:

NTSC/480p: 4320/4739
PAL: 128/117

Multiply each by 4/3 to get 16x9 equivalents.

You need to divide the height, or multiply the width by these quantities to get the correct aspect.

(eg leave width the same, multiply height by 117/128 will get you the correct aspect, or leave height and multiply the width by 128/117).

Cheers,
Jonathan

KidKiwi
2008-08-14, 05:45
Thx for that. Will give it a go.

KidKiwi
2008-08-14, 07:58
Okay...here are the results. Thought I would add this for future forum searches.

A screenshot of an anamorphic widescreen image produces (running in PAL SD 16x9 widescreen) a 576x720 image that is horizontally squashed. To correct the aspect of the image you multiply the width by 1.3333333 (720x1.333333)=960 pixels - leaving the height at 576 pixels.

Or...divide the height by 1.3333333 (576/1.3333333)= 432 pixels - leaving the width at 720 pixels.

This will result in an image that looks correct.

jmarshall
2008-08-14, 08:34
No, that's not correct at all. You are only correcting for the 16x9 vs 4x3 problem: Not for the fact that the pixels on a standard PAL screen aren't square.

For PAL 16x9, following my previous post you want:

Multiply the width by 128/117 * 4/3 = 1.4587, and leave the height as is, giving 1050x576.

OR: Divide the height by 1.4587, and leave the width at 720, giving 720x395.

That will then look correct.

Cheers,
Jonathan

KidKiwi
2008-08-14, 09:02
:eek::shocked:???

I thought this was right because the resultant image looks correct. When I adjust to 1050x576 or 395x720 the image is too stretched horizontally. Never was much of a math wiz :sniffle: I better go and crawl back into my hole :o

xb2iris
2008-08-14, 17:32
I'm still not understanding any of this tech talk... not very tech savvy... my bad...

nyways... any suggestions on what i can change in any cpp file or anywhere for that matter, to get a larger 16x9 screenshot... i am definately running at 1280x720... and if i change my system to 4x3, i still get an screenshot with the same size... which i really don't get...

any suggestions for this amateur???

kraqh3d
2008-08-14, 18:36
i honestly dont know. as far as i can tell from the code, it shouldn't do that. im getting screenshots that match my xbmc resolution but im running in windows and im not running full screen. (note it is the xbmc resolution that matters. not your desktop resolution.)

AJAcker
2009-11-01, 22:14
Best I have found is to open paint and Resize/Skew (CTRL+W), adjust height to 70% leaving Width 100%. Then Save as .jpg to reduce file size. I wrote a macro for it, well, an Autohotkey.

I spent ages on the settings of my XBMC before finding this thread.