[MPlayer-users] monitor size vs. aspect ratio vs. resolution

[Philip Prindeville]

Rich Felker wrote:

>On Mon, Aug 15, 2005 at 12:28:20AM -0500, Reshat Sabiq wrote:
>  
>
>>I'm not well versed in this, and appreciate any feedback.
>>
>>I'm trying to figure out what the best aspect ratio is for me to use. My 
>>monitor size is 33.2cm/20.9cm, which is roughly 1.6, and resolution i 
>>usually use is 1280x800 (max). This is a laptop. I tend to use xine more 
>>often, but hope this is an appropriate venue to ask.
>>
>>My questions are:
>>
>>1. Should i even try to use 16:9 aspect ratio w/ this monitor, even for 
>>widescreen DVDs?
>>   It appears that this causes some pixels to be lost, or distortion. 
>>I'd think this would cause only a black border on top and bottom, but it 
>>appeas to instead cause a loss of some pixels on left and right 
>>sometimes. Or maybe i'm just imagining it.
>>
>>2. If i bought a TV that has the actual 16:9 dimensions, would i be able 
>>to use this laptop for TV-out, and really have 16:9 on the TV monitor? I 
>>suppose i should be able to, using settings like below.
>>
>>3. My laptop has widescreen written on the monitor. But it appears the 
>>only way to be able to use 16:9 and utilize the whole screen for me is:
>>a. monitoraspect=1.78 with mplayer
>>b. anamorphic, + resize the output with Alt+z or Ctrl +z with xine
>>Both of these approaches appear to distort the video somewhat, 
>>especially given that most DVDs are 720x480. Can such a monitor really 
>>be called widescreen, or should only monitors with 16:9 (like 1280x720, 
>>which mine doesn't support) resolutions, or physical dimensions (like 
>>HDTV monitors) be called that way?
>>
>>4. Is it a correct statement that non-widescreen videos should be 
>>watched in 4:3, and widescreen ones in 16:9, regardless of resolution 
>>and physical dimensions? Doesn't 4:3 already mean a distortion, since 
>>most DVDs, for instance, are 720x480, which is a ratio of 1.5?
>>
>>Sorry if the questions seem basic, but i really am a little confused by 
>>all this. This doesn't stop me from enjoying both xine and mplayer on 
>>regular basis, but i want to be able to do that in an optimal way.
>>
>>Thanks all.
>>    
>>
>
>I don't understand your questions at all. However, you will have
>correct output in all cases if you just set monitoraspect to the
>*REAL* aspect ratio of your monitor. So in your case, -monitoraspect
>332/209 should work great. The number of pixels (in the movie file or
>on your screen in the current display mode) is totally irrelevant. All
>that matters is the physical aspect.
>
>As for your TV out question, yes, you can do 16:9 tvout just fine as
>long as you use -monitoraspect 16/9.
>
>Rich
>
>  
>

Umm...  If the monitor is DDC/EDID plug n play compatible (and there's no
reason why the builtin LCD screen on a laptop wouldn't be), then it will 
sense
(via EDID) both the resolution (obviously) as well as the physical 
monitor size.

 From this you can derive the pixel aspect (I think the original posting 
assumed
that all pixels are round, which is frequently not the case).

-Philip