[MPlayer-users] Hypothetical question regarding libass scaling

[Eric Appleman]

(Feel free to correct me if I am mistaken regarding MPlayer functionality.)

Suppose I have 2 fansubs.

File 1: 480p widescreen (848x480) mkv
File 2: 720p mkv

Assume that both files use a script that has a playres matching the 
video resolution.

If I have an LCD screen (16:10 or 16:9) that has a native resolution 
that is larger than the aforementioned resolutions, the videos will be 
resized (while maintaining aspect ratio) to fit in fullscreen or 
non-fullscreen window. However, the subtitles will also be resized. By 
virtue of its resolution, File 1 will have to stretch the video and 
subtitles more than File 2 in order to fit the screen. It is understood 
that resizing a video upwards cannot improve its quality, but because 
subtitles are overlayed, they are not necessarily bound by this. 
However, since they are normally treated as part of the video during a 
resize, sharpness is sacrificed.

My laptop has a 14.1 inch WSXGA (1440x900) screen. For a 16:9 video in 
fullscreen, the ideal subtitle resolution is 1440x810. For 4:3, 1200x900.

Is it possible to have the videos resized to fit a resolution within the 
video's aspect ratio, fullscreen or otherwise, but not have the ass 
subtitles lose their sharpness?

That is, why does MPlayer treat subtitles differently when the scaling 
filter is used, as opposed to a normal resize?

- Eric