Re: Defining safe areas for media devices and set top boxes

2010-12-02 19:45 EEST: João Eiras:
> My team is working with set top boxes and other media devices which
> connect to TVs. Depending on how the device is connect to the TV
> (HDMI, RCA cable, etc), and depending on the TV itself, content might
> be cropped. Therefore, one needs to define the safe area, which is
> the part of the browser/application viewport that is not cropped and
> can be safely used to render meaningful content,  while the parts
> that can be cropped should just have content that is not important or
> purely aesthetic, so the cropped parts will look smoothly integrated
> with the TV edges, instead of the browser just rendering a couple of
> black stripes.

I understand the problem and have worked my every display to not crop
the content (and I do research before buying any display to make sure
that I can set it to not crop the image). However, I'm totally aware
that many devices sold as "TV"s, are lacking even the controls to
disable the cropping and some (most?) 1080p native TV sets crop even
1080p signal transferred over HDMI (which obviously does not make sense
at all, but this is still the real behavior).

Regardless of all that, I don't think that this mess should be exposed
to content authors using HTML. Instead, the UA should allow configuring
the viewable content area and in practice, creating following user style
sheet:

:root {
padding: 1px 2px 3px 4px !important;
}

Where numbers 1-4 are set according to user input (using some kind of
test image, probably).

This prevents real content from ever going "under the frame" and still
allows background to fill the screen. If an author decides to use
negative margins for e.g. body element, the content may end up "under
the frame", but that's expected.

Do you have any examples, where a simple user style sheet such as one
above would not be enough to fix the "my display incorrectly crops the
content" problem?

-- 
Mikko