On 5/13/12 7:26 AM, David Goss wrote:
but it'd be irresponsible to just serve an
<img> with the high res source to all users, making them wait longer
for the download even though they can't see the extra quality on their
screen.
Except when they can, e.g. by printing or moving the display to another
screen.
Basically, in this case not sending the high-res image is optimizing a
bit for one common use case while degrading the user experience in other
use cases. Maybe that's OK, but that requires a careful analysis of
user behavior for the particular content involved. And in particular,
I'm not sure what I think of labeling content that aims to be usable by
the user in the widest variety of circumstances as "irresponsible".
Past examples of us doing that sort of thing led to it being considered
"irresponsible" to allow website layouts to scale above or below certain
widths, amongst other current usability disasters.
Note that these concerns argue, to a certian extent, *against* reusing a
very general syntax that can express constraints that aren't relevant to the
actual use cases, or that provide an attractive nuisance that encourages
developers to do things that can't be implemented in a performant way.
Dumping<picture> as it is won't prevent this, as it's already in the
door in the form of<video>.
<video> has quite different dynamic behavior from <img> and quite
different author expectations (e.g. authors don't expect videos to be
preloaded in their entirety, by default; there are other significant
expectation differences too).
-Boris
