[whatwg] Interpretation of video poster attribute

[Philip Jägenstedt]

Hi!

I'm a bit puzzled about how to interpret the poster attribute on
HTMLVideoElement:

"The poster attribute gives the address of an image file that the user
agent can show while no video data is available. The attribute, if
present, must contain a URI (or IRI)."

Is the intention that this image should be stretched to the size of the
video element, or that it should be centered in the frame? If the width
and height attributes are not given, should the video element initially
be given the size of the poster image, or should the user agent wait
until it has the dimensions of the video (thereby making the poster
useless)?

In short, what is the intended use of poster?

-- Philip Jägenstedt