jpiesing
commented
4 years ago I just found this in 5.2.2.4.
With setting up a source buffer for a video media type, either: • a pre-determined display window that matches the aspect ratio and size of the content (height and width) is established, or • a full-screen display is established. With setting up a source buffer for an audio media type, an audio output is established.
If the display window here is the same as the "video output window" in the observations then this issue becomes purely editorial - I would suggest changing 5.2.2.4 to use "video output window" and perhaps add a cross-reference to 5.2.2.4 from the first place where "video output window" is used.
haudiobe
gitwjr
(Edited now I've seen WAVE 10.2.1) Many places in the Device Playback spec have language like this;
There doesn't appear to be a definition of "video output window".
Section 10.2.1 of the WAVE device spec requires a selection of 16:9 resolutions be supported which is fine when the video output window is also 16:9 but what if the video output window isn't 16:9?
Scaling that doesn't preserve aspect ratio may not be tested at all except to a limited extent, e.g. if required by global content providers or if required by resident apps in a particular device. Alternatively attempting to fill a rectangle whose aspect ratio is not 16:9 may be implemented by keeping the video as 16:9 and leaving the remainder as black. The latter is what HbbTV requires.
I propose (request?) that the device playback spec be changed to either 1) permit video scaling that preserves aspect ratio and fills the remainder with black or 2) make behaviour out of scope when the video output window doesn't have the same aspect ratio as the video.