Actually, mike, the OP’s are correct – the app doesn’t call the Video API in such a way as to enable full-screen.
The iPad Air 2, for example, outputs video at 1600x900 resolution, not 1920x1080, when in “Screen Mirroring” mode, but it sets the HDMI output mode to 1920x1080 (or whatever the display supports) and downscales the video to 1600x900 within that resolution.
But apps like NetFlix, Infuse Player, Buzz Player HD, etc and the Safari Browser video playback do output full screen. The video playback goes to the HDMI port, and the main display of the iDevice says “Video Output to TV”
This helps explain it – I’m using an old HDMI monitor at work (which is not 1920x1080; it’s 1900x1050 or something like that)
WD’s app, even in “Full Screen” mode:
Note that the video is playing on BOTH displays – “Full Screen” on the iPad (but with letterboxes because iPad display is not 16:9), but not even close to it on the monitor – large pillar & letterboxes all around as shown with the red line.
Note also that this CANNOT be overcome by using most “Zoom” modes on most TVs, as the output *is* 1920x1080 with everything appearing in a 1600x900 virtual box. And even if the TV’s will ZOOM (deliberate overscan, basically), it’s not complete.
Other apps, same file (this is the Infuse app, but other apps are similar if not identical):
No video display (only controls) on the Ipad, and full-screen playback on the monitor with NO pillars (only letterboxes because of the odd non-16:9 aspect of the monitor).
BTW, using the overpriced Apple A/V adapter is “so yesterday” if one has set up his home network…
… yeah, but not in any other place – I travel a lot, and my HDMI adapter is Required Packing. I put my iPad on the hotel nightstand and run a 20-30 foot HDMI to the TV to watch movies from my WiFi drive – works almost every time (unless the hotel TV lacks working HDMI or “locked” HDMI).
No need to pack any other gizmos.
Simply put, WD’s app is overlooking the use of a built-in iOS feature (which has been there since iOS 6…) to do video playback; relying instead on using screen mirroring which doesn’t work well.
