The Error
LG webOS is a great system to use. Unfortunately, when you decide to use these displays in Portrait mode, the video quality decreased.
The reason is inside the internal handling of webOS and until the webOS 4.0 cannot be resolved.
The video resolution on FullHD displays playing fullscreen video in the Portrait is 960 x 1080px!
The video quality is relatively ok while you are not having small texts within your videos.
Why it's happening
The error is caused by the insufficient video memory on webOS 3.0 and 3.2 device.
How to Resolve
In order to play the video in the full FullHD resolution on LG webOS 3.0 and 3.2 devices, you can rotate the video via ffmpeg and serve them already pre-rotated.
Downside In this case, you have to setup your display into the Fake Portrait mode. Fake Portrait mode will rotate all HTML5 content into the Portrait excluding videos from this process.
In case you need more detailed information on this topic, please contact our support to schedule explanatory call.