Hope this has not been covered elsewhere and correct me if I have missed something obvious, but I was surprised there is no volume control during playback.
I own an ASUS O-Play as well which does control volume of video files.
There are unassigned buttons that perform no function (directionals) during video playback that could be used.
Nick
Your post sounds more like an Idea or a Feature Request. The best place for this is in our Ideas Lab. This way someone from WD will be sure to see it. However, I would search first and make sure that there isn’t another idea similar to yours that you could add your post to and vote on.
Ideas Lab
http://community.wdc.com/t5/community/categorypage/category-id/idea