Thanks for the info.
Movie 1, Swing Time, is playing at 480p because it is a 480p movie (note width, height, & videoResolution).
Media id="7486" duration="6214542" bitrate="5873" width="720" height="480" aspectRatio="1.33" audioChannels="2" audioCodec="ac3" videoCodec="mpeg2video" videoResolution="480" container="mkv" videoFrameRate="NTSC" videoProfile="main">
Movie 2, Notorious, is playing at 1080p because it is a 1080p movie (note width, height, & videoResolution).
<Media id="10768" duration="6097220" bitrate="31116" width="1920" height="1080" aspectRatio="1.78" audioChannels="1" audioCodec="pcm" videoCodec="h264" videoResolution="1080" container="mkv" videoFrameRate="24p" audioProfile="pcm_s24le" videoProfile="high">
