Embedded subtitle support in MP4 files
I'm using Serviio on Windows Server 2008 R2 to stream files to a Philips TV, a PlayStation 3 and a bunch of Android devices with BubbleUPNP and MX Player.
All my video files are .mp4 files with a H264 video stream (720p or 1080p), an AAC audio stream and embedded subtitles. The files are encoded with the latest stable version of Handbrake and they work fine if I play them directly with VLC for Windows or MX Player for Android. There is always a button to enable subtitles if they aren't enabled (depends on the language) automatically.
But when I use Serviio I never see subtitles. Not on my Philips TV, neither on my PS3 and neither on my Android devices. All these devices have buttons to enable subtitles but they're always greyed out. What should I change in Serviio's settings to enable subtitles? The subtitles are in English or in Dutch ("Nederlands").