Transcoding cannot support chinese subtitle on Sony TV,iPad

I have a Sony W800 TV, the Serviio works fine with it. Except on issue. When I play mkv or avi files with external chinese subtitle files(ass or srt format), all the chinese characters are displayed as empty rectangle frame. I had already make sure the srt file is saved with UFT-8 encoding. also I try to play it on my iPad uses Aceplayer, The result is the same, the Chinese characters just displayed as empty rectangle frame as like the TV.

After all, I had just try using Windows as Serviio Server , the Chinese will come out as normal, but if I use the Synology as server, the Chinese characters still will become empty rectangle frame, they are play at same file and same directory. It work perfectly on Windows, but cannot display on Synology side ?

I really want to use Synology rather than PC as server, I don't know what can I do to make it work at Synology side, What is the different between the windows server and Synology Server (same at version 1.21) ? How can I make it work ?

Patters, Can you help me out ? any idea ?

Thanks A Lot !

I had ask Zip about this here:http://forum.serviio.org/viewtopic.php?f=7&t=10508,
He tell me maybe some libraries missing in FFmpeg for special character sets,
Can someone tell me how to install back those missing libraries or fonts for Chinese character?

Many Thanks ~~!!!