Subtitle (such as the .srt file format) is not supported by the Digital Living Network Alliance® server (DLNA) hence will not be displayed when streaming videos.
NOTE: Subtitles can be added to movies without a separate subtitle file. However, it displays permanently during movie playback. To do this, the subtitle information must be superimposed on the movie itself during the recording process. If you are using a Sony video editing software, visit the support page for further assistance and instructions regarding how to superimpose the text in the video.