Are the subtitles part of the video file or are they coming from an external subtitle file? If they are part of the video file, what is the video file type (MKV, AVI, etc.), and do you know whether they are hardcoded or softcoded? Softcoded means you can switch the subtitles on/off; hardcoded means they're just there as part of the video -- as a general rule of thumb, if the file type is anything other than MKV, they're probably hardcoded.