import os
os.system( 'omxplayer --win "0 0 {0} {1}" {2}'.format( playerWidth, playerHeight, videoPath ))
os.system( 'omxplayer --win "0 0 {0} {1}" {2} --subtitles {3} --font-size {4}'.format( playerWidth, playerHeight, videoPath, subtitlesPath, subtitlesSize ))
Subtitles file must be in UTF-8 srt format.