title: how to add a text stream (subtitle) into a .mp4 or .m4v
body: <p>I use ffmpeg to convert video using H264 for video encoding, and FAAC for audio encoding. The output should be .mp4 or m4v in order to play on both Android and iPhone. I want to add a subtitle STREAM to video file using ffmpeg, but the ffmpeg's documentation doesnt help much. </p>
  
  <p>Can anyone help me with this?</p>