[FFmpeg-user] Live Stream of Video/Audio + Subtitles

[Shilpi Gupta - NOAA Affiliate]

Hi,

In my code, I would like to read in a live broadcast of video and audio,
and then multiplex that with subtitle data that is generated live.  This
combo would then be sent to a server (not necessarily ffserver, but that is
an option), and a client would subscribe to that stream and decode it and
extract the subtitle stream.  Ideally, the incoming subtitle format would
be MPEG 4 Timed Text.  In general, I would like to associate a live
video/audio stream with a live stream of text data, both of which can be
decoded in parallel by a client.

Questions:
--Is it possible to multiplex live video/audio streams with live subtitle
stream?  Do you have any leads to such scenarios?
--It seems like ffserver can handle subtitle streams, based on the
documentation.  Is this true?  Does ffserver support multiple types of
subtitle formats, like srt and ttxt?
--ffmpeg defines video/audio/subtitle/attachment/data streams.  What
exactly is meant by a data stream?  Could this be any arbitrary stream,
like a text stream?

Thanks.