Tvheadend

Hi,

I'm replacing my STB by a TVH+Kodi using a RPi 4. My IPTV service provides play-backwards as well as fast-forward (1x, 2x, 4x, 8x, 16x, 32x), rewind, "jump back", play, pause and even record in server side. It requires just to send a RTSP PLAY command, using standard SDP messages. As an example, for play-backwards the SDP content (apart from URL) is:
CSeq: 18\r\n
User-Agent: CTC RTSP/1.0\r\n
Session: 3746902668
Range: clock=20200806T001926Z\r\n
Scale: 16\r\n
\r\n
With this command the stream (UDP or RTP) will play backwards from the server at 16x speed!.
So I think it could be an "easy" feature to implement. I'm not an expert programmer but I think I can try in this lockdown days. To do that it will be great to know the TVH API so I can understand:
- Add more detailed RTSP support (maybe with libcurl RTSP implementation https://curl.haxx.se/libcurl/c/rtsp.html) to keep alive a RTSP channel (sending OPTIONS or GET-PARAMETER messages) so timeshift commands can be passed
- How to replace local storage timeshift calls by RTSP commands. (Maybe add some restriction to RTSP links with this features to only use server timeshift instead of local storage)
- How to grab a date from EPG and pass it to RTSP-Server-Timeshift by SDP command