Feature request: When ultragrid looses syphon stream, it keeps looking.

[maybites]

Hi

When ultragrid starts without the required syphon stream, it keeps waiting until it appears. Once it gets unavailable, ultragrid just hangs:

uv -t syphon:app='Simple Server':name=''                                                              
UltraGrid 1.7+ (tags/continuous rev 928249cf built Sep 30 2022 12:07:42)

Display device   : none
Capture device   : syphon
Audio capture    : none
Audio playback   : none
MTU              : 1500 B
Video compression: none
Audio codec      : PCM
Network protocol : UltraGrid RTP
Audio FEC        : none
Video FEC        : none

Display initialized-none
Video capture initialized-syphon
Created new RTP session with SSRC 0x492999a9.
[Syphon capture] No server(s) found!
[Syphon capture] No server(s) found!
...
[Syphon capture] No server(s) found!
[Syphon capture] No server(s) found!
[Syphon capture] FPS set to 60. Use override_fps to override if you know FPS of the server.
[Syphon capture] Using server - app: Simple Server name: 
[Syphon capture] 52 frames in 5.01139 seconds = 10.3764 FPS

--> now the syphon server stopped, but no reaction from ultragrid.

My feature request:

UltraGrid starts looking again for the server, instead of just stopping.

This works for spout on windows.

[MartinPulec]

This seems to be quite easy in the end. I believe it should be working in current continuous build.

[maybites]

Marvelous. Works like a charm. Thanks you!