Using ffmpeg to receive SRT stream - high delay

[Tung Le]

Hello,
I'm trying to receive SRT stream from Larix Broadcaster and Larix Screencaster using ffmpeg v5.1.2
I could receive the stream and put it to a DeckLink card but the delay is very high (more than 6 seconds). The same apply why I use ffplay.
I tried the basic code

ffmpeg -mode listener -i srt://:20001 -c:v v210 -vf setfield=tff -r 25 -s 1920x1080 -ac 2 -ar 48000 -f decklink 'DeckLink Quad (8)'

as well as playing with all the parameters

ffmpeg -rcvbuf 3000000 -mss 1000 -oheadbw 5 -maxbw 3000000 -snddropdelay 100000 -latency 100000 -mode listener -i srt://:20001 -c:v v210 -vf setfield=tff -r 25 -s 1920x1080 -ac 2 -ar 48000 -f decklink 'DeckLink Quad (8)'

still the same result.
Also the same delay when I use ffplay

ffplay -mode listener -i srt://:20001

Is there a way to reduce this delay? When I tried with software such as OBS or vMix the delay should be around 1 second.
Thanks

[Carl Eugen Hoyos]

If you want to report a bug please test current FFmpeg git head and provide the ffmpeg command line you tested together with the complete, uncut console output to make this a valid ticket.
If you have support question please send an email to the FFmpeg user mailing list.