Can I inject scte triggers into a UDP stream?

[arlovande]

I'm using Vmix to send out a stream via UDP to another server. Would I need to point the udp stream to local host and then relay it to the server to be able to inject a scte splice in there? Or can I just point threefive to the outgoing stream and it will inject a scte into it?

[superkabuki]

You can use the threefive.SuperKabuki class or the cli to inject SCTE-35 from a sidecar file.
I would inject first and then stream the output. Do it the easiest way possible.

https://github.com/superkabuki/threefive/blob/main/inject.md
https://github.com/superkabuki/threefive/blob/main/encode.md

Using the library you can do it like this

import sys
from threefive import SuperKabuki
sk=SuperKabuki()

# set input

sk.infile = input.ts 
#   or 
sk.infile = 'udp://1.2.3.4:567'    # <-- read udp 
#   or 
sk.infile =sys.stdin.buffer      # <--  read from stdin 

# set output file

sk.outfile='output,ts'
# or
sk.outfile = 'sys.stdout.buffer'     #    <-- write to stdout and pipe it.

# set sidecar file 

sk.sidecar_file= "sidecar.txt"    # default is sidecar.txt

# set scte35 pid

sk.scte35_pid = 134    # default is 134

# encode

sk.encode()

[arlovande]

So I'm trying to get from a vMix to AWS mediaconnect where the SCTE 35 needs to be passed. I want the user to be able to trigger a powershell script that will insert an immediate scte-35 trigger into the stream. Giving the user the ability to hit a button and "cut to commercial" in vMix. So if I update the sidecar.txt file mid stream... is that going to insert the scte trigger into the stream still? Or do I need to know all my commercial breaks before the stream is started?

From your explanation I think it might be possible to go from Vmix to UDP, read the UDP and possibly inject SCTE trigger from .txt and then send to stdout buffer to be sent via SRT to mediaconnect. But that would only work if the sidecar were being constantly read and could be inject in time before it went to stdout and on it's way.

[superkabuki]

I'm sorry but I'm unfamiliar with vmix or powershell.
with a sidecar file you can add to it at anytime and if you specify 0 for the PTS it does a splice immediate.
Take a look at https://github.com/superkabuki/adbreak3 and there is more sidecar file in the x9k3 docs. x9k3 is HLS but the sidecar files work the same way.

threefive will check the sidecar file every iframe for new SCTE-35

I do stuff like

printf ' 130.12,/DAWAAAAAAAAAP/wBQb+ALKOoAAAJte19A==' >> sidecarfile.txt