Question: Setting Latency for output.srt in Liquidsoap

[esraell]

Hey all,

I'm looking for a way to set latency for the output.srt function in Liquidsoap. When using FFmpeg, I know you can easily configure latency using the ?latency=100 parameter in the SRT URL. However, I'm not sure how to achieve the same thing in Liquidsoap.

I’ve seen that output.srt supports a socket_options parameter, which includes options like SRTO_LATENCY. For example:

output.srt(
  live_source_1,
  mode="caller",
  host="example.com",
  port=1234,
  socket_options=[
    ("SRTO_LATENCY", 2000)  # Set latency to 2000ms
  ]
)

However, I’m running into issues where this configuration doesn’t seem to take effect or throws errors. Is there a recommended way to set latency, or does Liquidsoap handle it differently?

Would appreciate any guidance or examples!

Thanks!

[toots]

Hi! I think that your problem here is that this configuration option does not exist! I imagine someone (or something!) must have hallucinated it.. 😄

The source of truth for our documentation is our online API reference. Here's the link for output.srt with all the options: https://www.liquidsoap.info/doc-2.3.0/reference.html#output.srt

You can also use the command line:

% liquidsoap -h output.srt
...

I'm looking at the doc and it does not appear that we support setting SRT sockets options at the moment. I'm creating a ticket for it, I think it'll be a nice new feature to have.

[esraell]

That would be awesome, thanks!