Why does annotate not work with input.http?

[Moonbase59]

For use in AzuraCast, we’d like to add some metadata to an input.http, like the internal playlist id.

When I try

playlist_remote = mksafe(buffer(buffer=10., input.http('annotate:playlist_id=217:https://example.com/radio.mp3')))

radio = playlist_remote

this produces an error

2024/06/30 08:25:37 [input.http:2] Decoding failed: Avutil.Error(Protocol not found)

Is there an easy way to use annotate, so that we could use PHP to add some metadata to this?

I know I could use something like

def metadata_remote(m) = [...m, ("playlist_id", "217")] end
playlist_remote = mksafe(buffer(buffer=10., input.http(metadata_filter=metadata_remote, 'https://example.com/radio.mp3')))

radio = playlist_remote

but that seems overdoing it a little, because we’d have to have one function per playlist, and add all that to the LS configuration.

[toots]

Internally, for liquidsoap, (request) protocols and annotate: (a request protocol) are for request resolution.

The protocol mention in the failed logs refers in fact to ffmpeg's notion of protocols, which is different than us.

Generally speaking, Liquidsoap requests are tracks that are acquired through rounds of resolutions. Each resolution is expected to last a finite time, with a timeout. The eventual result is a local file that can be played.

Live operators such as input.http, input.ffmpeg and etc. are designed to play a source as that is potentially infinite such as a icecast stream.

If you want to inject metadata, the generic methods, indendent of the nature of your source are insert_metadata and metadata.map. If you do like the annotate way of passing them, you can even parse a annotate: string using string.annotate.parse