X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=monitoring.rst;h=6165e76a717bb31c2aaee11896ad2be5b2a09303;hb=f2fb154081bf8d73aa8b750132fb17ba0fda12a9;hp=8e64307e4ef9ce1b9f8e3ad2ecdf18906ae2f2b7;hpb=99faa4cff027ee5c4760c3e098e65f14b7498480;p=nageru-docs diff --git a/monitoring.rst b/monitoring.rst index 8e64307..6165e76 100644 --- a/monitoring.rst +++ b/monitoring.rst @@ -31,3 +31,35 @@ backward compatibility in metrics, so if Nageru internals change significantly, some graphs could stop working. Of course, you can change the dashboard as you see fit; if you don't use e.g. HDMI/SDI output, you will probably want to remove the panels related to it. + + +Tally display +------------- + +Not related to Prometheus per se, but yet an important part of monitoring is the +*tally light*, or just tally for short. The tally is a talkback signal from the +mixer to the camera, showing the cameraperson that they are indeed on air (or are +about to get to). Professional studio cameras will often not only have a tally +light for the operator, but also for the subject (to know which camera to look +into). However, most cheaper cameras will have none at all. + +Nageru does not have functionality to talk to tally lights directly (there are too +many kinds of interfaces and standards), but it does have functionality to expose +tally *data*. Using this, you can build your own tally light, be in through injecting +the right bits on an SDI cable, having a single-board computer set some GPIO pins +for a LED, or simply show a red or green dot on a mobile phone with a web browser. + +Nageru's tally data is automatically exposed over HTTP, just as any other monitoring. +You can get one JSON file with a list of all channels (at “http://yourserver.example.org:9095/channels”), +or you can ask for a specific channel and get just its color in plain text +(at “http://yourserver.example.org:9095/channels/2”, where 2 is the lowest +channel ID, since live and preview don't have tally). The tally color values +are taken automatically from the theme's *channel_color* function, so that they +match the borders around the input in the producer's mixer display—typically +green for on preview and red for live. This also means they can be CSS textual +colors (like “red”), although you can of course make the theme return only +“#ff0000” or similar if this makes your tally application simpler. + +Note that the tally endpoints have fully open `CORS `_ +headers, so that they can be queried from anywhere; tally data is not sensitive, +and this makes it significantly easier to query them from a web page.