Skip to content

README.md

Latest commit

 

History

History
37 lines (23 loc) · 2.24 KB

README.md

File metadata and controls

37 lines (23 loc) · 2.24 KB
Raw

Now playing

Sends what each deck is playing to the computer plugged into the rear USB-B port: the title, the track id, the BPM, the tempo and whether the channel is on air. Use it for a stream overlay, a VJ screen or a set list, while the RX3 plays standalone, with no rekordbox and no PRO DJ LINK.

Off by default. Tick it on the Modules screen, build, and on the computer run:

python3 scripts/now_playing.py

Each line it prints is the state of both decks. Allow inbound UDP 50123 through the computer's firewall.

What it sends

One JSON datagram to UDP port 50123, on the directed broadcast of the link-local network the USB-B port brings up (169.254.255.255). It goes out when something changes on a deck, and every two seconds anyway, so a listener started mid-set catches up at once. Each datagram carries both decks whole:

{"type":"now-playing","version":1,"sequence":42,"reason":"change",
 "decks":[{"deck":1,"loaded":true,"onAir":true,"trackId":1234,
           "bpmX100":12800,"tempoRaw":0,"playModeRaw":3,"title":"..."},
          {"deck":2,"loaded":false, ...}]}

reason is start, change or heartbeat. scripts/now_playing.py adds bpm in beats per minute.

What is not established yet

  • Nothing here has run on hardware. The event hooks and accessors are checked against the 1.19 player binary, not yet observed on a deck.
  • tempoRaw and playModeRaw are sent as the player stores them. Which values mean playing, paused or cued, and the unit of the tempo, wait for a capture on a deck.
  • The artist, the album and the key are not sent: where the standalone player keeps them has not been found.
  • trackId is the id the player loaded the track with, not yet shown to be stable across exports.
  • The datagrams are not authenticated. Anything on the USB link can read them, and anything on it could send look-alikes to a listener.

If it gets in the way

Create /tmp/rx3-now-playing.off on the player and the module stays out from the next insertion until the next power cycle.

Credits

The event hooks, the accessors and the protocol design come from evanpurkhiser's USB telemetry prototype (#32). The UDP transport over the USB link comes from jacksight's Now Playing export (#20).