An EBU R128 loudness meter for Axia Livewire streams with a short-term (3 sec.) and/or momentary (100ms) loudness readouts. 100ms Resolution.
###What is Axia Livewire? Axia Livewire is an IP networked audio protocol used in broadcast. Among other things, it allows for 32767 channels of raw multicast PCM audio distributed over a standard IP network. Axia nodes are connected to the network and provide audio I/O. ###What does a Livewire audio stream consist of? Raw PCM (big endian, 24-bit signed, 48000 kHz, stereo interleaved) delivered in the form of multicast IP/UDP/RTP packets. ###How does this work? PCM from each packet is buffered and handed to libebur128 for loudness measurement. ###To Do Buffer input / confirm packet sequence. (UDP does not guarantee packets arrive in order; xNodes buffer 15-100ms the recieve side.) ###Setup and Use
- Get
libebur128, and then compile axialufs.c. - Update index.js to point to the axialufs binary & supply an Axia multicast address.
- Lauch the node server:
node index.js - Visit
localhost:3000in your browser.