Lyrebird APP ETH Network Audio System Overview

ETH Network Audio is the lightweight implementation of a DANTE, Audinate network audio listener and monitor for the audio streams in an Ethernet/IP network (similar to AVB, AES67). It supports the standardized protocols in order to decode the audio streaming based on UDP, based on public protocols. It does not decode, monitor any propritary, company related intellectual property protocols.

Lyrebird APP ETH is based in a STM32F796I-DISCO board and uses the Ethernet connection, onboard DAC for Headphone, SPDIF Output etc.

You do not need any special hardware or extension in order to monitor or listen to ETH Network Audio, even it is intended to be used on the Lyrebird APP DualMCU platform (as the high-professional Audio Processing Platform).

ETH Network Audio

DANTE is an Ethernet/IP network audio protocol which can be licensed from the company Audinate. It is the defacto-standard for Network Audio where you can use Ethernet/IP switches for the audio streaming.

The audio is transmitted as UPD packets, with a fix length (e.g. 297 bytes per UDP packet, 1 byte for channel number, 8 byte for audio time stamp, all other payload as audio samples 24-bit, big endian).

The Lyrebird APP ETH is capable to monitor such a network, figure out where the UDP audio is running, to connect to a running audio stream and decode, forward it to other interfaces, such as headphone out, SPDIF Out, I2S out.

All the protocols related to Device Discovery, Audio Routing, Announcements etc. is not (yet) supported. The implementation of the Lyrebird APP ETH is based on the public standards and implementation for network data/audio reception.

Lyrebird APP ETH uses the FreeRTOS and LwIP in order to monitor and listen to ETH Network Audio network audio streams.

Lyrebird APP ETH is developed for STM32F7 board, e.g. STM232F769I-DISCO, in combination with ARM GNU GCC, AC6/SystemWorkbench and does not need any additional hardware to run.

Monitoring ETH Network Audio

You need a running DANTE audio network. A player has to send audio via Ethernet/IP networks to an audio sink. Lyrebird APP ETH can monitor (a passive listener), decode and play the audio running in such a network. It will not (yet) act as full compliant participant in a DANTE network. If so in future, it will be based on a legal license, or Lyrebird APP ETH will be implemented completely on public network standards.

Without a DANTE receiver it will not work. Lyrebird APP ETH is not (yet) a full compliant participant in such an audio network. As a player you can use DANTE Virtual Soundcard (DVS).

Lyrebird APP ETH will find the audio stream in a DANTE audio network, opens the connection, gathers and decodes the audio, forwards the audio to a different output interface (e.g. SPDIF, I2S). It does not act as a clock device, not as an ingress device (to insert audio into network).

Remarks and important information

Lyrebird APP ETH supports the subset of Network Audio for the public standard based audio streaming (IP/UDP). It does not support or implements network protocols which are licenced or propriatary, an intellectual properties of other companies.

You can make use of the provided firmware, called Lyrebird APP ETH, but without any warranty or expected maintenance, no future bug fixes or notifications about changes, improvements etc.