User Guide User guide
Table Of Contents
- What is VN-MATRIX?
 - Functional Overview
 - Example System Application
 - Front Panel Features
 - Rear Panel Features
 - Accessories
 - Choosing a Suitable Location
 - Mains Power Connection (via PSU)
 - Mains Power Cord (for PSU)
 - Setup and Connection Procedure
 - The VN-MATRIX Web Interface
 - Configuring a VN-MATRIX as an Encoder (source)
 - Configuring a VN-MATRIX as a Decoder (display)
 - Troubleshooting
 - Encoder Set Up
 - Decoder Set Up
 - System Set Up
 - Overview
 - Setting-up a Serial Data Stream
 - Setting-up a Serial Passthrough Group
 - Setting-up a Remote Control Group
 - Serial / Telnet Commands
 - Overview
 - VN-MATRIX Hardware
 - Serial Interface – Quick Reference
 - Telnet Interface – Quick Reference
 - Web Interface – Quick Reference
 - Network Characteristics
 

VN-MATRIX User Guide    Section 4: Advanced Setup Procedures 
I458GB issue 6    Page 73 
Audio Compression 
The S/PDIF digital data bus can carry two types of data: 
  2 channel (stereo) uncompressed audio, or 
  encoded digital data, typically AC-3 (Dolby Digital) format. 
VN-MATRIX supports limited compression of S/PDIF audio sources. This is controlled by the 
Compression setting on the Configure (audioPort) page. The following compression options are 
available: 
Compression  2 channel audio source  AC-3 audio source 
no compression  24 bit native data 
(2975 kbps) 
24 bit native data 
(2975 kbps) 
compress 1  16 bit data, full sample rate 
(1517 kbps) 
16 bit data, zeros run length encoded 
(430 kbps) 
compress 2  16 bit data, 1/2 sample rate 
(784 kbps) 
16 bit data, zeros run length encoded 
(430 kbps) 
compress 4  16 bit data, 1/4 sample rate 
(418 kbps) 
16 bit data, zeros run length encoded 
(430 kbps) 
NOTE: The native uncompressed setting passes the full 24 bit payload plus the 4 S/PDIF control bits 
updating on a continuous frame basis. Other modes only transmit 16 bit data and reduce the 
S/PDIF control bits update rate to once per second. 










