DAB multiplexing

Revision as of 14:24, 6 November 2013

The multiplexer gather different program streams (DAB, DAB+ or T-DMB), produces necessary signalling and output a single 2Mbit/s stream in ETI format (Ensemble Transport Interface).

Multiplexing with CRC-DabMux

• CRC-DabMux Free/open source DAB/DAB+/T-DMB multiplexer from CRC.

This multiplexer can work with a professional modulator by using a E1 G.703 interface card. For example, Farsite is manufacturing an E1 card supported under linux

Live multiple input

The multiplexer takes files as input. Standard input (/dev/stdin) can be used to get an encoded stream as input. In order to input many live streams, it is necessary to use FIFO files (also called "named pipe") created with "mkfifo" unix command.

Example, with 3 DAB 128kbps channels (1.ff to 3.ff are the FIFO files)

CRC-DabMux -L "LabelSuisse"  -A 1.ff -b 128 -i 1 -S -L "Label1" -C \
-A 2.ff -b 128 -i 2 -S -L "Label2" -C \
-A 3.ff -b 128 -i 3 -S -L "Label3" -C \
-O fifo:///dev/stdout

Example with 4 DAB+ inputs on one DAB input, non-blocking file input mode is used with option "-k" to avoid incomplete DAB+ frames from the encoder.

CRC-DabMux -L "TuxMux"  \
-A 1.ff -b 128 -i 10 -S -L "L2_128" -C \
-F 2.ff -k -b 48 -i 2 -S -L "AAC48" -C \
-F 3.ff -k -b 64 -i 3 -S -L "AAC64" -C \
-F 4.ff -k -b 128 -i 4 -S -L "AAC128" -C \
-O fifo:///dev/stdout

Other projects

• Nova Radio labs opendab project in Norway

Ensemble Transport Interface

Check Ensemble Transport Interface page for implementations.