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Denny Sheirer edited this page Nov 24, 2019 · 7 revisions

JMBE Library

The Java Multi-Band Excitation (JMBE) library provides decoder support for converting IMBE encoded audio frames to normal audio so that you can listen to the audio calls over your computer speakers.

Website: JMBE

Patent Warning

The JMBE library contains source code that may be patent protected. Users should check local laws before downloading, compiling, using, or DISTRIBUTING compiled versions of the JMBE library.

Copyright Notice

Copyrights for the terms MBE and IMBE are the property of their respective owners.

Adding JMBE to SDRTrunk for decoding MBE audio

  • JMBE Download Site Follow the instructions on this site for building the JMBE library.

  • You can use the compiled jmbe-x.x.x.jar file right where you compiled it, or it may make sense to copy it to a more permanent location on your computer that is always accessible for sdrtrunk.

  • Start the SDRTrunk application.

  • Open the View >> Preferences menu item to open the Preferences window.

  • In the Decoder >> JMBE Audio Library section, click the Change... button to specify the location for the 'jmbe-1.0.0.jar' library is located. (or whichever version you just compiled)

  • Start (or restart) any P25 decoder channels to start using the audio library.


SDRTrunk will generate several log entries to let you know if it discovered the jmbe library correctly and where it was looking for the library:

16:59:28.404 INFO i.g.d.a.c.m.JmbeAudioModule - Loading JMBE library from [/home/denny/JMBE/jmbe-1.0.0.jar]

16:59:28.415 INFO i.g.d.a.c.m.JmbeAudioModule - JMBE audio conversion library loaded: JMBE Audio Conversion Library v1.0.0

P25 Phase 1 channels when started will log the following entry:

16:59:28.415 INFO i.g.d.a.c.m.ImbeAudioModule - JMBE audio conversion library IMBE CODEC successfully loaded - P25-1 audio will be available

P25 Phase 2 channels when started will log the following entry:

16:59:28.415 INFO i.g.d.a.c.m.AmbeAudioModule - AMBE CODEC successfully loaded - P25-2/DMR/NXDN audio will be available

Note: Phase 2, DMR and NXDN protocols all use the same audio codec. Decoder support for DMR and NXDN may be added at a future time

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