DSD+ (Digital Speech Decoder+) is a popular decoding tool that can be used to listen to P25, DMR and other unencrypted digital speech signals. Recently DSD+ has been updated from version 1.074 to version 1.101.

The new version brings several changes, including the ability to decode Hytera Extended Pseudo Trunk (XPT) systems, Airspy compatibility, performance improvements and a TCP/IP link from FMP to DSD+ (no longer need to use a virtual audio cable). The full change log is as follows:

DSD+: Fixed AMBE tone frame audio generation.

FMA: Added Airspy-compatible FMP (FMPA.exe)

DSD+: Significant reduction in CPU usage when monitoring busy control channels. Improvement will be most noticeable on low power processors.

DSD+: Detection and decoding of Hytera Extended Pseudo Trunk (XPT) systems.

DSD+: The DSD+ -i command line parameter can contain an IPV4 address; this lets DSD+ connect to a copy of FMP that is running on a different PC in your local network or on the Internet

Example: DSDPlus -i192.168.1.150:20001

DSD+: NEXEDGE radio alias editing

DSD+ now marks auto-generated NEXEDGE radio aliases in the DSDPlus.radios file by prepending an asterisk like so:

NEXEDGE, … yyyy/mm/dd hh:mm, *”aliastext”

If you edit a NEXEDGE alias, you must remove the asterisk; this tells DSD+ that the new alias text is NOT auto-generated and DSD+ will not replace it with OTA alias text

FMP: FMP command line processing

The FMP command line format has been modified and is now similar to the DSD+ command line. A summary is listed here:

FMP rev 1.4t

Usage:

FMP [options] Normal operation

FMP -h Show help

Options:

-i<num> RTL SDR device number (1-255) [-i1]

-o<num> Output audio device (1-255) [-o1]

-o<port> Output audio TCP port (256-65535)

-P<num> PPM value (-999.9-999.9) [-P0.0]

-g<num> RF gain (dB) [max]

-f<MHz> Initial tuned frequency [-f99.9]

-b<kHz> Initial filter bandwidth (4, 7, 9.5, 12.5) [-b7]

-z<num> Show zoomed spectrum (0-1) [-z1]

-e<num> Enable/disable economy mode (0-1) [-e1]

-n<num> Select noise filter (0-2) [-n0]

-v<num> Set volume level (0-500) [-v100]

-s<num> Enable/disable scanner mode (0-1) [-s0]

-wsl<v>.<h> Spectrum window location [-wsl50.50]

-_<num> Minimize windows at startup; bitmapped

-rv Role is trunk voice channel monitor

-rv puts FMP into voice following mode (same as pressing ‘V’ in FMP)

Any shortcuts or batch files that run FMP will have to be modified to match the new command line format.

DSD+: Less processor loading (probably only noticeable on very slow processors)

DSD+: Much faster groups/radios files loading/saving

DSD+: Editing existing radio aliases

In previous versions of DSD+, editing of pre-existing radio aliases can not be done with an external text editor while DSD+ is running; only radio records with no alias text can be edited

With DSD+ 1.092, existing radio alias text can be edited in an

external text editor while DSD+ is running; DSD+ will load and display any updated radio aliases

DSD+: A DSDPlus.radios file corruption bug has been fixed

DSD+: A command line option to add system details to event log entries has been added

-E Add NAC/RAN/DCC/RAS data to event log file entries

DSD+: Decoding of more DMR and TIII messages has been added

DSD+: A symbol recovery bug has been fixed

DSD+: Con+ handling has been modified; previous versions of DSD+ would create “DMR” entries in the DSDPlus.groups and DSDPlus.radios files for traffic on monitored voice channels; DSD+ 1.090 creates “Con+” entries; if you have “DMR” entries with nonzero NID fields, you should either bulk delete them or change their protocol string from “DMR” to “Con+”; Notepad has a simple search/replace function that can be used to do this

DSD+: A command line option to minimize windows at startup has been added

-_<num> Minimize selected windows at startup (bitmapped, 0-15) [-_0]

value window

1 console

2 source audio

4 channel activity

8 event log

sum values to minimize multiple windows

DSD+: Several high contrast display modes have been added

-H<num> High contrast mode (bitmapped, 0-63) [-H0]

two bits are used per graphical window; pressing ‘H’ in a window will cycle it to the next display mode; pressing ‘W’ displays the current -H<num> value in the event log window

DSD+: Control of AMBE and IMBE unvoiced audio levels has been added

-UA<num> AMBE unvoiced speech level (0-100) [-UA50]

-UI<num> IMBE unvoiced speech level (0-100) [-UI50]

pressing ‘A’/’a’/’I’/’i’ will also adjust the levels;

lower levels may reduce the “underwater” sound of some comms

DSD+: DSD+ can get its raw audio source from FMP via a TCP link instead of via Virtual Audio Cable or VB-Cable

-i<TCPport> FMP TCP link port number (256-65535)

linking FMP to DSD+ via VAC or VBC is deprecated; please use the TCP

link feature instead; any port number between 10000 and 65000 should be fine

DSD+: DSD+ can record separate .wav files for each voice call

-P<wav|mp3> Also create per-call wav or mp3 files

the file names encode metadata:

time

duration

protocol

NID

site number

NAC/RAN/DCC/slot

call type (group/private)

target

source

note: per-call mp3 files are not supported at this time

FMP: A command line option to minimize windows at startup has been added

-_<num> Minimize selected windows at startup (bitmapped, 0-3) [-_0]

value window

1 console

2 spectrum display