This is a complete list of commands Mpxgen recognizes. The API is not yet stable.
Create the control pipe and enable FIFO control:
mkfifo rds_ctl
./mpxgen --ctl rds_ctl
Then you can send “commands” to change PS, RT, TA and PTY:
cat > rds_ctl
PS MyText
RT A text to be sent as radiotext
PTY 10
TA ON
PS OtherTxt
TA OFF
...
Every line must start with a valid command, followed by one space character, and the desired value. Any other line format is silently ignored. TA ON switches the Traffic Announcement flag to on, and any other value switches it to off.
Sets the PI code. This takes 4 hexadecimal digits.
PI 1000
The Program Service text. Maximum is 8 characters. This is usually static, such as the station's callsign, but can be dynamically updated.
PS Hello
The Radiotext to be displayed. This can be up to 64 characters.
RT This is a Radiotext message
To signal to receivers that there is traffic information currently being broadcast.
TA 1
To signal to receivers that the broadcast can carry traffic info.
TP 1
The Music/Speech flag. Music is 1 and speech is 0.
MS 1
The Radiotext A/B flag. This should not be used, as updates to RT automatically toggle this flag.
AB A
Decoder Identification. A 4-bit decimal number. Usually only the "stereo" flag (1) is set.
DI 1
Pick between normal (0) and "polar" (1) stereo. Don't use polar stereo unless you know what it is and have a need for it.
ST 0
Set the Program Type. Used to identify the format the station is broadcasting. Valid range is 0-31. Each code corresponds to a Program Type text.
PTY 0
Set volumes in percent modulation for individual MPX subcarrier signals.
MPX 9,9,9,9,9
Set the output volume in percent.
VOL 100
Sets the output sampling rate offset in PPM. This can be used to compensate for clock drift in the sound card.
PPM -20
Program Type Name. Used for broadcasting a more specific format identifier. PTYN OFF disables broadcasting the PTYN.
PTYN CHR
Mpxgen implements RT+ to allow some radios to display indivdual MP3-like metadata tags like artist and song titles from within RT.
For more information, see EBU Technical Review: RadioText Plus
Radiotext Plus tagging data. Comma-separated values specifying content type, start offset and length. Format: <content type 1>,<start 1>,<length 1>,<content type 2>,<start 2>,<length 2>.
RTP 0,0,0,0,0,0
Sets the Radiotext Plus "Running" and "Toggle" flags.
RTPF 1,0