gen_packets1
Generate audio file for ax.25 frames.
Usage
gen_packets -o
wav-file-out
[options]
[{text-file | -}]
Overview
gen_packets is a test application which converts text to AX.25 audio for testing packet decoders.
It is very flexible allowing a wide range of audio sample rates, data speeds, and AFSK tones. It will even generate the scrambled signals commonly used for 9600 baud operation.
Options
-
-a n -
Signal amplitude in range of 0-200%. Default 50. Note that 100% is corresponds to signal peaks of +/- 16383 so we have plenty of headroom to avoid saturation.
-
-b n -
Bits / second for data. Default is 1200.
-
-B n -
Data rate in bits/sec for first channel. Standard values are 300, 1200, 2400, 4800, 9600.
300 bps defaults to AFSK tones of 1600 & 1800.
1200 bps uses AFSK tones of 1200 & 2200.
2400 bps uses QPSK based on V.26 standard.
4800 bps uses 8PSK based on V.27 standard.
9600 bps and up uses K9NG/G3RUH standard.
EAS for Emergency Alert System (EAS) Specific Area Message Encoding (SAME).
-
-g -
Force G3RUH modem regardless of data rate.
-
-j -
2400 bps QPSK compatible with Dire Wolf <= 1.5.
-
-J -
2400 bps QPSK compatible with MFJ-2400.
-
-X n -
1 to enable FX.25 transmit. 16, 32, 64 for specific number of check bytes.
-
-I n -
Enable IL2P transmit. n=1 is recommended. 0 uses weaker FEC.
-
-i n -
Enable IL2P transmit, inverted polarity. n=1 is recommended. 0 uses weaker FEC.
-
-m n -
Mark frequency. Default is 1200.
-
-s n -
Space frequency. Default is 2200.
-
-r n -
Audio sample Rate. Default is 44100.
-
-n n -
Generate specified number of frames with increasing noise. (For built-in message only.)
-
-o file -
Send output to .wav file.
-
-8 -
8 bit audio rather than 16.
-
-2 -
2 channels of audio rather than 1.
-
-vmax[,incr] -
Variable speed with specified maximum error and optional increment.
Examples
gen_packets -o x.wav
With all defaults, a built-in test message is generated with standard Bell 202 tones used for packet radio on ordinary VHF FM transceivers.
gen_packets -o x.wav -g -b 9600
gen_packets -o x.wav -B 9600
Both of these are equivalent. "-B 9600" automatically selects scrambled baseband rather than AFSK.
gen_packets -o x.wav -m 1600 -s 1800 -b 300
gen_packets -o x.wav -B 300
Both of these generate 200 Hz shift, 300 baud, suitable for HF SSB transceiver.
echo -n 'WB2OSZ>WORLD:Hello, world!' | gen_packets -a 25 -o x.wav -
atest x.wav
Read message from stdin and put quarter volume sound into the file x.wav. Decode the sound file.
Releases
5 releases since Debian 9 (Stretch); the text changed 3 times.
-I since Debian 13 (Trixie);
-J since Debian 11 (Bullseye);
-X since Debian 13 (Trixie);
-i since Debian 13 (Trixie);
-j since Debian 11 (Bullseye);
-v since Debian 13 (Trixie).