SYNOPSIS

gen_packets -o wav-file-out [ options ] [ text-file | - ]

wav-file-out is the result. The -o option is required.

text-file may contain AX.25 packets in the standard monitoring format. Use "-" to read from stdin. If not specified, a default builtin message will be used.

DESCRIPTION

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

Bits / second for data. Proper modem selected for 300, 1200, 9600.

-g

Scrambled baseband rather than AFSK.

-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.

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.