Record WAV file

[wanters]

Whether there is a plan to add the function of admitting WAV files？ Because I see there is a parse input WAV file.

[jvde-github]

You can already read wav files indeed (which you record with SDR# for example) and there is no plan to add recording to WAV files to the program. It is not that difficult though.

Is the question to write the raw radio signal before AIS decoding to a WAV file? On Raspberry/Linux recording can be quite easily be done with the rtl_sdr utility, so try to understand the use case and how frequently it will be used?

[wanters]

Oh, all right! If there is one more way to record the WAV file, this may enrich the project, and the recorded WAV file can be used by other SDR software, which is a desirable thing. It is recommended to join the program.

[jvde-github]

Ok, it is on the list to add, might take some time though.

[sprs123]

Hi Jasper, please help. How do I use a recorded WAV file in AIS-catcher. I want to use it instead of a RTL-sdr dongle for test purposes. I have a pre-recorded ais-WAV file that I can use. If possible could you reply to [email protected] many thanks

[jvde-github]

Hi Richard, you can read in WAV files with:

AIS-catcher -w filename

But note that the file needs to be an IQ recording at 162 MHz, i.e. with two channels. Something that SDR# records for example. Give it a try and let me know if it does not work and feel free to email to follow up.

[jvde-github]

Added something experimental. It can be activated via -m 9 -go file output.wav.

It is essentially a decoding model that only writes the IQ stream to file. So, to enable this decoding model and the regular one and take input from a file (posterholt.raw for testing):

$ ./AIS-catcher -r cu8 posterholt.raw -m 9 -go file output.wav -m 2 -q -v
AIS-catcher (build Jan 12 2025) v0.61-211-g85b86377
(C) Copyright 2021-2025 jvde-github and other contributors
This is free software; see the source for copying conditions.There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Device    : File (RAW)
Settings  : rate 1536K format CU8 file posterholt.raw loop OFF
Model #0 -> (Src: 1, Grp: 1): [Export output]
Model #1 -> (Src: 2, Grp: 2): [AIS engine v0.61] ps_ema ON afc_wide ON droop ON fp_ds OFF dsk OFF

----------------------
[Export output #0-0]                    total: 0 msgs
[AIS engine v0.61 #0-1]                 total: 38 msgs

Now I can decode this wav file as follows:

$ ./AIS-catcher -w output.wav -v -q
AIS-catcher (build Jan 12 2025) v0.61-211-g85b86377
(C) Copyright 2021-2025 jvde-github and other contributors
This is free software; see the source for copying conditions.There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Device    : File (WAV)
Settings  : rate 1536K format CU8 file output.wav
Model #0 -> (Src: 1, Grp: 1): [AIS engine v0.61] ps_ema ON afc_wide ON droop ON fp_ds OFF dsk OFF

----------------------
[AIS engine v0.61 #0-0]                 total: 38 msgs

This has not been thoroughly tested.