FDMDV_DEMOD(1)

💖 FDMDV_DEMOD — the girlies' guide 💖

okay so bestie, welcome to fdmdv_demod, a whole diagnostic tool from the codec2 library ✨ its entire job? taking a series of FDMDV modem samples and turning them into a codec2 bit file. it's giving lab-girlie main character energy and honestly we're obsessed 🎀

(also it lives in the User commands section of the manual, iykyk 🦋)

✨ SYNOPSIS ✨

fdmdv_demod usage: InputModemRawFile OutputBitFile [Nc] [OctaveDumpFile]

that's the whole vibe check right there. four slots, two of them optional 💅

🌸 DESCRIPTION 🌸

so here's the tea ☕ you hand it an input raw file — and bestie, that file is 8kHz, 16 bit shorts, no cap — full of FDMDV modem samples, and it hands you back a file of bits. simple. iconic. periodt.

the output file is assumed to be arranged as codec frames of 56 bits (7 bytes) which are received as two 28 bit modem frames. that's the structure, don't fight it 🙈

and here's the cute bonus: demod states can optionally be logged out to an Octave file, which you can then display using the Octave script fdmdv_demod_c.m. genuinely so useful for checking demod performance, like a lil x-ray for your demod 🔥

🦋 EXAMPLE 🦋

fdmdv_dmod hts1a_fdmdv.raw hts1a.c2

yes bestie, that is exactly how it's written in the manual — fdmdv_dmod, no "e" in demod, we are keeping it verbatim because we do not touch the facts, only the vibes 💀

👑 OPTIONS 👑

• InputModemRawFile (first argument) — the file name of a file holding FDMDV modem samples. and if you pass - instead? the input gets taken from stdin. piping queen behavior 🫶
• OutputBitFile (second argument) — the file name of a file that gets created with codec2 bits. pass - here and the output gets sent to stdout. slay 💅
• [Nc] (optional third argument) — the number of carriers to use in the modem. the default is 14, the minimum is 2, and the maximum is 20. so like, stay in your lane between 2 and 20 bestie 🌈
• [OctaveDumpFile] (optional fourth argument) — the name of the Octave data file to create. yes, the Octave data file. dump those demod states, we love a data moment 📊✨

💜 SEE ALSO 💜

• c2dec(1)
• c2enc(1)
• fdmdv_mod(1)
• fdmdv_get_test_bits(1)
• fdmdv_put_test_bits(1)

go read those next, bestie, one of them literally does the opposite of this one 🧚

and that's the whole page!! 💖 this was fdmdv_demod from the User commands manual, dated 2020-12-04, filed under FDMDV_DEMOD(1) — mwah, go demod something, you got this 👑✨💅