zretune(1)

✨ zretune — the pitch-shifting bestie ✨

ok so like. this is zretune(1), a USER COMMAND, and bestie it is so good at one very specific thing: resampling your audio so the pitch changes. that's it. that's the whole vibe. 💖

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🦋 NAME 🦋

zretune — resample an audio file in order to change its pitch

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🌸 SYNOPSIS 🌸

zretune [options] input-file output-file

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💅 DESCRIPTION 💅

okay so here's the tea, bestie: zretune resamples an audio file by the inverse of a ratio — and that ratio is either handed to it directly or expressed in cents. and the whole time it does not touch the nominal sample rate. not even a little. 🫶

the result? you change the musical pitch and the length of the file. both. at once. main character energy fr fr. ✨

your input can be literally any audio file that the libsndfile library can read. iconic. and the output file type is either WAV, WAVEX, CAF, AIFF or FLAC — you get to pick. 💖

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🔥 OPTIONS 🔥

• --help — display a short help text. the classic. the icon. 🙈
• --ratio pitch ratio — the accepted range is 0.5 to 2.0. the useful range in practice will be smaller, ngl. so don't get too feral with it.
• --cent pitch change in cents — the number of cents by which the pitch is changed. the accepted range is +/- 1200 cents, and the useful range in practice will be something like +/- 100 cents. yes, 1200 is a whole octave, and yes that's a lot. 🌈

🎀 Output file type 🎀

• --wav — produce a WAV file, or for more than 2 channels, a WAVEX file. this is the default. the moment. the standard. 👑
• --amb — produce a WAVEX file with the Ambisonic GUID. such files should have the .amb filename extension. iykyk. 🦋
• --caf — produce a Core Audio file.
• --aiff — produce an AIFF file.
• --flac — produce a FLAC file.

⭐ Output sample format ⭐

• --16bit — output sample format is signed 16-bit. this option also enables the use of dithering, described below. so keep reading bestie, don't skip. 💀
• --24bit — output sample format is 24-bit. this is the default. she's the moment.
• --float — output sample format is 32-bit floating point.

🌸 Dithering 🌸

• --rec — add white dithering noise with a rectangular distribution. this is the best option if the output data is going to be processed again — but in that case it would be advisable to use 24-bit or float. bestie please, listen to her. 🥺
• --tri — add filtered noise with a triangular distribution. compared to the rectangular dither, this reduces the noise density in the lower frequency range. lowkey a glow-up for your low end. 🎀
• --lips — this uses the optimal error feedback filter described by Stanley Lipschitz. this is recommended if the output is the final distribution format, e.g. for a CD. periodt. 💿

🧚 Timing 🧚

• --pad — insert zero valued input samples at the start and end so that the output includes the full symmetric filter response even for the first and last samples. no crumbs left behind, we love a thorough queen. ✨

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🌈 EXIT STATUS 🌈

zero in case there are no errors, non-zero otherwise. she keeps it simple. 🫶

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💜 AUTHOR 💜

Fons Adriaensen — fons (at) linuxaudio.org

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okay bestie that's the whole page, go forth and retune 💖✨

version 0.0.1, from Sept 2012 — signed, sealed, slayed. 🎀🦋💅