Simulate cassette tape audio profiles using FFmpeg

xxterminal about 3 hours ago 21 commentsRead Article on github.com

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tom_•5 minutes ago

Well, rather your ears than mine.

gwbas1c•about 1 hour ago

Has anyone come across a Dolby B (or similar) encode / decode program?

I've been wanting to experiment with quantizing Dolby (or similar) encoded audio to 8 bits, and then unencoding to see how well it can sound.

secretsatan•9 minutes ago

Well i would say wow and flutter is a property of the device playing the tape, not of the tape itself

massagedpelican•about 2 hours ago

How would one go about determining what effect to add for each cassette type? I don't know much about cassettes, I'm curious if this was something that could be done by ear or if these are commonly held opinions about the sound of each tape.

Again knowing nothing about tape, if I were tasked with this I would probably try to record the same audio to each of the tapes and then compare it with the original.

dylan604•about 1 hour ago

Similar to how the different film stocks affected the look of the image, the different tape formats would effect the sound similarly. Crudely explained, the more light brown the tape, the more noisy it would be. The darker the tape, the cleaner it could be. If you like the sound of someone standing behind you constantly saying shhhhhhhhhhhhhhhhhhhh, then choose a brown tape.

By now, the audiophiles have lots of profiles of what the various tape formats would sound like. It's been ages since I've looked at audio plugins, but I would be shocked if there's not presets to make your pristine audio sound like a Maxell cassette that's been played hundreds of times.

tempoponet•about 1 hour ago

There's great VST plugins like "Sketch Cassette 2" that will do hiss, flutter, all of that, along with some great presets. That one's less about creating authentic sound profiles, more like creating lo-fi tracks and instruments for music production.

_def•about 2 hours ago

What is "wow"?

TheOtherHobbes•39 minutes ago

Half of wow and flutter. The tape speed wasn't perfectly constant, so the pitch wobbled.

Wow was slow speed variations (under 4Hz). Flutter was quicker warbles.

Both were caused mechanically. The rubber wheel - pinch roller - that moved the tape might not be perfectly circular, the motor that pulled the reels might be uneven, and the tape case sometimes pressed on the tape reels causing variable friction.

Analog media really were a bit crap. I get the creative distortion idea, but even so - ewww. I'm so happy these kinds of imperfections are optional now, and not baked into music distribution systems as an expected flaw.

sodapopcan•7 minutes ago

I wouldn't call the pro reel-to-reels crap. The imperfections were barely noticeable. Besides, there were other pros to the analogue days, like records having their actual own sound with human imperfections in-tact (unless you had a tonne of money and could afford to spend hours slicing tape). I despise how perfect and same-y everything sounds over the past 20 years. Of course I understand that this is all very subjective, but there just isn't as much access to more raw sounding records as, even very talented musicians who are probably capable of getting great takes which still quantize everything.

But ya ya, old man yells at clouds, I know.

I still record to tape, it's a lot of fun (cassette tape)! There are a bunch of problems to solve that take away from "just being creative" but I don't mind it. Part of that is that it's a forcing factor to improve musicianship because punching in on those consumer four-track machines doesn't really work (even though they have the capability).

gwbas1c•about 1 hour ago

Basically, on analog media, playback speed isn't perfect. There's constant speedups and slowdowns. This creates a "waa waa" or "wow wow" effect that's noticeable when playing a constant pure tone.

dylan604•about 1 hour ago

don't forget that tapes also stretch so that can also give similar sounds

sctb•about 2 hours ago

It's a kind of pitch instability: https://en.wikipedia.org/wiki/Wow_(recording)

atoav•about 1 hour ago

To which analog gain would 0 dBFS be mapped?

pitchlatte•6 minutes ago

i don’t think any dynamic range manipulation is being done, beyond the slight variations as a consequence of the other processing.

generally 0dBVU is mapped to -18dBFS with VU style RMS metering being used on the digital side as well. but that isn’t some kind of physical translation, it’s rather arbitrary and more a convention.

westurner•about 1 hour ago

Can this be modeled with Neural Amp Modeler (open source) and Tone 3000 like a Space or a Pedal or an Outboard? https://www.tone3000.com/amalgamaudio

lateralux•about 1 hour ago

Of course ! By the way, I'd love to see more HN posts about NAM. I've been following the project since day one, and it's been an absolute game changer for guitar amp modeling. It's genuinely exciting to see an open-source project have such a profound impact on the entire industry,not just modelers but software plugins and hardware solutions

i_am_proteus•about 1 hour ago

You might want to have a look at https://github.com/jatinchowdhury18/AnalogTapeModel

Available as a (free) DSP: https://chowdsp.com/products.html#tape

westurner•about 1 hour ago

From https://github.com/jatinchowdhury18/AnalogTapeModel :

> CHOW Tape is an analog tape machine physical model, originally based on the Sony TC-260. The current version can be used to emulate a wide variety of reel-to-reel tape machines. Feel free to build and use for your own enjoyment.

> CHOW Tape is currently available in the following formats: VST, VST3, AU, AAX, AUv3, CLAP, LV2, Standalone plugin

That's like all of the DAW/DSP plugin formats.

Hopefully BespokeSynth VST3/LV2/CLAP plug-in hosting on Linux w/ Pipewire will be stable for it.

I found ToobAmp, which has a Neural Amp Modeler plug-in and also "TooB ML Amplifier" Artificial-Intelligence/Machine-Learning-based emulation of a number of different guitar amps and overdrive/distortion pedals based on Jatin Chowdhury's ML Amplifier library" https://github.com/rerdavies/ToobAmp

lateralux•about 1 hour ago

Robin Davis is also the creator of the amazing PiPedal project : https://github.com/rerdavies/pipedal

lateralux•about 1 hour ago

If you're interested in this topic, here are a few projects I found particularly interesting :

LTSpice Guitar Pedals : A collection of LTspice simulations of classic guitar pedals, useful for studying, modifying, and experimenting with analog circuits. https://github.com/cushychicken/ltspice-guitar-pedals

spiceAmp : An analog guitar amplifier simulator based on SPICE, designed to model tube amp circuits with high fidelity. https://github.com/olegkapitonov/spiceAmp

LiveSPICE : A real-time SPICE circuit simulator that lets you play audio through virtual analog circuits, making it possible to prototype and audition pedals and amplifiers interactively. https://github.com/dsharlet/LiveSPICE

AmazingEveryDay•about 3 hours ago

Interesting! What tape simulation do you find yourself favoriting?