Ask Justin Frankel

justin = { main feed , music , code , askjf , pubkey };

Ask Justin Frankel
No reasonable question unanswered since 2009!

Suggested topics: programming, music, sleep, coffee, etc.

Note: please do not ask questions about REAPER features, bugs or scheduling, use the forums instead.

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Question: I've noticed an uptick in people posting tools which are created in assistance with AI. Most seem useful and many are actually great, they develop fast thanks to this community since it's ingrained in the platform you developed; Because of your opennes within REAPER people are making a monster out of it with these tools which also adopt your ideas in a way when 99% of them have been free. And so on.. What do you think of this?
Asked by alex (187.213.136.x) on February 22 2026, 7:22pm

Question: When developing an audio player for FLAC (16/24-bit) and Opus using FFmpeg, how would you provide data to audio systems (e.g., DirectSound)? I understand that a system converts all data to 32-bit float before downsampling to 16/24-bit for DAC output, so native formats work. But when playing a 24-bit file on a 16-bit DAC, wouldn’t providing 16-bit dithered data help prevent quantization errors during the system’s subsequent conversion from 32-bit float back to 16-bit (which is probably not dithered)?
Asked by fladd (84.87.223.x) on February 22 2026, 12:16pm
Reply on February 22 2026, 5:55pm:

2 Comments...

Question: Hi Justin. Are you an analogue guy or more on the Kemper/Quad Cortex side? Or something different? Have a nice day!
Asked by gideonstar (87.147.219.x) on February 20 2026, 9:50am
Reply on February 20 2026, 3:57pm:

I'm pragmatic about music stuff, but the most fun I've had in a long time is my Reuss Plasmatron through a 2010-era AC30. Comment...

Question: Hi, I'm no longer seeing the support for newer ffmpeg as part of the changelog on the changelog landoleet website. Have you pulled it from development?
Asked by Ffmpeg (102.176.75.x) on February 19 2026, 10:26pm
Reply on February 19 2026, 10:48pm:

you can read up on the version types etc on the landoleet.org web site, or discuss in the pre-release forum, this isn't the right venue to have this discussion! it will not be in 7.62, but it will return in the next +dev series. Comment...

Question: Can you do B chord? I'm struggling with barre (?) version, any tips.
Asked by Sawit (140.213.40.x) on February 19 2026, 7:51am
Reply on February 19 2026, 5:16pm:

Amaj, and Bmaj at the second fret, probably my least favorite. smearing the ring finger on those three strings. Amin (Bmin at the second fret) is easier.. but there’s always the E chord at the 7th fret… Comment...

Question: This is interesting. Do you ever target the "native" API for perf? codeberg.org/ziglang/zig/issues/31131
Asked by Will (99.100.219.x) on February 18 2026, 4:49pm
Reply on February 18 2026, 5:38pm:

hah try to avoid that.. might be interesting to make SWELL target it, though! Comment...

Question: i made a plugin suite called LMS that turns all of reaper into a full-project sequencer and allows all the plugins in the suite to talk to each other over gmem, wanna see?
Asked by bryan (71.205.89.x) on February 18 2026, 2:53pm
Reply on February 18 2026, 3:20pm:

interesting, but probably too busy with other things to look at the moment 1 Comment...

Question: who are you ?
Asked by Robert (188.50.72.x) on February 17 2026, 5:59pm
Reply on February 17 2026, 6:08pm:

the answer is on the tin Comment...

Question: After rendering, all keyboard hotkeys in the preview interface are broken, play, stop, fast forward and backward, repeat, etc
Asked by nicotomia (167.234.251.x) on February 17 2026, 10:36am
Reply on February 17 2026, 2:23pm:

should probably post this on the forums -- when you do, include any relevant info like: OS, reaper version, whether you're using a screen reader, etc. does the render window have focus? Comment...

Question: Could you tell me some ways to maximize CPU utilization for file rendering in REAPER? Ideally, I want to hit 90% CPU usage, or even max it out completely. The current rendering speed is way too slow. I understand that the default configuration is balanced for stability and other specific considerations, but I want to push my CPU to its full potential.
Asked by helo (221.215.214.x) on February 17 2026, 1:59am
Reply on February 17 2026, 2:14am:

it is parallelized across cores, but each track runs on at most one core at once. so if you have one very intensive track, it will be the limiting factor. if you can break that track into multiple tracks (with routing), that might help. 5 Comments...

Question: I saw people pressing you here about supporting new versions of ffmpeg, and you replied it was a pain to do because of their constantly changing API. I just saw that you have done it. Well done! Was it a pain while doing it or it was not as painful as you envisioned??? Also, wouldn't their continous changing of API cause same issue again of latest version not being supported?
Asked by Ffmpeg (197.251.240.x) on February 16 2026, 1:52pm
Reply on February 16 2026, 2:17pm (edited at February 16 2026, 2:21pm):

Turns out, this is was a task that an LLM could assist on. I provided some minimal source to Claude Opus 4.6, and with a simple prompt, got it to do 90% of the work (producing about 500 lines of new code in version-specific #ifdefs for 5.x/6.x/7.x -- it wasn't aware of ffmpeg 8.x, I guess it didn't exist when it was trained, so I added that manually, but it was pretty close to 7.x). It didn't produce perfect results, but it took care of the tedious part of digging through the API changes. I have mixed feelings about using this (what will the external downsides be?), but for now I'll take it as a win. As for future versions, yes we'll need to update it for the eventual ffmpeg 9.x etc. 9 Comments...

Question: I can use ASIO for free, and pretty much everyone should be able to use it for free. Do you think it’s reliable? As long as I install it, I can start using it with ASIO in REAPER. What’s the principle behind this? Would you consider implementing this kind of virtual ASIO feature inside REAPER?github.com/dechamps/FlexASIO
Asked by catst (221.215.214.x) on February 15 2026, 1:51pm
Reply on February 15 2026, 5:56pm:

ASIO the API is reliable, sure? Do we want to improve REAPER's ASIO support in order to support multiple devices? Hmm maybe it could be useful, but having people use ASIO drivers that do it themselves sounds fine for now... 1 Comment...

Question: Someone said it seems all humans have something in them that makes them wish a higher power actually existed that they could look up to and communicate personally with. Have you ever had that wish for even a moment?
Asked by HigherPower (154.161.41.x) on February 13 2026, 10:00pm
Reply on February 14 2026, 3:24am:

Can't say I really have 2 Comments...

Question: What do you think about Temple OS and the future of OS development?
Asked by Elijah Flowers (207.160.233.x) on February 13 2026, 7:25pm
Reply on February 13 2026, 7:51pm:

lol can't say I think about that much Comment...

Question: May I interview you for my school project? I'm in SF! If you are open to it, my email is here ...
Asked by Arie (147.144.3.x) on February 11 2026, 6:45pm
Reply on February 12 2026, 3:25am:

by email, sure -- send me an email, you should be able to figure out my address. Comment...

Question: Do you ever try using other DAWs to get a feel of what's out there?
Asked by artiliano (123.136.24.x) on February 11 2026, 12:45am
Reply on February 11 2026, 3:08am:

Occasionally use them when testing things, but never really try to use them properly, because meh Comment...

Question: Is having a beard a prerequisite to work at cockos, man, just saw Schwa for the first time. You guys have the same mindset, philosophy, and beardology.
Asked by Beard (102.176.65.x) on February 7 2026, 1:42am
Reply on February 7 2026, 9:25pm:

I'm not super beardy now, go between a mustache and a light beard 2 Comments...

Question: Ayo justin! I'm a jazz musician who owns a production house in south asia, Reaper has been a staple platform for us for years, in regards to its no nonsense design and utility plus the honest licensing allows alot of us from outside the first world to legally own and produce music on a world class DAW. All of us here at Aukaabi are extremely indebted to the dudes at cockos, if possible i would love to interview you about your philosophy regarding Reaper; your intent and advise for the future.
Asked by Strato IV (72.255.51.x) on February 6 2026, 8:51am
Reply on February 6 2026, 4:58pm:

send me an email, firstname-at-companydomain :) Comment...

Question: When implementing license expire after one year for an application, how do we detect the expiration? Do we have trusted time source if the pc does not have internet?
Asked by Ruchira (175.157.46.x) on February 4 2026, 5:32am
Reply on February 4 2026, 11:22pm (edited at February 4 2026, 11:23pm):

I'd trust the computer's clock, I mean if you really want to keep your clock wrong then I guess go for it, but a lot of things will break if you do that, like TLS connections, even. Comment...

Question: Yo Justin! Would you ever consider regional pricing models for Reaper? My currency is worth nothing in the world.
Asked by Piet (154.47.30.x) on February 3 2026, 12:01pm
Reply on February 3 2026, 5:51pm:

will investigate the feasibility of that Comment...

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