Gyroflow: Advanced open-source gyro-assisted video stabilization
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Look at all the HN articles pouring in with this TLD: https://hn.algolia.com/?dateRange=all&page=0&prefix=false&qu...
But you're right. Spatial domain products should jump all in on this.
Here’s an example comparison of flight footage from a RunCam 5 Orange on a 5” freestyle quadcopter: https://youtu.be/1ZORzfJ1sog
One decision that such a program needs to make is how to smooth out the movement, and what this one seems to be doing is a sort of a "piecewise linear" function which is a bit jarring to watch when it suddenly transitions between 2 speeds.
There are several different smoothing algorithms that you can choose from - I don’t recall the name of the one I used here, but it was specifically called out in the docs to be most suitable for acrobatic flight.
You can set up key frames, which can give a lot more control over where and how the stabilization is applied. I just used the ones that gyroflow chose for me here.
> what this one seems to be doing is a sort of a "piecewise linear" function which is a bit jarring to watch when it suddenly transitions between 2 speeds.
I made this example specifically to learn how to stabilize that kind of footage, because that’s what I do the most of and that’s where I think I’ll find the biggest benefit.
Also… this is my favorite quadcopter at the moment, and can do some pretty crazy stuff. It’s got 5x5x3 props, 1,950KV motors, and uses 6S batteries. Assuming 24V and no load, that’s around 47,000 RPM. I don’t have a GPS receiver on it, but I’ve handily outrun a friend’s flying wing that was moving at 120MPH according to its onboard telemetry. All of that is to say that a lot of that speed transition isn’t an artifact of the stabilization. :)
For slow, “cinematic” footage, Premier and DaVinci Resolve’s image-based stabilization does an adequate job with less work.
That one uses the default smoothing algorithm, which isn’t really suitable for anything acrobatic.
If you’re dead set on only buying one, go with a durable “cinewhoop” like a Diatone Taycan. It’ll likely survive the abuses can carry a GoPro or RunCam, and will be useful if you decide to go deeper in the hobby. Otherwise I recommend starting with a “mini whoop” like a BetaFPV 2S Pro or a Mobula8.
Realize that you also need goggles and a radio (controller). Those will set you back $400 and $200 respectively if you’re trying to “buy once cry once”. If you’re seeing if you’re into it, the BetaFPV 2S Pro “RTF” (ready to fly) kit is a good introduction, as is the Emax Tiny Hawk 2.
If you’re interested in getting into the hobby, let me know and I’ll get you my contact information so we can chat.
In that case, I recommend the DJI Mini2 if you’re going with new. If you want to save a few bucks, the DJI Mavic Mini “Fly More kit” can be had for ~$300 used. It includes three batteries, a charging bank, and everything you need except a cellphone to use for a screen.
I took this with a Mavic Mini when I was just getting started with it: https://youtu.be/-uZYxg8FmY8
Speaking for myself, I wanted to feel like I was piloting something, not just stiffly moving a camera around. I thought I wanted long flight times but have since realized that I really wanted acrobatic ability.
A 2S TinyWhoop drone is about $100-150 and is very durable. I wouldn't call it indestructible, because you can definitely break it if you try, but it will bounce off things or even plummet from the sky. It can't carry a GoPro unfortunately but it's a good pick for learning. The costs will come from ground equipment like your radio or goggles, which can be reused on future drones.
One of the newer "toothpick" drones could carry an Insta360 Go.
There's currently a few big shifts in drones right now:
- ExpressLRS: Open source radio control protocol. Range will exceed your battery.
- HDZero / SharkByte: DJI alternative for HD video. Not as good quality but slightly more open (although not truly open).
- "Sub 250" - Upcoming US FAA regulations put sub 250g drones in a special category, which could have some use.
> ExpressLRS: Open source radio control protocol. Range will exceed your battery.
This is probably a good call for this audience. I expect ELRS will win out in the mid- to long-term for most things. A few people will stick with other protocols like TBS Crossfire or Tracer - I plan to, but honestly they don’t offer anything that ELRS doesn’t as far as I can tell. I just like TBS as a company and some of their products like the TBS SIXTY9.
Generally speaking, choose a protocol and stick with it. Only change (or add more protocols) if you have a good reason to.
Radios come in two broad flavors: protocol-specific and “multi-module”. I’d go with the latter unless you really want a tiny portable controller.
The RadioMaster TX16S is far and away my pick here. It’s bulky, but it supports almost everything out of the box. If you want to add TBS Crossfire/Tracer, ELRS, FrSky ACCESS, etc. you only have to add a small module to the back.
FrSky radios used to be considered top-end, but they’ve moved toward a more closed protocol that limits compatibility for both their radios and their receivers. If you have one already, by all means use it - they’re good radios - but I wouldn’t buy one today.
> HDZero / SharkByte: DJI alternative for HD video. Not as good quality but slightly more open (although not truly open).
This is what I meant earlier when I was talking about digital vs. analog - the “protocol war” here is still in its early stages. For all its warts and drawbacks, analog isn’t going anywhere. If my guess on the outcome is correct, I’ll probably end up with an HDZero setup in about a year.
Note that you can put a (digital) SharkByte receiver on analog goggles, and you can put an analog receiver on (digital) DJI FPV goggles.
> "Sub 250" - Upcoming US FAA regulations put sub 250g drones in a special category, which could have some use.
UAS under 250g that are used only for recreational use don’t require registration ($5, your name in a database, and a sticker). I’m not aware of any upcoming regulations that will impact the hobby.
For non-recreational use, there is a category for UAS <250g with enclosed props that can be flown over people legally. There is currently no off-the-shelf offering that meets those requirements, but it can be done with a slightly modified DJI Mavic Mini or Mini2 using a special battery and guards.
At the end of the day, the RPIC (“remote pilot in command”, the person flying it) must maintain VLOS (“visual line of sight”) to the UAS at all times to be legal. You can have a VO (“visual observer”) to help with that, but there is no legal way to fly FPV at the moment without a second person present.
To be brutally honest, the FPV hobby ignores a lot of the laws and regulations around it. Most of our video transmitters output quite a bit more power than legally allowed with being a HAM, and effectively none of us make sure to have a VO when we fly. Being a 107 pilot I do my best to comply to the extent that it’s practical to do so, but even I don’t bother with the VO stuff. It makes no sense, and serves no purpose with the type of quads I fly. If my video feed dies I’m going to crash, period. I’m pretty good about being able to put it down gently while blinded and I make absolutely sure I’m not putting anyone at risk when I fly.
Otherwise, these quads are far too crude - or more accurately, “stripped down” - to automatically return to home or something. Most of mine are set up to attempt to transition to a hover and descend to land in a semi-controlled way if I turn off my radio, but honestly doing that is more dangerous than just aiming it in the general direction of the safest place to land from memory and hoping for the best. I’ve ditched into water more than once because that was the best way to be sure I wasn’t going to hit anything or anyone. Sometimes that means wading into a creek or puddle to pull it out and letting it dry for a few days, sometimes that means replacing some parts, sometimes that means it’s 15’ underwater and unrecoverable. Such is the nature of this hobby.
Re: TX16S. I have both the TX16S (running EdgeTX) and the T-Lite. I strongly prefer the T-Lite for it's compactness and portability. If I succeed in shifting the fleet over to ELRS, I'll probably get a nano ELRS module for it. The TX16S is a very nice radio but I can fit the T-Lite, a whoop or 'pick, and my goggles in my backpack with tons of room to spare.
For SharkByte, I bought goggles with HDMI-in (Skyzone Cobra-X), with the anticipation of upgrading if my interest in the hobby held and the technology evolved. People look down on box goggles but I really appreciate the compatibility with glasses and being able to hand them to anyone with no adjustment needed. DJI's vendor lock-in puts right next to Apple in tech that I've just written off.
I believe sub250 is exempt from RemoteID for hobbyists because they are not required to be registered. If you're 107, then you still need it, of course.
Also, if you add a GPS to your quads, Betaflight can already RTH them fairly well (though more "disarm while the quad is flying towards your head" than "RTH", but still). With a compass, INAV can bring it back and land it fairly accurately.
I haven’t been using iNav in a way where it’s an issue - my wings are mostly just for recreational FPV, and the big features for me are autotune, altitude hold, position hold, and RTH. Between those, I’m able to get a wing flying stable very quickly and am able to fly further away without worrying about RXLOSS meaning that I have to chase the thing down across three counties.
I had a few close calls where it almost crashed into various objects while circling to RTH, and I decided I didn't want to lose a wing (or, worse, falling on someone's head), so I switched.
I'm looking to mess around to autonomous planning and stuff. This might be more for the parent, but any recs for a drone that can carry a camera and do some autonomous path stuff?
Also check out OpenHD. It's a 100% open source HD/Digital FPV system with unconventional use of Wifi (I think it's monitor mode or something?). It's not typically used for FPV because of the high latency and time to reacquire after signal loss. But if you're going autonomous then why not?
The cheapest path here is a used DJI Mavic Mini. It’s not nearly as capable as the current generation stuff, but it’s cheap, and well-supported in Dronelink.
If you want DIY, the choices I know best are iNav and ArduPilot. Both of those are generally run on custom-built UAS, and in my experience any quad you buy like that will end up changing over time with replacement and upgraded components.
I buy my parts at GetFPV and Pyrodrone most often, with RaceDayQuads as an occasional vendor. I’ve had particularly good experiences lately with Pyrodrone. I got a ~$130 charger that failed in the first few hours of use; not only did they issue me a credit almost immediately, they gave me permission to tear down the charger I had to see if I could fix it first. Not many companies out there would do that!
Unfortunately, all of the pre-built stuff I see out there at the moment runs Betaflight. I love Betaflight for what it is, but if you’re interested primarily in mission planning you’re going to be disappointed.
I recommend joining a couple of iNav and ArduPilot Facebook groups and just looking around. There are lots of people who are very knowledgeable there in extremely niche areas. Part of why I can’t just point you to a specific hardware setup is that there are a ton of tradeoffs that have to be taken into account and what is best for you depends on your very specific use case.
For example:
I use my Autel Evo 2 Pro for almost all of my videography stuff. It’s not supported by Dronelink (last I checked they were working on it), but the iOS app’s mission planning is sufficient for about 80% of what I do. I can manually pilot the rest. The E2P has a rated 40m flight time. In reality, I usually get about 28-32m of usable flight, because I’m not interested in trying to stretch the limits and risk my UAS.
If I were wanting to do large-scale orthomosiacs and mapping, I’d go with a custom flying wing. Those can easily get well over an hour of flight time and can carry a substantially larger payload. Mapping imagery is usually taken at “nadir” - straight down - so I could use a significantly simpler gimbaled camera. If my wing was stable enough, I might even be able to get away with no gimbal at all. I’d likely fly it through a separate onboard FPV camera, though I might omit that as well if I were using exclusively planned mission stored and executed onboard. I’d build that myself, and probably start with a body kit like an AR Pro: https://www.getfpv.com/sonicmodell-ar-wing-pro-1000mm-wingsp...
Note that the link above is a “PNP” kit, so technically you could add a receiver and start flying. It doesn’t come with a flight controller, camera(s), gimbal(s), or video transmitter. All of that would have to be added, and a down-facing camera would require modification to the body, gimbaled or not.
At that point, it becomes worthwhile to at least consider building the airframe yourself. There are lots of plans out there, and it’s not _that_ difficult to learn to design them from scratch. Fusion 360 has some F/OSS plugins to help with designing airfoils and calculating all the metrics you need to get it right.
The reason I’d go for a fixed-wing for mapping is twofold: Generally speaking they’re faster in a straight line (mapping missions are generally composed of a bunch of straight lines with turns between them), and they’re far more efficient and easy to get relatively long flight times.
A multirotor is always expending power to fight gravity and stay in the air. That gives it the ability to hover and do all kinds of crazy acrobatics, but it means that there is a point at which adding more batteries expends more power keeping it aloft than you gain from the additional capacity. A fixed-wing stays in the air because of the lift generated by the airfoils, and you only need to keep it moving fast enough to generate sufficient lift.
To give some idea of how that works out in real life: I have a “powered glider” that I fly for fun that uses a 3S 1300mAh battery. It can do mild acrobatics (lazy loops, Immelmann turns, etc.) for about 35 minutes. If I’m just flying level, it’ll fly for around 45-50 minutes. If I’m flying at one of my favorite spots - a small but steep hill with a creek at the bottom - and I’m trying to stay up as long as I can, I actually don’t know if there _is_ a maximum flight time. I’ve gotten up to 2.5 hours before I decided I’d had enough for the day. A light enough aircraft with enough lift, taking advantage of thermals and updrafts, doesn’t really rely on powered flight much.
My “for fun” AR Pro uses a 4S 3500mAh battery. It has ~3.6x more energy available, but I usually only get about 12-15 minutes of flight time. It’s flying a lot faster, though!
My favorite freestyle quadcopter is built on a 5” Armattan Badger frame. On a 6S 1300mAh battery, I get 3-4 minutes of acrobatic flight. At most, if I were only hovering, I might be able to push that to ~6 minutes.
In other words, the quadcopter above flies for <5 minutes, but the glider can easily fly 10x as long, given the same battery and flight style. The glider is also capable of flying far, far longer if that’s the main goal; the quadcopter isn’t.
All of the above use lithium polymer (“LiPo”) batteries. The care and feeding of those is a topic unto itself, but for the purposes of understanding efficiency, know that they’re rated based on the “per cell” capacity. A 3S battery has three cells, a 6S battery has six cells. Each cell is 4.2V at full charge and ~3.5V when discharged. A 3S 1300mAh battery has half the capacity of a 6S 1300mAh. The 3S outputs up to 12.6V while the 6S outputs up to 25.2V.
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It can do 4k30 or 2.7k60 - but it’s also 56g, and durable enough that I “recovered” it from the top of a metal building a few days ago by knocking it down with a quadcopter and letting it fall 12’ onto pavement.
Tradeoffs have to be made somewhere :)
I mostly use it for hobby stuff. While I can record on my goggles, the image quality is extremely poor and completely unsuitable for any real use. This is what I see while flying: https://youtu.be/xywVVS8eLSw
It looks quite a bit better in the moment, and on a screen that’s optimized for it. I use a Skyzone 04X, which was 1280x960 OLED screens with a 46º field of view. You can’t really get much better for analog video at the moment in this form factor. There are a couple of digital options (DJI and SharkByte), but I don’t want to spend the money on those until I feel like the technology has matured a bit more and I’m not going to need to spend another $500+ on goggles and ~$80 per airframe to upgrade. The RunCam 5 Orange gives me the ability to make videos for sharing with others and is “good enough” for some light commercial work.
In addition to flying FPV as a hobby, I have my FAA 107 certificate and do some photography/videography as a side hustle. I use an Autel Evo 2 Pro for that most of the time, which is capable of 6k30/4k60 and is stupid good for night photography. I occasionally mix in some video from my FPV quads if the situation calls for it. I rarely need to produce output that’s over 1080p, and 30fps is pretty standard there. If I were doing more interior fly-through and such, I’d pick up a more capable camera for that purpose. I’d still want the RunCam though, because of its balance of weight and durability.
While the drone demos are cool, the non-drone creative possibilities for amateur filmmakers will be equally impactful. Imagine being able to get perfect crane-style interior tracking shots just using a long pole. As great as they are, drones aren't allowed in a lot of environments due to noise, distraction, insurance, etc. Flying a four pound stabilized cinema rig usually requires a BIG hexacopter that is loud and, frankly, pretty scary to be close to. A lot of us low-to-no budget filmmakers (and students) rely on shooting in improvised locations because we don't have the budget to shut down a city street to get a shot.
I'm excited to try this on some handheld run-and-gun action footage. The Alpha 1 camera is amazingly small and light for the pro cinema level quality it delivers which is why it would be a shame to stick it in on a big stabilizing gimbal rig. Capturing gyro metadata natively is an inexpensive 'no-brainer' feature all 'serious' cameras should include.
The complexity of simultaneously capturing the gyro output and time syncing it to the video seems pretty high if the benefit is only marginal.
edit: A gyro-based algorithm is quite simple, while computer vision is still not a fully solved problem in general
Syncing “blackbox logs” from the flight controller’s gyroscope is a pain, for sure. There are some cameras on the market now that have their own gyroscope and automatically produce sidecar files for the same time period as the video, like the RunCam 5 Orange. For those, syncing the gyro readings is totally a non-issue.
I made this video comparison between GoPro6 4k video vs the stabilized with gyroflow
For iOS that’s not gonna happen at least with distributing via App Store considering GPL-3 license.
Admittedly, not a great solution and Android is just always going to be more friendly for apps and use cases that fall outside of mainstream.
Some alternative could be just instructions how to build yourself or distribution via AltStore.
I’d like to see how cameras that use this, stack up against the Osmo[0]. That’s a pretty awesome little camera.
See also - action movies, games.