I'm learning Factor and I thought it would be great to have a small program to capture images from the webcam that comes with my mac pro. I know every webcam will be very different but sounds like something I should be able to do. I want to create a library with support for Mac, Linux and Windows. The problem is that I'm not sure where to start.
Factor-based answers are welcome but I'm looking for the language agnostic solutio. When I google for it, all I get is programs that capture images. I want to learn how to interact (in the 3 big operative systems) with the drivers I guess.
I think the only clue I have is the ioctl wiki page. How would you start such a project? What kind of google keywords would you use? Books?
It's not clear if you want to write a driver for your particular webcam or a library that makes talking to the existing driver easier.
If you want to write a driver for your webcam, you probably want to investigate libusb for Mac and Linux and libusb-win32 for Windows. You would need to understand the protocol that your webcam talks, though. You could probably read the source code for the existing Linux driver (assuming there is one, which is pretty likely).
As for Google search terms, you might try "video capture" and maybe looking for Python/Ruby etc. code or Open Source programs will get you code you can look at to see how to do what you want to do.
Perhaps if you describe in a little more details what you're trying to accomplish someone could give you better suggestions.
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I've got a big ask here, but I am hoping someone might be able to help me. If there's another site you think this should be posted on, please let me know.
I'm the developer of the free app Amphetamine for macOS and I'm hoping to add a new feature to the app - keeping a Mac awake while in closed-display (clamshell) mode while not having a keyboard/mouse/power adapter/display connected to the Mac. I get requests to add this feature on an almost daily basis.
I've been working on a solution (and it's mostly ready) which uses a non-App Store helper app that must be download and installed separately. I could still go with that solution, but I want to explore one more option before pushing the separate app solution out to the world.
An Amphetamine user tipped me off that another app, AntiSleep can keep a Mac awake while in closed-display mode, while not meeting Apple's requirements. I've tested this claim, and it's true. After doing a bit of digging into how AntiSleep might be accomplishing this, I've come up with 2 possible theories so far (though there may be more to it):
In addition to the standard power assertion types, it looks like AntiSleep is using (a) private framework(s) to apply non-standard power assertions. The following non-standard power assertion types are active when AntiSleep is keeping a Mac awake: DenySystemSleep, UserIsActive, RequiresDisplayAudio, & InternalPreventDisplaySleep. I haven't been able to find much information on these power assertion types beyond what appears in IOPMLibPrivate.h. I'm not familiar at all with using private frameworks, but I assume I could theoretically add the IOPMLibPrivate header file to a project and then create these power assertion types. I understand that would likely result in an App Store review rejection for Amphetamine, of course. What about non-App Store apps? Would Apple notarize an app using this? Beyond that, could someone help me confirm that the only way to apply these non-standard power assertions is to use a private framework?
I suspect that AntiSleep may also be creating a virtual keyboard and mouse. Certainly, the idea of creating a virtual keyboard and mouse to get around Apple's requirement of having a keyboard and mouse connected to the Mac when using closed-display mode is an intriguing idea. After doing some searching, I found foohid. However, I ran into all kinds of errors trying to add and use the foohid files in a test project. Would someone be willing to take a look at the foohid project and help me understand whether it is theoretically possible to include this functionality in an App Store compatible app? I'm not asking for code help with that (yet). I'd just like some help determining whether it might be possible to do.
Thank you in advance for taking a look.
Would Apple notarize an app using this?
I haven't seen any issues with notarising code that uses private APIs. Currently, Apple only seems to use notarisation for scanning for inclusion of known malware.
Would someone be willing to take a look at the foohid project and help me understand whether it is theoretically possible to include this functionality in an App Store compatible app?
Taking a quick glance at the code of that project, it's clear it implements a kernel extension (kext). Those are not allowed on the App Store.
However, since macOS 10.15 Catalina, there's a new way to write HID drivers, using DriverKit. The idea is that the APIs are very similar to the kernel APIs, although I suspect it'll be a rewrite of the kext as a DriverKit driver, rather than a simple port.
DriverKit drivers are permitted to be included in App Store apps.
I don't know if a DriverKit based HID driver will solve your specific power management issue.
If you go with a DriverKit solution, this will only work on 10.15+.
I suspect that AntiSleep may also be creating a virtual keyboard and mouse.
I haven't looked at AntiSleep, but I do know that in addition to writing an outright HID driver, it's possible to generate HID events using user space APIs such as IOHIDPostEvent(). I don't know if those are allowed on the App Store, but as far as I'm aware, IOKitLib is generally fine.
It's possible you might be able to implement your virtual input device using those.
I was wondering how i would be able to get started with controlling my nikon DSLR camera? I have been reading on the Nikon SDK and MPT/PTP and is really confused on how to start with writing a script to control it. Thanks for helping me.
If you are just wanting to script stuff, under Linux libgphoto2 and gphoto2 are a good start.
You can use them under windows, I'm not sure if there are pre-compiled build available, but that would also require installing the USB wrapper libraries, and that a touch fiddly.
The next step above that is to compile libgphoto2 in cygwin (there are some good guides how to this on the web), but that overkill.
I am currently using digicamcontrol in windows, and for Nikon and C# code it's really nice to use, and very fast, plus it has no hassle on the USB front. It wouldn't be too hard to write a small C# that does what you want (unknown) and then run that from scripts.
this is what you are looking for:
http://sourceforge.net/projects/nikoncswrapper/
Good luck
In case anybody is still looking at this: the answer is a bit more complex if what you are looking to do is write your own code to access a Nikon DSLR. Thomas Dideriksen's SDK wrapper referenced above is great in making it easy to access Nikon's SDK to control almost all camera functions - but it is restricted to USB-cable access since that SDK does not support wireless access. If the latter is what you want, your best option may be Duka Istvan's digiCamControl, which Simeon suggests above. This open-source C# project can be used as a standalone library. (See the development documentation page.) It is not all that well documented, though, so figuring out how to control all camera parameters can be tricky.
I am looking a bit of simple code that will take whatever data comes from the keyboard at a given moment and let me check it for certain button presses. It doesn't matter what language it is in.
I am looking for a console solution, no GUI.
It sounds like you are looking for the curses library (you may also find an implementation as "ncurses", which is probably already installed on your system). This library powers most of the "full-screen" console programs that you might see on Linux.
We're in process of developing a desktop application which needs to record user's screen once he clicks a button. I read a tutorial about Adobe AIR, which says it is easy to do with AIR: http://www.adobe.com/devnet/air/flex/articles/air_screenrecording.html
But our preference is Titanium as we've explored it a little bit. So I want to know is that even possible? If yes, how can we get started with?
There's also an interesting solution which uses Java applet for recording, as demonstrated here: http://www.screencast-o-matic.com/create?step=info&sid=default&itype=choose
But again, we're not sure about JAVA and would like to know how can it be done? or if its even possible to run a JAVA applet in Titanium?
When you say "record screen", I'm assuming you mean video. Correct?
The only way to do this in Titanium Desktop right now is to take a bunch of screenshots and string them together (encoding would probably need to be done server-side).
Depending on how long your videos need to be, this probably won't work for you. I'm also not confident in how quickly you could capture screenshots, and if it would have a high enough frame rate to be usable.
Past that, a module could be developed for Desktop to support some native APIs to record video. That's not something I see on the horizon, though.
I hope this helps, albiet a rather dismal answer. -Dawson
I would like to be able to programmatically emulate a shutter button press on my Casio Exilim EX-F1 digital camera.
It comes with a USB tethered remote control that can emulate a shutter press, so I would think there is a way to emulate that from a PC.
I've looked and can't find any libraries or anything for controlling this camera.
Anybody have any ideas? How about a way to "sniff" the USB being sent from the remote (I can't imagine that's easy).
Ok although it might be out-of-the-box thinking the easiest solution I can think of, without having the patent documentation + technical specs in-front of me (that is the normal route people use to do this sort of thing) you could always use Lego Mindstorm robotics.
Edit: Anyways besides the Lego, which would be my course of action, I mentioned, the hard-core way is to use the Spec sheets, you can normally get them off the website, but then your basically into driver programming. If you find that prospect attractive in anyway this link will give you some ideas for doing it on Windows.
In case anyone finds this question, Casio finally released an official way to do this with the free EX-F1 Controller software (with special firmware included):
http://support.casio.com/download.php?rgn=5&cid=001&pid=573
It has its limitations but it makes more possible for sure.
There's a non-official API to control the Casio EX-F1. It's a reverse enginyering free (as in freedom) product.
http://code.google.com/p/exf1ctrl/