Firstly, I am a newbie on Mac programming. I have downloaded macam project and successfully compiled debug version to 32-bit code with Xcode 4.1. The output is a QuickTime component that I manually copy to Library/QuickTime folder. Now I want to debug the component but have no luck. I enable multiple breakpoints in the code and then use Product->Debug->Attach to Process to check the webcam output in Skype. Skype shows the (dummy) webcam running but my breakpoints do not work. I am sure my functions are called as they are the ones drawing color stripes as webcam output.
Apple documents on debugging a shared library are not very good. Is there something fundamental wrong with my approach or something simple I need to do first? Any guidance is much appreciated.
The approach I used for debugging of my QuickTime component project was to use NSLog() in the beginning and return of every major function in the format ClassName functionName: parameters... I then used Console (Search for console in spotlight) app to view the logs.
This might not be the easiest/best way but I did succeed to debug and complete my component.
Edit: this question provide some more useful information about NSLog How to print out the method name and line number and conditionally disable NSLog?
One of the easiest ways of debugging this, if you are going to use a third-party application like Skype, is going to be thru debug statements or a network socket.
What you can do, is create a UDP socket to send messages, as well as a client application to listen for them. This will provide you access to realtime information from your application...
You can also put in UDP listen statements to wait for (your other testing app) to send parameters.
I know this isn't the traditional way of debugging, and it can cause its own problems, but if done properly, can provide tons of useful debugging when all other tools fall short.
Related
I need to check if an app is making a certain sound. This app only produces a single specific sound, so a solution that simply checks if there's any sound whatsoever from the app will also work.
I don't need to find out which app makes a sound or anything like that. I know the app that should produce a sound and I know what sound it's going to be, I simply need to detect the exact time this sound is played.
The only solution I know of is to listen to the audio output for the whole OS and then detect my specific sound with some audio recognition software, but it won't work properly if there's music or a movie playing on the background, so it's not an option.
I need a solution to do it via WinAPI methods. The language isn't very important here - I can use C#, javascript, Python or another language. I just need to find out a general approach on how to extract sound produced by a specific application in Windows 7.
The general approach here is to trace calls from a given process to OS to play audio. These calls are more commonly known as "system calls".
This will show only direct attempts by a process to produce sound.
The only hardest part here is to identify all the system calls, that play sound in windows.
This question has some answers on how to trace system calls on Windows
Have you looked at SO answer on similar topic with a bunch of useful .Net wrappers for IAudioSessionManager2 and related API: Controlling Application's Volume: By Process-ID
I think that general approach of
Finding IAudioSession by process name
Subscribing to its events via IAudioSessionEvents
Listening to the OnStateChanged event
should do it for you.
And don't forget that you should pump Windows messages which might require some explicit code in non-UI applications. In UI applications this is what Application.Run does internally anyway.
This is question is about the general architecture, I do not require anyone to solve this little hack for me, although I won't be angry if someone does ;).
Suppose I have a web app that spawns standard unix processes (like Travis CI). While it seems simple enough to pick the stdout of such a process, I'd rather like to make the whole thing asynchronous (like e.g. Travis). So I thought of passing the whole output through a websocket and into some web-based terminal emulator.
However, the only emulators I could find were fully interactive (i.e. they allow for user input and thus have some custom server-side component). My goal would be to have a piece of client side code and just stuff the output into it.
So what is necessary to create a websocket, attach it to the stdout of a server-side process (preferably emulating a tty for colors and fancyness) and display a terminal client-side? I recon there are control codes to distinguish a tty from a text file and these control codes need to be encoded on the websocket somehow, but is there some documentation on this?
I have done this for .NET applications. I think this may be worth for you as example.
I have a small .NET project named NLog.Contrib.Targets.WebSocketServer that is a log watcher with WebSocket and AngularJS. Basically, it broadcasts the data that is being logged through a WebSocket, and there is an AngularJS directive that shows the data. How to highlight data is more a presentation stuff, so it will depend on the framework you use. Basically, this component attaches to whatever .NET application that uses NLog as logging framework, so you can try to find some extensibility point in Travis yourself and attach your thing there.
About attaching to stdout, I have a proof of concept about a web interactive CMD.exe also in .NET, although you can disregard the stdin part. If you use Mono, probably is the same thing than in Windows.
I think this is very similar to what you are looking for. If you have a more specific question let me know.
You can use STDWebsocket in order to achieve this. For examples, simply read the index.html script tag. It should solve your problem (or anyone that go through this question)
Can anyone offer any advice on options in getting real world events, ie sound, visual, motion, to trigger events on the mac?
The simplest event I think might be sound.
I simply need sound of a certain volume, to start an application on the desktop,
This application would be web based (ie javascript) or possibly standalone.
Most likely the former.
The first thing that comes to mind is Arduino but I was wondering, since I'm a total novice at Arduino coding, if there are other 3rd party apps that might make this possible.
There are a number of pre-built applications available from the arduino site here:
http://arduino.cc/en/Tutorial/HomePage
They will all invariably need some customization, but hey that's half the fun right? Here's an example that seems to do something similar to what you're describing. You would just need write an app on the computer to listen for the right serial output.
http://arduino.cc/en/Tutorial/DigitalReadSerial
OR
http://arduino.cc/en/Tutorial/AnalogReadSerial
And remember, you can always ask more questions here on SO if you run into a problem.
Yes, you can :)
1) First of all, you'll need the Arduino to "listen" to a sensor. This can be achieved by the digitalRead or analogRead methods, depending which kind of sensor you're gonna use.
2) You'll need send something to your mac when the condition you want to check happens. This involves using the Serial Port to send some kind of message from the Arduino to your mac.
3) On you're mac, you'll need to check messages on the serial port. I often use Processing to listen the serial port. You're lucky, you're on a mac, you have AppleScript :) This means Processing will have to launch a simple Applescript that will tell your selected application to open
That's it. For further details, check google to see how to send messages from arduino to processing, and how to trigger Applescript via Processing
I'm ready to outsource the screen capture functionality of our application, because it's not our core business and I've spent too much time trying to get our code to do all the things I need. Time for a specialist, I think. My requirements, in decreasing order of importance, are below. Does anyone have experience with any commercial or free libraries that meet most or all of these requirements?
Has to work in Windows XP and higher. (But not Win95/98/Me.)
Visual C++ 2005 compatible, where screenshot can be triggered from my code. Preferably a static library, but a DLL or COM object is OK. I'd prefer not to shell out to a standalone EXE because there are some users that will try to tamper with our application and I think having an obvious separate screenshot EXE makes that too easy.
Must be able to take full screenshots of multiple monitor systems. (Preferably the way the "Print Screen" key does in Windows, by making a bitmap of the displays stitched together, but if I have to take the pictures separately and combine them myself that's acceptable.)
Must be able to capture screen correctly when Remote Desktop Client (or any RDP client or VM) is in full screen mode. (Of course, it should also work when RDP is in windowed mode, but that shouldn't be a problem as long as it doesn't operate by simulating a key press that might get transmitted to the remote OS instead of being handled locally.)
Must be able to capture screen correctly when Windows Media Player (or any other media player) is in full screen mode.
Must be able to capture screen correctly when game (e.g. World of Warcraft) is in full screen mode.
Would be nice to be able to capture a few seconds of user activity as a video.
I don't know of a library that would do what you want.
If I had to code your requirements, I would probably use the source code of the TightVNC server as my starting point. I think it has the technology to do everything on your list EXCEPT....
I'm not sure that technically there's ANYTHING that can do a screen capture of somebody's Remote Desktop session. Think about it: There can be multiple remote desktop sessions (the csrss.exe process) occuring using the same physical remote desktop server. If you were sitting in front of the machine looking at the video monitor, you wouldn't see anything happening at all. So what woould you expect to capture. VNC is only going to capture what's happening with the "real" video (the non-remote csrss.exe).
I dont know if this really helps, but the best imaging libraries available are available from
www.accusoft.com and
www.leadtools.com
Both support creatting screenshots, though i don't know, if hey will properly capture movie player output that displays through graphics acceleration or the recording of movies from screen.
If I were you I would investigate WindowsClippings, a pretty mature and extensible application written in C++ that does precisely what you need. It has an API you can extend to your requirements and is pretty cheap at 18$
Some people in our office are using Magick++ (an ImageMagick library) to make screenshots. I don't know all the specs, but you could take a look at it and see if it matches your requirements.
I'd like to write a packet sniffer and editor for Windows. I want to able to see the contents of all packets entering and leaving my system and possibly modify them. Any language is fine but I'd like it to run fast enough that it won't burden the system.
I've read a little about WinPcap but the documentation claims that you can't use WinPcap to create a firewall because it can't drop packets. What tools will help me write this software?
Been there, done that :-) Back in 2000 my first Windows program ever was a filter hook driver.
What I did was implementing the filter hook driver and writing a userspace application that prepared a filter table on what to allow and what to disallow. When you get around your initial set of blue screens (see below for my debug tip in kernel mode) the filter mode driver is quite easy to use ... it gives each packet to a function you wrote and depending on the return code drops it or lets it pass.
Unfortunatley packets at that level are QUITE raw, fragments are not reassembled and it looks more like the "network card" end of things (but no ethernet headers anymore). So you'll have quite a bad time decoding the packets to filter with that solution.
There also is the firewall hook driver, as discussed in this codeproject article.
If you are on Vista or Server 2008 you'd better have a look at WFP (Windows Filtering Platform) instead, that seems to be the mandated API of the day for writing firewalls.
I don't know about it other than google turing it up some minutes ago when I googled for the filter hook driver.
Update: Forgot the debug tip:
Sysinternals DbgView shows kernel-mode DbgPrint output, and more important - it can also read them from the dump file your last blue screen produced. So sprinkle your code with dbgprint and if it bluescreens just load the dump into dbgview to see what happened before it died ... VERY useful. Using this I managed without having a kernel debugger.
I'm pretty sure you'd need to write a filter driver. http://en.wikipedia.org/wiki/Filter_driver I don't know much more than that :). It would definitely be a C/C++ Win32 app and you'd likely being doing some kernel side work. Start by downloading the DDK and finding some of the sample filter drivers.
If you just want to monitor what goes in and out of IIS, consider an ISAPI filter. Still C/C++ in Win32, but relatively easier than writing a device driver.
C# code to do this is here
I actually did this, several years ago. I'm hazy on the details at this point, but I had to develop a filter/pass-thru/intermediate driver using the Windows DDK. I got a lot of good information from pcausa. Here's a url which points to their product that does this: http://www.pcausa.com/pcasim/Default.htm
If you're doing this for practical reasons, and not just for fun, then you should take a look at Microsoft Network Monitor. The home page talks about the version 3.3 beta, but you can download version 3.2 from the Downloads page. There is also an SDK for NM, and the ability to write parsers for your own network protocols.
There's a question you need to ask which you don't know you need to ask; do you want to know which applications sockets belong to? or are you happy to be restricted to the IP:port quad for a connection?
If you want to know applications, you need to write a TDI filter driver, but that makes handling the receive almost impossible, since you can't block on the receive path.
If you're happy with IP:port, go in at the NDIS level, and I believe you can block on receive to your hearts content.
A word of warning; if you have no prior kernel experience, writing either of these drivers (although TDI is significantly harder) will take about two years, full time.
this:
TdiFw is a simple TDI-Based Open Source Personal Firewall for Windows NT4/2000/XP/2003
http://tdifw.sourceforge.net/
may help you