How to check programmatically if an app is making a certain sound? - windows

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.

Related

Trigger a mac application to start from a sound or other physical (real world) event

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

Access to System Audio on Mac

For a some-what small (at least hopefully) project, I am hoping to gain access to the current audio being played through the "main line" (i.e. what is heard through the speakers.) Specifically, I'd like to create a visual equalizer of the audio currently being played. I do not wish to capture or "tamper" with the audio in any way, just run a little analysis on it. That being said, I'd imagine access to such information is not handed out nicely in a high-level API.
I noticed a similar question which is concerned with looking at system sound. The accepted answer points to looking into Soundflower's source code. I am not completely adverse to doing this but I'd like to ensure there isn't a simpler way before I got into it (especially because I have no real audio programming experience, especially at the system level.)
Any input is very much appreciated,
--Sam
There is no simple way to do this on OS X. You really have to do this from a kext, unfortunately.

Media players that can be programmatically controlled? (Ruby)

I already know that iTunes has an interface that I can control, but the API is a bit opaque and I can't find it documented anywhere. Does anyone know of any good open-source or at least well-working media players that can be programmatically controlled?
In particular, I would like to be able to search a media library for a song by title or artist, and play, pause, resume, stop the song.
Ruby would be nice, because I'm working in it, but C would work too. I could write a wrapper.
Edit: My solution has to work on Windows, as that is the environment I am developing in.
XMMS works on a server / client basis. This means that it is relatively easy to control the playback, and the song queue. I'm not sure how easy is to handle file metadata (song info), but maybe that part can be handled independently.
Check this guide to get an overview of functions you can use.
Back in the day, I used MPD.

How to implement a voice changer?

I want to write a app which change the microphone input voice and make it like robot or some funny man's voice.It must support send changed voice to all application like IM Software or Game Client. Which technology should I pick up? Windows WaveForm Api? DirectX?
audio driver?
Thank you very much!
There's an MSDN Coding4Fun article that explains how to create a voice changer that operates over Skype, in C# (.NET). The full source code is also hosted as a project on CodePlex. In addition, it should be fairly easy do something else with the audio (as opposed to streaming it via Skype), since the project is based around the NAudio framework, which contains a good level of abstraction. Anyway, it is a reasonably complete (and stable) example - definitely worth checking out in my opinion.
If you want/need to use C++ or some other language for development, then this project should at least give you some ideas about how to go about it. Still, if you can use .NET, then you're in luck I think.
Robot voice is often done with a ring modulator effect, mixing the voice with a sine wave - this is easier. Or use a vocoder effect, modulating the voice onto some other waveform, like rectangle - might be a bit more tricky. Go read up how the effects work, get a program with which you can check out how they sound (Audacity works for the ring modulator, finding and using a vocoder may be a bit harder). Then read how it's done or get a library which will do the processing for you.
You are looking to support VSTi or DXi plugins.
There are tons that also act as vocoders, even for free.
You just need to write the host application.
Take a look here :)
Now that's a neat idea, especially for a mobile app.
I'd probably start off-line by using a .wav file as input to get the effects working the way I wanted. You can use any high level language for this, but you probably want something that will map reasonably well into C/C++.
In terms of a production version, I'd go native and do this in C or C++. You want something fast for real time audio processing & I like to avoid dependencies on things like .net for distribution. (Not that I have anything against .net, it's great for servers and distribution within a company but I'm not so keen on having it as a dependency for shrink wrap software.)
Windows DirectShow would be a tempting option - you could do some interesting effects with multi-media as well if you had the voice morpher implemented as a direct show filter.
What you're looking for is a vocoder. I don't know if any of the technologies listed above has a vocoder effect, but the best chance would be with DirectX.
Try this sample app .I think its useful to you.Link

Call another program's functions?

So I have this program that I really like, and it doesn't support Applescript. I'd like to automate it a little bit. Now, I know that I could use applescript to tell the program to tell the menu to tell the submenu to tell the menuitem to activate or whatever, but frankly I don't like applescript very much anyway.
When I open the NIB file in IB, I can see the messages that are being sent to FirstResponder; for example, the Copy menu item sends "copy:". Is there any way for me to invoke this directly from another program?
No. It's called protected memory for a reason, you know. The other program is completely insulated from your application. There are ways to put code into other apps, but (a) it's very inadvisable (b) requires root privileges, which means the rest of your app needs to be ROCK SOLID AND IMPREGNABLE, and (c) writing such code is a black art requiring knowledge of the operating system kernel interfaces, virtual memory management, the ABI, the internals of the linker/loader, assembler programming, and the operational parameters and other specifics of the particular processor upon which your app happens to be running.
Really, AppleEvents and other such IPC mechanisms are there for a reason.
Your other alternatives (all of which are a bit hacky, to be honest, and give you the fairly significant burden of ensuring the target app is in the state you want/expect) the access the data you're looking for are:
The Accessibility APIs from the ApplicationServices framework, through which you can traverse the UI tree to grab the text from wherever you need it directly, or can activate the menu item. Access for your app has to be explicitly granted by the user, however (although this is much the same as the requirement for UI scripting).
You can use the CoreGraphics APIs (within the ApplicationServices framework again) to send keyboard events to the target application (or just to the system) directly. This would mean sending four events: Command-down, C-down, C-up, Command-up.
None of these are ideal. To be honest, your best approach would be to look at your requirements and figure out how you can best engineer around the problem by changing those requirements in some way, i.e. instead of grabbing something directly, ask the user to provide some input, etc.
You might be interested in SIMBL or in mach_inject. SIMBL is a daemon (in my fork based on mach_inject, in the original version based on injection via some ScriptingAdditions hack) which does the injection for you, so you just need to put a bundle with your code into the SIMBL directory and SIMBL will inject it for you into the target application. Or you can do so yourself via mach_inject. Or probably more convenient, mach_inject_framework which injects and runs code which just loads some framework.
I think Jim may overstate the point a bit; he's not wrong, but it seems misleading. There are lots of ways to cause a Cocoa program to execute its own code under you control (Carbon is harder). The Accessibility API is very commonly used this way (so commonly that I expect it to be repurposed eventually). Fscript can give you all kinds of access to the innards of another Cocoa program. While Input Managers may well exit the scene at some point, SIMBL is still out there today to do this kind of stuff.
Whether you like Applescript or not, Apple Events are the primary way Apple provides for inter-program control. Have you double-checked Script Editor's Open Library function to find out if the program really does have any Applescript support? You can code Apple Events entirely in Objective-C these days using Leopard's Scripting Bridge. I wrote up a tutorial if you like (it's still under-documented by Apple).
Cocoa is a reverse-engineer's dream. The same guys who host SIMBL have a nice intro to the subject. "Wolf" also writes a lot of useful information on this.
Jim's right. Many of these approaches can completely destabilize the system if done incorrectly (sometimes even if done correctly). I don't do much of this stuff on my production systems; I need them to work. But there are a lot of things you can make a Mac app do, and it's a good part of a Mac developer's training to understand how all the pieces really work.

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