I would like to do some fairly simple audio programming on OS X (using Lion and Xcode 4.3) -- synthesizing tones with given frequencies, mainly. Trouble is, Apple's documentation on the subject is way too high-level for my current knowledge of the subject. I've searched for weeks now for something that will get me started, to no avail.
Does anyone know of some Core Audio basic tutorial, or even some sample code, that will help me do fairly simple Core Audio tasks so that I can progress to understanding the Apple documentation?
I would suggest the book Learning Core Audio There is also sample code from the book at that site.
If you are looking to synthesize audio fairly easy, you are going to want to use a 3rd party library. Two possible solutions are FMOD and SuperCollider.
The pros and cons between the two are really that supercollider runs as a server that you can connect from app as a client and FMOD is compiled into an app and uses core audio to synthesize the sound. FMOD is clearly the choice if you are planning on distributing this app. SuperCollider also has it's own language that you'd have to learn the basics of to start tailoring your sounds synthesis. Here are some links:
FMOD:
FMOD Downloads (Comes with a bunch of sample code)
Super Collider:
SC Server Download
Sine Wave Generator Sample App
Great source of SC scripts and examples
Related
I have a project just starting up that requires the kind of expertise I have none of (yet!). Basically, I want to be able to use the user's webcam to track the position of their index finger, and make a particular graphic follow their finger around, including scaling and rotating (side to side of course, not up and down).
As I said, this requires the kind of expertise I have very little of - my experience consists mostly of PHP and some Javascript. Obviously I'm not expecting anyone to solve this for me, but if anyone was able to direct me to a library or piece of software that could get me started, I'd appreciate it.
Cross compatibility is of course always preferred but not always possible.
Thanks a lot!
I suggest you to start reading about OpenCV
OpenCV (Open Source Computer Vision) is a library of programming functions mainly aimed at real-time computer vision, developed by Intel Russia research center in Nizhny Novgorod, and now supported by Willow Garage and Itseez.1 It is free for use under the open-source BSD license. The library is cross-platform. It focuses mainly on real-time image processing.
But first, as PHP and JavaScript are mainly used for web development, you should start reading about a programming language which is supported by OpenCV like C, C++, Java, Python or even C# (using EmguCV) etc.
Also, here are some nice tutorials to get you started with hand gestures recognition using OpenCV. Link
Good luck!
I've been looking for things online that teach how to use audio units in an application, with no luck. I'm trying to make an application that allows the user to apply AUTimePitch to the playback of audio files, on the fly. But i can't find anything online to teach a total beginner how to use audio units.
also, i'm making this for mac, not iOS
The best document by far on the subject is Apple's Audio Unit Hosting Guide for iOS in the dev library. For a more general introduction, you can check out the Core Audio Overview.
I also found the MixerHost and iPhoneMultichannelMixerTest sample code incredibly helpful in starting to use audio units.
Finally, I find class references and service references like the Audio Unit Processing Graph Services Reference and the Audio Unit Component Services Reference useful for exploring the functionality of particular methods, constants, classes, and so on.
Edit: I realized that your question doesn't say whether you're working in Mac OS or iOS. This answer is obviously heavily iOS-centric. Could you edit your question to tell us what environment you're in?
I am working on an application in which I need to migrate the whole code of it from carbon to cocoa.I have experience in programming of C,C++,python and Java during my college time and internship but have never touched objective C or have done any programming for Mac(Carbon and Cocoa) before this.
So Can you please suggest me some sources to start with, also how should I go about the whole migration ?
After researching on net I have found that most the people have suggested following books
Cocoa Programming for Mac® OS X, Third Edition by Aaron Hillegass
Programming in Objective C - Stephen Kochan
I have got both these books.
Should I read them first and then should start with the code change? (it will take some time to read both of these)
OR
after having a decent fimiliarity with Obj C and Cocoa, should I directly get started with code migration?
Also,
since I don't know carbon , what should I refer to learn carbon to have sufficient knowledge to migrate the carbon code to cocoa?
First, learn Carbon so you can read the program and understand how it's currently implemented.
Install the Legacy documentation set in Xcode to gain access to the Carbon guides. You'll want to read the Carbon Overview, then Getting Started with Carbon, then everything that Getting Started links to. You'll also need to learn Core Foundation, which some of the more modern parts of Carbon use; read Core Foundation Design Concepts and the Memory Management Programming Guide for Core Foundation.
Then, learn Cocoa.
I didn't learn by the Hillegass book, but a lot of people swear by it. My current favorite Cocoa book is “Cocoa and Objective-C: Up and Running” by Scott Stevenson. The way I learned Cocoa was using Apple's own docs. Start with The Objective-C Programming Language, the Cocoa Fundamentals Guide, and the Memory Management Programming Guide for Cocoa. Much of the last document will seem really familiar, but skip nothing. Read every one of those guides from beginning to end and all the way through.
Once you've learned Cocoa's general concepts, you can move on to more application-specific material. Start with the Application Architecture Overview and most of what that document links to. The Cocoa Guides list has the full list of guides.
Down the road, you'll also need to make the application compatible with 64-bit mode. If you still have any Carbon code by that point, you'll need to read the 64-bit Guide for Carbon Developers; either way, you'll also need the general 64-bit Transition Guide and the 64-bit Transition Guide for Cocoa.
I am working on this process myself right now, and it's a fairly complex undertaking for a full document-based application that uses a few frameworks. My Carbon app has dozens of menu items, the interface is built with Carbon Nibs and implemented using Carbon event hooks. The programming language is C++. Going back in history, the original Mac classic version was implemented in straight C, so there's a little bit of legacy from that era too. Resource-based PICS for example!
There are several approaches one can take, so it depends on your particular situation how to proceed. In my case I decided to start with a bare Cocoa document-based project and start building the document loading code, because the hooks for that are already in place in the empty project. This seems like a good place to start for me, because it gets me into the mode of working with Cocoa and thinking about the app in terms of smaller pieces.
You really have to take a methodical approach and look at what your app depends on in Carbon versus which parts of your app are independent - for instance your abstract classes. If your app is in C++ there may be some pitfalls with converting over to pure Objective-C. Operator overrides can be tricky to notice, for example.
You can mix C++ with Objective-C, as described in Apple's Carbon-Cocoa Integration Guide and around the web you can find plenty of C++ wrappers for Cocoa foundation objects like NSStrings. So if you already have C++ classes that wrap CFString, these can come in handy.
Generally-speaking, you can leave your data storage just as it is. If you use malloc() and calloc() to make a linked list of structs, there's no special reason to move over to an NSArray. You won't get better performance. The real change comes in the interfaces, the way you call and access that data from other objects. If you decide to mix C++ and Objective-C objects in the same app it helps to encapsulate as much as possible. That is, as much as possible make your abstract C++ classes only refer to their own data and that of other C++ objects. Eventually this will make it easier to transition them to Objective-C.
If you're transitioning from one event model to another or from Carbon port-based imaging to Cocoa's views-based imaging, it's probably best to start with a fresh Objective-C app and bring over your model classes first. Add some test functions to make sure they all work within the new language. If your app is anything like mine (old) then it probably needs to display some things larger, and to have more polish in the interface. This is a good time to rebuild those parts piece-by-piece.
There's definitely no great shortcut. The PDF linked above is the best document I've found on the topic.
Looking on-line I saw that I can write most of the application in Ansi-C code or as a website and present it in a webView control.
Then besides some general knowledge about iOS and the API... Do I really need to learn Objective C?
You could use something like PhoneGap, which wraps an HTML-based application into a native launcher app. It may not be as powerful as what you can do with a pure native app, but on the other hand, your code will not only run on iOS.
PhoneGap does offer access to some of the phone's API (camera, notifications, accelerometer and so on) that you normally only get in native apps (it exposes them as JavaScript objects), so you can do more than you could in a regular HTML5 webapp, even without learning Objective-C.
Most people overlook the fact the iPhone has an extremely capable web browser. You can create very powerful web apps and therefore avoid having to learn objective C.
Safari on the iPhone has a bunch of great HTML5 features, including local sqlite stoage - so for example you could easily make a todo list app which could sync up with your server when there's a net connection.
You can even add home screen icons etc.. personally I'm astonished people don't write iPhone web apps more!
This is a super useful guide on how to do it:
http://building-iphone-apps.labs.oreilly.com/
You can use C# to write iPhone apps using MonoTouch, but it costs money. Then again, so does developing for the iPhone the normal way.
The other answers are correct in that you /can/ use other languages... you really don't want to. You are never going to create a pleasant to use, standard, and HIG-abiding application without learning Objective-C. Truly, though, there's no reason /not/ to learn something new. It's not particularly difficult (like, say, C++), and Cocoa is a well-designed API.
Somewhat related, I personally refuse to install all the PhoneGap/etc apps in the App Store as I find them of significantly less inherent quality (especially as compared to the rest of the apps on the device), and I would suspect many non-developers would have similar issues with them, if not so specific.
Unless your app is all web, or uses a framework such as PhoneGap you have to have some working knowledge of obj-C. It's actually not that bad. It's C with Smalltalk bolted onto it.
It's generally much simpler than C++.
if u want true native app that can take advantage of the latest features on the latest iOS release, Objective-C is da language you gotta learn.
Objective-C is a very powerful language, and there are a ton of great frameworks - you are doing yourself a HUGE disservice by not learning the language, and your app quality will suffer as a result.
You can write an entire iPhone app in C++ using a framework like libnui.
I've been programming in VB.net for a while now, and I finally got access to a mac to make ipod apps. What are some useful sites, videos, etc. that could help me get used to Objective C and the Xcode IDE? I've stumbled upon the samples on the apple dev site, but none of them really give good examples which I could learn the syntax of the language from.
Thanks for the help, Objective C is really a big change from VB.net!
Here are some helpful starter references from the Apple site, first for Objective-C itself, then for the Cocoa frameworks.
Learning Objective-C: A Primer
Cocoa Fundamentals Guide
There are also "getting started" videos available from http://developer.apple.com/iphone (you have to register as a developer to get access, but that's free)
You might want to take a look at MonoTouch if you like working with .Net. As far as I'm aware, it only works with C#, but it will let you use the .NET api to program for the iPhone. Might be worth looking into if you don't want to learn Objective C.