Cocoa Touch™ for iPhone® OS 3

Chapter 27. Recording Audio

In This Chapter

Setting the appropriate audio category for recording audio

Recording audio with AVAudioRecorder

Understanding the settings associated with audio recording

You've seen how to play audio in your application using the AV Foundation Framework as well as using OpenAL. You've also seen how to access your iPod library from within your application so that you can play the media from the user's music collection.

In this chapter, you're going to see how you record audio in your application. Recording audio is about as simple as playing audio. It uses the same AV Foundation Framework as you used to play audio. In this case, however, you're going to use the AVAudioRecorder class to do your work.

Setting up Your AVAudioSession

Just like when playing audio, you have to initialize an AVAudioSession appropriately before you can begin recording audio. There are two session categories associated with recording audio. The first category is AVAudioSessionCategoryRecord, which allows you to just record audio. This category mutes all playback while recording. The second category, AVAudioSessionCategoryPlayAndRecord, allows playback to continue while you're recording. This is more typically suited to voice-over IP applications and the like. Typically, for simply recording audio, you may prefer to use the AVAudioSessionCategoryRecord category.

Note

Remember, to use the AV Foundation Framework, you must add it as a linked framework to your project.

To configure the audio ...