ios 录制音频

转载 自：http://stackoverflow.com/questions/1010343/how-do-i-record-audio-on-iphone-with-avaudiorecorder
Although this is an answered question (and kind of old) i have decided to post my full working code for others that found it hard
to find good working (out of the box) playing and recording example - including encoded, pcm, play via speaker, write to file here it is:AudioPlayerViewController.h:

#import <UIKit/UIKit.h>
#import <AVFoundation/AVFoundation.h>

@interface AudioPlayerViewController : UIViewController {
AVAudioPlayer *audioPlayer;
AVAudioRecorder *audioRecorder;
int recordEncoding;
enum
{
ENC_AAC = 1,
ENC_ALAC = 2,
ENC_IMA4 = 3,
ENC_ILBC = 4,
ENC_ULAW = 5,
ENC_PCM = 6,
} encodingTypes;
}

-(IBAction) startRecording;
-(IBAction) stopRecording;
-(IBAction) playRecording;
-(IBAction) stopPlaying;

@end

AudioPlayerViewController.m:

#import "AudioPlayerViewController.h"@implementation AudioPlayerViewController- (void)viewDidLoad
{
[super viewDidLoad];
recordEncoding = ENC_AAC;
}-(IBAction) startRecording
{
NSLog(@"startRecording");
[audioRecorder release];
audioRecorder = nil;// Init audio with record capability
AVAudioSession *audioSession = [AVAudioSession sharedInstance];
[audioSession setCategory:AVAudioSessionCategoryRecord error:nil];NSMutableDictionary *recordSettings = [[NSMutableDictionary alloc] initWithCapacity:10];
if(recordEncoding == ENC_PCM)
{
[recordSettings setObject:[NSNumber numberWithInt: kAudioFormatLinearPCM] forKey: AVFormatIDKey];
[recordSettings setObject:[NSNumber numberWithFloat:44100.0] forKey: AVSampleRateKey];
[recordSettings setObject:[NSNumber numberWithInt:2] forKey:AVNumberOfChannelsKey];
[recordSettings setObject:[NSNumber numberWithInt:16] forKey:AVLinearPCMBitDepthKey];
[recordSettings setObject:[NSNumber numberWithBool:NO] forKey:AVLinearPCMIsBigEndianKey];
[recordSettings setObject:[NSNumber numberWithBool:NO] forKey:AVLinearPCMIsFloatKey];
}
else
{
NSNumber *formatObject;switch (recordEncoding) {
case (ENC_AAC):
formatObject = [NSNumber numberWithInt: kAudioFormatMPEG4AAC];
break;
case (ENC_ALAC):
formatObject = [NSNumber numberWithInt: kAudioFormatAppleLossless];
break;
case (ENC_IMA4):
formatObject = [NSNumber numberWithInt: kAudioFormatAppleIMA4];
break;
case (ENC_ILBC):
formatObject = [NSNumber numberWithInt: kAudioFormatiLBC];
break;
case (ENC_ULAW):
formatObject = [NSNumber numberWithInt: kAudioFormatULaw];
break;
default:
formatObject = [NSNumber numberWithInt: kAudioFormatAppleIMA4];
}[recordSettings setObject:formatObject forKey: AVFormatIDKey];
[recordSettings setObject:[NSNumber numberWithFloat:44100.0] forKey: AVSampleRateKey];
[recordSettings setObject:[NSNumber numberWithInt:2] forKey:AVNumberOfChannelsKey];
[recordSettings setObject:[NSNumber numberWithInt:12800] forKey:AVEncoderBitRateKey];
[recordSettings setObject:[NSNumber numberWithInt:16] forKey:AVLinearPCMBitDepthKey];
[recordSettings setObject:[NSNumber numberWithInt: AVAudioQualityHigh] forKey: AVEncoderAudioQualityKey];
}NSURL *url = [NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/recordTest.caf", [[NSBundle mainBundle] resourcePath]]];NSError *error = nil;
audioRecorder = [[ AVAudioRecorder alloc] initWithURL:url settings:recordSettings error:&error];if ([audioRecorder prepareToRecord] == YES){
[audioRecorder record];
}else {
int errorCode = CFSwapInt32HostToBig ([error code]);
NSLog(@"Error: %@ [%4.4s])" , [error localizedDescription], (char*)&errorCode);}
NSLog(@"recording");
}-(IBAction) stopRecording
{
NSLog(@"stopRecording");
[audioRecorder stop];
NSLog(@"stopped");
}-(IBAction) playRecording
{
NSLog(@"playRecording");
// Init audio with playback capability
AVAudioSession *audioSession = [AVAudioSession sharedInstance];
[audioSession setCategory:AVAudioSessionCategoryPlayback error:nil];NSURL *url = [NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/recordTest.caf", [[NSBundle mainBundle] resourcePath]]];
NSError *error;
audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:url error:&error];
audioPlayer.numberOfLoops = 0;
[audioPlayer play];
NSLog(@"playing");
}-(IBAction) stopPlaying
{
NSLog(@"stopPlaying");
[audioPlayer stop];
NSLog(@"stopped");
}- (void)dealloc
{
[audioPlayer release];
[audioRecorder release];
[super dealloc];
}@end