原文链接：http://www.cnblogs.com/A–G/p/4624526.html
最近学习AVFoundation里的audio操作，最基本的录制和播放，参考了一个Code4pp的 一个 demo后，发现写的不错，但是里面有一些问题，1，由于没有添加控制输入输出流的AVAudioSession，真机播放无法录音；2.真机播放的音量很小；
下面是源代码：
//
// ViewController.h
// AudioRecorder
//
// Created by MZN on 15-7-1.
// Copyright (c) 2015年 MZN. All rights reserved.
// #import <UIKit/UIKit.h>
#import <AudioToolbox/AudioToolbox.h>
#import <AVFoundation/AVFoundation.h> @interface ViewController : UIViewController<AVAudioRecorderDelegate>
{
AVAudioRecorder *recorder;
NSTimer *timer;
NSURL *urlPlay; }
@property (retain, nonatomic) IBOutlet UIButton *btn;
@property (retain, nonatomic) IBOutlet UIImageView *imageView;
@property (retain, nonatomic) IBOutlet UIButton *playBtn;
@property (retain, nonatomic) AVAudioPlayer *avPlay; @end
//
// ViewController.m
// AudioRecorder
//
// Created by MZN on 15-7-1.
// Copyright (c) 2014年 MZN. All rights reserved.
// #import "ViewController.h" @interface ViewController () @end @implementation ViewController
@synthesize btn;
@synthesize imageView = _imageView;
@synthesize playBtn = _playBtn;
@synthesize avPlay = _avPlay; - (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
[self audio];
[self.btn addTarget:self action:@selector(btnDown:) forControlEvents:UIControlEventTouchDown];
[self.btn addTarget:self action:@selector(btnUp:) forControlEvents:UIControlEventTouchUpInside];
[self.btn addTarget:self action:@selector(btnDragUp:) forControlEvents:UIControlEventTouchDragExit];
[self.playBtn addTarget:self action:@selector(playRecordSound:) forControlEvents:UIControlEventTouchDown]; } - (IBAction)playRecordSound:(id)sender
{
if (self.avPlay.playing) {
[self.avPlay stop];
return;
}
AVAudioPlayer *player = [[AVAudioPlayer alloc] initWithContentsOfURL:urlPlay error:nil];
self.avPlay = player;
[player release];
[self.avPlay play];
} - (IBAction)btnDown:(id)sender
{ //创建录音文件，准备录音
if ([recorder prepareToRecord]) {
//开始
[recorder record];
} //设置定时检测
timer = [NSTimer scheduledTimerWithTimeInterval: target:self selector:@selector(detectionVoice) userInfo:nil repeats:YES];
} - (IBAction)btnUp:(id)sender
{
double cTime = recorder.currentTime;
if (cTime > ) {//如果录制时间<2 不发送
NSLog(@"发出去");
}else {
//删除记录的文件
[recorder deleteRecording];
//删除存储的
}
[recorder stop];
[timer invalidate];
} - (IBAction)btnDragUp:(id)sender
{
//删除录制文件
[recorder deleteRecording];
[recorder stop];
[timer invalidate]; NSLog(@"取消发送");
} - (void)audio
{
//录音设置
NSMutableDictionary *recordSetting = [[NSMutableDictionary alloc] init];
//设置录音格式 AVFormatIDKey==kAudioFormatLinearPCM
[recordSetting setValue:[NSNumber numberWithInt:kAudioFormatMPEG4AAC] forKey:AVFormatIDKey];
//设置录音采样率(Hz) 如：AVSampleRateKey==8000/44100/96000（影响音频的质量）
[recordSetting setValue:[NSNumber numberWithFloat:] forKey:AVSampleRateKey];
//录音通道数 1 或 2
[recordSetting setValue:[NSNumber numberWithInt:] forKey:AVNumberOfChannelsKey];
//线性采样位数 8、16、24、32
[recordSetting setValue:[NSNumber numberWithInt:] forKey:AVLinearPCMBitDepthKey];
//录音的质量
[recordSetting setValue:[NSNumber numberWithInt:AVAudioQualityHigh] forKey:AVEncoderAudioQualityKey];
//是否使用浮点数采样
[recordSetting setValue:@(YES) forKey:AVLinearPCMIsFloatKey]; NSString *strUrl = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
NSURL *url = [NSURL fileURLWithPath:[NSString stringWithFormat:@"%@/lll.aac", strUrl]];
urlPlay = url; NSError *error;
//初始化
recorder = [[AVAudioRecorder alloc]initWithURL:url settings:recordSetting error:&error];
//开启音量检测
recorder.meteringEnabled = YES;
recorder.delegate = self;
} - (void)detectionVoice
{
[recorder updateMeters];//刷新音量数据
//获取音量的平均值 [recorder averagePowerForChannel:0];
//音量的最大值 [recorder peakPowerForChannel:0]; double lowPassResults = pow(, (0.05 * [recorder peakPowerForChannel:]));
NSLog(@"%lf",lowPassResults);
//最大50 0
//图片 小-》大
if (<lowPassResults<=0.06) {
[self.imageView setImage:[UIImage imageNamed:@"record_animate_01.png"]];
}else if (0.06<lowPassResults<=0.13) {
[self.imageView setImage:[UIImage imageNamed:@"record_animate_02.png"]];
}else if (0.13<lowPassResults<=0.20) {
[self.imageView setImage:[UIImage imageNamed:@"record_animate_03.png"]];
}else if (0.20<lowPassResults<=0.27) {
[self.imageView setImage:[UIImage imageNamed:@"record_animate_04.png"]];
}else if (0.27<lowPassResults<=0.34) {
[self.imageView setImage:[UIImage imageNamed:@"record_animate_05.png"]];
}else if (0.34<lowPassResults<=0.41) {
[self.imageView setImage:[UIImage imageNamed:@"record_animate_06.png"]];
}else if (0.41<lowPassResults<=0.48) {
[self.imageView setImage:[UIImage imageNamed:@"record_animate_07.png"]];
}else if (0.48<lowPassResults<=0.55) {
[self.imageView setImage:[UIImage imageNamed:@"record_animate_08.png"]];
}else if (0.55<lowPassResults<=0.62) {
[self.imageView setImage:[UIImage imageNamed:@"record_animate_09.png"]];
}else if (0.62<lowPassResults<=0.69) {
[self.imageView setImage:[UIImage imageNamed:@"record_animate_10.png"]];
}else if (0.69<lowPassResults<=0.76) {
[self.imageView setImage:[UIImage imageNamed:@"record_animate_11.png"]];
}else if (0.76<lowPassResults<=0.83) {
[self.imageView setImage:[UIImage imageNamed:@"record_animate_12.png"]];
}else if (0.83<lowPassResults<=0.9) {
[self.imageView setImage:[UIImage imageNamed:@"record_animate_13.png"]];
}else {
[self.imageView setImage:[UIImage imageNamed:@"record_animate_14.png"]];
}
} - (void) updateImage
{
[self.imageView setImage:[UIImage imageNamed:@"record_animate_01.png"]];
} - (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
} @end
一、问题1:添加AVAudioSession， 这里由于录制和play都需要，所以设置Category为AVAudioSessionCategoryPlayAndRecord:
NSError *categoryError = nil;
AVAudioSession *audioSession = [AVAudioSession sharedInstance];
[audioSession setCategory:AVAudioSessionCategoryPlayAndRecord error:&categoryError];
[audioSession setActive:YES error:&categoryError];
二、问题2:真机播放音量太小，有人说设置AudioSession属性里把sizeof设成1可行:
// UInt32 doChangeDefault = 1;
// AudioSessionSetProperty(kAudioSessionProperty_OverrideCategoryDefaultToSpeaker, sizeof(doChangeDefault), &doChangeDefault);
使用后的确可以，但是ios7.0之后，AudioSessionSetProperty已经被弃用了，于是乎
~keep looking for~~~
____________ 15分钟之后_______________
在stackoverflow上，一位朋友说audioSession的属性基本迁移到AVFoundation里了，建议我们多使用AVFoundation里的API。
NSError *audioError = nil;
BOOL success = [audioSession overrideOutputAudioPort:AVAudioSessionPortOverrideSpeaker error:&audioError];
if(!success)
{
NSLog(@"error doing outputaudioportoverride - %@", [audioError localizedDescription]);
}
初步实现了录制和播放功能，进一步的研究正在进行ing~~~~
需要修改过demo的朋友可以从这里下载：http://files.cnblogs.com/files/A–G/AudioRecorder%E6%94%B9%E8%BF%9B%E6%92%AD%E6%94%BE%E9%9F%B3%E9%87%8F.zip
参考链接： 1，http://code4app.com/ios/%E5%BD%95%E9%9F%B3%E5%92%8C%E6%92%AD%E6%94%BE/51ba821b6803fa6901000000
本文属于原创，转载请注明，谢谢 http://www.cnblogs.com/A–G/p/4624526.html
