IOS开发之使用Speex格式实现简单的语音聊天功能（二）

来源：互联网发布：游戏碎片整理软件编辑：程序博客网时间：2024/05/22 04:56

今天我们继续上一篇博客“IOS开发之使用Speex格式实现简单的语音聊天功能（一）”继续往下讲，主要是讲述一下PlayManager与RecorderManager两个类的功能。

首先要讲的是RecorderManager，该类的主要功能就是负责对用户的语音进行录制，和停止录制。

#import <Foundation/Foundation.h>#import "Encapsulator.h"@protocol RecordingDelegate <NSObject>- (void)recordingFinishedWithFileName:(NSString *)filePath time:(NSTimeInterval)interval;- (void)recordingTimeout;- (void)recordingStopped;  //录音机停止采集声音- (void)recordingFailed:(NSString *)failureInfoString;@optional- (void)levelMeterChanged:(float)levelMeter;@end@interface RecorderManager : NSObject <EncapsulatingDelegate> {        Encapsulator *encapsulator;    NSString *filename;    NSDate *dateStartRecording;    NSDate *dateStopRecording;    NSTimer *timerLevelMeter;    NSTimer *timerTimeout;}@property (nonatomic, weak)  id<RecordingDelegate> delegate;@property (nonatomic, strong) Encapsulator *encapsulator;@property (nonatomic, strong) NSDate *dateStartRecording, *dateStopRecording;@property (nonatomic, strong) NSTimer *timerLevelMeter;@property (nonatomic, strong) NSTimer *timerTimeout;+ (RecorderManager *)sharedManager;- (void)startRecording;- (void)stopRecording;- (void)cancelRecording;- (NSTimeInterval)recordedTimeInterval;@end

该类的主要结构就是上面头文件中所展示的，包括一个委托RecordingDelegate，以及RecorderManager本身的类函数。该类使用了单例模式，通过调用函数shareManager即可获取它实例本身。

startRecording函数负责录音工作：

- (void)startRecording {    if ( ! mAQRecorder) {                mAQRecorder = new AQRecorder();                OSStatus error = AudioSessionInitialize(NULL, NULL, interruptionListener, (__bridge void *)self);        if (error) printf("ERROR INITIALIZING AUDIO SESSION! %d\n", (int)error);        else        {            UInt32 category = kAudioSessionCategory_PlayAndRecord;            error = AudioSessionSetProperty(kAudioSessionProperty_AudioCategory, sizeof(category), &category);            if (error) printf("couldn't set audio category!");                        //添加属性监听，一旦有属性改变则调用其中的propListener函数            error = AudioSessionAddPropertyListener(kAudioSessionProperty_AudioRouteChange, propListener, (__bridge void *)self);            if (error) printf("ERROR ADDING AUDIO SESSION PROP LISTENER! %d\n", (int)error);            UInt32 inputAvailable = 0;            UInt32 size = sizeof(inputAvailable);                        // we do not want to allow recording if input is not available            error = AudioSessionGetProperty(kAudioSessionProperty_AudioInputAvailable, &size, &inputAvailable);            if (error) printf("ERROR GETTING INPUT AVAILABILITY! %d\n", (int)error);                        // we also need to listen to see if input availability changes            error = AudioSessionAddPropertyListener(kAudioSessionProperty_AudioInputAvailable, propListener, (__bridge void *)self);            if (error) printf("ERROR ADDING AUDIO SESSION PROP LISTENER! %d\n", (int)error);                        error = AudioSessionSetActive(true);             if (error) printf("AudioSessionSetActive (true) failed");        }            }        //获取音频存放地址    filename = [NSString stringWithString:[Encapsulator defaultFileName]];    NSLog(@"filename:%@",filename);        if ( ! self.encapsulator) {        self.encapsulator = [[Encapsulator alloc] initWithFileName:filename];        self.encapsulator.delegete = self;    }    else {        [self.encapsulator resetWithFileName:filename];    }        if ( ! mAQRecorder->IsRunning()) {        NSLog(@"audio session category : %@", [[AVAudioSession sharedInstance] category]);        Boolean recordingWillBegin = mAQRecorder->StartRecord(encapsulator);        if ( ! recordingWillBegin) {            if ([self.delegate respondsToSelector:@selector(recordingFailed:)]) {                [self.delegate recordingFailed:@"程序错误，无法继续录音，请重启程序试试"];            }            return;        }    }    self.dateStartRecording = [NSDate date];        if (!levelMeterStates)    {        levelMeterStates = (AudioQueueLevelMeterState *)malloc(sizeof(AudioQueueLevelMeterState) * 1);    }    self.timerLevelMeter = [NSTimer scheduledTimerWithTimeInterval:0.1 target:self selector:@selector(updateLevelMeter:) userInfo:nil repeats:YES];    self.timerTimeout = [NSTimer scheduledTimerWithTimeInterval:60 target:self selector:@selector(timeoutCheck:) userInfo:nil repeats:NO];}

在startRecording函数中，先实例化类AQRecorder，该类是用C++实现的，主要用作录制音频文件（核心类）。随后调用函数AudioSessionInitialize初始化音频，并添加回调函数interruptionListener，若监听被打断则停止AQRecorder类的录制工作。若返回值不是error则对音频添加相应的属性，并且回调函数为propListener，若监听的属性不正确，就停止录音。当然了，所有的音频都是以文件为单位的，在startRecording函数中利用[EncapsulatordefaultFileName]来获取音频的存放地址，Encapsulator类也是一个很重要的类，它封装了ogg,极大的方便了我们调用它里面的函数来实现录音。

函数- (void)stopRecording的作用大家想必都知道就是停止录音，但是不取消音频；

函数- (void)cancelRecording的作用则是停止录音并且取消；

函数recordedTimeInterval则是获取录音时间，单位为float;

接下来，我们来说一下PlayerManager这个类，该类主要负责解析音频文件并播放音频。类结构如下：

#import <Foundation/Foundation.h>#import <AVFoundation/AVFoundation.h>#import "Decapsulator.h"@protocol PlayingDelegate <NSObject>- (void)playingStoped;@end@interface PlayerManager : NSObject <DecapsulatingDelegate, AVAudioPlayerDelegate> {    Decapsulator *decapsulator;    AVAudioPlayer *avAudioPlayer;    }@property (nonatomic, strong) Decapsulator *decapsulator;@property (nonatomic, strong) AVAudioPlayer *avAudioPlayer;@property (nonatomic, weak)  id<PlayingDelegate> delegate;+ (PlayerManager *)sharedManager;- (void)playAudioWithFileName:(NSString *)filename delegate:(id<PlayingDelegate>)newDelegate;- (void)stopPlaying;@end

可以看到该类与RecordingManager一样，也使用了单例并且其中有委托对象PlayingDelegate，函数playingStoped用于暂停播放。

该类有两个主要函数"playAudioWithFileName"与“stopPlaying”前者可以根据音频的文件名字来播放音频，后者则是停止播放。

- (void)playAudioWithFileName:(NSString *)filename delegate:(id<PlayingDelegate>)newDelegate {    if ( ! filename) {        return;    }    if ([filename rangeOfString:@".spx"].location != NSNotFound) {        [[AVAudioSession sharedInstance] setActive:YES error:nil];                [self stopPlaying];        self.delegate = newDelegate;                self.decapsulator = [[Decapsulator alloc] initWithFileName:filename];        self.decapsulator.delegate = self;        [[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback error:nil];        [self.decapsulator play];        //开启距离监听        [self startProximityMonitering];    }    else if ([filename rangeOfString:@".mp3"].location != NSNotFound) {        if ( ! [[NSFileManager defaultManager] fileExistsAtPath:filename]) {            NSLog(@"要播放的文件不存在:%@", filename);            [self.delegate playingStoped];            [newDelegate playingStoped];            return;        }        [self.delegate playingStoped];        self.delegate = newDelegate;                NSError *error;        self.avAudioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL URLWithString:filename] error:&error];        if (self.avAudioPlayer) {            [[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback error:nil];            [[AVAudioSession sharedInstance] setActive:YES error:nil];            self.avAudioPlayer.delegate = self;            [self.avAudioPlayer play];            [self startProximityMonitering];        }        else {            [self.delegate playingStoped];        }    }    else {        [self.delegate playingStoped];    }}

该函数首先判断音频文件是.spx格式的还是.mp3格式，随后通过解析类Decapsulator来解析音频并播放之（与Encapsulator类对应）。再类中还实现了距离监听的功能，当用户脸靠近手机时则会按掉屏幕打开听他，当远离时则打开扬声器屏幕变亮。

总而言之，对好奇想尝试一下开发ios语音的人来说，这几个类绝对是个福音，封装的很好，调用起来也很方便。若想用作开发语音聊天的产品，则需要我们要加深理解他背后压缩与解压缩的的原理了。

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