版本记录

前言

以前我写过关于声音和视频的多媒体文件的播放，接下来几篇，我们就讲述一下有关声音的录制工作。希望能帮助大家，下面我们开始。

功能需求

实现对声音的录制。

功能实现

下面我们就看一下相关代码。

1. ViewController.m

#import "ViewController.h"
#import <AVFoundation/AVFoundation.h>
#import <CoreAudio/CoreAudioTypes.h>

#define kViewControllerAudioDirectoryName   ("Audio")

@interface ViewController () <AVAudioRecorderDelegate>

@property (weak, nonatomic) IBOutlet UIButton *recordButton;
@property (nonatomic, strong) AVAudioRecorder *recorder;
@property (nonatomic, copy) NSString *recordStorePathStr;
@property (nonatomic, copy) NSString *dirPath;


@end

@implementation ViewController

#pragma mark - Override Base Function

- (void)viewDidLoad
{
    [super viewDidLoad];

    [self loadStoreDirPath];
    [self loadFilePath];
}

#pragma mark - Object Private Function

//创建文件夹

- (void)loadStoreDirPath
{
    NSString *cacheStr = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES).firstObject;
    NSString *dirPath = [cacheStr stringByAppendingPathComponent:@kViewControllerAudioDirectoryName];
    NSError *dirError;
    self.dirPath = dirPath;
    if ([[NSFileManager defaultManager] fileExistsAtPath:dirPath])
    {
        NSLog(@"文件夹已经存在,不需要创建");
    }
    else
    {
        if ([[NSFileManager defaultManager] createDirectoryAtPath:dirPath withIntermediateDirectories:YES attributes:nil error:&dirError]) {
            NSLog(@"常见文件夹成功，目录 = %@", dirPath);
        }
        else {
            NSLog(@"创建文件夹失败，原因是 = %@", dirError);
        }
    }
}

//创建文件

- (void)loadFilePath
{
    //创建文件
//    NSString *timeStampStr = [NSString stringWithFormat:@"%lf.mp3", [[NSDate date] timeIntervalSince1970]];
    NSString *filePath = [self.dirPath stringByAppendingPathComponent:@"demo.aac"];
    self.recordStorePathStr = filePath;
    if (![[NSFileManager defaultManager] fileExistsAtPath:filePath]) {
        BOOL isSuccess = [[NSFileManager defaultManager] createFileAtPath:filePath contents:nil attributes:nil];
        if (isSuccess) {
            NSLog(@"创建文件成功，路径 = %@", filePath);
        }
        else {
            NSLog(@"创建文件失败");
        }
    }
}

/**
 *  取得录音文件设置
 *
 *  @return 录音设置
 */
- (NSMutableDictionary *)getAudioSetting
{
    NSMutableDictionary *dicM = [NSMutableDictionary dictionary];
    //设置录音格式
    [dicM setObject:@(kAudioFormatMPEG4AAC) forKey:AVFormatIDKey];
    //设置录音采样率，8000是电话采样率，对于一般录音已经够了
    [dicM setObject:@(8000) forKey:AVSampleRateKey];
    //设置通道,这里采用单声道
    [dicM setObject:@(1) forKey:AVNumberOfChannelsKey];
    //每个采样点位数,分为8、16、24、32
    [dicM setObject:@(8) forKey:AVLinearPCMBitDepthKey];
    //是否使用浮点数采样
    [dicM setObject:@(YES) forKey:AVLinearPCMIsFloatKey];
    //....其他设置等
    return dicM;
}

#pragma mark - Action && Notification

- (IBAction)recordButtonDidClick:(UIButton *)sender
{
    sender.selected = !sender.selected;
    if (sender.selected) {
        NSURL *pathURL = [NSURL fileURLWithPath:self.recordStorePathStr];
        NSError *error;
        self.recorder = [[AVAudioRecorder alloc] initWithURL:pathURL settings:[self getAudioSetting] error:&error];
        // 以下代码让设备开启录音模式
        AVAudioSession *audioSession = [AVAudioSession sharedInstance];
        [audioSession setCategory:AVAudioSessionCategoryPlayAndRecord error:nil];
        [audioSession setActive:YES error:nil];
        if (error) {
            NSLog(@"创建失败，原因是 = %@", error);
            /**
             2018-01-11 16:32:59.004348+0800 JJAudio_demo1[40108:8220593] 创建失败，原因是 = Error Domain=NSOSStatusErrorDomain Code=1718449215 "(null)"
             2018-01-11 16:32:59.004706+0800 JJAudio_demo1[40108:8222727] XPC connection interrupted
             */
        }
        else {
           NSLog(@"创建成功");
        }
        self.recorder.delegate = self;
        [self.recorder prepareToRecord];
        [self.recorder record];
    }
    else {
        [self.recorder stop];
    }
}

#pragma mark - AVAudioRecorderDelegate

- (void)audioRecorderDidFinishRecording:(AVAudioRecorder *)recorder successfully:(BOOL)flag
{
    NSLog(@"结束录制，存储地址是%@", self.recordStorePathStr);
}

- (void)audioRecorderEncodeErrorDidOccur:(AVAudioRecorder *)recorder error:(NSError * __nullable)error;
{
    NSLog(@"出现了错误 = %@", error);
}

@end

下面看一下输出结果

2018-01-11 21:50:45.012017+0800 JJAudio_demo1[40157:8295697] 文件夹已经存在,不需要创建
2018-01-11 21:50:58.720493+0800 JJAudio_demo1[40157:8295697] 创建成功
2018-01-11 21:51:01.027892+0800 JJAudio_demo1[40157:8295697] 结束录制，存储地址是/var/mobile/Containers/Data/Application/DA652CF0-BA9C-4B52-93FE-B731FBEAB702/Library/Caches/Audio/demo.aac

小插曲

下面和大家说一下小插曲。

如果我们像下面这样设置录音格式的话：

    //设置录音格式
//    [dicM setObject:@(kAudioFormatMPEG4AAC) forKey:AVFormatIDKey];
     [dicM setObject:@(kAudioFormatMPEGLayer3) forKey:AVFormatIDKey];

然后，就会发现

 self.recorder = [[AVAudioRecorder alloc] initWithURL:pathURL settings:[self getAudioSetting] error:&error];

这个实例化是失败的，self.recorder打印就是nil，并给出下面这个提示。

2018-01-11 21:56:44.820363+0800 JJAudio_demo1[40161:8297302] 创建失败，原因是 = Error Domain=NSOSStatusErrorDomain Code=1718449215 "(null)"

研究了一会才发现是录音格式的问题。后来修改了格式，解决了这个问题。

功能效果

下面我们就看一下需求效果。

后记

未完，待续~~~