音视频

音频播放#

  音频播放从形式上可以分为音效播放和音乐播放，音效主要指一些短音频，通常不超过30s(格式一般为.caf, .aif, .wav)。

音效播放

#import "ViewController.h"
// 导入头文件
#import 

- (void)viewDidLoad {
    [super viewDidLoad];
    
    // 打印沙箱路径
    //NSLog(@"%@",NSHomeDirectory());
    
    [self playSoundEffect:[[NSBundle mainBundle] pathForResource:@"音效.caf" ofType:nil]];
}

-(void) playSoundEffect:(NSString *) filename{
    // 通过文件路径获得文件的统一资源定位符
    NSURL *fileURL = [NSURL fileURLWithPath:filename];
    SystemSoundID sysSoundId;
    // 调用Core Service层的函数给音效文件创建一个系统ID
    AudioServicesCreateSystemSoundID((__bridge CFURLRef)(fileURL), &sysSoundId);
    // 通过指定系统ID来播放对应的音效文件
    AudioServicesPlaySystemSound(sysSoundId);
    // 播放时会产生振动
    //AudioServicesPlayAlertSound(sysSoundId);
}

重复播放

#import "ViewController.h"
#import 

void foo(SystemSoundID sysSoundId, void *context) {
    AudioServicesPlayAlertSound(sysSoundId);
}

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    NSString *filename = [[NSBundle mainBundle] pathForResource:@"音效" ofType:@"caf"];
    [self playSoundEffect:filename withCallback:foo];
}

- (void) playSoundEffect:(NSString *) filename withCallback:(void (*)(SystemSoundID, void *)) callback{
    // 通过文件路径获得文件的统一资源定位符
    NSURL *fileURL = [NSURL fileURLWithPath:filename];
    SystemSoundID sysSoundId;
    // 调用Core Service层的函数给音效文件创建一个系统ID
    AudioServicesCreateSystemSoundID((__bridge CFURLRef)(fileURL), &sysSoundId);
    // 设置音效文件播放完毕后的回调函数
    // 注册在播放完之后执行的回调函数
    // 第二个和第三个参数跟循环播放有关
    // 第五个参数是指向传给回调函数的数据的指针
    AudioServicesAddSystemSoundCompletion(sysSoundId, NULL, NULL, callback, NULL);
    // 通过指定系统ID来播放对应的音效文件
    AudioServicesPlaySystemSound(sysSoundId);
}
@end

音乐播放##

#import "ViewController.h"
#import 

@interface ViewController ()
{
    // 必须写成成员变量
    AVAudioPlayer *myPlayer;
    NSTimer *timer;
}
// 插座变量，用来显示歌曲的相关信息
@property (weak, nonatomic) IBOutlet UILabel *albumLabel;
@property (weak, nonatomic) IBOutlet UILabel *artistLabel;
@property (weak, nonatomic) IBOutlet UILabel *titleLabel;
@property (weak, nonatomic) IBOutlet UIImageView *coverImageView;
@property (weak, nonatomic) IBOutlet UIProgressView *playProgressView;
@property (weak, nonatomic) IBOutlet UIButton *button;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    NSString *filename = [[NSBundle mainBundle] pathForResource:@"遇到" ofType:@"mp3"];
    NSURL *fileurl = [NSURL fileURLWithPath:filename];
    myPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:fileurl error:nil];
    
    // 设置支持后台播放
    // 需要在项目中设置支持后台播放 capablities,Background Modes,Audio and AirPlay
    // 获得当前音频会话对象的单例
    AVAudioSession *session = [AVAudioSession sharedInstance];
    [session setActive:YES error:nil];
    [session setCategory:AVAudioSessionCategoryPlayback error:nil];
    
    // 设置应用程序支持远程控制事件(耳机控制) 需要在项目中设置 capablities,Background Modes,Ramote Notifications
    [[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
    
    // 声道切换(-1左 1右 0双声道)
    myPlayer.pan = 0;
    // 音量设置0~1之间(硬放大) 如果大于1就是软放大
    myPlayer.volume = 1;
    // 允许快进
    myPlayer.enableRate = YES;
    // 快进率
    //myPlayer.rate = 2;
    // 设置开始播放时间(单位:秒)
    myPlayer.currentTime = 10;
    // 绑定委托
    myPlayer.delegate = self;
    
    [myPlayer prepareToPlay];
    [myPlayer play];
    // 刷新界面
    [self updateUI:fileurl];
    
    timer = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(progress:) userInfo:nil repeats:YES];
    
    // 更改进度条高度
    _playProgressView.transform = CGAffineTransformMakeScale(1.0f,5.0f);
}

- (void) progress:(NSTimer *) sender{
    _playProgressView.progress = myPlayer.currentTime / myPlayer.duration;
}

// 视图控制器显示音乐相关信息(歌曲名、歌手、专辑、图片)
- (void) updateUI:(NSURL *) fileUrl{
    AVURLAsset *asset = [[AVURLAsset alloc] initWithURL:fileUrl options:nil];
    // 根据指定的元数据格式获得对应的元数据项的数组
    NSArray *metaDataItems = [asset metadataForFormat:[[asset availableMetadataFormats] firstObject]];
    for (AVMetadataItem *item in metaDataItems) {
        if ([item.commonKey isEqualToString:@"artist"]) {
            _artistLabel.text = [item.value description];
        }
        else if ([item.commonKey isEqualToString:@"title"]){
            _titleLabel.text = [item.value description];
        }
        else if ([item.commonKey isEqualToString:@"albumName"]){
            _albumLabel.text = [item.value description];
        }
        else if ([item.commonKey isEqualToString:@"artwork"]){
            _coverImageView.image = [UIImage imageWithData:(id)item.value];
        }
    }
}

// 播放完之后的回调方法
- (void)audioPlayerDidFinishPlaying:(AVAudioPlayer *)player successfully:(BOOL)flag{
    NSString *filename = [[NSBundle mainBundle] pathForResource:@"吻别" ofType:@"mp3"];
    NSURL *fileurl = [NSURL fileURLWithPath:filename];
    [self updateUI:fileurl];
    myPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:fileurl error:nil];
    myPlayer.delegate = self;
    [myPlayer prepareToPlay];
    [myPlayer play];

}

// 暂停/播放按钮
- (IBAction)buttonClicked:(UIButton *)sender {
    sender.selected = !sender.selected;
    if(myPlayer.isPlaying){
        [myPlayer pause];
        [sender setTitle:@"暂停" forState:UIControlStateNormal];
        timer.fireDate = [NSDate distantFuture];
    }
    else{
        [myPlayer play];
        [sender setTitle:@"播放" forState:UIControlStateNormal];
        timer.fireDate = [NSDate distantPast];
    }
}

- (void) dealloc{
    if (timer) {
        [timer invalidate];
        timer = nil;
    }
}
@end

录音##

#import "ViewController.h"
#import 

@interface ViewController (){
    AVAudioRecorder *audioRecorder;
}
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
     
}
- (IBAction)buttonClicked:(UIButton *)sender {
    
    // 录音的相关设置
    NSDictionary *dict = @{
                           AVEncoderAudioQualityKey:@(AVAudioQualityLow),
                           AVEncoderBitRateKey:@(16),
                           AVNumberOfChannelsKey:@(2),
                           AVSampleRateKey:@(44100.0)
                           };
    if (!audioRecorder) {
        NSError *error = nil;
        NSString *filePath = [NSHomeDirectory() stringByAppendingString:[NSString stringWithFormat:@"/Documents/%@.caf", [self generateFilenameWithDateTime]]];
        audioRecorder = [[AVAudioRecorder alloc] initWithURL:[NSURL fileURLWithPath:filePath] settings:dict error:&error];
        if (!error) {
            // 准备录音
            [audioRecorder prepareToRecord];
            // 开始录音
            [audioRecorder record];
            [sender setTitle:@"停止" forState:UIControlStateNormal];
        }
        else {
            audioRecorder = nil;
        }
    }
    else { // 结束录音
        if (audioRecorder.isRecording) {
            [audioRecorder stop];
            audioRecorder = nil;
        }
        [sender setTitle:@"录音" forState:UIControlStateNormal];
    }
}

// 用日期和时间生成文件名
- (NSString *) generateFilenameWithDateTime {
    // 获得当前系统的时间日期
    NSDate *date = [NSDate date];
    // 创建时间日期格式化器
    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
    // 指定时间日期的样式
    formatter.dateFormat = @"yyyyMMddHHmmssSSS";
    // 指定时区为当前系统时区
    formatter.timeZone = [NSTimeZone systemTimeZone];
    return [formatter stringFromDate:date];
}
@end

视频播放##

#import "ViewController.h"
#import 

@interface ViewController () {
    MPMoviePlayerController *mpc;
}

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    NSString *filePath = [[NSBundle mainBundle] pathForResource:@"test.mov" ofType:nil];
    // 创建视频播放器视图控制器
    mpc = [[MPMoviePlayerController alloc] initWithContentURL:[NSURL fileURLWithPath:filePath]];
    // 指定视图控制器视图的位置和尺寸
    mpc.view.frame = self.view.bounds;
    // 设置视频播放器视图控制器的视图可以自动调整宽高
    mpc.view.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
    
    // 将视频播放器视图控制器的视图贴到当前视图控制器的视图上
    [self.view addSubview:mpc.view];
    // 开始播放
    [mpc play];
}