和音訊播放一樣，ios也提供個很多的API。如mediaPlayer.framework下的MPMediaPlayerController、AVFounditon.framework下的AVPlayer和AVKit下的AVPlayerViewcontroller。MPMovieplayerController已經在ios9.0中被廢棄了，用來替代的是AVPlayerViewcontroller。

        所以下面我主要介紹一下AVPlayer。

        AVPlayer既可以播放音樂又可以播放視訊；使用AVPlayer不能直接顯示視訊，必須要加入AVPlayerLayer中，並新增到其他能顯示的layer中。

        AVPlayer和AVAudioPlayer，如果要使用的話，需要新增 AVFoundation.framework 和其標頭檔案 #import <AVFoundation/AVFoundation>

主要程式碼如下（接上一篇文章）

/*
 iOS9預設禁用http協議，改為https協議，如果繼續使用http則會報錯
 App Transport Security has blocked a cleartext HTTP (http://) resource load since it is insecure. Temporary exceptions can be configured via your app's Info.plist file.
 因此需要修改info.plist檔案，新增如下
 <key>NSAppTransportSecurity</key>
 <dict>
 <key>NSAllowsArbitraryLoads</key>
 <true/>
 </dict>
 */
-(void)addAVPlayerLayer {
    //NSString *path = [[NSBundle mainBundle] pathForResource:@"183" ofType:@"wav"];
    //NSURL *url = [NSURL fileURLWithPath:path];
    //NSURL *url = [NSURL URLWithString:@"http://v.jxvdy.com/sendfile/w5bgP3A8JgiQQo5l0hvoNGE2H16WbN09X-ONHPq3P3C1BISgf7C-qVs6_c8oaw3zKScO78I--b0BGFBRxlpw13sf2e54QA"];
    NSURL *url = [NSURL URLWithString:@"http://static.tripbe.com/videofiles/20121214/9533522808.f4v.mp4"];
    
    //'MPMoviePlayerController' is deprecated: first deprecated in iOS 9.0 - Use AVPlayerViewController in AVKit
    //[self.view addSubview:[MPMoviePlayerController new].view];
    self.avPlayerItem = [AVPlayerItem playerItemWithURL:url];
    self.avPlayer = [AVPlayer playerWithPlayerItem:self.avPlayerItem];
    AVPlayerLayer *avPlayerLayer = [AVPlayerLayer playerLayerWithPlayer:self.avPlayer];
    CGRect screenRect = [UIScreen mainScreen].bounds;
    avPlayerLayer.frame = CGRectMake(0, screenRect.size.height/2, screenRect.size.width, screenRect.size.height/2);
    /*
    AVF_EXPORT NSString *const AVLayerVideoGravityResizeAspect NS_AVAILABLE(10_7, 4_0);
    AVF_EXPORT NSString *const AVLayerVideoGravityResizeAspectFill NS_AVAILABLE(10_7, 4_0);
    AVF_EXPORT NSString *const AVLayerVideoGravityResize NS_AVAILABLE(10_7, 4_0);
     */
    avPlayerLayer.videoGravity = AVLayerVideoGravityResizeAspect;
    avPlayerLayer.repeatCount = 1;
    //avPlayerLayer.backgroundColor = [UIColor blueColor].CGColor;
    [self.view.layer addSublayer:avPlayerLayer];
    
    //呼叫
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(avPlayerDidEnd) name:AVPlayerItemDidPlayToEndTimeNotification object:self.avPlayerItem];
    /*
     status共有三種屬性
     (1)AVPlayerStatusUnknown,
     (2)AVPlayerStatusReadyToPlay,
     (3)AVPlayerStatusFailed
     */
    [self.avPlayerItem addObserver:self forKeyPath:@"status" options:NSKeyValueObservingOptionNew context:nil];
    //loadedTimeRanges 表示已經緩衝的進度，監聽此屬性可以在UI中更新緩衝進度
    [self.avPlayerItem addObserver:self forKeyPath:@"loadedTimeRanges" options:NSKeyValueObservingOptionNew context:nil];
    NSLog(@"AVPlayerItemStatus enum = {%ld, %ld, %ld}", AVPlayerItemStatusUnknown, AVPlayerStatusReadyToPlay, AVPlayerItemStatusFailed);
}

-(void)playAVPlayer {
    NSLog(@"AVPlayer play");
    [self.avPlayerItem seekToTime:kCMTimeZero];
    [self.avPlayer play];
}

-(void)avPlayerDidEnd {
    NSLog(@"AVPlayer end");
}

//定義在@interface NSKeyValueObserving.h
//Given that the receiver has been registered as an observer of the value at a key path relative to an object, be notified of a change to that value.
-(void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {
    NSLog(@"observeValueForKeyPath");
    AVPlayerItem *playerItem = (AVPlayerItem *)object;
    if([keyPath isEqualToString:@"status"]) {
        switch (playerItem.status) {
            case AVPlayerItemStatusUnknown:
                NSLog(@"AVPlayerItemStatusUnknown");
                break;
            case AVPlayerItemStatusReadyToPlay:
            {
                NSLog(@"AVPlayerItemStatusReadyToPlay");
                CMTime duration = playerItem.duration;
                //轉換為時間戳(1970到現在的秒數)，timescale是 時間表[尺度],時標,時間量程(value/timescale = seconds)
                CGFloat totalSecond = duration.value / duration.timescale;
                CGFloat totalSecond2 = CMTimeGetSeconds(duration);
                NSLog(@"AVPlayer getSeconds(value/timescale) = %f", totalSecond);
                NSLog(@"AVPlayer getSeconds(CMTimeGetSeconds) = %f", totalSecond2);
                NSString *totalTimeStr = [self convertTime:totalSecond];
                NSLog(@"AVPlayer totalTimeStr = %@", totalTimeStr);
                //監聽播放狀態
                [self monitoringPlayback:playerItem];
            }
                break;
            case AVPlayerItemStatusFailed:
                NSLog(@"AVPlayerItemStatusFailed");
                break;
            default:
                break;
        }
    } else if([keyPath isEqualToString:@"loadedTimeRanges"]) {
        //計算緩衝進度
        NSTimeInterval timeInterval = [self aVPlayerLoadedEndTime];
        NSLog(@"AVPlayer timeInterval = %f", timeInterval);
        CMTime duration = playerItem.duration;
        CGFloat totalDuration = CMTimeGetSeconds(duration);
        CGFloat progress = timeInterval / totalDuration;
        NSLog(@"AVPlayer loadedTimeRanges = %f", progress);
    }
}

-(NSString *)convertTime:(CGFloat)second {
    //second為1970年到現在的TimeInterval(秒數)
    NSDate *date = [NSDate dateWithTimeIntervalSince1970:second];
    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
    if(second / 3600 >= 1) {
        [formatter setDateFormat:@"HH:mm:ss"];
    } else {
        [formatter setDateFormat:@"mm:ss"];
    }
    NSString *timeStr = [formatter stringFromDate:date];
    return timeStr;
}

-(void)monitoringPlayback:(AVPlayerItem *)playerItem {
    __block ViewController *myClass = self;
    //CMTimeMake(a,b)        a當前第幾幀，b每秒多少幀。當前播放時間為a/b
    //CMTimeMakeWithSeconds  a當前時間，b每秒多少幀。當前的幀序號為a＊b
    //Periodic是週期性, 佇列傳NULL代表在主執行緒中執行
    [self.avPlayer addPeriodicTimeObserverForInterval:CMTimeMake(1, 1) queue:NULL usingBlock:^(CMTime time) {
        //計算當前在第幾秒
        CGFloat currentSecond = self.avPlayerItem.currentTime.value/self.avPlayerItem.currentTime.timescale;
        //Capturing 'self' strongly in this block is likely to lead to a retain cycle
        NSString *currentTimeStr = [myClass convertTime:currentSecond];
        NSLog(@"AVPlayer monitoringPlayback currentSecond = %f (%@)", currentSecond, currentTimeStr);
    }];
}

//獲取當前緩衝的進度，換算成與1970年相差的秒數
-(NSTimeInterval)aVPlayerLoadedEndTime {
    //NSValue物件是用來儲存一個C或Objective－C資料的簡單容器。它可以儲存任意型別的資料（既包括基本型別，也包括point、struct、id）
    //NSValue類的目標就是允許以上資料型別的資料結構能夠被新增到集合裡。
    NSArray<NSValue *> *loadedTimeRanges = self.avPlayer.currentItem.loadedTimeRanges;
    NSLog(@"AVPlayer timeRanges = %@", loadedTimeRanges);
    /*
    獲取緩衝區域
    typedef struct
    {
        CMTime			start;		//@field start The start time of the time range.
        CMTime			duration;	// @field duration The duration of the time range.
    } CMTimeRange;
    */
    CMTimeRange timeRange = [loadedTimeRanges.firstObject CMTimeRangeValue];
    //Converts a CMTime to seconds.
    float startSeconds = CMTimeGetSeconds(timeRange.start);
    float durationSeconds = CMTimeGetSeconds(timeRange.duration);
    NSTimeInterval endSeconds = startSeconds + durationSeconds;
    return endSeconds;
}
 

執行列印截圖

開啟程式，但還未按下播放按鈕時，會顯示第一幀。

（此處略去一些列印內容。。。。。。）

可以看到如果不等其全部緩衝好，就按下 “播放”按鈕其也可以正常播放，這就說明AVPlayer是一個網路播放器（即AVPlayer支援變下邊播的流媒體播放器）

左圖為等其全部載入好再按下"播放"按鈕；右圖為還未全部緩衝完就點選"播放"按鈕

（此處略去一些列印內容。。。。。。）

週期性的列印每幀的資訊。

播放完畢後會停在最後一幀