File:  AVPlayerViewController.h

Framework:  AVKit

Copyright © 2014-2017 Apple Inc. All rights reserved.

导入库头文件

#import <UIKit/UIKit.h>

#import <AVFoundation/AVFoundation.h>

NS_ASSUME_NONNULL_BEGIN

//AVPlayerViewController有这个代理，这个代理方法就在下面

@protocol AVPlayerViewControllerDelegate;

@class           AVPlayerViewController

这个摘要说明了AVPlayerViewController这个控制器的基本特征

@abstract        AVPlayerViewController is a subclass of UIViewController that can be used to display the visual content of an AVPlayer object and the standard playback controls.

// 8.0之后有的AVPlayerViewController

API_AVAILABLE(ios(8.0))

@interface AVPlayerViewController : UIViewController

// 简单的播放器AVPlayer属性

@property        player

@abstract        The player from which to source the media content for the view controller.

@property (nonatomic, strong, nullable) AVPlayer *player;

// 是否展示添加在上面的子控件

@property        showsPlaybackControls

@abstract        Whether or not the receiver shows playback controls. Default is YES.

@discussion        Clients can set this property to NO when they don't want to have any playback controls on top of the visual content (e.g. for a game splash screen).

@property (nonatomic) BOOL showsPlaybackControls;

// 这个属性字面意思是视频重力  其实它是用来确定在承载层的范围内视频可以拉伸或者缩放的程度

// 具体的在下面@discussion部分有讨论，我们再总结一下它三个值分别代表的含义

// AVLayerVideoGravityResizeAspect 会在承载层的范围内缩放视频的大小来保持视频的原始比例宽高，默认值

// AVLayerVideoGravityResizeAspectFill 保留视频的宽高比，并且通过缩放填满整个播放界面

// AVLayerVideoGravityResize 会将视频内容拉伸匹配承载层的范围，一般不常用，因为会把图片扭曲导致变形

@property        videoGravity

@abstract        A string defining how the video is displayed within an AVPlayerLayer bounds rect.

@discussion      Options are AVLayerVideoGravityResizeAspect, AVLayerVideoGravityResizeAspectFill and AVLayerVideoGravityResize. AVLayerVideoGravityResizeAspect is default.

 See <AVFoundation/AVAnimation.h> for a description of these options.

@property (nonatomic, copy) NSString *videoGravity;

// 通过这个bool类型的值确定视频是否已经准备好展示

@property        readyForDisplay

@abstract        Boolean indicating that the first video frame has been made ready for display for the current item of the associated AVPlayer.

@property (nonatomic, readonly, getter = isReadyForDisplay) BOOL readyForDisplay;

// 视频的尺寸

@property        videoBounds

@abstract        The current size and position of the video image as displayed within the receiver's view's bounds.

@property (nonatomic, readonly) CGRect videoBounds;

// 有自定义的控件可以添加在这里UIView上

@property        contentOverlayView

@abstract        Use the content overlay view to add additional custom views between the video content and the controls.

@property (nonatomic, readonly, nullable) UIView *contentOverlayView;

// 是否允许使用画中画播放模式，这个画中画播放在下面会写Demo  9.0之后的属性

@property        allowsPictureInPicturePlayback

@abstract        Whether or not the receiver allows Picture in Picture playback. Default is YES.

@property (nonatomic) BOOL allowsPictureInPicturePlayback API_AVAILABLE(ios(9.0));

// 10.0之后的属性

@property        updatesNowPlayingInfoCenter

@abstract        Whether or not the now playing info center should be updated. Default is YES.

@property (nonatomic) BOOL updatesNowPlayingInfoCenter API_AVAILABLE(ios(10.0));

// 理解摘要的意思是是否允许点击播放之后自动全屏播放视频  默认值是NO

@property        entersFullScreenWhenPlaybackBegins

@abstract        Whether or not the receiver automatically enters full screen when the play button is tapped. Default is NO.

@discussion      If YES, the receiver will show a user interface tailored to this behavior.

@property (nonatomic) BOOL entersFullScreenWhenPlaybackBegins API_AVAILABLE(ios(11.0));

// 也是理解摘要，是否允许退出全屏播放在播放结束之后

@property        exitsFullScreenWhenPlaybackEnds

@abstract        Whether or not the receiver automatically exits full screen when playback ends. Default is NO.

@discussion      If multiple player items have been enqueued, the receiver exits fullscreen once no more items are remaining in the queue.

@property (nonatomic) BOOL exitsFullScreenWhenPlaybackEnds API_AVAILABLE(ios(11.0));

// AVPlayerViewControllerDelegate代理

@property        delegate

@abstract        The receiver's delegate.

@property (nonatomic, weak, nullable) id <AVPlayerViewControllerDelegate> delegate API_AVAILABLE(ios(9.0));

@end

// 下面就是AVPlayerViewControllerDelegate代理方法  下面的代理方法都是optional可选的

@protocol        AVPlayerViewControllerDelegate

@abstract        A protocol for delegates of AVPlayerViewController.

@protocol AVPlayerViewControllerDelegate <NSObject>

@optional

@method          playerViewControllerWillStartPictureInPicture:

@param           playerViewController The player view controller.

@abstract        Delegate can implement this method to be notified when Picture in Picture will start.

// 即将开始画中画播放

- (void)playerViewControllerWillStartPictureInPicture:(AVPlayerViewController *)playerViewController;

@method          playerViewControllerDidStartPictureInPicture:

@param           playerViewController  The player view controller.

@abstract        Delegate can implement this method to be notified when Picture in Picture did start.

// 已经开始了画中画播放模式

- (void)playerViewControllerDidStartPictureInPicture:(AVPlayerViewController *)playerViewController;

@method          playerViewController:failedToStartPictureInPictureWithError:

@param           playerViewController  The player view controller.

@param           error An error describing why it failed.

@abstract        Delegate can implement this method to be notified when Picture in Picture failed to start.

// 这个摘要已经给我们说的比较清楚了，当画中画模式播放失败之后就会走这个代理方法

- (void)playerViewController:(AVPlayerViewController *)playerViewController failedToStartPictureInPictureWithError:(NSError *)error;

@method          playerViewControllerWillStopPictureInPicture:

@param           playerViewController The player view controller.

@abstract        Delegate can implement this method to be notified when Picture in Picture will stop.

// 画中画播放模式即将结束

- (void)playerViewControllerWillStopPictureInPicture:(AVPlayerViewController *)playerViewController;

@method          playerViewControllerDidStopPictureInPicture:

@param           playerViewController  The player view controller.

@abstract        Delegate can implement this method to be notified when Picture in Picture did stop.

// 画中画播放已经结束

- (void)playerViewControllerDidStopPictureInPicture:(AVPlayerViewController *)playerViewController;

@method          playerViewControllerShouldAutomaticallyDismissAtPictureInPictureStart:

@param           playerViewController   The player view controller.

@abstract        Delegate can implement this method and return NO to prevent（阻止） player view controller from automatically being dismissed when Picture in Picture starts.

// 要是在画中画开始播放的时候 播放的底层控制器要是消失就返回NO

- (BOOL)playerViewControllerShouldAutomaticallyDismissAtPictureInPictureStart:(AVPlayerViewController *)playerViewController;

@method          playerViewController:restoreUserInterfaceForPictureInPictureStopWithCompletionHandler:

@param           playerViewController  The player view controller.

@param           completionHandler  The completion handler the delegate needs to call after restore.

@abstract        Delegate can implement this method to restore（恢复） the user interface（交互） before Picture in Picture stops.

//  画中画播放结束恢复用户交互

- (void)playerViewController:(AVPlayerViewController *)playerViewController restoreUserInterfaceForPictureInPictureStopWithCompletionHandler:(void (^)(BOOL restored))completionHandler;

@end

NS_ASSUME_NONNULL_END

#pragma mark --

#pragma mark -- CMTime的简单的使用

-(void)CMTimeCalculate{

        CMTime timeO = CMTimeMake(1,10);

        CMTime timeT = CMTimeMake(1,5);

        // 加

        CMTime timeA = CMTimeAdd(timeO,timeT);

        CMTimeShow(timeA);

        //减

        CMTime timeS = CMTimeSubtract(timeO,timeT);

        CMTimeShow(timeS);

        //乘 整形

        CMTime timeB = CMTimeMake(1,10);

        CMTime timeI = CMTimeMultiply(timeB,5);

        CMTimeShow(timeI);

        //乘 浮点型

        CMTime timeF = CMTimeMultiplyByFloat64(timeB,5.6);

        CMTimeShow(timeF);

        // 比较  1是大于  0是相等  -1是小于

        int timeC = CMTimeCompare(timeO,timeT);

        NSLog(@"比较得到大的是%d",timeC); // -1

        //求绝对值

        CMTime timeAB = CMTimeAbsoluteValue(timeS);

        CMTimeShow(timeAB);

}

/*!

	@typedef	CMTimeRange

	@abstract	A time range represented as two CMTime structures.

*/

typedef struct

{

	CMTime			start;		/*! @field start The start time of the time range. */

	CMTime			duration;	/*! @field duration The duration of the time range. */

} CMTimeRange;

#pragma mark --

#pragma mark -- 视频压缩方法

-(void)compressVideoWithFileUrl:(NSURL *)fileUrl{

    /*

      这里需要注意的一点就是在重复的路径上保存文件是不行的，可以选择在点击开始的时候删除之前的

      也可以这样按照时间命名不同的文件保存

      在后面的 AVAssetWriter 也要注意这一点

     */

    // 压缩后的视频的方法命名

    NSDateFormatter * formatter = [[NSDateFormatter alloc]init];

    [formatter setDateFormat:@"yyyy-MM-dd-HH:mm:ss"];

    // 压缩后的文件路径

    self.videoPath = [NSString stringWithFormat:@"%@/%@.mov",NSTemporaryDirectory(),[formatter stringFromDate:[NSDate date]]];

    // 先根据你传入的文件的路径穿件一个AVAsset

    AVAsset * asset = [AVAsset  assetWithURL:fileUrl];

    /*

     根据urlAsset创建AVAssetExportSession压缩类

     第二个参数的意义：常用 压缩中等质量  AVAssetExportPresetMediumQuality

     AVF_EXPORT NSString *const AVAssetExportPresetLowQuality        NS_AVAILABLE_IOS(4_0);

     AVF_EXPORT NSString *const AVAssetExportPresetMediumQuality     NS_AVAILABLE_IOS(4_0);

     AVF_EXPORT NSString *const AVAssetExportPresetHighestQuality    NS_AVAILABLE_IOS(4_0);

    */

    AVAssetExportSession * exportSession = [[AVAssetExportSession alloc]initWithAsset:asset presetName:AVAssetExportPresetMediumQuality];

    // 优化压缩，这个属性能使压缩的质量更好

    exportSession.shouldOptimizeForNetworkUse = YES;

    // 到处的文件的路径

    exportSession.outputURL =  [NSURL fileURLWithPath:self.videoPath];

    // 导出的文件格式

    /*!

      @constant  AVFileTypeMPEG4  mp4格式的   AVFileTypeQuickTimeMovie mov格式的

      @abstract A UTI for the MPEG-4 file format.

      @discussion

      The value of this UTI is @"public.mpeg-4".

      Files are identified with the .mp4 extension.

      可以看看这个outputFileType格式，比如AVFileTypeMPEG4也可以写成public.mpeg-4，其他类似

    */

    exportSession.outputFileType = AVFileTypeQuickTimeMovie;

    NSLog(@"视频压缩后的presetName: %@",exportSession.presetName);

    // 压缩的方法  export 导出  Asynchronously 异步

    [exportSession exportAsynchronouslyWithCompletionHandler:^{

        /*

         exportSession.status 枚举属性

         typedef NS_ENUM(NSInteger, AVAssetExportSessionStatus) {

         AVAssetExportSessionStatusUnknown,

         AVAssetExportSessionStatusWaiting,

         AVAssetExportSessionStatusExporting,

         AVAssetExportSessionStatusCompleted,

         AVAssetExportSessionStatusFailed,

         AVAssetExportSessionStatusCancelled

         };

         */

        int exportStatus = exportSession.status;

        switch (exportStatus) {

            case AVAssetExportSessionStatusFailed:

                NSLog(@"压缩失败");

                break;

            case AVAssetExportSessionStatusCompleted:

            {

                /*

                 压缩后的大小

                 也可以利用exportSession的progress属性，随时监测压缩的进度

                 */

                NSData * data = [NSData dataWithContentsOfFile:self.videoPath];

                float dataSize = (float)data.length/1024/1024;

                NSLog(@"视频压缩后大小 %f M", dataSize);

            }

                break;

            default:

                break;

        }

    }];

}