self.RLMNotificationTokenReadun =  self.downDataUnderwayArray.addNotificationBlock { [weak self] (results:RLMResults<RLMDownloads>?, change:RLMCollectionChange? , error) in
            if change != nil{
               self?.underwayTableView.reloadData()
            }
        }

  NSString *path = [[NSBundle mainBundle] bundlePath];
  NSLog(@"%@", path);
Documents: 最常用的目录，iTunes同步该应用时会同步此文件夹中的内容，适合存储重要数据。
  NSString *path = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES).firstObject;
  NSLog(@"%@", path);
Library/Caches: iTunes不会同步此文件夹，适合存储体积大，不需要备份的非重要数据。
  NSString *path = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES).firstObject;
  NSLog(@"%@", path);
Library/Preferences: iTunes同步该应用时会同步此文件夹中的内容，通常保存应用的设置信息。
tmp: iTunes不会同步此文件夹，系统可能在应用没运行时就删除该目录下的文件，所以此目录适合保存应用中的一些临时文件，用完就删除。
  NSString *path = NSTemporaryDirectory();
  NSLog(@"%@", path);
plist文件
plist文件是将某些特定的类，通过XML文件的方式保存在目录中。

NSArray;
NSMutableArray;
NSDictionary;
NSMutableDictionary;
NSData;
NSMutableData;
NSString;
NSMutableString;
NSNumber;
NSDate;
1.获得文件路径
    NSString *path = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES).firstObject;
    NSString *fileName = [path stringByAppendingPathComponent:@"123.plist"];
    
2.存储
NSArray *array = @[@"123", @"456", @"789"];
[array writeToFile:fileName atomically:YES];
3.读取
NSArray *result = [NSArray arrayWithContentsOfFile:fileName];
NSLog(@"%@", result);

  //1.遵循NSCoding协议 
  @interface Person : NSObject <NSCoding>
  //2.设置属性
  @property (strong, nonatomic) UIImage *avatar;
  @property (copy, nonatomic) NSString *name;
  @property (assign, nonatomic) NSInteger age;
  @end
实现协议方法
  //解档
  - (id)initWithCoder:(NSCoder *)aDecoder {
      if ([super init]) {
          self.avatar = [aDecoder decodeObjectForKey:@"avatar"];
          self.name = [aDecoder decodeObjectForKey:@"name"];
          self.age = [aDecoder decodeIntegerForKey:@"age"];
      }
      return self;
  }
  //归档
  - (void)encodeWithCoder:(NSCoder *)aCoder {
      [aCoder encodeObject:self.avatar forKey:@"avatar"];
      [aCoder encodeObject:self.name forKey:@"name"];
      [aCoder encodeInteger:self.age forKey:@"age"];
  }

  NSString *file = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES).firstObject stringByAppendingPathComponent:@"person.data"];
  Person *person = [[Person alloc] init];
  person.avatar = self.avatarView.image;
  person.name = self.nameField.text;
  person.age = [self.ageField.text integerValue];
  [NSKeyedArchiver archiveRootObject:person toFile:file];
需要从文件中解档对象就调用NSKeyedUnarchiver的一个工厂方法 unarchiveObjectWithFile: 即可。
  NSString *file = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES).firstObject stringByAppendingPathComponent:@"person.data"];
  Person *person = [NSKeyedUnarchiver unarchiveObjectWithFile:file];
  if (person) {
     self.avatarView.image = person.avatar;
     self.nameField.text = person.name;
     self.ageField.text = [NSString stringWithFormat:@"%ld", person.age];
  }

/**
*  打开数据库并创建一个表
*/
- (void)openDatabase {
   //1.设置文件名
   NSString *filename = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES).firstObject stringByAppendingPathComponent:@"person.db"];
   //2.打开数据库文件，如果没有会自动创建一个文件
   NSInteger result = sqlite3_open(filename.UTF8String, &_sqlite3);
   if (result == SQLITE_OK) {
       NSLog(@"打开数据库成功！");
       //3.创建一个数据库表
       char *errmsg = NULL;
       sqlite3_exec(_sqlite3, "CREATE TABLE IF NOT EXISTS t_person(id integer primary key autoincrement, name text, age integer)", NULL, NULL, &errmsg);
       if (errmsg) {
           NSLog(@"错误：%s", errmsg);
       } else {
           NSLog(@"创表成功！");
       }
   } else {
       NSLog(@"打开数据库失败！");
   }
}
执行指令
使用 sqlite3_exec() 方法可以执行任何SQL语句，比如创表、更新、插入和删除操作。但是一般不用它执行查询语句，因为它不会返回查询到的数据。
/**
*  往表中插入1000条数据
*/
- (void)insertData {
NSString *nameStr;
NSInteger age;
for (NSInteger i = 0; i < 1000; i++) {
  nameStr = [NSString stringWithFormat:@"Bourne-%d", arc4random_uniform(10000)];
  age = arc4random_uniform(80) + 20;
  NSString *sql = [NSString stringWithFormat:@"INSERT INTO t_person (name, age) VALUES('%@', '%ld')", nameStr, age];
  char *errmsg = NULL;
  sqlite3_exec(_sqlite3, sql.UTF8String, NULL, NULL, &errmsg);
  if (errmsg) {
      NSLog(@"错误：%s", errmsg);
  }
}
NSLog(@"插入完毕！");
}

NSString *path = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES).firstObject stringByAppendingPathComponent:@"person.db"];
FMDatabase *database = [FMDatabase databaseWithPath:path];    
if (![database open]) {
    NSLog(@"数据库打开失败！");
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    //增加监听，当键盘出现或改变时收出消息
    [[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(keyboardWillShow:)
                                             name:UIKeyboardWillShowNotification
                                           object:nil];
    //增加监听，当键退出时收出消息
    [[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(keyboardWillHide:)
                                             name:UIKeyboardWillHideNotification
                                           object:nil];    
}
 //当键盘出现或改变时调用
- (void)keyboardWillShow:(NSNotification *)aNotification
{
    //获取键盘的高度
    NSDictionary *userInfo = [aNotification userInfo];
    NSValue *aValue = [userInfo objectForKey:UIKeyboardFrameEndUserInfoKey];
    CGRect keyboardRect = [aValue CGRectValue];
   int height = keyboardRect.size.height;
}
//当键退出时调用
- (void)keyboardWillHide:(NSNotification *)aNotification{}

NSString *accountName = [wrapper objectForKey:(id)kSecAttrAccount];

//
//NSString+SHA.h
//
 
#import <Foundation/Foundation.h>
#import <CommonCrypto/CommonDigest.h>
#import <CommonCrypto/CommonCryptor.h>
 
@interface NSString(SHA)
-(NSString *) sha1;
-(NSString *) sha224;
-(NSString *) sha256;
-(NSString *) sha384;
-(NSString *) sha512;
@end
 
#import "NSString+SHA.h"
@implementation NSString (SHA)
-(NSString *) sha1{
    const char *cstr = [self cStringUsingEncoding:NSUTF8StringEncoding];
    NSData *data = [NSData dataWithBytes:cstr length:self.length];
    uint8_t digest[CC_SHA1_DIGEST_LENGTH];
    CC_SHA1(data.bytes, (CC_LONG)data.length, digest);
    NSMutableString *output = [NSMutableString stringWithCapacity:CC_SHA1_DIGEST_LENGTH * 2];
    for (int i=0; i<CC_SHA1_DIGEST_LENGTH; i++) {
        [output appendFormat:@"%02x",digest[i]];
    }
    return output;
}
-(NSString *) sha224{
    const char *cstr = [self cStringUsingEncoding:NSUTF8StringEncoding];
    NSData *data = [NSData dataWithBytes:cstr length:self.length];
    uint8_t digest[CC_SHA224_DIGEST_LENGTH];
    CC_SHA224(data.bytes, (CC_LONG)data.length, digest);
    NSMutableString *output = [NSMutableString stringWithCapacity:CC_SHA224_DIGEST_LENGTH*2];
    for (int i=0; i<CC_SHA224_DIGEST_LENGTH; i++) {
        [output appendFormat:@"%02x",digest[i]];
    }
    return output;
    
}
- (NSString*) sha256
{
    const char *cstr = [self cStringUsingEncoding:NSUTF8StringEncoding];
    NSData *data = [NSData dataWithBytes:cstr length:self.length];
    
    uint8_t digest[CC_SHA256_DIGEST_LENGTH];
    
    CC_SHA256(data.bytes, (CC_LONG)data.length, digest);
    
    NSMutableString* output = [NSMutableString stringWithCapacity:CC_SHA256_DIGEST_LENGTH * 2];
    
    for(int i = 0; i < CC_SHA256_DIGEST_LENGTH; i++)
        [output appendFormat:@"%02x", digest[i]];
    
    return output;
}
- (NSString*) sha384
{
    const char *cstr = [self cStringUsingEncoding:NSUTF8StringEncoding];
    NSData *data = [NSData dataWithBytes:cstr length:self.length];
    
    uint8_t digest[CC_SHA384_DIGEST_LENGTH];
    
    CC_SHA384(data.bytes, (CC_LONG)data.length, digest);
    
    NSMutableString* output = [NSMutableString stringWithCapacity:CC_SHA384_DIGEST_LENGTH * 2];
    
    for(int i = 0; i < CC_SHA384_DIGEST_LENGTH; i++)
        [output appendFormat:@"%02x", digest[i]];
    
    return output;
}
- (NSString*) sha512
{
    const char *cstr = [self cStringUsingEncoding:NSUTF8StringEncoding];
    NSData *data = [NSData dataWithBytes:cstr length:self.length];
    
    uint8_t digest[CC_SHA512_DIGEST_LENGTH];
    
    CC_SHA512(data.bytes, (CC_LONG)data.length, digest);
    
    NSMutableString* output = [NSMutableString stringWithCapacity:CC_SHA512_DIGEST_LENGTH * 2];
    
    for(int i = 0; i < CC_SHA512_DIGEST_LENGTH; i++)
        [output appendFormat:@"%02x", digest[i]];
    
    return output;
}
@end

//  
//  HmacUtils.m  
//  Inspector  
//  
//  Created by yaoliangjun on 16/5/20.  
//  Copyright © 2016年 yaoliangjun. All rights reserved.  
//  
  
#import "HmacUtils.h"  
#import <CommonCrypto/CommonDigest.h>  
#import <CommonCrypto/CommonHMAC.h>  
  
@implementation HmacUtils  
  
/** 
 *  加密方式,MAC算法: HmacSHA256 
 * 
 *  @param plaintext 要加密的文本 
 *  @param key       秘钥 
 * 
 *  @return 加密后的字符串 
 */  
+ (NSString *)hmac:(NSString *)plaintext withKey:(NSString *)key  
{  
    const charchar *cKey  = [key cStringUsingEncoding:NSASCIIStringEncoding];  
    const charchar *cData = [plaintext cStringUsingEncoding:NSASCIIStringEncoding];  
    unsigned char cHMAC[CC_SHA256_DIGEST_LENGTH];  
    CCHmac(kCCHmacAlgSHA256, cKey, strlen(cKey), cData, strlen(cData), cHMAC);  
    NSData *HMACData = [NSData dataWithBytes:cHMAC length:sizeof(cHMAC)];  
    const unsigned charchar *buffer = (const unsigned charchar *)[HMACData bytes];  
    NSMutableString *HMAC = [NSMutableString stringWithCapacity:HMACData.length * 2];  
    for (int i = 0; i < HMACData.length; ++i){  
        [HMAC appendFormat:@"%02x", buffer[i]];  
    }  
      
    return HMAC;  
}  
  
@end

#import "ViewController.h"
#import <AVFoundation/AVFoundation.h>
#import "MBProgressHUD+MJ.h"
@interface ViewController ()
/** 用于播放 */
@property (weak, nonatomic) IBOutlet UIImageView *imageView;
@end
@implementation ViewController
- (void)viewDidLoad {
    [super viewDidLoad];
}
- (IBAction)mergeAction:(UIButton *)sender {
    [self merge];
}
// 混合音乐
- (void)merge{
    // mbp提示框
    [MBProgressHUD showMessage:@"正在处理中"];
    // 路径
    NSString *documents = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents"];
    // 声音来源
    NSURL *audioInputUrl = [NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:@"五环之歌" ofType:@"mp3"]];
    // 视频来源
    NSURL *videoInputUrl = [NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:@"myPlayer" ofType:@"mp4"]];
    // 最终合成输出路径
    NSString *outPutFilePath = [documents stringByAppendingPathComponent:@"merge.mp4"];
    // 添加合成路径
    NSURL *outputFileUrl = [NSURL fileURLWithPath:outPutFilePath];
    // 时间起点
    CMTime nextClistartTime = kCMTimeZero;
    // 创建可变的音视频组合
    AVMutableComposition *comosition = [AVMutableComposition composition];
    
    
    // 视频采集
    AVURLAsset *videoAsset = [[AVURLAsset alloc] initWithURL:videoInputUrl options:nil];
    // 视频时间范围
    CMTimeRange videoTimeRange = CMTimeRangeMake(kCMTimeZero, videoAsset.duration);
    // 视频通道 枚举 kCMPersistentTrackID_Invalid = 0
    AVMutableCompositionTrack *videoTrack = [comosition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
    // 视频采集通道
    AVAssetTrack *videoAssetTrack = [[videoAsset tracksWithMediaType:AVMediaTypeVideo] firstObject];
    //  把采集轨道数据加入到可变轨道之中
    [videoTrack insertTimeRange:videoTimeRange ofTrack:videoAssetTrack atTime:nextClistartTime error:nil];
    
    
   
    // 声音采集
    AVURLAsset *audioAsset = [[AVURLAsset alloc] initWithURL:audioInputUrl options:nil];
    // 因为视频短这里就直接用视频长度了,如果自动化需要自己写判断
    CMTimeRange audioTimeRange = videoTimeRange;
    // 音频通道
    AVMutableCompositionTrack *audioTrack = [comosition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
    // 音频采集通道
    AVAssetTrack *audioAssetTrack = [[audioAsset tracksWithMediaType:AVMediaTypeAudio] firstObject];
    // 加入合成轨道之中
    [audioTrack insertTimeRange:audioTimeRange ofTrack:audioAssetTrack atTime:nextClistartTime error:nil];
    
    // 创建一个输出
    AVAssetExportSession *assetExport = [[AVAssetExportSession alloc] initWithAsset:comosition presetName:AVAssetExportPresetMediumQuality];
    // 输出类型
    assetExport.outputFileType = AVFileTypeQuickTimeMovie;
    // 输出地址
    assetExport.outputURL = outputFileUrl;
    // 优化
    assetExport.shouldOptimizeForNetworkUse = YES;
    // 合成完毕
    [assetExport exportAsynchronouslyWithCompletionHandler:^{
    // 这里还得把状态监听下 assetExport status ,AVAssetExportSessionStatusCompleted
        // 回到主线程
        dispatch_async(dispatch_get_main_queue(), ^{
            // 调用播放方法
            [self playWithUrl:outputFileUrl];
        });
    }];
    // assetExport.progress  进度 time 定时去检测
}
/** 播放方法 */
- (void)playWithUrl:(NSURL *)url{
    // 传入地址
    AVPlayerItem *playerItem = [AVPlayerItem playerItemWithURL:url];
    // 播放器
    AVPlayer *player = [AVPlayer playerWithPlayerItem:playerItem];
    // 播放器layer
    AVPlayerLayer *playerLayer = [AVPlayerLayer playerLayerWithPlayer:player];
    playerLayer.frame = self.imageView.frame;
    // 视频填充模式
    playerLayer.videoGravity = AVLayerVideoGravityResizeAspect;
    // 添加到imageview的layer上
    [self.imageView.layer addSublayer:playerLayer];
    // 隐藏提示框 开始播放
    [MBProgressHUD hideHUD];
    [MBProgressHUD showSuccess:@"合成完成"];
    // 播放
    [player play];
}

  // 声音采集2
 AVURLAsset *audioAsset2 = [[AVURLAsset alloc] initWithURL:audioInputUrl2 options:nil];
 // 因为视频短这里就直接用视频长度了,如果自动化需要自己写判断 , 注: 如果两个音频接着播放的得,得考虑 两个长度问题, 这个会以长的做节点, 自己计算基准事件和音频时间
 CMTime aduioTime2 =  CMTimeMakeWithSeconds(10, audioAsset2.duration.timescale);//audioAsset2.duration;//CMTimeMake(videoAsset.duration.value - audioAsset.duration.value, audioAsset2.duration.timescale);
 CMTimeRange audioTimeRange2 = CMTimeRangeMake(kCMTimeZero, aduioTime2);//videoTimeRange;
 // 音频通道
// AVMutableCompositionTrack *audioTrack2 = [comosition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
 // 音频采集通道
 AVAssetTrack *audioAssetTrack2 = [[audioAsset2 tracksWithMediaType:AVMediaTypeAudio] firstObject];
 
 
 
 // 加入合成轨道之中
 //[audioTrack insertTimeRange:audioTimeRange ofTrack:audioAssetTrack atTime:nextClistartTime error:nil];
 [audioTrack insertTimeRanges:@[[NSValue valueWithCMTimeRange:audioTimeRange],[NSValue valueWithCMTimeRange:audioTimeRange2]] ofTracks:@[audioAssetTrack,audioAssetTrack2] atTime:nextClistartTime error:nil];

  双轨道合成备注下 但是最好一个轨道
/**
 片头拼接
 @param exportVideoFilePath <#exportVideoFilePath description#>
 @param inputeVideoURL <#inputeVideoURL description#>
 @param videoHiveURL <#videoHiveURL description#>
 */
-(void)builderVideoHiveToMp4Pth: (NSString *)exportVideoFilePath
             withInputeVideoURL: (NSURL *)inputeVideoURL
               withVideoHiveURL: (NSURL*)videoHiveURL{
    _effectType = 1;
     unlink([exportVideoFilePath UTF8String]);
    if (!inputeVideoURL || ![inputeVideoURL isFileURL] || !exportVideoFilePath || [exportVideoFilePath isEqualToString:@""]){
        //没有输入或者输出等, 返回NO
        NSLog(@"inputeVideoURL 或者 exportVideoFilePath 地址有错");
        return;
    }
    // 创建asset 从输入url
    AVURLAsset *videoAsset = [[AVURLAsset alloc] initWithURL:inputeVideoURL options:nil];
    AVURLAsset *videoAsset2 = [[AVURLAsset alloc] initWithURL:videoHiveURL options:nil];
    if (videoAsset == nil || [[videoAsset tracksWithMediaType:AVMediaTypeVideo] count]<1 || [[videoAsset2 tracksWithMediaType:AVMediaTypeVideo] count]<1){
        // 没有建立成功,或者没有视频轨道 + 音频判断
        return;
    }
    NSParameterAssert(videoAsset);
    // 视频和音频的合成类
    AVMutableComposition *mixComposition = [[AVMutableComposition alloc] init];
    /// MARK视频轨道 合成类 先add 的会显示在最底层
    // 空的轨道
    AVMutableCompositionTrack *videoTrack2 = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
    AVMutableCompositionTrack *videoTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
    
    
    // 轨道数据
    AVAssetTrack *assetVideoTrack = [[videoAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];
    AVAssetTrack *assetVideoTrack2 = [[videoAsset2 tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];
    
    [videoTrack2 insertTimeRange:CMTimeRangeMake(kCMTimeZero, videoAsset2.duration ) ofTrack:assetVideoTrack2 atTime:kCMTimeZero error:nil];
    [videoTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, videoAsset.duration ) ofTrack:assetVideoTrack atTime:videoAsset2.duration error:nil];
    
    // layer 数据轨道的合成指令集
    AVMutableVideoCompositionLayerInstruction *videolayerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:assetVideoTrack];
    AVMutableVideoCompositionLayerInstruction *videolayerInstruction2 = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:assetVideoTrack2];
    [videolayerInstruction2 setOpacity:0.0 atTime:videoAsset2.duration];
    
    //    AVMutableVideoCompositionLayerInstruction *audiolayerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:assetAudioTrack];
    
    //Make a "pass through video track" video composition.
    /// 视频合成的指令
    AVMutableVideoCompositionInstruction *mainInstruction = [AVMutableVideoCompositionInstruction videoCompositionInstruction];
    mainInstruction.timeRange = CMTimeRangeMake(kCMTimeZero, CMTimeAdd(videoAsset.duration, videoAsset2.duration));
    mainInstruction.layerInstructions = [NSArray arrayWithObjects:videolayerInstruction,videolayerInstruction2, nil];
    // 视频合成类
    AVMutableVideoComposition *mainVideoComposition = [[AVMutableVideoComposition alloc] init];
    mainVideoComposition.instructions = [NSArray arrayWithObjects:mainInstruction, nil];
    mainVideoComposition.frameDuration = CMTimeMake(1, 30);
    mainVideoComposition.renderSize = assetVideoTrack.naturalSize;
    
    // 所有效果的父类
    CALayer *parentLayer = [CALayer layer];
    CALayer *videoLayer = [CALayer layer];
    parentLayer.contentsScale = [UIScreen mainScreen].scale;
    videoLayer.contentsScale = [UIScreen mainScreen].scale;
    parentLayer.frame = CGRectMake(0, 0, assetVideoTrack.naturalSize.width, assetVideoTrack.naturalSize.height);
    videoLayer.frame = parentLayer.frame;
    [parentLayer addSublayer:videoLayer];
    mainVideoComposition.animationTool = [AVVideoCompositionCoreAnimationTool videoCompositionCoreAnimationToolWithPostProcessingAsVideoLayer:videoLayer inLayer:parentLayer];
    if (_animationlayer){
        [_animationlayer setAllFrame:parentLayer.bounds];
        [parentLayer addSublayer:_animationlayer];
    }
    
    // export to mp4
    NSString *mp4Quality = AVAssetExportPresetHighestQuality;
    NSString *exportPath = exportVideoFilePath;
    NSURL *exportUrl = [NSURL fileURLWithPath:exportPath];
    _videotoTalTime = CMTimeGetSeconds(videoAsset.duration);
    _exportSession = [[AVAssetExportSession alloc] initWithAsset:mixComposition presetName:mp4Quality];
    _exportSession.outputURL = exportUrl;
    _exportSession.outputFileType = AVFileTypeQuickTimeMovie;// 转换格式
    _exportSession.shouldOptimizeForNetworkUse = YES;
  
    _exportSession.videoComposition = mainVideoComposition;
    __weak typeof(self) weakSelf = self;
    dispatch_async(dispatch_get_main_queue(), ^{
        // 定时更新进度
        _timerEffect = [NSTimer CZ_scheduledTimerWithTimeInterval:0.1f repeats:YES callback:^{
            [weakSelf retrievingProgressMP4];
        }];
    });
    [_exportSession exportAsynchronouslyWithCompletionHandler:^{
        
        if (!weakSelf){return;}
        NSLog(@"转码状态 %ld",(long)[weakSelf.exportSession status]);
        switch ([weakSelf.exportSession status]) {
            case AVAssetExportSessionStatusCompleted:
            {
                dispatch_async(dispatch_get_main_queue(), ^{
                    
                    
                    if (weakSelf.delegate && [weakSelf.delegate respondsToSelector:@selector(AVAssetExportVideoHiveMP4SessionStatus:)]){
                        
                        [weakSelf.delegate AVAssetExportVideoHiveMP4SessionStatus:[weakSelf.exportSession status]];
                        
                    }
                    [weakSelf clearAll];
                });
                
                NSLog(@"视频转码成功");
                break;
            }
            case AVAssetExportSessionStatusFailed:
            {
                dispatch_async(dispatch_get_main_queue(), ^{
                    
                    if (weakSelf.delegate && [weakSelf.delegate respondsToSelector:@selector(AVAssetExportVideoHiveMP4SessionStatus:)]){
                        
                        [weakSelf.delegate AVAssetExportVideoHiveMP4SessionStatus:[weakSelf.exportSession status]];
                        
                    }
                    [weakSelf clearAll];
                });
                NSLog(@"视频转码失败%@",[weakSelf.exportSession error]);
                break;
            }
            case AVAssetExportSessionStatusCancelled:
                break;
            case AVAssetExportSessionStatusWaiting:
                break;
            case AVAssetExportSessionStatusExporting:
                break;
            case AVAssetExportSessionStatusUnknown:
                
            default:
                break;
        }
    }];
    
}