iOS實(shí)現(xiàn)微信朋友圈視頻截取功能

更新時(shí)間：2018年07月18日 14:24:15 作者：suiling

這篇文章主要介紹了iOS實(shí)現(xiàn)微信朋友圈視頻截取功能，微信使用非常普遍，功能也很強(qiáng)大，不知道大家對(duì)微信朋友圈視頻截取功能有沒有了解，下面腳本之家小編給大家?guī)碓斀饨榻B，感興趣的朋友一起看看吧

序言

微信現(xiàn)在這么普及，功能也做的越來越強(qiáng)大，不知大家對(duì)于微信朋友圈發(fā)視頻截取的功能或者蘋果拍視頻對(duì)視頻編輯的功能有沒有了解（作者這里也猜測(cè)，微信的這個(gè)功能也是仿蘋果的）。感覺這個(gè)功能確實(shí)很方便實(shí)用，近來作者也在研究音視頻功能，所以就實(shí)現(xiàn)了一下這個(gè)功能。

功能其實(shí)看著挺簡(jiǎn)單，實(shí)現(xiàn)過程也踩了不少坑。一方面記錄一下；另一方面也算是對(duì)實(shí)現(xiàn)過程的再一次梳理，這樣大家看代碼也會(huì)比較明白。

效果

我們先看看我實(shí)現(xiàn)的效果

實(shí)現(xiàn)

實(shí)現(xiàn)過程分析

整個(gè)功能可以分為三部分：

視頻播放

這部分我們單獨(dú)封裝一個(gè)視頻播放器即可

下邊的滑動(dòng)視圖

這部分實(shí)現(xiàn)過程比較復(fù)雜，一共分成了4部分?；疑谏w、左右把手滑塊、滑塊中間上下兩條線、圖片管理視圖

控制器視圖邏輯組裝和功能實(shí)現(xiàn)

視頻播放器的封裝

這里使用AVPlayer、playerLayer、AVPlayerItem這三個(gè)類實(shí)現(xiàn)了視頻播放功能；由于整個(gè)事件都是基于KVO監(jiān)聽的，所以增加了Block代碼提供了對(duì)外監(jiān)聽使用。

#import "FOFMoviePlayer.h"
@interface FOFMoviePlayer()
{
  AVPlayerLooper *_playerLooper;
  AVPlayerItem *_playItem;
  BOOL _loop;
}
@property(nonatomic,strong)NSURL *url;
@property(nonatomic,strong)AVPlayer *player;
@property(nonatomic,strong)AVPlayerLayer *playerLayer;
@property(nonatomic,strong)AVPlayerItem *playItem;
@property (nonatomic,assign) CMTime duration;
@end
@implementation FOFMoviePlayer
-(instancetype)initWithFrame:(CGRect)frame url:(NSURL *)url superLayer:(CALayer *)superLayer{
  self = [super init];
  if (self) {
    [self initplayers:superLayer];
    _playerLayer.frame = frame;
    self.url = url;
  }
  return self;
}
-(instancetype)initWithFrame:(CGRect)frame url:(NSURL *)url superLayer:(CALayer *)superLayer loop:(BOOL)loop{
  self = [self initWithFrame:frame url:url superLayer:superLayer];
  if (self) {
    _loop = loop;
  }
  return self;
}
- (void)initplayers:(CALayer *)superLayer{
  self.player = [[AVPlayer alloc] init];
  self.playerLayer = [AVPlayerLayer playerLayerWithPlayer:self.player];
  self.playerLayer.videoGravity = AVLayerVideoGravityResize;
  [superLayer addSublayer:self.playerLayer];
}
- (void)initLoopPlayers:(CALayer *)superLayer{
  self.player = [[AVQueuePlayer alloc] init];
  self.playerLayer = [AVPlayerLayer playerLayerWithPlayer:self.player];
  self.playerLayer.videoGravity = AVLayerVideoGravityResize;
  [superLayer addSublayer:self.playerLayer];
}
-(void)fof_play{
  [self.player play];
}
-(void)fof_pause{
  [self.player pause];
}
#pragma mark - Observe
-(void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary*)change context:(void *)context{
  if ([keyPath isEqualToString:@"status"]) {
    AVPlayerItem *item = (AVPlayerItem *)object;
    AVPlayerItemStatus status = [[change objectForKey:@"new"] intValue]; // 獲取更改后的狀態(tài)
    if (status == AVPlayerItemStatusReadyToPlay) {
      _duration = item.duration;//只有在此狀態(tài)下才能獲取，不能在AVPlayerItem初始化后馬上獲取
      NSLog(@"準(zhǔn)備播放");
      if (self.blockStatusReadyPlay) {
        self.blockStatusReadyPlay(item);
      }
    } else if (status == AVPlayerItemStatusFailed) {
      if (self.blockStatusFailed) {
        self.blockStatusFailed();
      }
      AVPlayerItem *item = (AVPlayerItem *)object;
      NSLog(@"%@",item.error);
      NSLog(@"AVPlayerStatusFailed");
    } else {
      self.blockStatusUnknown();
      NSLog(@"%@",item.error);
      NSLog(@"AVPlayerStatusUnknown");
    }
  }else if ([keyPath isEqualToString:@"tracking"]){
    NSInteger status = [change[@"new"] integerValue];
    if (self.blockTracking) {
      self.blockTracking(status);
    }
    if (status) {//正在拖動(dòng)
      [self.player pause];
    }else{//停止拖動(dòng)
    }
  }else if ([keyPath isEqualToString:@"loadedTimeRanges"]){
    NSArray *array = _playItem.loadedTimeRanges;
    CMTimeRange timeRange = [array.firstObject CMTimeRangeValue];//本次緩沖時(shí)間范圍
    CGFloat startSeconds = CMTimeGetSeconds(timeRange.start);
    CGFloat durationSeconds = CMTimeGetSeconds(timeRange.duration);
    NSTimeInterval totalBuffer = startSeconds + durationSeconds;//緩沖總長度
    double progress = totalBuffer/CMTimeGetSeconds(_duration);
    if (self.blockLoadedTimeRanges) {
      self.blockLoadedTimeRanges(progress);
    }
    NSLog(@"當(dāng)前緩沖時(shí)間：%f",totalBuffer);
  }else if ([keyPath isEqualToString:@"playbackBufferEmpty"]){
    NSLog(@"緩存不夠，不能播放！");
  }else if ([keyPath isEqualToString:@"playbackLikelyToKeepUp"]){
    if (self.blockPlaybackLikelyToKeepUp) {
      self.blockPlaybackLikelyToKeepUp([change[@"new"] boolValue]);
    }
  }
}
-(void)setUrl:(NSURL *)url{
  _url = url;
  [self.player replaceCurrentItemWithPlayerItem:self.playItem];
}
-(AVPlayerItem *)playItem{
  _playItem = [[AVPlayerItem alloc] initWithURL:_url];
  //監(jiān)聽播放器的狀態(tài)，準(zhǔn)備好播放、失敗、未知錯(cuò)誤
  [_playItem addObserver:self forKeyPath:@"status" options:NSKeyValueObservingOptionNew context:nil];
  //  監(jiān)聽緩存的時(shí)間
  [_playItem addObserver:self forKeyPath:@"loadedTimeRanges" options:NSKeyValueObservingOptionNew context:nil];
  //  監(jiān)聽獲取當(dāng)緩存不夠，視頻加載不出來的情況：
  [_playItem addObserver:self forKeyPath:@"playbackBufferEmpty" options:NSKeyValueObservingOptionNew context:nil];
  //  用于監(jiān)聽緩存足夠播放的狀態(tài)
  [_playItem addObserver:self forKeyPath:@"playbackLikelyToKeepUp" options:NSKeyValueObservingOptionNew context:nil];
  [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(private_playerMovieFinish) name:AVPlayerItemDidPlayToEndTimeNotification object:nil];
  return _playItem;
}
- (void)private_playerMovieFinish{
  NSLog(@"播放結(jié)束");
  if (self.blockPlayToEndTime) {
    self.blockPlayToEndTime();
  }
  if (_loop) {//默認(rèn)提供一個(gè)循環(huán)播放的功能
    [self.player pause];
    CMTime time = CMTimeMake(1, 1);
    __weak typeof(self)this = self;
    [self.player seekToTime:time completionHandler:^(BOOL finished) {
      [this.player play];
    }];
  }
}
-(void)dealloc{
  NSLog(@"-----銷毀-----");
}
@end

視頻播放器就不重點(diǎn)講了，作者計(jì)劃單獨(dú)寫一篇有關(guān)視頻播放器的。

下邊的滑動(dòng)視圖

灰色遮蓋

灰色遮蓋比較簡(jiǎn)單這里作者只是用了UIView

self.leftMaskView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 0, height)];
self.leftMaskView.backgroundColor = [UIColor grayColor];
self.leftMaskView.alpha = 0.8;
[self addSubview:self.leftMaskView];
self.rightMaskView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 0, height)];
self.rightMaskView.backgroundColor = [UIColor grayColor];
self.rightMaskView.alpha = 0.8;

滑塊中間上下兩條線

這兩根線單獨(dú)封裝了一個(gè)視圖Line,一開始也想到用一個(gè)UIView就好了，但是發(fā)現(xiàn)一個(gè)問題，就是把手的滑動(dòng)與線的滑動(dòng)速度不匹配,線比較慢。

@implementation Line
-(void)setBeginPoint:(CGPoint)beginPoint{
  _beginPoint = beginPoint;
  [self setNeedsDisplay];
}
-(void)setEndPoint:(CGPoint)endPoint{
  _endPoint = endPoint;
  [self setNeedsDisplay];
}
- (void)drawRect:(CGRect)rect {
  CGContextRef context = UIGraphicsGetCurrentContext();
  CGContextSetLineWidth(context, 3);
  CGContextSetStrokeColorWithColor(context, [UIColor colorWithWhite:0.9 alpha:1].CGColor);
  CGContextMoveToPoint(context, self.beginPoint.x, self.beginPoint.y);
  CGContextAddLineToPoint(context, self.endPoint.x, self.endPoint.y);
  CGContextStrokePath(context);
}

圖片管理視圖

這里封裝了一個(gè)VideoPieces，用來組裝把手、線、遮蓋的邏輯，并且用來顯示圖片。由于圖片只有10張，所以這里緊緊是一個(gè)for循環(huán)，增加了10個(gè)UIImageView

@interface VideoPieces()
{
  CGPoint _beginPoint;
}
@property(nonatomic,strong) Haft *leftHaft;
@property(nonatomic,strong) Haft *rightHaft;
@property(nonatomic,strong) Line *topLine;
@property(nonatomic,strong) Line *bottomLine;
@property(nonatomic,strong) UIView *leftMaskView;
@property(nonatomic,strong) UIView *rightMaskView;
@end
@implementation VideoPieces
-(instancetype)initWithFrame:(CGRect)frame{
  self = [super initWithFrame:frame];
  if (self) {
    [self initSubViews:frame];
  }
  return self;
}
- (void)initSubViews:(CGRect)frame{
  CGFloat height = CGRectGetHeight(frame);
  CGFloat width = CGRectGetWidth(frame);
  CGFloat minGap = 30;
  CGFloat widthHaft = 10;
  CGFloat heightLine = 3;
  _leftHaft = [[Haft alloc] initWithFrame:CGRectMake(0, 0, widthHaft, height)];
  _leftHaft.alpha = 0.8;
  _leftHaft.backgroundColor = [UIColor colorWithWhite:0.9 alpha:1];
  _leftHaft.rightEdgeInset = 20;
  _leftHaft.lefEdgeInset = 5;
  __weak typeof(self) this = self;
  [_leftHaft setBlockMove:^(CGPoint point) {
    CGFloat maxX = this.rightHaft.frame.origin.x-minGap;
    if (point.x=minX) {
      this.topLine.endPoint = CGPointMake(point.x-widthHaft, heightLine/2.0);
      this.bottomLine.endPoint = CGPointMake(point.x-widthHaft, heightLine/2.0);
      this.rightHaft.frame = CGRectMake(point.x, 0, widthHaft, height);
      this.rightMaskView.frame = CGRectMake(point.x+widthHaft, 0, width-point.x-widthHaft, height);
      if (this.blockSeekOffRight) {
        this.blockSeekOffRight(point.x);
      }
    }
  }];
  [_rightHaft setBlockMoveEnd:^{
    if (this.blockMoveEnd) {
      this.blockMoveEnd();
    }
  }];
  _topLine = [[Line alloc] init];
  _topLine.alpha = 0.8;
  _topLine.frame = CGRectMake(widthHaft, 0, width-2*widthHaft, heightLine);
  _topLine.beginPoint = CGPointMake(0, heightLine/2.0);
  _topLine.endPoint = CGPointMake(CGRectGetWidth(_topLine.bounds), heightLine/2.0);
  _topLine.backgroundColor = [UIColor clearColor];
  [self addSubview:_topLine];
  _bottomLine = [[Line alloc] init];
  _bottomLine.alpha = 0.8;
  _bottomLine.frame = CGRectMake(widthHaft, height-heightLine, width-2*widthHaft, heightLine);
  _bottomLine.beginPoint = CGPointMake(0, heightLine/2.0);
  _bottomLine.endPoint = CGPointMake(CGRectGetWidth(_bottomLine.bounds), heightLine/2.0);
  _bottomLine.backgroundColor = [UIColor clearColor];
  [self addSubview:_bottomLine];
  [self addSubview:_leftHaft];
  [self addSubview:_rightHaft];
  self.leftMaskView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 0, height)];
  self.leftMaskView.backgroundColor = [UIColor grayColor];
  self.leftMaskView.alpha = 0.8;
  [self addSubview:self.leftMaskView];
  self.rightMaskView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 0, height)];
  self.rightMaskView.backgroundColor = [UIColor grayColor];
  self.rightMaskView.alpha = 0.8;
  [self addSubview:self.rightMaskView];
}
-(void)touchesBegan:(NSSet*)touches withEvent:(UIEvent *)event{
  UITouch *touch = touches.anyObject;
  _beginPoint = [touch locationInView:self];
}

把手的實(shí)現(xiàn)

把手的實(shí)現(xiàn)這里優(yōu)化了一點(diǎn)，就是滑動(dòng)的時(shí)候比較靈敏，一開始用手指滑動(dòng)的時(shí)候不是非常靈敏，經(jīng)常手指滑動(dòng)了，但是把手沒有動(dòng)。

增加了靈敏度的方法其實(shí)就是增加了接收事件區(qū)域的大小，重寫了-(BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event這個(gè)方法

@implementation Haft
-(instancetype)initWithFrame:(CGRect)frame{
  self = [super initWithFrame:frame];
  if (self) {
    self.userInteractionEnabled = true;
  }
  return self;
}
-(BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event{
  CGRect rect = CGRectMake(self.bounds.origin.x-self.lefEdgeInset, self.bounds.origin.y-self.topEdgeInset, CGRectGetWidth(self.bounds)+self.lefEdgeInset+self.rightEdgeInset, CGRectGetHeight(self.bounds)+self.bottomEdgeInset+self.topEdgeInset);
  if (CGRectContainsPoint(rect, point)) {
    return YES;
  }
  return NO;
}
-(void)touchesBegan:(NSSet*)touches withEvent:(UIEvent *)event{
  NSLog(@"開始");
}
-(void)touchesMoved:(NSSet*)touches withEvent:(UIEvent *)event{
  NSLog(@"Move");
  UITouch *touch = touches.anyObject;
  CGPoint point = [touch locationInView:self.superview];
  CGFloat maxX = CGRectGetWidth(self.superview.bounds)-CGRectGetWidth(self.bounds);
  if (point.x>maxX) {
    point.x = maxX;
  }
  if (point.x>=0&&point.x<=(CGRectGetWidth(self.superview.bounds)-CGRectGetWidth(self.bounds))&&self.blockMove) {
    self.blockMove(point);
  }
}
-(void)touchesEnded:(NSSet*)touches withEvent:(UIEvent *)event{
  if (self.blockMoveEnd) {
    self.blockMoveEnd();
  }
}
- (void)drawRect:(CGRect)rect {
  CGFloat width = CGRectGetWidth(self.bounds);
  CGFloat height = CGRectGetHeight(self.bounds);
  CGFloat lineWidth = 1.5;
  CGFloat lineHeight = 12;
  CGFloat gap = (width-lineWidth*2)/3.0;
  CGFloat lineY = (height-lineHeight)/2.0;
  CGContextRef context = UIGraphicsGetCurrentContext();
  CGContextSetLineWidth(context, lineWidth);
  CGContextSetStrokeColorWithColor(context, [[UIColor grayColor] colorWithAlphaComponent:0.8].CGColor);
  CGContextMoveToPoint(context, gap+lineWidth/2, lineY);
  CGContextAddLineToPoint(context, gap+lineWidth/2, lineY+lineHeight);
  CGContextStrokePath(context);
  CGContextSetLineWidth(context, lineWidth);
  CGContextSetStrokeColorWithColor(context, [[UIColor grayColor] colorWithAlphaComponent:0.8].CGColor);
  CGContextMoveToPoint(context, gap*2+lineWidth+lineWidth/2, lineY);
  CGContextAddLineToPoint(context, gap*2+lineWidth+lineWidth/2, lineY+lineHeight);
  CGContextStrokePath(context);
}

控制器視圖邏輯組裝和功能實(shí)現(xiàn)

這部分邏輯是最重要也是最復(fù)雜的。

獲取10張縮略圖

- (NSArray *)getVideoThumbnail:(NSString *)path count:(NSInteger)count splitCompleteBlock:(void(^)(BOOL success, NSMutableArray *splitimgs))splitCompleteBlock {
  AVAsset *asset = [AVAsset assetWithURL:[NSURL fileURLWithPath:path]];
  NSMutableArray *arrayImages = [NSMutableArray array];
  [asset loadValuesAsynchronouslyForKeys:@[@"duration"] completionHandler:^{
    AVAssetImageGenerator *generator = [AVAssetImageGenerator assetImageGeneratorWithAsset:asset];
//    generator.maximumSize = CGSizeMake(480,136);//如果是CGSizeMake(480,136)，則獲取到的圖片是{240, 136}。與實(shí)際大小成比例
    generator.appliesPreferredTrackTransform = YES;//這個(gè)屬性保證我們獲取的圖片的方向是正確的。比如有的視頻需要旋轉(zhuǎn)手機(jī)方向才是視頻的正確方向。
    /**因?yàn)橛姓`差，所以需要設(shè)置以下兩個(gè)屬性。如果不設(shè)置誤差有點(diǎn)大，設(shè)置了之后相差非常非常的小**/
    generator.requestedTimeToleranceAfter = kCMTimeZero;
    generator.requestedTimeToleranceBefore = kCMTimeZero;
    Float64 seconds = CMTimeGetSeconds(asset.duration);
    NSMutableArray *array = [NSMutableArray array];
    for (int i = 0; i
      CMTime time = CMTimeMakeWithSeconds(i*(seconds/10.0),1);//想要獲取圖片的時(shí)間位置
      [array addObject:[NSValue valueWithCMTime:time]];
    }
    __block int i = 0;
    [generator generateCGImagesAsynchronouslyForTimes:array completionHandler:^(CMTime requestedTime, CGImageRef _Nullable imageRef, CMTime actualTime, AVAssetImageGeneratorResult result, NSError * _Nullable error) {
      i++;
      if (result==AVAssetImageGeneratorSucceeded) {
        UIImage *image = [UIImage imageWithCGImage:imageRef];
        [arrayImages addObject:image];
      }else{
        NSLog(@"獲取圖片失?。。?！");
      }
      if (i==count) {
        dispatch_async(dispatch_get_main_queue(), ^{
          splitCompleteBlock(YES,arrayImages);
        });
      }
    }];
  }];
  return arrayImages;
}

10張圖片很容易獲取到，不過這里要注意一點(diǎn)：回調(diào)的時(shí)候要放到異步主隊(duì)列回調(diào)！要不會(huì)出現(xiàn)圖片顯示延遲比較嚴(yán)重的問題。

監(jiān)聽左右滑塊事件

[_videoPieces setBlockSeekOffLeft:^(CGFloat offX) {
  this.seeking = true;
  [this.moviePlayer fof_pause];
  this.lastStartSeconds = this.totalSeconds*offX/CGRectGetWidth(this.videoPieces.bounds);
  [this.moviePlayer.player seekToTime:CMTimeMakeWithSeconds(this.lastStartSeconds, 1) toleranceBefore:kCMTimeZero toleranceAfter:kCMTimeZero];
}];
[_videoPieces setBlockSeekOffRight:^(CGFloat offX) {
  this.seeking = true;
  [this.moviePlayer fof_pause];
  this.lastEndSeconds = this.totalSeconds*offX/CGRectGetWidth(this.videoPieces.bounds);
  [this.moviePlayer.player seekToTime:CMTimeMakeWithSeconds(this.lastEndSeconds, 1) toleranceBefore:kCMTimeZero toleranceAfter:kCMTimeZero];
}];

這里通過監(jiān)聽左右滑塊的事件，將偏移距離轉(zhuǎn)換成時(shí)間，從而設(shè)置播放器的開始時(shí)間和結(jié)束時(shí)間。

循環(huán)播放

self.timeObserverToken = [self.moviePlayer.player addPeriodicTimeObserverForInterval:CMTimeMakeWithSeconds(0.5, NSEC_PER_SEC) queue:dispatch_get_main_queue() usingBlock:^(CMTime time) {
  if (!this.seeking) {
    if (fabs(CMTimeGetSeconds(time)-this.lastEndSeconds)<=0.02) {
        [this.moviePlayer fof_pause];
        [this private_replayAtBeginTime:this.lastStartSeconds];
      }
  }
}];

這里有兩個(gè)注意點(diǎn)：

1. addPeriodicTimeObserverForInterval要進(jìn)行釋放，否則會(huì)有內(nèi)存泄漏。

-(void)dealloc{
  [self.moviePlayer.player removeTimeObserver:self.timeObserverToken];
}

2.這里監(jiān)聽了播放時(shí)間，進(jìn)而計(jì)算是否達(dá)到了我們右邊把手拖動(dòng)的時(shí)間，如果達(dá)到了則重新播放。這個(gè)問題作者思考了很久，怎么實(shí)現(xiàn)邊播放邊截??？差點(diǎn)進(jìn)入了一個(gè)誤區(qū)，真去截取視頻。其實(shí)這里不用截取視頻，只是控制播放時(shí)間和結(jié)束時(shí)間就可以了，最后只截取一次就行了。

總結(jié)

這次微信小視頻編輯實(shí)現(xiàn)過程中，確實(shí)遇到了挺多的小問題。不過通過仔細(xì)的研究，最終完美實(shí)現(xiàn)了，有種如釋重負(fù)的感覺。哈哈。

源碼

GitHub源碼

總結(jié)

以上所述是小編給大家介紹的iOS實(shí)現(xiàn)微信朋友圈視頻截取功能，希望對(duì)大家有所幫助，如果大家有任何疑問請(qǐng)給我留言，小編會(huì)及時(shí)回復(fù)大家的。在此也非常感謝大家對(duì)腳本之家網(wǎng)站的支持！

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