iOS 音视频合成

   <h1>前言</h1>    <p>因为最近做项目有遇到音视频合成的需求,但是网上的教程某些地方总是写的很模糊,所以自己调研完成之后决定写一篇博客分享出来,供大家一起学习进步</p>    <p>音视频主要是利用AVFoundation框架下的AVMutableComposition来合成音视频.</p>    <h2>在AVMutableComposition中传入两个数据流,一个是音频一个是视频,之后调用合成方法就可以了</h2>    <h1>上代码</h1>    <h2>storyBoard中拖入一个button,一个imageView</h2>    <div class="image-package" href="https://simg.open-open.com/show/3d644f9a4a89aa89567493b3d47c5df6.png">    <img src="https://simg.open-open.com/show/3d644f9a4a89aa89567493b3d47c5df6.png" width="468" height="718" data-original-src="http://upload-images.jianshu.io/upload_images/1298596-06106e4adf4f6758?imageMogr2/auto-orient/strip%7CimageView2/2" />     <br />     <div class="image-caption">     这里写图片描述     </div>    </div>    <h2>为了效果好可以将IamgeView的背景色调为黑色</h2>    <h2>然后在ViewController中添加以下代码</h2>    <pre class="brush:cpp; toolbar: true; auto-links: false;">#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:^{         // 回到主线程         dispatch_async(dispatch_get_main_queue(), ^{             // 调用播放方法             [self playWithUrl:outputFileUrl];         });     }]; }  /** 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]; }</pre>    <h2>MBP是一个第三方提示类,如果不关心这个功能可以删除这三行代码和头文件</h2>    <pre class="brush:cpp; toolbar: true; auto-links: false;">// mbp提示框     [MBProgressHUD showMessage:@"正在处理中"]; // 隐藏提示框 开始播放     [MBProgressHUD hideHUD];     [MBProgressHUD showSuccess:@"合成完成"];</pre>    <h1>效果图</h1>    <h3>因为是gif..请自己yy出Uber视频配上五环之歌(我感觉还挺配的)</h3>    <div class="image-package" href="https://simg.open-open.com/show/b1d89a1cbd23588541a54ebbd9be24e5.gif">    <img src="https://simg.open-open.com/show/b1d89a1cbd23588541a54ebbd9be24e5.gif" width="480" height="640" data-original-src="http://upload-images.jianshu.io/upload_images/1298596-e33e93f0878aa5cf?imageMogr2/auto-orient/strip" />     <br />     <div class="image-caption">     这里写图片描述     </div>    </div>    <h2>GitHub:<a href="/misc/goto?guid=4959652735440784332" target="_blank">https://github.com/Lafree317/MergeVideoAndMusic</a> </h2>    <hr />    <p>本人还是一只小菜鸡,不过是一只热心肠的菜鸡,如果有需要帮助或者代码中有更好的建议的话可以发邮件到lafree317@163.com中,我们一起进步XD</p>    <p>来自： <a href="/misc/goto?guid=4959652735542259825" rel="nofollow" target="_blank">http://www.jianshu.com/p/9f83af9dbbef</a></p>