iOS 音视频分离（导出视频中的音频）
/**
* 获取视频中的音频
*
* @param videoUrl 视频的本地路径
* @param newFile 导出音频的路径
* @completionHandle 音频路径的回调
*/
+ (void)VideoManagerGetBackgroundMiusicWithVideoUrl:(NSURL*)videoUrlnewFile:(NSString*)newFilecompletion:(void(^)(NSString*data))completionHandle{
AVURLAsset*videoAsset = [[AVURLAssetalloc]initWithURL:videoUrloptions:nil];;
NSArray *keys = @[@"duration",@"tracks"];
[videoAssetloadValuesAsynchronouslyForKeys:keys completionHandler:^{
NSError*error =nil;
AVKeyValueStatusstatus = [videoAssetstatusOfValueForKey:@"tracks"error:&error];
if(status ==AVKeyValueStatusLoaded) {//数据加载完成
AVMutableComposition *mixComposition = [[AVMutableComposition alloc] init];
// 2 - Video track
//Audio Recorder
//创建一个轨道,类型是AVMediaTypeAudio
AVMutableCompositionTrack *firstTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
//获取videoAsset中的音频,插入轨道
[firstTrackinsertTimeRange:CMTimeRangeMake(kCMTimeZero, videoAsset.duration) ofTrack:[[videoAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0] atTime:kCMTimeZero error:nil];
NSURL*url = [NSURLfileURLWithPath:newFile];
AVAssetExportSession *exporter = [[AVAssetExportSession alloc] initWithAsset:mixComposition presetName:AVAssetExportPresetAppleM4A];//输出为M4A音频
exporter.outputURL= url;
exporter.outputFileType=@"com.apple.m4a-audio";//类型和输出类型一致
exporter.shouldOptimizeForNetworkUse = YES;
[exporterexportAsynchronouslyWithCompletionHandler:^{
dispatch_async(dispatch_get_main_queue(), ^{
if(exporter.status==AVAssetExportSessionStatusCompleted) {
completionHandle(newFile);
}else{
NSLog(@"提取失败原因：%@",exporter.error);
completionHandle(nil);
}
});
}];
}
}];
}
