最近接触一个音频的项目，之前接触过，不过都是用系统自带的去实现，没有仔细研究

在网上找到了一个demo，挺好用，反正效果是实现，非常不错。具体链接忘记了。

#pragma mark - 音视频剪辑,如果是视频把下面的类型换为AVFileTypeAppleM4V

// assetURL 本地路径地址

//startTime 开始时间

//endTime 结束时间

//outputPath 裁剪完成后的地址

+ (void)cutAudioVideoResourcePath:(NSURL *)assetURL startTime:(CGFloat)startTime endTime:(CGFloat)endTime complition:(void (^)(NSURL *outputPath,BOOL isSucceed)) completionHandle{

    //    素材

    AVAsset *asset = [AVAsset assetWithURL:assetURL];

    //    导出素材

    AVAssetExportSession *exporter = [[AVAssetExportSession alloc]initWithAsset:asset presetName:AVAssetExportPresetAppleM4A];

    //剪辑(设置导出的时间段)

    CMTime start = CMTimeMakeWithSeconds(startTime, asset.duration.timescale);

    CMTime duration = CMTimeMakeWithSeconds(endTime - startTime,asset.duration.timescale);

    exporter.timeRange = CMTimeRangeMake(start, duration);

//    输出路径

    NSURL *outputPath = [self exporterPath];

    exporter.outputURL = [self exporterPath];

//    输出格式

    exporter.outputFileType = AVFileTypeAppleM4A;

    exporter.shouldOptimizeForNetworkUse= YES;

//    合成后的回调

    [exporter exportAsynchronouslyWithCompletionHandler:^{

        switch ([exporter status]) {

            case AVAssetExportSessionStatusFailed: {

                NSLog(@"合成失败：%@",[[exporter error] description]);

                completionHandle(outputPath,NO);

            } break;

            case AVAssetExportSessionStatusCancelled: {

                completionHandle(outputPath,NO);

            } break;

            case AVAssetExportSessionStatusCompleted: {

                completionHandle(outputPath,YES);

            } break;

            default: {

                completionHandle(outputPath,NO);

            } break;

        }

    }];

}

#pragma mark - 输出路径

+ (NSURL *)exporterPath {

    NSInteger nowInter = (long)[[NSDate date] timeIntervalSince1970];

    NSString *fileName = [NSString stringWithFormat:@"output%ld.mp4",(long)nowInter];

    NSString *documentsDirectory = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES).lastObject;

    NSString *outputFilePath =[documentsDirectory stringByAppendingPathComponent:fileName];

    if([[NSFileManager defaultManager]fileExistsAtPath:outputFilePath]){

        [[NSFileManager defaultManager]removeItemAtPath:outputFilePath error:nil];

    }

    return [NSURL fileURLWithPath:outputFilePath];

}