我想将数据库中的多段音频合成一段，需要使用什么包？

我想将数据库中的多段音频合成一段，需要使用什么插件或者可以直接使用函数完成拼接？

不是很明白你的问题，可以描述得更详细些吗？
/**
音频合成

@param paths 要合成音频的路径（NSURL)按照先后顺序
@param outputFilePath 合成后输出的路径
@param fileName 文件名称
@param success 合成成功
@param failure 合成失败
/
-(void)voiceCompoundWithVoicePaths:(NSArray *)paths outPutFilePath:(NSString *)outputFilePath withFileName:(NSString *)fileName compoundSuccess:(void(^)(NSString *path))success failure:(void(^)(NSError error))failure{

    // 音频合成
    AVMutableComposition *composition = [AVMutableComposition composition];
    AVMutableCompositionTrack *comTrack = [composition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
    CMTime beginTime = kCMTimeZero;

    for (int i = 0; i < paths.count; i++) {
    NSURL *voiceUrl = paths[i];
    AVURLAsset *voiceSet = [[AVURLAsset alloc] initWithURL:voiceUrl options:nil];
    AVAssetTrack *voiceTrack = [[voiceSet tracksWithMediaType:AVMediaTypeAudio] firstObject];
        [comTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, voiceSet.duration) ofTrack:voiceTrack atTime:beginTime error:nil];
        beginTime = CMTimeAdd(beginTime, voiceSet.duration);
    }

    NSFileManager *fileManager = [NSFileManager defaultManager];
    BOOL judge = [fileManager fileExistsAtPath:outputFilePath];
    // 判断该路径下是否存在对应的文件
    if (!judge){
        [fileManager createDirectoryAtPath:outputFilePath withIntermediateDirectories:YES attributes:nil error:nil];
    }
    // 最终合成输出路径
    NSString *outPutFilePath = [outputFilePath stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.m4a",fileName]];
    // 添加合成路径
    NSURL *fileUrl = [NSURL fileURLWithPath:outPutFilePath];
    // 输出
    AVAssetExportSession *assetExport = [[AVAssetExportSession alloc] initWithAsset:composition presetName:AVAssetExportPresetAppleM4A];
    assetExport.outputFileType = AVFileTypeAppleM4A;
    assetExport.outputURL = fileUrl;
    // 优化
    assetExport.shouldOptimizeForNetworkUse = YES;
    [assetExport exportAsynchronouslyWithCompletionHandler:^{
        dispatch_async(dispatch_get_main_queue(), ^{
            if (!assetExport.error) {
                //合成成功
                success(outPutFilePath);
            }else{
                //合成失败
                failure(assetExport.error);
            }
        });
    }];
}