def main():
    args = parse_args()

    if args.out is not None and not args.out.endswith(('.pkl', '.pickle')):
        raise ValueError('The output file must be a pkl file.')

    cfg = mmcv.Config.fromfile(args.config)
    # set cudnn_benchmark
    if cfg.get('cudnn_benchmark', False):
        torch.backends.cudnn.benchmark = True
    cfg.data.test.test_mode = True

    dataset = obj_from_dict(cfg.data.test, datasets, dict(test_mode=True))
    if args.gpus == 1:
        model = build_detector(
            cfg.model, train_cfg=None, test_cfg=cfg.test_cfg)
        load_checkpoint(model, args.checkpoint, strict=True)
        model = MMDataParallel(model, device_ids=[0])

        data_loader = build_dataloader(
            dataset,
            imgs_per_gpu=1,
            workers_per_gpu=cfg.data.workers_per_gpu,
            num_gpus=1,
            dist=False,
            shuffle=False)
        outputs = single_test(model, data_loader)
    else:
        model_args = cfg.model.copy()
        model_args.update(train_cfg=None, test_cfg=cfg.test_cfg)
        model_type = getattr(detectors, model_args.pop('type'))
        outputs = parallel_test(
            model_type,
            model_args,
            args.checkpoint,
            dataset,
            _data_func,
            range(args.gpus),
            workers_per_gpu=args.proc_per_gpu)

    if args.out:
        print('writing results to {}'.format(args.out))
        mmcv.dump(outputs, args.out)

    eval_type = args.eval
    if eval_type:
        print('Starting evaluate {}'.format(eval_type))

        result_file = osp.join(args.out + '.csv')
        results2csv(dataset, outputs, result_file)

        ava_eval(result_file, eval_type,
                 args.label_file, args.ann_file, args.exclude_file)