Following the [documentation](https://www.idiap.ch/software/bob/docs/bob/docs/master/bob/bob.pad.base/doc/vanilla_pad_intro.html#running-a-biometric-experiment-with-vanilla-pad), the vanilla-pad baseline can be invoked with: ```python bob pad vanilla-pad replay-attack svm-frames -o results -vv ``` This leads to the following exception: ```python Traceback (most recent call last): File "/remote/idiap.svm/temp.biometric03/cecabert/bob_beta/src/bob.pipelines/bob/pipelines/wrappers.py", line 808, in _fit self.estimator = self.estimator.fit(X, y, **fit_params) File "/remote/idiap.svm/temp.biometric03/cecabert/bob_beta/src/bob.pipelines/bob/pipelines/wrappers.py", line 337, in fit self.estimator = self.estimator.fit(X, **kwargs) File "/remote/idiap.svm/temp.biometric03/cecabert/mambaforge/envs/bob_deps/lib/python3.10/site-packages/sklearn/svm/_base.py", line 190, in fit X, y = self._validate_data( File "/remote/idiap.svm/temp.biometric03/cecabert/mambaforge/envs/bob_deps/lib/python3.10/site-packages/sklearn/base.py", line 581, in _validate_data X, y = check_X_y(X, y, **check_params) File "/remote/idiap.svm/temp.biometric03/cecabert/mambaforge/envs/bob_deps/lib/python3.10/site-packages/sklearn/utils/validation.py", line 964, in check_X_y X = check_array( File "/remote/idiap.svm/temp.biometric03/cecabert/mambaforge/envs/bob_deps/lib/python3.10/site-packages/sklearn/utils/validation.py", line 794, in check_array raise ValueError( ValueError: Found array with dim 4. Estimator expected <= 2. ``` The `fit` method of the SVM classifier is expecting its input to be `(n_samples, n_features)` which is not what is provided by the `VideoToFrames` transformer. One possible solution would be to add an intermediate step between the two operations to flatten the data.