keras-team/keras · error · ValueError

Scaling is invalid, it must be `None`, 'density' or 'spectru

Error message

Scaling is invalid, it must be `None`, 'density' or 'spectrum'. Received scaling={scaling}

What it means

Error "Scaling is invalid, it must be `None`, 'density' or 'spectrum'. Received scaling={scaling}" thrown in keras-team/keras.

Source

Thrown at keras/src/layers/preprocessing/stft_spectrogram.py:178

                f"Received fft_length={fft_length}, frame_length={frame_length}"
            )

        if fft_length is not None and (fft_length & -fft_length) != fft_length:
            warnings.warn(
                "`fft_length` is recommended to be a power of two. "
                f"Received fft_length={fft_length}"
            )

        all_modes = ["log", "magnitude", "psd", "real", "imag", "angle", "stft"]

        if mode not in all_modes:
            raise ValueError(
                "Output mode is invalid, it must be one of "
                f"{', '.join(all_modes)}. Received: mode={mode}"
            )

        if scaling is not None and scaling not in ["density", "spectrum"]:
            raise ValueError(
                "Scaling is invalid, it must be `None`, 'density' "
                f"or 'spectrum'. Received scaling={scaling}"
            )

        if padding not in ["valid", "same"]:
            raise ValueError(
                "Padding is invalid, it should be 'valid', 'same'. "
                f"Received: padding={padding}"
            )

        if isinstance(window, str):
            # throws an exception for invalid window function
            scipy.signal.get_window(window, 1)

        super().__init__(**kwargs)

        self.mode = mode

View on GitHub (pinned to 7a34a03db6)

When it happens

Trigger: Thrown at keras/src/layers/preprocessing/stft_spectrogram.py:178 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of keras-team/keras@7a34a03db6 (2026-08-25). Data as JSON: /api/errors/15f759e719093ea4. Report an issue: GitHub.