keras-team/keras · error · ValueError

Output mode is invalid, it must be one of {', '.join(all_mod

Error message

Output mode is invalid, it must be one of {', '.join(all_modes)}. Received: mode={mode}

What it means

Error "Output mode is invalid, it must be one of {', '.join(all_modes)}. Received: mode={mode}" thrown in keras-team/keras.

Source

Thrown at keras/src/layers/preprocessing/stft_spectrogram.py:172

                f"frame_length={frame_length}"
            )

        if fft_length is not None and fft_length < frame_length:
            raise ValueError(
                "`fft_length` should be not less than `frame_length`. "
                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

View on GitHub (pinned to 7a34a03db6)

When it happens

Trigger: Thrown at keras/src/layers/preprocessing/stft_spectrogram.py:172 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/4a1dd9d7d4633aff. Report an issue: GitHub.