How to use the spleeter.utils.audio.ffmpeg.input function in spleeter

:param codec: (Optional) Writing codec to use.
        :param bitrate: (Optional) Bitrate of the written audio file.
        :raise IOError: If any error occurs while using FFMPEG to write data.
        """
        directory = os.path.split(path)[0]
        if not os.path.exists(directory):
            os.makedirs(directory)
        get_logger().debug('Writing file %s', path)
        input_kwargs = {'ar': sample_rate, 'ac': data.shape[1]}
        output_kwargs = {'ar': sample_rate, 'strict': '-2'}
        if bitrate:
            output_kwargs['audio_bitrate'] = bitrate
        if codec is not None and codec != 'wav':
            output_kwargs['codec'] = codec
        process = (
            ffmpeg
            .input('pipe:', format='f32le', **input_kwargs)
            .output(path, **output_kwargs)
            .overwrite_output()
            .run_async(pipe_stdin=True, quiet=True))
        try:
            process.stdin.write(data.astype('

if 'streams' not in probe or len(probe['streams']) == 0:
            raise IOError('No stream was found with ffprobe')
        metadata = next(
            stream
            for stream in probe['streams']
            if stream['codec_type'] == 'audio')
        n_channels = metadata['channels']
        if sample_rate is None:
            sample_rate = metadata['sample_rate']
        output_kwargs = {'format': 'f32le', 'ar': sample_rate}
        if duration is not None:
            output_kwargs['t'] = _to_ffmpeg_time(duration)
        if offset is not None:
            output_kwargs['ss'] = _to_ffmpeg_time(offset)
        process = (
            ffmpeg
            .input(path)
            .output('pipe:', **output_kwargs)
            .run_async(pipe_stdout=True, pipe_stderr=True))
        buffer, _ = process.communicate()
        waveform = np.frombuffer(buffer, dtype='