def get_bytes_per_data_block(header):
    """Calculates the number of bytes in each 60 or 128 sample datablock."""
    bytes_per_block = header['num_samples_per_data_block'] * 4
    bytes_per_block = bytes_per_block + header['num_samples_per_data_block'
        ] * 2 * header['num_amplifier_channels']
    bytes_per_block = bytes_per_block + header['num_samples_per_data_block'
        ] / 4 * 2 * header['num_aux_input_channels']
    bytes_per_block = bytes_per_block + 1 * 2 * header[
        'num_supply_voltage_channels']
    bytes_per_block = bytes_per_block + header['num_samples_per_data_block'
        ] * 2 * header['num_board_adc_channels']
    if header['num_board_dig_in_channels'] > 0:
        bytes_per_block = bytes_per_block + header['num_samples_per_data_block'
            ] * 2
    if header['num_board_dig_out_channels'] > 0:
        bytes_per_block = bytes_per_block + header['num_samples_per_data_block'
            ] * 2
    if header['num_temp_sensor_channels'] > 0:
        bytes_per_block = bytes_per_block + 1 * 2 * header[
            'num_temp_sensor_channels']
    return bytes_per_block
