Dear Peter,

Thank you for your response.

Yes. it is a custom binary file type. I attached the sample binary files.

humanK562C_d2.splib is the original one.

temp.splib is the uploaded and corrupted one.

For definition in Galaxy, I just simply inherit the binary.Binary. 

The definition is below:

In Python script:

class Splib( binary.Binary ):

        """ Class describing a spectral library (splib)"""

        file_ext = "splib"  

I did not add the sniffer but specify the file format manually in the page of "get data".