read dfc files from BrainSuite

dfcread.py

import struct
import numpy

class DFC(object):
    def __init__(self, fname):
        self.fname = fname
        # http://brainsuite.org/formats/dfc/
        with open(fn, 'rb') as fd:
            self.magic = fd.read(8)
            self.version = struct.unpack('B' * 4, fd.read(4))
            (self.header_size,
             self.data_start,
             self.metadata_offset,
             self.subject_data_offset,
             self.n_curves) = struct.unpack('IIIIi', fd.read(20))
            self.curves = list()
            fd.seek(data_start)
            for i in range(self.n_curves):
                n_points, = struct.unpack('I', fd.read(4))
                curve = fd.read(4 * 3 * n_points)
                self.curves.append(
                    numpy.fromstring(curve, dtype=numpy.float32)
                        .reshape((n_points, 3))
                )