def _find_blob_start(self):
<EOL>self._setup_chans()<EOL>blob_time_start = self.t_start<EOL>blob_freq_start = self.chan_start_idx<EOL>blob_start = blob_time_start * self.n_channels_in_file + blob_freq_start<EOL>return blob_start<EOL>
Find first blob from selection.