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Slepi/Code/Utilities/spm12/external/mne/fiff_setup_read_raw.m
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fiff_setup_read_raw.m
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function [data] = fiff_setup_read_raw(fname,allow_maxshield)
%
% [data] = fiff_setup_read_raw(fname,allow_maxshield)
%
% Read information about raw data file
%
% fname Name of the file to read
% allow_maxshield Accept unprocessed MaxShield data
%
%
% Author : Matti Hamalainen, MGH Martinos Center
% License : BSD 3-clause
%
% Revision 1.12 2009/03/30 11:37:37 msh
% Added copying of measurement info blocks from the original like in mne_browse_raw
%
% Revision 1.11 2008/09/30 17:22:39 msh
% Added possibility to load unprocessed MaxShield data
%
% Revision 1.10 2008/06/16 20:26:03 msh
% Added some semicolons to avoid unncessary output.
%
% Revision 1.9 2008/06/16 19:48:32 msh
% Added some comments
%
% Revision 1.8 2008/06/16 19:46:30 msh
% Fixed handling of initial skip so that the result is compatible with the event files
%
% Revision 1.7 2007/06/08 14:44:16 msh
% Fixed problem appearing with multiple skips in a data file
%
% Revision 1.6 2006/05/03 18:53:05 msh
% Approaching Matlab 6.5 backward compatibility
%
% Revision 1.5 2006/04/23 15:29:40 msh
% Added MGH to the copyright
%
% Revision 1.4 2006/04/21 16:17:48 msh
% Added handling of CTF compensation
%
% Revision 1.3 2006/04/21 14:23:16 msh
% Further improvements in raw data reading
%
% Revision 1.2 2006/04/21 11:33:18 msh
% Added raw segment reading routines
%
% Revision 1.1 2006/04/10 23:26:54 msh
% Added fiff reading routines
%
%
global FIFF;
if isempty(FIFF)
FIFF = fiff_define_constants();
end
me='MNE:fiff_setup_read_raw';
if nargin ~= 1 && nargin ~= 2
error(me,'Incorrect number of arguments');
end
if nargin == 1
allow_maxshield = false;
end
%
% Open the file
%
fprintf(1,'Opening raw data file %s...\n',fname);
[ fid, tree ] = fiff_open(fname);
%
% Read the measurement info
%
[ info, meas ] = fiff_read_meas_info(fid,tree);
%
% Locate the data of interest
%
raw = fiff_dir_tree_find(meas,FIFF.FIFFB_RAW_DATA);
if isempty(raw)
raw = fiff_dir_tree_find(meas,FIFF.FIFFB_CONTINUOUS_DATA);
if allow_maxshield
raw = fiff_dir_tree_find(meas,FIFF.FIFFB_SMSH_RAW_DATA);
if isempty(raw)
error(me,'No raw data in %s',fname);
end
else
if isempty(raw)
error(me,'No raw data in %s',fname);
end
end
end
%
% Set up the output structure
%
info.filename = fname;
data.fid = fid;
data.info = info;
data.first_samp = 0;
data.last_samp = 0;
%
% Process the directory
%
dir = raw.dir;
nent = raw.nent;
nchan = info.nchan;
first = 1;
first_samp = 0;
first_skip = 0;
%
% Get first sample tag if it is there
%
if dir(first).kind == FIFF.FIFF_FIRST_SAMPLE
tag = fiff_read_tag(fid,dir(first).pos);
first_samp = tag.data;
first = first + 1;
end
%
% Omit initial skip
%
if dir(first).kind == FIFF.FIFF_DATA_SKIP
%
% This first skip can be applied only after we know the buffer size
%
tag = fiff_read_tag(fid,dir(first).pos);
first_skip = tag.data;
first = first + 1;
end
%
% Get first sample tag if it is there
%
if dir(first).kind == FIFF.FIFF_FIRST_SAMPLE
tag = fiff_read_tag(fid,dir(first).pos);
first_samp = first_samp + tag.data;
first = first + 1;
end
data.first_samp = first_samp;
%
% Go through the remaining tags in the directory
%
rawdir = struct('ent',{},'first',{},'last',{},'nsamp',{});
nskip = 0;
ndir = 0;
for k = first:nent
ent = dir(k);
if ent.kind == FIFF.FIFF_DATA_SKIP
tag = fiff_read_tag(fid,ent.pos);
nskip = tag.data;
elseif ent.kind == FIFF.FIFF_DATA_BUFFER
%
% Figure out the number of samples in this buffer
%
switch ent.type
case FIFF.FIFFT_DAU_PACK16
nsamp = ent.size/(2*nchan);
case FIFF.FIFFT_SHORT
nsamp = ent.size/(2*nchan);
case FIFF.FIFFT_FLOAT
nsamp = ent.size/(4*nchan);
case FIFF.FIFFT_INT
nsamp = ent.size/(4*nchan);
otherwise
fclose(fid);
error(me,'Cannot handle data buffers of type %d',ent.type);
end
%
% Do we have an initial skip pending?
%
if first_skip > 0
first_samp = first_samp + nsamp*first_skip;
data.first_samp = first_samp;
first_skip = 0;
end
%
% Do we have a skip pending?
%
if nskip > 0
ndir = ndir+1;
rawdir(ndir).ent = [];
rawdir(ndir).first = first_samp;
rawdir(ndir).last = first_samp + nskip*nsamp - 1;
rawdir(ndir).nsamp = nskip*nsamp;
first_samp = first_samp + nskip*nsamp;
nskip = 0;
end
%
% Add a data buffer
%
ndir = ndir+1;
rawdir(ndir).ent = ent;
rawdir(ndir).first = first_samp;
rawdir(ndir).last = first_samp + nsamp - 1;
rawdir(ndir).nsamp = nsamp;
first_samp = first_samp + nsamp;
end
end
data.last_samp = first_samp - 1;
%
% Add the calibration factors
%
cals = zeros(1,data.info.nchan);
for k = 1:data.info.nchan
cals(k) = data.info.chs(k).range*data.info.chs(k).cal;
end
%
data.cals = cals;
data.rawdir = rawdir;
data.proj = [];
data.comp = [];
%
fprintf(1,'\tRange : %d ... %d = %9.3f ... %9.3f secs\n',...
data.first_samp,data.last_samp,...
double(data.first_samp)/data.info.sfreq,...
double(data.last_samp)/data.info.sfreq);
fprintf(1,'Ready.\n');
fclose(data.fid);
data.fid = -1;
return;
function [tag] = find_tag(node,findkind)
for p = 1:node.nent
kind = node.dir(p).kind;
pos = node.dir(p).pos;
if kind == findkind
tag = fiff_read_tag(fid,pos);
return;
end
end
tag = [];
return
end
end
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