Dawn@4: function i = sf_info(i)
Dawn@4: % i=sf_info(i) - extract useful info from file
Dawn@4: 
Dawn@4: % Alain de Cheveigné, CNRS/Ircam, 2002.
Dawn@4: % Copyright (c) 2002 Centre National de la Recherche Scientifique.
Dawn@4: %
Dawn@4: % Permission to use, copy, modify, and distribute this software without 
Dawn@4: % fee is hereby granted FOR RESEARCH PURPOSES only, provided that this
Dawn@4: % copyright notice appears in all copies and in all supporting 
Dawn@4: % documentation, and that the software is not redistributed for any 
Dawn@4: % fee (except for a nominal shipping charge). 
Dawn@4: %
Dawn@4: % For any other uses of this software, in original or modified form, 
Dawn@4: % including but not limited to consulting, production or distribution
Dawn@4: % in whole or in part, specific prior permission must be obtained from CNRS.
Dawn@4: % Algorithms implemented by this software may be claimed by patents owned 
Dawn@4: % by CNRS, France Telecom, Ircam or others.
Dawn@4: %
Dawn@4: % The CNRS makes no representations about the suitability of this 
Dawn@4: % software for any purpose.  It is provided "as is" without express
Dawn@4: % or implied warranty.  Beware of the bugs.
Dawn@4: 
Dawn@4: if ~nargin ; error('sf_info: no input arguement'); end
Dawn@4: if ~isa(i, 'struct')
Dawn@4: 	j.fname=i;
Dawn@4:     i=j;
Dawn@4: 	i=sf_info(i);
Dawn@4: 	return
Dawn@4: end
Dawn@4: if ~isfield(i, 'fname'); error('sf_info: no fname field'); end
Dawn@4: 
Dawn@4: % guess format only if unknown
Dawn@4: if ~isfield(i, 'format') | isempty(i.format);
Dawn@4: 	i = sf_format(i);
Dawn@4: 	if ~strcmp(i.format, 'matrix') disp(i.format); end	
Dawn@4: end
Dawn@4: 
Dawn@4: % handle workspace matrices as if they were files
Dawn@4: if strcmp(i.format, 'matrix')
Dawn@4: 	[nrows, ncols] = size(i.fname);
Dawn@4: 	i.nchans=ncols;
Dawn@4: 	i.nsamples=nrows;
Dawn@4: 	i.totalsamples = i.nsamples*i.nchans;
Dawn@4:     i.sr=[];
Dawn@4: 	return;
Dawn@4: end
Dawn@4: 
Dawn@4: % close file if open
Dawn@4: if exist('i.fd') & fopen(i.fd)
Dawn@4: 	fclose(i.fd);
Dawn@4: end
Dawn@4: 
Dawn@4: % use standard matlab functions for AU and WAV and MACSND
Dawn@4: if strcmp(i.format, 'AU')
Dawn@4: 	if isempty(findstr('.', i.fname))
Dawn@4: 		disp(['WARNING: matlab function AUREAD requires '...
Dawn@4: 		'.au or .snd suffix on file name: ' i.fname]);
Dawn@4: 	end
Dawn@4: 	sz = auread(i.fname, 'size');
Dawn@4: 	i.nsamples=sz(1);
Dawn@4: 	i.nchans=sz(2);
Dawn@4: 	i.totalsamples = i.nsamples*i.nchans;
Dawn@4: 	[dummy, i.sr, i.samplebits] = auread(i.fname, 1);
Dawn@4: 	return;
Dawn@4: end
Dawn@4: if strcmp(i.format, 'WAV')
Dawn@4: 	if isempty(findstr('.wav', i.fname)) & isempty(findstr('.WAV', i.fname))
Dawn@4: 		disp(['WARNING: matlab function WAVREAD requires '...
Dawn@4: 		'.wav suffix on file name: ' i.fname]);
Dawn@4: 	end
Dawn@4: 	sz = wavread(i.fname, 'size');
Dawn@4: 	i.nsamples=sz(1);
Dawn@4: 	i.nchans=sz(2);
Dawn@4: 	i.totalsamples = i.nsamples*i.nchans;
Dawn@4: 	[dummy, i.sr, i.samplebits] = wavread(i.fname, 1);
Dawn@4: 	return;
Dawn@4: end
Dawn@4: if strcmp(i.format, 'MACSND')
Dawn@4: 	% must load the data to get info - this is stupid
Dawn@4: 	if ~isempty(findstr(':', i.fname))
Dawn@4: 		disp(['matlab function READSND cannot handle an '...
Dawn@4: 		'indirect path: ' i.fname]);
Dawn@4: 	end
Dawn@4: 	if 3==exist('readsnd')		
Dawn@4: 		[data, i.sr] = eval('readsnd(i.fname)');
Dawn@4: 	else
Dawn@4: 		error('cannot read MACSND on this platform');
Dawn@4: 	end
Dawn@4: 	i.nsamples = size(data,2);
Dawn@4: 	i.nchans = size(data,1);
Dawn@4: 	i.totalsamples = i.nsamples*i.nchans;
Dawn@4: 	return
Dawn@4: end
Dawn@4: 
Dawn@4: % reopen file
Dawn@4: if strcmp(i.format, 'ascii') ...
Dawn@4: 	| strcmp(i.format, 'csv') | strcmp(i.format, '|WAVE')
Dawn@4: 	[i.fd, msg] = fopen(i.fname, 'rt');
Dawn@4: else
Dawn@4: 	[i.fd, msg] = fopen(i.fname, 'r', 'ieee-be.l64');
Dawn@4: end
Dawn@4: if i.fd == -1
Dawn@4: 	if isempty(msg)
Dawn@4: 		error(['could not open: ', i.fname]);
Dawn@4: 	else
Dawn@4: 		error(msg)
Dawn@4: 	end
Dawn@4: end
Dawn@4: fd = i.fd;
Dawn@4: if ~isfield(i, 'nbytes')
Dawn@4: 	if (-1 == fseek(i.fd, 0, 1)) ; error ('fseek failed');  end;	
Dawn@4: 	i.nbytes = ftell(i.fd);
Dawn@4: end
Dawn@4: fseek(fd, 0, -1);	% rewind
Dawn@4: 
Dawn@4: 
Dawn@4: switch i.format
Dawn@4: %%%%%%%%%%%%%%%%%%% AIFF %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Dawn@4: case {'AIFF','AIFC'}
Dawn@4: 	fseek(fd, 12, 0); % skip container chunk
Dawn@4: 	% skip over spurious chunks
Dawn@4:         idx=ftell(fd);
Dawn@4: 	while 1
Dawn@4:         	magic=char(fread(fd,4,'uchar'))';
Dawn@4:                 if strcmp(magic,'COMM'); break; end;
Dawn@4:                 idx = idx+1;
Dawn@4:                 status = fseek(fd,idx,-1);
Dawn@4: 		if status == -1
Dawn@4: 			error('expected COMM magic word, found eof');
Dawn@4: 		end;
Dawn@4: 	end;
Dawn@4: 
Dawn@4:         %ckSize=fread(fd,1,'int32');
Dawn@4: 	%status = fseek(fd, ckSize, 0);		% skip to end of chunk
Dawn@4:         %if status == -1
Dawn@4:         %      error('unexpected eof');
Dawn@4:         %end
Dawn@4: 
Dawn@4: 	%while (1) 
Dawn@4: 	%	magic = char(fread(fd, 4, 'char'))';
Dawn@4: 	%	if ~strcmp(magic, 'SSND')
Dawn@4: 	%		fseek(fd, -4, 0);	% skip back
Dawn@4: 	%		break;
Dawn@4: 	%	end
Dawn@4: 	%	ckSize = fread(fd, 1, 'long');
Dawn@4: 	%	fseek(fd, ckSize, 0);	% skip to end of sound chunk
Dawn@4: 	%end
Dawn@4: 	%magic = char(fread (fd, 4, 'char'))';
Dawn@4: 	%if ~strcmp(magic, 'COMM'); error(['expected COMM, found ', magic]) ; end
Dawn@4: 	commsz = fread(fd, 1, 'int32'); 
Dawn@4: 	i.nchans = fread(fd, 1, 'int16');
Dawn@4: 	i.nsamples = fread(fd, 1, 'uint32');
Dawn@4: 	i.totalsamples = i.nsamples*i.nchans;
Dawn@4: 	i.samplebits = fread(fd, 1, 'int16');
Dawn@4: 	switch i.samplebits
Dawn@4: 	case 16
Dawn@4: 		i.sample_bytes = 2;
Dawn@4: 		i.sample_type = 'int16';
Dawn@4: 	case 32
Dawn@4: 		i.sample_bytes = 4;
Dawn@4: 		i.sample_type = 'int32';	% or float?
Dawn@4: 	otherwise
Dawn@4: 		error(['unexpected samplebits: ' num2str(i.samplebits) ]);
Dawn@4: 	end
Dawn@4: 	% read sampling rate using Hideki Kawahara's code:
Dawn@4: 	srex1=fread(fd,1,'uint16');
Dawn@4: 	srex2=fread(fd,1,'uint64');
Dawn@4: 	if strcmp(char(i.format),'AIFC')
Dawn@4: 	    compress=fread(fd,4,'uchar');
Dawn@4: 		if ~strcmp(char(compress),'NONE')
Dawn@4: 		    error('Compression is not supported.');
Dawn@4: 		end;
Dawn@4: 	    	fseek(fd, commsz-22, 0);
Dawn@4: 	end;
Dawn@4: 	i.sr = 2^(srex1-16383)*srex2/hex2dec('8000000000000000');
Dawn@4: 	%fseek(fd, 12, -1);	% skip back to end of container chunk
Dawn@4: 	% skip over eventual common chunk
Dawn@4: 	%while(1)
Dawn@4: 	%	magic = char(fread(fd, 4, 'char'))';
Dawn@4: 	%	if ~strcmp(magic, 'COMM')
Dawn@4: 	%		fseek(fd, -4, 0);	% skip back
Dawn@4: 	%		break;
Dawn@4: 	%	end
Dawn@4: 	%	ckSize = fread(fd, 1, 'long');
Dawn@4: 	%	fseek(fd, ckSize, 0);	% skip over chunk
Dawn@4: 	%end
Dawn@4: 	magic=char(fread(fd,4,'uchar'))';
Dawn@4: 	while ~strcmp(char(magic),'SSND')
Dawn@4: 		[ckSize, count]=fread(fd,1,'int32');
Dawn@4: 		if ~count; 			
Dawn@4: 			error('expected chunk size field, found eof');
Dawn@4: 			return
Dawn@4: 		end
Dawn@4: 		status = fseek(fd, ckSize, 0);		% skip to end of chunk
Dawn@4: 		if status == -1
Dawn@4: 			error('expected SSND magic word, found eof');
Dawn@4: 			return
Dawn@4: 		end;
Dawn@4: 		magic=char(fread(fd,4,'uchar'))';
Dawn@4: 	end;
Dawn@4: 
Dawn@4: 	%magic = char(fread(fd, 4, 'char'))';
Dawn@4: 	%if ~strcmp(magic, 'SSND')
Dawn@4: 	%	error (['expected SSND, found' magic]);
Dawn@4: 	%end
Dawn@4: 	fseek(fd, 12, 0);	% skip over ckSize, offset and blocksize fields
Dawn@4: 	i.bytes_to_data = ftell(fd);
Dawn@4: 	if i.totalsamples*i.sample_bytes ~= i.nbytes-i.bytes_to_data
Dawn@4: 		disp(['WARNING: header fields sample_bytes: ' ...
Dawn@4: 		num2str(i.sample_bytes)]); 
Dawn@4: 		disp (['and sample and channel count: ' num2str(i.nsamples) ...
Dawn@4: 		', ' num2str(i.nchans)]);
Dawn@4: 		disp(['are inconsistent with offset to data: ' ...
Dawn@4: 		num2str(i.bytes_to_data) ' and file size: ' ...
Dawn@4: 		num2str(i.nbytes)]);
Dawn@4: 		disp (['(' num2str(i.totalsamples*i.sample_bytes) ...
Dawn@4: 		' ~= ' num2str(i.nbytes-i.bytes_to_data) ')']);
Dawn@4: 	end
Dawn@4: 	
Dawn@4: 	return
Dawn@4: %%%%%%%%%%%%%%%%%%% NIST %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Dawn@4: case 'NIST'
Dawn@4: %	fseek(fd, 0, -1);
Dawn@4: %	line = fscanf(fd, '%s' , 1);
Dawn@4: %	if ~strcmp(line, 'NIST_1A'); error(['expected NIST_1A, found ', magic]); end
Dawn@4: 	fseek(fd, 8, 0);	% skip over magic string
Dawn@4: 	i.bytes_to_data = fscanf(fd, '%d', 1);
Dawn@4: 	while (1)
Dawn@4: 		key = fscanf(fd, '%s', 1);
Dawn@4: 		if strcmp(key, 'end_head'); break; end;
Dawn@4: 		% read third field according to spec in second field (type)
Dawn@4: 		% this may need refining...
Dawn@4: 		type = fscanf(fd, '%s', 1);
Dawn@4: 		if strcmp(type(1:2), '-s')
Dawn@4: 			bytes_to_read = sscanf(type(3:end), '%d', 1);
Dawn@4: 			fseek(fd, 1, 0);	% skip blank
Dawn@4: 			value = char(fread(fd, bytes_to_read, 'char'))';
Dawn@4: 		else 
Dawn@4: 			value = fscanf(fd, '%f', 1);
Dawn@4: 		end
Dawn@4: 		i = setfield(i, key, value);
Dawn@4: 	end
Dawn@4: 	% give standard names to useful fields
Dawn@4: 	if isfield(i, 'channel_count'); i.nchans = i.channel_count; end
Dawn@4: 	if isfield(i, 'sample_count'); i.nsamples = i.sample_count; end
Dawn@4: 	i.totalsamples = i.nsamples*i.nchans;
Dawn@4: 	if isfield(i, 'sample_rate'); 
Dawn@4: 		i.sr = i.sample_rate; 
Dawn@4: 		i.xunits = 's';
Dawn@4: 	end
Dawn@4: 	if ~isfield(i, 'sample_coding'); i.sample_coding = 'pcm'; end
Dawn@4: 	i.bytes_to_data = 1024; 	% needs checking
Dawn@4: 	i.sample_bytes=2;
Dawn@4: 	i.sample_type='int16';
Dawn@4: 	return
Dawn@4: %%%%%%%%%%%%%%%%%%% |WAVE %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Dawn@4: case '|WAV'
Dawn@4: 	line = fscanf(fd, '%s' , 1);	% skip first line
Dawn@4: 	i.nsamples = fscanf(fd, '%d', 1);
Dawn@4: 	i.nchans = fscanf(fd, '%d', 1);
Dawn@4: 	i.totalsamples = i.nsamples*i.nchans;
Dawn@4: 	i.bytes_to_data = ftell(fd);
Dawn@4: 	% channel info handled during data read
Dawn@4: 	i.totalsamples = i.nsamples * i.nchans;
Dawn@4: 	return
Dawn@4: %%%%%%%%%%%%%%%%%%% WFF %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Dawn@4: case 'wff'
Dawn@4: 	fseek(fd, 4, 0);	% skip magic number
Dawn@4: 	i.version = fread(fd, 1, 'long');
Dawn@4: 	i.type_code = fread(fd, 1, 'long');
Dawn@4: 	i.nchans = fread(fd, 1, 'long');
Dawn@4: 	i.info.channel_flags = fread(fd, 1, 'long');
Dawn@4: 	i.bytes_to_data = fread(fd, 1, 'long');
Dawn@4: 	fseek(fd, 40, 0);
Dawn@4: 	i.gen_prog_name = fread(fd, 32, 'char');
Dawn@4: 	i.comment = fread(fd, 32, 'char');
Dawn@4: 	i.sample_bytes = 2;
Dawn@4: 	i.sample_type = 'int16';
Dawn@4: 	return;
Dawn@4: % channel info handled later during channel read
Dawn@4: %%%%%%%%%%%%%%%%%%% ESPS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Dawn@4: case 'ESPS'
Dawn@4: % Based on Peter Kabal's afsp package.
Dawn@4: % This handles at least one kind of ESPS waveform file.  Others?
Dawn@4: 	i.machine_code = fread(fd, 1, 'uint');
Dawn@4: 	i.version_check_code = fread(fd, 1, 'uint');
Dawn@4: 	i.bytes_to_data = fread(fd, 1, 'uint');
Dawn@4: 	i.record_size = fread(fd, 1, 'uint');
Dawn@4: 	fseek(fd, 20, -1);
Dawn@4: 	i.EDR_ESPS_flag = fread(fd, 1, 'uint');
Dawn@4: 	i.align_pad_size = fread(fd, 1, 'uint');
Dawn@4: 	fseek(fd, 32, -1);
Dawn@4: 	i.file_type = fread(fd, 1, 'uint16');
Dawn@4: 	fseek(fd, 40, -1);
Dawn@4: 	i.file_creation_date_time = char(fread(fd, 26, 'char'))';
Dawn@4: 	i.header_version = char(fread(fd, 8, 'char'))';
Dawn@4: 	i.program_name = char(fread(fd, 16, 'char'))';
Dawn@4: 	i.program_version = char(fread(fd, 8, 'char'))';
Dawn@4: 	i.compile_date = char(fread(fd, 26, 'char'))';
Dawn@4: 	i.tag = fread(fd, 1, 'uint');
Dawn@4: 	fseek(fd, 132, -1);
Dawn@4: 	i.ndoubles = fread(fd, 1, 'uint');
Dawn@4: 	i.nfloats = fread(fd, 1, 'uint');
Dawn@4: 	i.nlongs = fread(fd, 1, 'uint');
Dawn@4: 	i.nshorts = fread(fd, 1, 'uint');
Dawn@4: 	i.nchars = fread(fd, 1, 'uint');
Dawn@4: 	i.fixed_header_size = fread(fd, 1, 'uint');
Dawn@4: 	i.var_header_size = fread(fd, 1, 'uint');
Dawn@4: 	%w.dunno_what = fread(fd, 1, 'uint');
Dawn@4: 	fseek(fd, 160, -1);
Dawn@4: 	i.user = char(fread(fd, 8, 'char'))';
Dawn@4: 	% scan the rest of the header to find sampling rate
Dawn@4: 	a = ftell(fd);
Dawn@4: 	bytes_left_in_header = i.bytes_to_data - ftell(fd);
Dawn@4: 	hunk = char(fread(fd, bytes_left_in_header, 'uchar'))';
Dawn@4: 	b = findstr(hunk, 'record_freq');
Dawn@4: 	%fseek(fd, a+b-1, -1);
Dawn@4: 	%w.xxxx = char(fread(fd, 12, 'char'))';
Dawn@4: 	%w.count = fread(fd, 1, 'uint');
Dawn@4: 	%w.data_code = fread(fd, 1, 'ushort');
Dawn@4: 	fseek(fd, a+b-1+12+2+4, -1);
Dawn@4: 	i.sr = fread(fd, 1, 'double');
Dawn@4: 	i.nchans = i.ndoubles+i.nfloats+i.nlongs ...
Dawn@4: 		+i.nshorts+i.nchars;
Dawn@4: 	recordsize = i.ndoubles*8 + i.nfloats*4 + i.nlongs*4 ...
Dawn@4: 		+i.nshorts*2+i.nchars;
Dawn@4: 	i.nsamples = (i.nbytes - i.bytes_to_data) / recordsize;
Dawn@4: 	i.totalsamples = i.nsamples * i.nchans;
Dawn@4: 	i.sample_bytes = 2;			% bug
Dawn@4: 	i.sample_type = 'int16'; 	% bug
Dawn@4: 	return;
Dawn@4: %%%%%%%%%%%%% PLAIN ASCII %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Dawn@4: case 'ascii'
Dawn@4: 	if isfield(i, 'bytes_to_data')
Dawn@4: 		fseek(fd, i.bytes_to_data, 0);
Dawn@4: 	else 
Dawn@4: 		i.bytes_to_data = 0;
Dawn@4: 	end
Dawn@4: 	line = fgetl(fd);
Dawn@4: 	i.nchans = size(sscanf(line, '%f'), 1);
Dawn@4: 	nlines = 1;
Dawn@4: 	while (1)
Dawn@4: 		line = fgets(i.fd);
Dawn@4: 		if isa(line, 'double') & -1 == line; break; end
Dawn@4: 		nlines = nlines+1;
Dawn@4: 	end
Dawn@4: 	i.nsamples = nlines;
Dawn@4: 	i.totalsamples = i.nsamples*i.nchans;
Dawn@4:     i.sr=1;
Dawn@4: 	return
Dawn@4: %%%%%%%%%%%%% COMMA-SEPARATED VALUES %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Dawn@4: case 'csv';
Dawn@4: 	if isfield(i, 'bytes_to_data')
Dawn@4: 		fseek(fd, i.bytes_to_data, 0);
Dawn@4: 	else 
Dawn@4: 		i.bytes_to_data = 0;
Dawn@4: 	end
Dawn@4: 	% todo
Dawn@4: 	return
Dawn@4: %%%%%%%%%%%%% Binary  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Dawn@4: case {'uchar'}; % should take care of signed/unsigned
Dawn@4: 	i.sample_bytes = 1;
Dawn@4: 	i.sample_type = 'uchar';	
Dawn@4: 	if isfield(i, 'bytes_to_data')
Dawn@4: 		fseek(fd, i.bytes_to_data, 0);
Dawn@4: 	else 
Dawn@4: 		i.bytes_to_data = 0;
Dawn@4: 	end
Dawn@4: 	if ~isfield(i, 'nchans')	
Dawn@4: 		i.nchans = 1;
Dawn@4: 	end
Dawn@4: 	i.nsamples = (i.nbytes-i.bytes_to_data)/i.sample_bytes;
Dawn@4: 	i.totalsamples = i.nsamples * i.nchans;
Dawn@4:     i.sr=1;
Dawn@4: 	return
Dawn@4: case {'short', 'int16'};
Dawn@4: 	i.sample_bytes = 2;
Dawn@4: 	i.sample_type = 'int16';	
Dawn@4: 	if isfield(i, 'bytes_to_data')
Dawn@4: 		fseek(fd, i.bytes_to_data, 0);
Dawn@4: 	else 
Dawn@4: 		i.bytes_to_data = 0;
Dawn@4: 	end
Dawn@4: 	if ~isfield(i, 'nchans')	
Dawn@4: 		i.nchans = 1;
Dawn@4: 	end
Dawn@4: 	i.nsamples = (i.nbytes-i.bytes_to_data)/i.sample_bytes;
Dawn@4: 	i.totalsamples = i.nsamples * i.nchans;
Dawn@4:     i.sr=1;
Dawn@4: 	return
Dawn@4: case {'long', 'int32'};
Dawn@4: 	i.sample_bytes = 4;
Dawn@4: 	i.sample_type = 'int32';	
Dawn@4: 	if isfield(i, 'bytes_to_data')
Dawn@4: 		fseek(fd, i.bytes_to_data, 0);
Dawn@4: 	else 
Dawn@4: 		i.bytes_to_data = 0;
Dawn@4: 	end
Dawn@4: 	if ~isfield(i, 'nchans')	
Dawn@4: 		i.nchans = 1;
Dawn@4: 	end
Dawn@4: 	i.nsamples = (i.nbytes-i.bytes_to_data)/i.sample_bytes;
Dawn@4: 	i.totalsamples = i.nsamples * i.nchans;
Dawn@4:     i.sr=1;
Dawn@4: 	return
Dawn@4: case {'float', 'float32'};
Dawn@4: 	i.sample_bytes = 4;
Dawn@4: 	i.sample_type = 'float32';	
Dawn@4: 	if isfield(i, 'bytes_to_data')
Dawn@4: 		fseek(fd, i.bytes_to_data, 0);
Dawn@4: 	else 
Dawn@4: 		i.bytes_to_data = 0;
Dawn@4: 	end
Dawn@4: 	if ~isfield(i, 'nchans')	
Dawn@4: 		i.nchans = 1;
Dawn@4: 	end
Dawn@4: 	i.nsamples = (i.nbytes-i.bytes_to_data)/i.sample_bytes;
Dawn@4: 	i.totalsamples = i.nsamples * i.nchans;
Dawn@4:     i.sr=1;
Dawn@4: 	return
Dawn@4: case {'double', 'float64'};
Dawn@4: 	i.sample_bytes = 8;
Dawn@4: 	i.sample_type = 'float64';	
Dawn@4: 	if isfield(i, 'bytes_to_data')
Dawn@4:  		fseek(fd, i.bytes_to_data, 0);
Dawn@4: 	else 
Dawn@4: 		i.bytes_to_data = 0;
Dawn@4: 	end
Dawn@4: 	if ~isfield(i, 'nchans')	
Dawn@4: 		i.nchans = 1;
Dawn@4: 	end
Dawn@4: 	i.nsamples = (i.nbytes-i.bytes_to_data)/i.sample_bytes;
Dawn@4: 	i.totalsamples = i.nsamples * i.nchans;
Dawn@4:     i.sr=1;
Dawn@4: 	return
Dawn@4: otherwise
Dawn@4: 	error(['unknown format: >' i.format '<']);
Dawn@4: end