Dawn@4: function y = sf_wave(i, samples, chans)
Dawn@4: % y=sf_wave(i,samples,chans) - read data from file
Dawn@4: %
Dawn@4: %  y: data read from file (column vector or matrix)
Dawn@4: % 
Dawn@4: %  i: structure containing information about file
Dawn@4: %  samples: range of samples to read ([start stop]) - default ([]) means entire file
Dawn@4: %  chans: range of channels to read ([lo hi]) - default ([]) means all channels\
Dawn@4: %
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 | ~isfield(i, 'fname')
Dawn@4: 	error('usage: i.fname = "file name", then call y=sf_wave(i)');
Dawn@4: end
Dawn@4: if ~isfield(i, 'format')
Dawn@4: 	i = sf_info(i);
Dawn@4: end
Dawn@4: % defaults
Dawn@4: if nargin<2 | isempty(samples);
Dawn@4: 	if (i.nsamples) samples=[1 i.nsamples]; end;
Dawn@4: end
Dawn@4: if nargin<3 | isempty(chans)
Dawn@4: 	if (i.nchans) chans=[1 i.nchans]; end;
Dawn@4: end
Dawn@4: 
Dawn@4: % clip
Dawn@4: if samples(1) < 1
Dawn@4: 	samples(1) = 1;
Dawn@4: end
Dawn@4: if samples(2) > i.nsamples
Dawn@4: 	samples(2) = i.nsamples;
Dawn@4: end
Dawn@4: if samples(2) < samples(1)
Dawn@4: 	y=[];return
Dawn@4: 	error(['start sample after stop sample: ' num2str(samples(1)) '-' num2str(samples(2))]);
Dawn@4: end
Dawn@4: if chans(1) < 1 | chans(2) > i.nchans
Dawn@4: 	error(['requested inexistent channels: ' num2str(chans(1)) '-' num2str(chans(2))]);
Dawn@4: end
Dawn@4:     
Dawn@4: 
Dawn@4: % workspace matrix
Dawn@4: if strcmp(i.format, 'matrix')
Dawn@4: 	y = i.fname(samples(1):samples(2), chans(1):chans(2));
Dawn@4: 	return
Dawn@4: end
Dawn@4: 
Dawn@4: % use matlab functions for AU and WAV and MACSND
Dawn@4: if strcmp(i.format, 'AU')
Dawn@4: 	y=auread(i.fname, [samples(1) samples(2)]);
Dawn@4:     y=y(:,chans(1):chans(2));
Dawn@4: 	return;
Dawn@4: end
Dawn@4: if strcmp(i.format, 'WAV')
Dawn@4: 	y=wavread(i.fname, [samples(1) samples(2)]); 
Dawn@4:     y=y(:,chans(1):chans(2));
Dawn@4: 	return;
Dawn@4: end
Dawn@4: if strcmp(i.format, 'MACSND')
Dawn@4: 	if 3==exist('readsnd')		
Dawn@4: 		y = eval('readsnd(i.fname)');
Dawn@4: 	else
Dawn@4: 		error('cannot read MACSND on this platform');
Dawn@4: 	end
Dawn@4: 	y = y(samples(1):samples(2),chans(1):chans(2)); 
Dawn@4: 	return;
Dawn@4: end
Dawn@4: 
Dawn@4: % close if open
Dawn@4: % if fopen(i.fd)
Dawn@4: % 	fclose(i.fd);
Dawn@4: % end
Dawn@4: 
Dawn@4: if ~isfield(i, 'bytes_to_data')
Dawn@4: 	i.bytes_to_data=0;
Dawn@4: end
Dawn@4: 
Dawn@4: % ascii formats
Dawn@4: if strcmp(i.format, 'ascii') | strcmp(i.format, 'csv') | strcmp(i.format, 'IWAVE')
Dawn@4: 	i.fd = fopen(i.fname, 'rt');
Dawn@4: 	fseek(i.fd, i.bytes_to_data, -1);
Dawn@4: 
Dawn@4: 	switch i.format
Dawn@4: 	case 'ascii'
Dawn@4: 		nsamples = samples(2) - samples(1) + 1;
Dawn@4: 		nchans = chans(2) - chans(1) + 1;
Dawn@4: 		y = zeros(nsamples, nchans);
Dawn@4: 		% skip to start
Dawn@4: 		for j=1:samples(1)-1
Dawn@4: 			line = fgetl(i.fd);
Dawn@4: 			if isempty(line) | line == -1; error('unexpected eof'); end
Dawn@4: 		end
Dawn@4: 		k=1;
Dawn@4: 		% read 
Dawn@4: 		for j=samples(1) : samples(2)
Dawn@4: 			line = fgetl(i.fd);
Dawn@4: 			if isempty(line) | line == -1; error('unexpected eof'); end
Dawn@4: 			a = sscanf(line, '%f');
Dawn@4: 			y(k,:) = a(chans(1):chans(2))';	
Dawn@4: 			k = k+1;
Dawn@4: 		end
Dawn@4: 	case 'cvs'
Dawn@4: 		error('not implemented');
Dawn@4: 	case 'IWAVE'
Dawn@4: 		error('not implemented');
Dawn@4: 	end
Dawn@4: 	fclose(i.fd);
Dawn@4: 	return
Dawn@4: end
Dawn@4: 
Dawn@4: % binary formats
Dawn@4: fr = samples(2) - samples(1) + 1;
Dawn@4: skip_samples = i.nchans * (samples(1) - 1);
Dawn@4: switch i.format
Dawn@4: case 'uchar'
Dawn@4: 	i.fd = fopen(i.fname, 'r');
Dawn@4: 	fseek(i.fd, i.bytes_to_data, -1);
Dawn@4: 	fseek(i.fd, skip_samples * 1, 0);
Dawn@4: 	y = fread(i.fd, [fr, i.nchans], 'uchar');	
Dawn@4: 	fclose(i.fd);
Dawn@4: case 'short'
Dawn@4: 	i.fd = fopen(i.fname, 'r');
Dawn@4: 	fseek(i.fd, i.bytes_to_data, -1);
Dawn@4: 	fseek(i.fd, skip_samples * 2, 0);
Dawn@4: 	y = fread(i.fd, [fr, i.nchans], 'short');	
Dawn@4: 	fclose(i.fd);
Dawn@4: case 'long'
Dawn@4: 	i.fd = fopen(i.fname, 'r');
Dawn@4: 	fseek(i.fd, i.bytes_to_data, -1);
Dawn@4: 	fseek(i.fd, skip_samples * 4, 0);
Dawn@4: 	y = fread(i.fd, [fr, i.nchans], 'long');	
Dawn@4: 	fclose(i.fd);
Dawn@4: case 'float'
Dawn@4: 	i.fd = fopen(i.fname, 'r');
Dawn@4: 	fseek(i.fd, i.bytes_to_data, -1);
Dawn@4: 	fseek(i.fd, skip_samples * 4, 0);
Dawn@4: 	y = fread(i.fd, [fr, i.nchans], 'float');	
Dawn@4: 	fclose(i.fd);
Dawn@4: case 'double'
Dawn@4: 	i.fd = fopen(i.fname, 'r');
Dawn@4: 	fseek(i.fd, i.bytes_to_data, -1);
Dawn@4: 	fseek(i.fd, skip_samples * 8, 0);
Dawn@4: 	y = fread(i.fd, [fr, i.nchans], 'double');	
Dawn@4: 	fclose(i.fd);
Dawn@4: case 'NIST'
Dawn@4: 	i.fd = fopen(i.fname, 'r');
Dawn@4: 	fseek(i.fd, i.bytes_to_data, -1);
Dawn@4: 	y = zeros(i.nsamples, i.nchans);
Dawn@4: 	switch i.sample_coding
Dawn@4: 	case 'pcm'
Dawn@4: 		fseek(i.fd, skip_samples * 2, 0);
Dawn@4: 		y = fread(i.fd, [fr, i.nchans], 'short');
Dawn@4: 	otherwise
Dawn@4: 		error(['cannot handle NIST sample_coding = ', i.sample_coding]);
Dawn@4: 	end
Dawn@4: 	fclose(i.fd);
Dawn@4: case 'ESPS'
Dawn@4: 	i.fd = fopen(i.fname, 'r');
Dawn@4: 	fseek(i.fd, i.bytes_to_data, -1);
Dawn@4: 	fseek(i.fd, skip_samples * 2, 0);
Dawn@4: 	y = fread(i.fd, [fr, i.nchans], 'short');
Dawn@4: 
Dawn@4: case 'AIFF'
Dawn@4: 	i.fd = fopen(i.fname, 'r', 's');
Dawn@4: 	fseek(i.fd, i.bytes_to_data, -1);
Dawn@4: 	% should check sample size
Dawn@4: 	fseek(i.fd, skip_samples * 2, 0);
Dawn@4: 	y = fread(i.fd, [fr, i.nchans], 'short');
Dawn@4: 	fclose(i.fd);
Dawn@4: 	
Dawn@4: otherwise
Dawn@4: 	error(['don''t know how to load format = ', i.format]);
Dawn@4: end
Dawn@4: 
Dawn@4: y = y(:,chans(1):chans(2));