dawn@0: function y = sf_wave(i, samples, chans)
dawn@0: % y=sf_wave(i,samples,chans) - read data from file
dawn@0: %
dawn@0: %  y: data read from file (column vector or matrix)
dawn@0: % 
dawn@0: %  i: structure containing information about file
dawn@0: %  samples: range of samples to read ([start stop]) - default ([]) means entire file
dawn@0: %  chans: range of channels to read ([lo hi]) - default ([]) means all channels\
dawn@0: %
dawn@0: 
dawn@0: % Alain de Cheveigné, CNRS/Ircam, 2002.
dawn@0: % Copyright (c) 2002 Centre National de la Recherche Scientifique.
dawn@0: %
dawn@0: % Permission to use, copy, modify, and distribute this software without 
dawn@0: % fee is hereby granted FOR RESEARCH PURPOSES only, provided that this
dawn@0: % copyright notice appears in all copies and in all supporting 
dawn@0: % documentation, and that the software is not redistributed for any 
dawn@0: % fee (except for a nominal shipping charge). 
dawn@0: %
dawn@0: % For any other uses of this software, in original or modified form, 
dawn@0: % including but not limited to consulting, production or distribution
dawn@0: % in whole or in part, specific prior permission must be obtained from CNRS.
dawn@0: % Algorithms implemented by this software may be claimed by patents owned 
dawn@0: % by CNRS, France Telecom, Ircam or others.
dawn@0: %
dawn@0: % The CNRS makes no representations about the suitability of this 
dawn@0: % software for any purpose.  It is provided "as is" without express
dawn@0: % or implied warranty.  Beware of the bugs.
dawn@0: 
dawn@0: if ~nargin | ~isfield(i, 'fname')
dawn@0: 	error('usage: i.fname = "file name", then call y=sf_wave(i)');
dawn@0: end
dawn@0: if ~isfield(i, 'format')
dawn@0: 	i = sf_info(i);
dawn@0: end
dawn@0: % defaults
dawn@0: if nargin<2 | isempty(samples);
dawn@0: 	if (i.nsamples) samples=[1 i.nsamples]; end;
dawn@0: end
dawn@0: if nargin<3 | isempty(chans)
dawn@0: 	if (i.nchans) chans=[1 i.nchans]; end;
dawn@0: end
dawn@0: 
dawn@0: % clip
dawn@0: if samples(1) < 1
dawn@0: 	samples(1) = 1;
dawn@0: end
dawn@0: if samples(2) > i.nsamples
dawn@0: 	samples(2) = i.nsamples;
dawn@0: end
dawn@0: if samples(2) < samples(1)
dawn@0: 	y=[];return
dawn@0: 	error(['start sample after stop sample: ' num2str(samples(1)) '-' num2str(samples(2))]);
dawn@0: end
dawn@0: if chans(1) < 1 | chans(2) > i.nchans
dawn@0: 	error(['requested inexistent channels: ' num2str(chans(1)) '-' num2str(chans(2))]);
dawn@0: end
dawn@0:     
dawn@0: 
dawn@0: % workspace matrix
dawn@0: if strcmp(i.format, 'matrix')
dawn@0: 	y = i.fname(samples(1):samples(2), chans(1):chans(2));
dawn@0: 	return
dawn@0: end
dawn@0: 
dawn@0: % use matlab functions for AU and WAV and MACSND
dawn@0: if strcmp(i.format, 'AU')
dawn@0: 	y=auread(i.fname, [samples(1) samples(2)]);
dawn@0:     y=y(:,chans(1):chans(2));
dawn@0: 	return;
dawn@0: end
dawn@0: if strcmp(i.format, 'WAV')
dawn@0: 	y=wavread(i.fname, [samples(1) samples(2)]); 
dawn@0:     y=y(:,chans(1):chans(2));
dawn@0: 	return;
dawn@0: end
dawn@0: if strcmp(i.format, 'MACSND')
dawn@0: 	if 3==exist('readsnd')		
dawn@0: 		y = eval('readsnd(i.fname)');
dawn@0: 	else
dawn@0: 		error('cannot read MACSND on this platform');
dawn@0: 	end
dawn@0: 	y = y(samples(1):samples(2),chans(1):chans(2)); 
dawn@0: 	return;
dawn@0: end
dawn@0: 
dawn@0: % close if open
dawn@0: % if fopen(i.fd)
dawn@0: % 	fclose(i.fd);
dawn@0: % end
dawn@0: 
dawn@0: if ~isfield(i, 'bytes_to_data')
dawn@0: 	i.bytes_to_data=0;
dawn@0: end
dawn@0: 
dawn@0: % ascii formats
dawn@0: if strcmp(i.format, 'ascii') | strcmp(i.format, 'csv') | strcmp(i.format, 'IWAVE')
dawn@0: 	i.fd = fopen(i.fname, 'rt');
dawn@0: 	fseek(i.fd, i.bytes_to_data, -1);
dawn@0: 
dawn@0: 	switch i.format
dawn@0: 	case 'ascii'
dawn@0: 		nsamples = samples(2) - samples(1) + 1;
dawn@0: 		nchans = chans(2) - chans(1) + 1;
dawn@0: 		y = zeros(nsamples, nchans);
dawn@0: 		% skip to start
dawn@0: 		for j=1:samples(1)-1
dawn@0: 			line = fgetl(i.fd);
dawn@0: 			if isempty(line) | line == -1; error('unexpected eof'); end
dawn@0: 		end
dawn@0: 		k=1;
dawn@0: 		% read 
dawn@0: 		for j=samples(1) : samples(2)
dawn@0: 			line = fgetl(i.fd);
dawn@0: 			if isempty(line) | line == -1; error('unexpected eof'); end
dawn@0: 			a = sscanf(line, '%f');
dawn@0: 			y(k,:) = a(chans(1):chans(2))';	
dawn@0: 			k = k+1;
dawn@0: 		end
dawn@0: 	case 'cvs'
dawn@0: 		error('not implemented');
dawn@0: 	case 'IWAVE'
dawn@0: 		error('not implemented');
dawn@0: 	end
dawn@0: 	fclose(i.fd);
dawn@0: 	return
dawn@0: end
dawn@0: 
dawn@0: % binary formats
dawn@0: fr = samples(2) - samples(1) + 1;
dawn@0: skip_samples = i.nchans * (samples(1) - 1);
dawn@0: switch i.format
dawn@0: case 'uchar'
dawn@0: 	i.fd = fopen(i.fname, 'r');
dawn@0: 	fseek(i.fd, i.bytes_to_data, -1);
dawn@0: 	fseek(i.fd, skip_samples * 1, 0);
dawn@0: 	y = fread(i.fd, [fr, i.nchans], 'uchar');	
dawn@0: 	fclose(i.fd);
dawn@0: case 'short'
dawn@0: 	i.fd = fopen(i.fname, 'r');
dawn@0: 	fseek(i.fd, i.bytes_to_data, -1);
dawn@0: 	fseek(i.fd, skip_samples * 2, 0);
dawn@0: 	y = fread(i.fd, [fr, i.nchans], 'short');	
dawn@0: 	fclose(i.fd);
dawn@0: case 'long'
dawn@0: 	i.fd = fopen(i.fname, 'r');
dawn@0: 	fseek(i.fd, i.bytes_to_data, -1);
dawn@0: 	fseek(i.fd, skip_samples * 4, 0);
dawn@0: 	y = fread(i.fd, [fr, i.nchans], 'long');	
dawn@0: 	fclose(i.fd);
dawn@0: case 'float'
dawn@0: 	i.fd = fopen(i.fname, 'r');
dawn@0: 	fseek(i.fd, i.bytes_to_data, -1);
dawn@0: 	fseek(i.fd, skip_samples * 4, 0);
dawn@0: 	y = fread(i.fd, [fr, i.nchans], 'float');	
dawn@0: 	fclose(i.fd);
dawn@0: case 'double'
dawn@0: 	i.fd = fopen(i.fname, 'r');
dawn@0: 	fseek(i.fd, i.bytes_to_data, -1);
dawn@0: 	fseek(i.fd, skip_samples * 8, 0);
dawn@0: 	y = fread(i.fd, [fr, i.nchans], 'double');	
dawn@0: 	fclose(i.fd);
dawn@0: case 'NIST'
dawn@0: 	i.fd = fopen(i.fname, 'r');
dawn@0: 	fseek(i.fd, i.bytes_to_data, -1);
dawn@0: 	y = zeros(i.nsamples, i.nchans);
dawn@0: 	switch i.sample_coding
dawn@0: 	case 'pcm'
dawn@0: 		fseek(i.fd, skip_samples * 2, 0);
dawn@0: 		y = fread(i.fd, [fr, i.nchans], 'short');
dawn@0: 	otherwise
dawn@0: 		error(['cannot handle NIST sample_coding = ', i.sample_coding]);
dawn@0: 	end
dawn@0: 	fclose(i.fd);
dawn@0: case 'ESPS'
dawn@0: 	i.fd = fopen(i.fname, 'r');
dawn@0: 	fseek(i.fd, i.bytes_to_data, -1);
dawn@0: 	fseek(i.fd, skip_samples * 2, 0);
dawn@0: 	y = fread(i.fd, [fr, i.nchans], 'short');
dawn@0: 
dawn@0: case 'AIFF'
dawn@0: 	i.fd = fopen(i.fname, 'r', 's');
dawn@0: 	fseek(i.fd, i.bytes_to_data, -1);
dawn@0: 	% should check sample size
dawn@0: 	fseek(i.fd, skip_samples * 2, 0);
dawn@0: 	y = fread(i.fd, [fr, i.nchans], 'short');
dawn@0: 	fclose(i.fd);
dawn@0: 	
dawn@0: otherwise
dawn@0: 	error(['don''t know how to load format = ', i.format]);
dawn@0: end
dawn@0: 
dawn@0: y = y(:,chans(1):chans(2));