Daniel@0: function [data,Fs,nBits,formChunk] = aiffread(filePath,indexRange)
Daniel@0: %AIFFREAD   Read AIFF (Audio Interchange File Format) sound file.
Daniel@0: %   Y = AIFFREAD(FILE) reads an AIFF file specified by the string FILE,
Daniel@0: %   returning the sampled data in Y. The ".aif" extension is appended if no
Daniel@0: %   extension is given.
Daniel@0: %
Daniel@0: %   [Y,FS,NBITS,CHUNKDATA] = AIFFREAD(FILE) returns the sample rate (FS) in
Daniel@0: %   Hertz, the number of bits per sample (NBITS) used to encode the data in
Daniel@0: %   the file, and a complete structure of the chunk data (CHUNKDATA)
Daniel@0: %   contained in the AIFF file (minus the actual audio data returned in Y).
Daniel@0: %   See below for a description of CHUNKDATA.
Daniel@0: %
Daniel@0: %   [...] = AIFFREAD(FILE,N) returns only the first N samples from each
Daniel@0: %   channel in the file.
Daniel@0: %
Daniel@0: %   [...] = AIFFREAD(FILE,[N1 N2]) returns only samples N1 through N2 from
Daniel@0: %   each channel in the file.
Daniel@0: %
Daniel@0: %   [SIZ,...] = AIFFREAD(FILE,'size') returns the size of the audio data
Daniel@0: %   contained in the file in place of the actual audio data, where
Daniel@0: %   SIZ = [nSampleFrames nChannels].
Daniel@0: %
Daniel@0: %-NOTES--------------------------------------------------------------------
Daniel@0: %
Daniel@0: %   A note on compressed files:
Daniel@0: %
Daniel@0: %      Both AIFF and AIFC/AIFF-C (compressed) file types can be read by
Daniel@0: %      AIFFREAD, but the data returned for AIFC/AIFF-C files will be the
Daniel@0: %      raw, compressed data (i.e. AIFFREAD loads the data from the file
Daniel@0: %      without modification). Currently, since there are many compression
Daniel@0: %      formats, it is the responsibility of the user to uncompress the
Daniel@0: %      sound data using parameters defined in the COMM chunk (contained in
Daniel@0: %      the returned CHUNKDATA structure). When loading AIFC/AIFF-C files,
Daniel@0: %      any optional numerical subranges are ignored and the entire set of
Daniel@0: %      compressed data is returned as a column vector of signed bytes
Daniel@0: %      (INT8 type).
Daniel@0: %
Daniel@0: %   A note on the CHUNKDATA structure:
Daniel@0: %
Daniel@0: %      The CHUNKDATA structure has the following fields:
Daniel@0: %
Daniel@0: %         -'chunkID': The 4-character ID for the chunk. This will always be
Daniel@0: %                     the string 'FORM'.
Daniel@0: %         -'chunkSize': The size (in bytes) of the remaining data in the
Daniel@0: %                       file.
Daniel@0: %         -'formType': A 4-character string for the file type that should
Daniel@0: %                      be either 'AIFF' or 'AIFC'.
Daniel@0: %         -'chunkArray': An array of structures, one entry for every chunk
Daniel@0: %                        that is in the file (not counting this parent FORM
Daniel@0: %                        chunk). The fields of this structure are:
Daniel@0: %                           -'chunkID': The 4-character ID for the chunk.
Daniel@0: %                           -'chunkSize': The size (in bytes) of the
Daniel@0: %                                         remaining data in the chunk.
Daniel@0: %                           -'chunkData': A structure of data for the
Daniel@0: %                                         chunk. The form of this data for
Daniel@0: %                                         a given chunkID can be found at
Daniel@0: %                                         the links given below for the
Daniel@0: %                                         file format standards.
Daniel@0: %
Daniel@0: %      The data portion of certain chunks may not have a clearly defined
Daniel@0: %      format, or that format may be dependent on the implementation or
Daniel@0: %      application that will be using the data. In such cases, the data
Daniel@0: %      returned for that chunk in the CHUNKDATA structure will be in a raw
Daniel@0: %      format (vectors of signed or unsigned 8-bit integers) and it will be
Daniel@0: %      up to the user/application to parse and format this data correctly.
Daniel@0: %      The following is a list of such AIFF/AIFF-C chunks:
Daniel@0: %
Daniel@0: %         -Audio Recording Chunk (chunkID = 'AESD'): The chunkData
Daniel@0: %          structure has one field 'aesChannelStatusData' that stores a
Daniel@0: %          column vector of 24 8-bit unsigned integers.
Daniel@0: %         -Application Specific Chunk (chunkID = 'APPL'): The chunkData
Daniel@0: %          structure has two fields. 'applicationSignature' stores a
Daniel@0: %          4-character string identifying the application. 'data' stores a
Daniel@0: %          column vector of 8-bit signed integers.
Daniel@0: %         -MIDI Data Chunk (chunkID = 'MIDI'): The chunkData structure has
Daniel@0: %          one field 'midiData' that stores a column vector of 8-bit
Daniel@0: %          unsigned integers.
Daniel@0: %         -Sound Accelerator (SAXEL) Chunk (chunkID = 'SAXL'): There is no
Daniel@0: %          finalized format for Saxel chunks, so the chunkData structure
Daniel@0: %          follows the draft format given in Appendix D of the AIFF-C
Daniel@0: %          standard.
Daniel@0: %
Daniel@0: %   Description for the AIFF standard can be found here:
Daniel@0: %
Daniel@0: %      http://muratnkonar.com/aiff/index.html
Daniel@0: %
Daniel@0: %   Descriptions for the AIFC/AIFF-C standard can be found here:
Daniel@0: %
Daniel@0: %      http://www.cnpbagwell.com/aiff-c.txt
Daniel@0: %      http://www-mmsp.ece.mcgill.ca/Documents/AudioFormats/AIFF/Docs/...
Daniel@0: %             AIFF-C.9.26.91.pdf
Daniel@0: 
Daniel@0: % Author: Ken Eaton
Daniel@0: % Last modified: 3/17/09
Daniel@0: %--------------------------------------------------------------------------
Daniel@0: 
Daniel@0:   % Initializations:
Daniel@0: 
Daniel@0:   aiffChunkPrecedence = {'COMM' 'SSND' 'MARK' 'INST' 'COMT' 'NAME' ...
Daniel@0:                          'AUTH' '[c] ' 'ANNO' 'AESD' 'MIDI' 'APPL'};
Daniel@0:   aiffChunkLimits = [1 1 1 1 1 1 1 1 inf 1 inf inf];
Daniel@0:   aifcChunkPrecedence = {'FVER' 'COMM' 'INST' 'SAXL' 'COMT' 'MARK' ...
Daniel@0:                          'SSND' 'NAME' 'AUTH' '[c] ' 'ANNO' 'AESD' ...
Daniel@0:                          'MIDI' 'APPL'};
Daniel@0:   aifcChunkLimits = [1 1 1 inf 1 1 1 1 1 1 inf 1 inf inf];
Daniel@0:   fid = -1;
Daniel@0: 
Daniel@0:   % Check the number of input arguments:
Daniel@0: 
Daniel@0:   switch nargin,
Daniel@0:     case 0,
Daniel@0:       error(error_message('notEnoughInputs'));
Daniel@0:     case 1,
Daniel@0:       indexRange = [1 inf];
Daniel@0:   end
Daniel@0: 
Daniel@0:   % Check the file name input argument:
Daniel@0: 
Daniel@0:   if ~ischar(filePath),
Daniel@0:     error(error_message('badArgumentType','File name','char'));
Daniel@0:   end
Daniel@0:   [filePath,fileName,fileExtension] = fileparts(filePath);
Daniel@0:   if isempty(fileExtension),
Daniel@0:     fileExtension = '.aif';
Daniel@0:   end
Daniel@0:   if ~any(strcmpi(fileExtension,{'.aif' '.afc' '.aiff' '.aifc'})),
Daniel@0:     error(error_message('unknownExtension',fileExtension));
Daniel@0:   end
Daniel@0: 
Daniel@0:   % Check the optional input argument:
Daniel@0: 
Daniel@0:   if isnumeric(indexRange),  % Numeric range specification
Daniel@0: 
Daniel@0:     indexRange = double(indexRange);
Daniel@0:     nRange = numel(indexRange);
Daniel@0:     if (nRange > 2) || any(indexRange < 1) || any(isnan(indexRange)),
Daniel@0:       error(error_message('badIndexValue'));
Daniel@0:     end
Daniel@0:     indexRange = [ones(nRange ~= 2) round(indexRange) inf(nRange == 0)];
Daniel@0: 
Daniel@0:   elseif ischar(indexRange),  % Specification for returning just the size
Daniel@0: 
Daniel@0:     if ~strncmpi(indexRange,'size',numel(indexRange)),
Daniel@0:       error(error_message('invalidString'));
Daniel@0:     end
Daniel@0:     indexRange = [];
Daniel@0: 
Daniel@0:   else  % Invalid input
Daniel@0: 
Daniel@0:     error(error_message('badArgumentType','Optional argument',...
Daniel@0:                         'numeric or char'));
Daniel@0: 
Daniel@0:   end
Daniel@0: 
Daniel@0:   % Check that the file exists and can be opened:
Daniel@0: 
Daniel@0:   fid = fopen(fullfile(filePath,[fileName fileExtension]),'r','b');
Daniel@0:   if fid == -1,
Daniel@0:     error(error_message('invalidFile',[fileName fileExtension]));
Daniel@0:   end
Daniel@0: 
Daniel@0:   % Initialize formChunk structure:
Daniel@0: 
Daniel@0:   formChunk = struct('chunkID',[],'chunkSize',[],'formType',[],...
Daniel@0:                      'chunkArray',[]);
Daniel@0: 
Daniel@0:   % Read FORM chunk data:
Daniel@0: 
Daniel@0:   formChunk.chunkID = read_text(fid,4);
Daniel@0:   if ~strcmp(formChunk.chunkID,'FORM'),
Daniel@0:     error(error_message('invalidFileFormat',fileExtension));
Daniel@0:   end
Daniel@0:   formChunk.chunkSize = fread(fid,1,'int32');
Daniel@0:   formType = read_text(fid,4);
Daniel@0:   if ~any(strcmp(formType,{'AIFF' 'AIFC'})),
Daniel@0:     error(error_message('invalidFileFormat',fileExtension));
Daniel@0:   end
Daniel@0:   formChunk.formType = formType;
Daniel@0: 
Daniel@0:   % Since the order of chunks is not guaranteed, first skip through the
Daniel@0:   %   file and read just the chunkIDs and chunkSizes:
Daniel@0: 
Daniel@0:   iChunk = 0;
Daniel@0:   chunkIDArray = {};
Daniel@0:   chunkSizeArray = {};
Daniel@0:   chunkDataIndex = [];
Daniel@0:   nextChunkID = read_text(fid,4);
Daniel@0:   while ~feof(fid),
Daniel@0:     iChunk = iChunk+1;
Daniel@0:     chunkIDArray{iChunk} = nextChunkID;
Daniel@0:     chunkSize = fread(fid,1,'int32');
Daniel@0:     chunkSizeArray{iChunk} = chunkSize;
Daniel@0:     chunkDataIndex(iChunk) = ftell(fid);
Daniel@0:     fseek(fid,chunkSize+rem(chunkSize,2),'cof');
Daniel@0:     nextChunkID = read_text(fid,4);
Daniel@0:   end
Daniel@0: 
Daniel@0:   % Check for the presence of required chunks:
Daniel@0: 
Daniel@0:   if ~ismember('COMM',chunkIDArray),
Daniel@0:     error(error_message('missingChunk','COMM',formType));
Daniel@0:   end
Daniel@0:   if strcmp(formType,'AIFC') && ~ismember('FVER',chunkIDArray),
Daniel@0:     error(error_message('missingChunk','FVER',formType));
Daniel@0:   end
Daniel@0: 
Daniel@0:   % Check for unknown chunks and order chunks based on chunk precedence:
Daniel@0: 
Daniel@0:   if strcmp(formType,'AIFF'),
Daniel@0:     [isChunk,orderIndex] = ismember(chunkIDArray,aiffChunkPrecedence);
Daniel@0:   else
Daniel@0:     [isChunk,orderIndex] = ismember(chunkIDArray,aifcChunkPrecedence);
Daniel@0:   end
Daniel@0:   if ~all(isChunk),
Daniel@0:     unknownChunks = [chunkIDArray(~isChunk); ...
Daniel@0:                      repmat({', '},1,sum(~isChunk)-1) {'.'}];
Daniel@0:     orderIndex = orderIndex(isChunk);
Daniel@0:     chunkIDArray = chunkIDArray(isChunk);
Daniel@0:     chunkSizeArray = chunkSizeArray(isChunk);
Daniel@0:     chunkDataIndex = chunkDataIndex(isChunk);
Daniel@0:     warning('aiffread:unknownChunk',...
Daniel@0:             ['The following chunk IDs are unknown for an ' formType ...
Daniel@0:              ' file and will be ignored: ' unknownChunks{:}]);
Daniel@0:   end
Daniel@0:   [index,orderIndex] = sort(orderIndex);
Daniel@0:   chunkIDArray = chunkIDArray(orderIndex);
Daniel@0:   chunkSizeArray = chunkSizeArray(orderIndex);
Daniel@0:   chunkDataIndex = chunkDataIndex(orderIndex);
Daniel@0: 
Daniel@0:   % Check for chunks that should not appear more than once:
Daniel@0: 
Daniel@0:   index = unique(index(diff(index) < 1));
Daniel@0:   if strcmp(formType,'AIFF'),
Daniel@0:     repeatChunks = aiffChunkPrecedence(aiffChunkLimits(index) == 1);
Daniel@0:   else
Daniel@0:     repeatChunks = aifcChunkPrecedence(aifcChunkLimits(index) == 1);
Daniel@0:   end
Daniel@0:   if ~isempty(repeatChunks),
Daniel@0:     repeatChunks = [repeatChunks; ...
Daniel@0:                     repmat({', '},1,numel(repeatChunks)-1) {'.'}];
Daniel@0:     error(error_message('repeatChunk',formType,[repeatChunks{:}]));
Daniel@0:   end
Daniel@0: 
Daniel@0:   % Initialize chunkArray data:
Daniel@0: 
Daniel@0:   formChunk.chunkArray = struct('chunkID',chunkIDArray,...
Daniel@0:                                 'chunkSize',chunkSizeArray,...
Daniel@0:                                 'chunkData',[]);
Daniel@0: 
Daniel@0:   % Read the data for each chunk:
Daniel@0: 
Daniel@0:   for iChunk = 1:numel(chunkIDArray),
Daniel@0:     chunkData = [];
Daniel@0:     fseek(fid,chunkDataIndex(iChunk),'bof');
Daniel@0:     switch chunkIDArray{iChunk},
Daniel@0: 
Daniel@0:       case '[c] ',  % Copyright Chunk
Daniel@0: 
Daniel@0:         chunkData.text = read_text(fid,chunkSizeArray{iChunk});
Daniel@0: 
Daniel@0:       case 'AESD',  % Audio Recording Chunk
Daniel@0: 
Daniel@0:         chunkData.aesChannelStatusData = ...
Daniel@0:           fread(fid,[chunkSizeArray{iChunk} 1],'*uint8');
Daniel@0: 
Daniel@0:       case 'ANNO',  % Annotation Chunk
Daniel@0: 
Daniel@0:         chunkData.text = read_text(fid,chunkSizeArray{iChunk});
Daniel@0: 
Daniel@0:       case 'APPL',  % Application Specific Chunk
Daniel@0: 
Daniel@0:         chunkData.applicationSignature = read_text(fid,4);
Daniel@0:         chunkData.data = fread(fid,[chunkSizeArray{iChunk}-4 1],'*int8');
Daniel@0: 
Daniel@0:       case 'AUTH',  % Author Chunk
Daniel@0: 
Daniel@0:         chunkData.text = read_text(fid,chunkSizeArray{iChunk});
Daniel@0: 
Daniel@0:       case 'COMM',  % Common Chunk
Daniel@0: 
Daniel@0:         nChannels = fread(fid,1,'int16');
Daniel@0:         chunkData.nChannels = nChannels;
Daniel@0:         nSampleFrames = fread(fid,1,'uint32');
Daniel@0:         if (nSampleFrames > 0) && ~ismember('SSND',chunkIDArray),
Daniel@0:           error(error_message('missingChunk','SSND',formType));
Daniel@0:         end
Daniel@0:         chunkData.nSampleFrames = nSampleFrames;
Daniel@0:         nBits = fread(fid,1,'int16');
Daniel@0:         chunkData.sampleSize = nBits;
Daniel@0:         exponent = fread(fid,1,'uint16');
Daniel@0:         highMantissa = fread(fid,1,'uint32');
Daniel@0:         lowMantissa = fread(fid,1,'uint32');
Daniel@0:         Fs = extended2double(exponent,highMantissa,lowMantissa);
Daniel@0:         chunkData.sampleRate = Fs;
Daniel@0:         if strcmp(formType,'AIFF'),
Daniel@0:           compressionType = 'NONE';
Daniel@0:         else
Daniel@0:           compressionType = read_text(fid,4);
Daniel@0:           chunkData.compressionType = compressionType;
Daniel@0:           chunkData.compressionName = read_pstring(fid);
Daniel@0:         end
Daniel@0: 
Daniel@0:       case 'COMT',  % Comments Chunk
Daniel@0: 
Daniel@0:         nComments = fread(fid,1,'uint16');
Daniel@0:         chunkData.nComments = nComments;
Daniel@0:         chunkData.commentArray = struct('timeStamp',cell(nComments,1),...
Daniel@0:                                         'marker',[],'count',[],'text',[]);
Daniel@0:         for iComment = 1:nComments,
Daniel@0:           chunkData.commentArray(iComment) = read_comment(fid);
Daniel@0:         end
Daniel@0: 
Daniel@0:       case 'FVER',  % Format Version Chunk (AIFC/AIFF-C only)
Daniel@0: 
Daniel@0:         timeStamp = fread(fid,1,'uint32');
Daniel@0:         if timeStamp ~= 2726318400,
Daniel@0:           warning('aiffread:unknownVersion',...
Daniel@0:                   ['File contains an unrecognized version of the ' ...
Daniel@0:                    'AIFC/AIFF-C standard.']);
Daniel@0:         end
Daniel@0:         chunkData.timeStamp = timeStamp;
Daniel@0: 
Daniel@0:       case 'INST',  % Instrument Chunk
Daniel@0: 
Daniel@0:         chunkData.baseNote = fread(fid,1,'int8');
Daniel@0:         chunkData.detune = fread(fid,1,'int8');
Daniel@0:         chunkData.lowNote = fread(fid,1,'int8');
Daniel@0:         chunkData.highNote = fread(fid,1,'int8');
Daniel@0:         chunkData.lowVelocity = fread(fid,1,'int8');
Daniel@0:         chunkData.highVelocity = fread(fid,1,'int8');
Daniel@0:         chunkData.gain = fread(fid,1,'int16');
Daniel@0:         chunkData.sustainLoop = read_loop(fid);
Daniel@0:         chunkData.releaseLoop = read_loop(fid);
Daniel@0: 
Daniel@0:       case 'MARK',  % Marker Chunk
Daniel@0: 
Daniel@0:         nMarkers = fread(fid,1,'uint16');
Daniel@0:         chunkData.nMarkers = nMarkers;
Daniel@0:         chunkData.markerArray = struct('id',cell(nMarkers,1),...
Daniel@0:                                        'position',[],'markerName',[]);
Daniel@0:         for iMarker = 1:nMarkers,
Daniel@0:           chunkData.markerArray(iMarker) = read_marker(fid);
Daniel@0:         end
Daniel@0:         markerIDs = [chunkData.markerArray.id];
Daniel@0:         if any(markerIDs < 1) || (numel(unique(markerIDs)) < nMarkers),
Daniel@0:           warning('aiffread:invalidMarkers',...
Daniel@0:                   'Invalid or repeated marker IDs were detected.');
Daniel@0:         end
Daniel@0: 
Daniel@0:       case 'MIDI',  % MIDI Data Chunk
Daniel@0: 
Daniel@0:         chunkData.midiData = fread(fid,[chunkSizeArray{iChunk} 1],...
Daniel@0:                                    '*uint8');
Daniel@0: 
Daniel@0:       case 'NAME',  % Name Chunk
Daniel@0: 
Daniel@0:         chunkData.text = read_text(fid,chunkSizeArray{iChunk});
Daniel@0: 
Daniel@0:       case 'SAXL',  % Sound Accelerator (SAXEL) Chunk (AIFC/AIFF-C only)
Daniel@0: 
Daniel@0:         nSaxels = fread(fid,1,'uint16');
Daniel@0:         chunkData.nSaxels = nSaxels;
Daniel@0:         chunkData.saxelArray = struct('id',cell(nSaxels,1),'size',[],...
Daniel@0:                                       'saxelData',[]);
Daniel@0:         for iSaxel = 1:nSaxels,
Daniel@0:           chunkData.saxelArray(iSaxel) = read_saxel(fid);
Daniel@0:         end
Daniel@0: 
Daniel@0:       case 'SSND',  % Sound Data Chunk
Daniel@0: 
Daniel@0:         nBytes = ceil(nBits/8);
Daniel@0:         chunkData.offset = fread(fid,1,'uint32');
Daniel@0:         chunkData.blockSize = fread(fid,1,'uint32');
Daniel@0:         if isempty(indexRange),
Daniel@0:           data = [nSampleFrames nChannels];
Daniel@0:         elseif strcmp(compressionType,'NONE'),
Daniel@0:           if (chunkSizeArray{iChunk}-8 ~= nChannels*nSampleFrames*nBytes),
Daniel@0:             error(error_message('sizeMismatch'));
Daniel@0:           end
Daniel@0:           fseek(fid,nBytes*nChannels*(indexRange(1)-1),'cof');
Daniel@0:           nRead = min(indexRange(2),nSampleFrames)-indexRange(1)+1;
Daniel@0:           data = fread(fid,[nChannels nRead],['*bit' int2str(nBytes*8)]).';
Daniel@0:           if nBits < nBytes*8,
Daniel@0:             data = data./(2^(nBytes*8-nBits));
Daniel@0:           end
Daniel@0:         else
Daniel@0:           data = fread(fid,[chunkSizeArray{iChunk}-8 1],'*int8');
Daniel@0:         end
Daniel@0: 
Daniel@0:     end
Daniel@0:     formChunk.chunkArray(iChunk).chunkData = chunkData;
Daniel@0:   end
Daniel@0: 
Daniel@0:   % Close the file:
Daniel@0: 
Daniel@0:   fclose(fid);
Daniel@0: 
Daniel@0: %~~~Begin nested functions~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Daniel@0: 
Daniel@0:   %------------------------------------------------------------------------
Daniel@0:   function errorStruct = error_message(errorCode,varargin)
Daniel@0:   %
Daniel@0:   %   Initialize an error message (and close open files, if necessary).
Daniel@0:   %
Daniel@0:   %------------------------------------------------------------------------
Daniel@0: 
Daniel@0:     % Close open files, if necessary:
Daniel@0: 
Daniel@0:     if ~isempty(fopen(fid)),
Daniel@0:       fclose(fid);
Daniel@0:     end
Daniel@0: 
Daniel@0:     % Initialize error message text:
Daniel@0: 
Daniel@0:     switch errorCode,
Daniel@0:       case 'badArgumentType',
Daniel@0:         errorText = [varargin{1} ' should be of type ' varargin{2} '.'];
Daniel@0:       case 'badIndexValue',
Daniel@0:         errorText = ['Index range must be specified as a scalar or ' ...
Daniel@0:                      '2-element vector of positive, non-zero, non-NaN ' ...
Daniel@0:                      'values.'];
Daniel@0:       case 'invalidFile',
Daniel@0:         errorText = ['Could not open file ''' varargin{1} '''.'];
Daniel@0:       case 'invalidFileFormat',
Daniel@0:         errorText = ['Not a valid ' varargin{1} ' file.'];
Daniel@0:       case 'invalidString',
Daniel@0:         errorText = '''size'' is the only valid string argument.';
Daniel@0:       case 'missingChunk',
Daniel@0:         errorText = ['''' varargin{1} ''' chunk is required for a ' ...
Daniel@0:                      varargin{2} ' file.'];
Daniel@0:       case 'notEnoughInputs',
Daniel@0:         errorText = 'Not enough input arguments.';
Daniel@0:       case 'repeatChunk',
Daniel@0:         errorText = ['The following chunk IDs should not appear more ' ...
Daniel@0:                      'than once in an ' varargin{1} ' file: ' varargin{2}];
Daniel@0:       case 'sizeMismatch',
Daniel@0:         errorText =  'Data size mismatch between COMM and SSND chunks.';
Daniel@0:       case 'unknownExtension',
Daniel@0:         errorText = ['Unknown file extension ''' varargin{1} '''.'];
Daniel@0:     end
Daniel@0: 
Daniel@0:     % Create error structure:
Daniel@0: 
Daniel@0:     errorStruct = struct('message',errorText,...
Daniel@0:                          'identifier',['aiffread:' errorCode]);
Daniel@0: 
Daniel@0:   end
Daniel@0: 
Daniel@0: %~~~End nested functions~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Daniel@0: 
Daniel@0: end
Daniel@0: 
Daniel@0: %~~~Begin subfunctions~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Daniel@0: 
Daniel@0: %--------------------------------------------------------------------------
Daniel@0: function value = extended2double(exponent,highMantissa,lowMantissa)
Daniel@0: %
Daniel@0: %   Converts an 80-bit extended floating-point type to a double.
Daniel@0: %
Daniel@0: %--------------------------------------------------------------------------
Daniel@0: 
Daniel@0:   signBit = bitand(exponent,32768);
Daniel@0:   exponent = bitand(exponent,32767);
Daniel@0:   highMantissa = bitand(highMantissa,4294967295);
Daniel@0:   lowMantissa = bitand(lowMantissa,4294967295);
Daniel@0:   if (exponent == 0) && (highMantissa == 0) && (lowMantissa == 0),
Daniel@0:     value = 0;
Daniel@0:   elseif exponent == 32767,
Daniel@0:     if (highMantissa > 0) || (lowMantissa > 0),
Daniel@0:       value = nan;
Daniel@0:     else
Daniel@0:       value = inf;
Daniel@0:     end
Daniel@0:   else
Daniel@0:     value = highMantissa*2^(exponent-16414)+lowMantissa*2^(exponent-16446);
Daniel@0:   end
Daniel@0:   if signBit,
Daniel@0:     value = -value;
Daniel@0:   end
Daniel@0: 
Daniel@0: end
Daniel@0: 
Daniel@0: %--------------------------------------------------------------------------
Daniel@0: function commentStruct = read_comment(fid)
Daniel@0: %
Daniel@0: %   Reads a structure of comment data from a file.
Daniel@0: %
Daniel@0: %--------------------------------------------------------------------------
Daniel@0: 
Daniel@0:   commentStruct = struct('timeStamp',fread(fid,1,'uint32'),...
Daniel@0:                          'marker',fread(fid,1,'int16'),...
Daniel@0:                          'count',[],'text',[]);
Daniel@0:   charCount = fread(fid,1,'uint16');
Daniel@0:   commentStruct.count = charCount;
Daniel@0:   commentStruct.text = read_text(fid,charCount);
Daniel@0: 
Daniel@0: end
Daniel@0: 
Daniel@0: %--------------------------------------------------------------------------
Daniel@0: function loopStruct = read_loop(fid)
Daniel@0: %
Daniel@0: %   Reads a structure of loop data from a file.
Daniel@0: %
Daniel@0: %--------------------------------------------------------------------------
Daniel@0: 
Daniel@0:   loopStruct = struct('playMode',fread(fid,1,'int16'),...
Daniel@0:                       'beginLoop',fread(fid,1,'int16'),...
Daniel@0:                       'endLoop',fread(fid,1,'int16'));
Daniel@0: 
Daniel@0: end
Daniel@0: 
Daniel@0: %--------------------------------------------------------------------------
Daniel@0: function markerStruct = read_marker(fid)
Daniel@0: %
Daniel@0: %   Reads a structure of marker data from a file.
Daniel@0: %
Daniel@0: %--------------------------------------------------------------------------
Daniel@0: 
Daniel@0:   markerStruct = struct('id',fread(fid,1,'int16'),...
Daniel@0:                         'position',fread(fid,1,'uint32'),...
Daniel@0:                         'markerName',read_pstring(fid));
Daniel@0: 
Daniel@0: end
Daniel@0: 
Daniel@0: %--------------------------------------------------------------------------
Daniel@0: function pascalString = read_pstring(fid)
Daniel@0: %
Daniel@0: %   Reads a Pascal-style string from a file, and afterwards shifts the file
Daniel@0: % pointer ahead by one byte if necessary to make the total number of bytes
Daniel@0: % read an even number.
Daniel@0: %
Daniel@0: %--------------------------------------------------------------------------
Daniel@0: 
Daniel@0:   charCount = fread(fid,1,'uint8');
Daniel@0:   pascalString = fread(fid,[1 charCount],'int8=>char');
Daniel@0:   if rem(charCount+1,2),
Daniel@0:     fseek(fid,1,'cof');
Daniel@0:   end
Daniel@0: 
Daniel@0: end
Daniel@0: 
Daniel@0: %--------------------------------------------------------------------------
Daniel@0: function saxelStruct = read_saxel(fid)
Daniel@0: %
Daniel@0: %   Reads a structure of saxel data from a file.
Daniel@0: %
Daniel@0: %--------------------------------------------------------------------------
Daniel@0: 
Daniel@0:   saxelStruct = struct('id',fread(fid,1,'int16'),'size',[],'saxelData',[]);
Daniel@0:   saxelBytes = fread(fid,1,'uint16');
Daniel@0:   saxelStruct.size = saxelBytes;
Daniel@0:   saxelStruct.saxelData = fread(fid,[saxelBytes 1],'*int8');
Daniel@0:   if rem(saxelBytes,2),
Daniel@0:     fseek(fid,1,'cof');
Daniel@0:   end
Daniel@0: 
Daniel@0: end
Daniel@0: 
Daniel@0: %--------------------------------------------------------------------------
Daniel@0: function textString = read_text(fid,charCount)
Daniel@0: %
Daniel@0: %   Reads ASCII text from a file, and afterwards shifts the file pointer
Daniel@0: % ahead by one byte if necessary to make the total number of bytes read an
Daniel@0: % even number.
Daniel@0: %
Daniel@0: %--------------------------------------------------------------------------
Daniel@0: 
Daniel@0:   textString = fread(fid,[1 charCount],'int8=>char');
Daniel@0:   if rem(charCount,2),
Daniel@0:     fseek(fid,1,'cof');
Daniel@0:   end
Daniel@0: 
Daniel@0: end
Daniel@0: 
Daniel@0: %~~~End subfunctions~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~