function [loadables,nonloadables,errors] = getLoadableFiles(varargin)%loadables = getLoadableFiles(...)%  Returns a cell array containing the names of files in the current%  directory that can be read with videoReader.  %%  Any arguments passed to this function are passed along directly to the%  videoReader constructor (e.g. allowing the caller to pick a non-default%  plugin). %%  If a file is not listed in LOADABLES, then either it contains some error%  or the appropriate codec is not installed.%%[loadables,nonloadables] = getLoadableFiles(...)%  Also returns a list of the rest of the files in the current directory%  that were not loadable.%%[loadables,nonloadables,errors] = getLoadableFiles(...)%  For each entry in NONLOADABLES, the corresponding error message%  describing its problem is given in ERRORS.%%Example:%  loadables = getLoadableFiles;%%Copyright (c) 2006 Gerald Dalley%See "MIT.txt" in the installation directory for licensing details (especially%when using this library on GNU/Linux). loadables    = cell(0);nonloadables = cell(0);errors       = cell(0);files = dir('.');for i=1:length(files)  try    % Try opening it    vr = videoReader(files(i).name, varargin{:});    % Can we get basic stream info?    info = getinfo(vr);    % Does it look valid?    if (info.width     <= 0), error('bad width');     end    if (info.height    <= 0), error('bad height');    end    if (info.bpp       <= 0), error('bad bpp');       end    %if (info.numFrames <= 0), error('bad numFrames'); end    % Can we read the first frame?    if (~next(vr)), error('first next call failed'); end    % Is it at least the right size?    frame = getframe(vr);    if (~all(size(frame) == [info.height info.width info.bpp/8])),       error('returned frame is the wrong size');     end    % Can we actually read every frame?    if (info.numFrames >= 0)      % number of frames supplied      for fnum=2:info.numFrames        try          if (~next(vr)), error('Could not read frame %d', fnum-1); end        catch          le = lasterror;          error('Could not read frame %d: %s', fnum-1, le.message);        end      end    else      % plugin (probalby ffmpeg) didn't tell us how many frames, so guess      % based on some hard-coded knowledge of files in the test/      % directory.       fnum = 2;      while 1        try          if (~next(vr)), error('Could not read frame %d', fnum-1); end        catch          le = lasterror;          nframes = inf;          if (~isempty(strmatch('intersection', files(i).name)))            nframes = sscanf(files(i).name, 'intersection%d');          elseif (~isempty(strmatch('numbers.', files(i).name)))            nframes = 300;          end          if fnum < nframes-4            error(['Could not read frame %d (the file has %d frames): ' ...                   '%s'], fnum-1, nframes, le.message);          end          break;        end        fnum = fnum+1;      end    end    % Close it since we're done with it for now.    vr = close(vr);        % It looks good, so squirrel the name away    loadables{end+1} = files(i).name; %#ok<AGROW>  catch    % do nothing... if there's an error, it's just not a loadable file    nonloadables{end+1} = files(i).name; %#ok<AGROW>    le = lasterror;    errors{end+1} = strrep(le.message, sprintf('\n'), '\n'); %#ok<AGROW>  endend