gusucode.com > audiovideo工具箱matlab源码程序 > audiovideo/@VideoReader/hasFrame.m
function flag = hasFrame(obj) %HASFRAME Determine if there is a frame available to read from a video file % % FLAG = HASFRAME(OBJ) returns TRUE if there is a video frame available % to read from the file. If not, it returns FALSE. % % Example: % % Construct a multimedia reader object associated with file % 'xylophone.mp4'. % vidObj = VideoReader('xylophone.mp4'); % % % Specify that reading should start at 0.5 seconds from the % % beginning. % vidObj.CurrentTime = 0.5; % % % Create an axes % currAxes = axes; % % % Read video frames until available % while hasFrame(vidObj) % vidFrame = readFrame(vidObj); % image(vidFrame, 'Parent', currAxes); % currAxes.Visible = 'off'; % pause(1/vidObj.FrameRate); % end % % See also AUDIOVIDEO, MOVIE, VIDEOREADER,VIDEOREADER/READFRAME, MMFILEINFO. % Copyright 2013-2014 The MathWorks, Inc. if obj.IsFrameBased error( message('MATLAB:audiovideo:VideoReader:NotSupportedFramesCounted', 'HASFRAME', 'HASFRAME') ); end % ensure that we pass in only 1 argument narginchk(1, 1); % ensure that we pass out only 1 output argument nargoutchk(0, 1); obj.IsStreamingBased = true; try flag = hasFrame( getImpl(obj) ); catch ME VideoReader.handleImplException(ME); end