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- function fn = step(vr, delta)
- %WORKED=STEP(VR,DELTA)
- % Moves the frame counter by DELTA frames for video VR. This is a
- % generalization of NEXT. Returns 0 on an unsuccessful STEP. Note that
- % not all plugins support stepping, especially with negative numbers. In
- % the following example, both IM1 and IM2 should be the same for most
- % plugins.
- % vr = videoReader(...myurl...);
- % if (~next(vr)), error('couldn''t read first frame'); end
- % im1 = getframe(vr);
- % if (~step(vr,-1)), error('could not step back to frame 0'); end
- % im2 = getframe(vr);
- % if (any(im1 ~= im2)),
- % error('first frame and frame 0 are not the same');
- % end
- % vr = close(vr);
- % FNUM should be an integer.
- %
- % After the videoReader constructor is called, NEXT, SEEK, or STEP should
- % be called at least once before GETFRAME is called.
- %
- % See videoReader/getinfo for more details on how many frames can be read
- % from a video.
- %
- %SEE ALSO
- % videoReader
- %
- %Copyright (c) 2006 Gerald Dalley
- %See "MIT.txt" in the installation directory for licensing details (especially
- %when using this library on GNU/Linux).
- fn = feval(vr.plugin, 'step', vr.handle, delta);
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