Problems using mmreader with struct

I am trying to use mmreader to upload a video into MATLAB. I am trying to follow the example in the documentation, however at the line move(1:nFrames) = struct('cdata',zeros(vidHeight,vidWidth,3,'uint8'),'colormap',[]);

I get the following error:

??? The following error occurred converting from struct to mmreader: Error using ==> which Argument must contain a string.

Error in ==> VIDEO2 at 16 mov(1:nFrames) = struct('cdata', zeros(vidHeight, vidWidth, 3, 'uint8'),'colormap',[]);

Any ideas what may be wrong?

Answer 1

[Geoff Hayes]

Bran - you must be using an older version of MATLAB; on R2014a, if I try to run through the example at mmreader, I observe the error message MMREADER has been removed. Use VIDEOREADER instead.

Using the same example in R2013a, it works fine and the xylophone video is played. Though if I do the following, after I've run through the example and NOT cleared any variables

 mov=xyloObj;

 mov(1:nFrames) = ...
     struct('cdata',zeros(vidHeight,vidWidth,3,'uint8'),'colormap',[]);

 Warning: MMREADER will be removed in a future release. Use VIDEOREADER  
 instead. 
 > In mmreader.mmreader>mmreader.mmreader at 120 
 The following error occurred converting from struct to mmreader:
 Argument must contain a string.

So nearly the same error message as you observed. Could it be that you accidentally set mov to an instance of the mmreader class?

Before running your VIDEO2 script, run the following command

 clear mov
 clear move

to clear the variable mov (and move since you reference both in your question). Now try your script again. Do you still observe the error message?