Learn more about Video and Image Processing Blockset

mplay - View video from MATLAB workspace, multimedia file, or Simulink model

Syntax

mplay mplay('filename.avi') mplay('filename.avi',FPS) mplay(A) mplay(A,FPS) mplay({line_handles}) mplay({'block',PORT})

Description

mplay opens an MPlay GUI that allows you to view video from files or the MATLAB workspace. The MPlay GUI does not play audio.

mplay('filename.avi') connects the MPlay GUI to the specified AVI file. You can also view video signals in Simulink models.

mplay('filename.avi',FPS) plays the specified frame rate in frames per second, (FPS). The FPS value equals that of the frame rate specified in the file.

mplay(A) connects the MPlay GUI to the variable in the MATLAB workspace, A.

mplay(A,FPS) plays the specified frame rate in frames per second, FPS. The FPS value defaults to 20.

mplay({line_handles}) connects the MPlay GUI to one or three Simulink signal lines to display, where all signals must originate from the same block.

mplay({'block',PORT}) connects the MPlay GUI to the output signal of the specified block, 'block', on output port port. The port index value defaults to 1.

Inputs

A

A is a variable in the MATLAB workspace, which must have one of the following formats:

MATLAB movie structure
Intensity video. This input is an M-by-N-by-T, or M-by-N-by-1-by-T array, where the size of each frame is M-by-N and there are T image frames.
RGB video array. This input is an M-by-N-by-3-by-T array, where the size of each RGB image is M-by-N-by-3 and there are T image frames.

For performance considerations, the video input A data type converts to unit8 as follows:

Supported Data Types	Converted to uint8
double	✓
single	✓
int8	✓
uint8
int16	✓
uint16
int32	✓
uint32	✓
Boolean	✓
Fixed point	✓

block

The block is a full path to a specified Simulink blockset block. To get the full block path name of the currently selected Simulink block, issue the command mplay({gcb,1}) on the MATLAB command line.

filename.avi

Filename.avi is a specified AVI file.

FPS

FPS stands for frames per second. You can specify the frame rate in frames per second.

line_handles

line_handles are Simulink signal lines. To get the handles to the Simulink signals, line_handles, issue the command mplay({gsl}) on the MATLAB command line.

port

The port refers to a Simulink block output port number.

Examples

Play a video created in MATLAB workspace.

fig=figure;  % create a video
set(gca,'xlim',[-80 80],'ylim',[-80 80],'NextPlot', ...
'replace','Visible','off');
x = -pi:.1:pi;
radius = 0:length(x);
video = []; % initialize video variable
   for i=length(x):-1:1
     patch(sin(x)*radius(i),cos(x)*radius(i), ...
[abs(cos(x(i))) 0 0]);
     F = getframe(gca);
    video = cat(4,video,F.cdata); % video is MxNx3xT
   end
   close(fig);
   mplay(video); % display a video