mmreader class -

Create object for reading video files

Note   mmreader will be removed in a future release. Use VideoReader instead. The mmreader class has been renamed VideoReader.

Description

Use mmreader with the read method to read video data from a multimedia file into the MATLAB workspace.

The file formats that mmreader supports vary by platform, as follows (with no restrictions on file extensions):

For more information, see Supported Video File Formats in the MATLAB Data Import and Export documentation.

Construction

obj = mmreader(filename) constructs obj to read video data from the file named filename. The mmreader constructor searches for the file on the MATLAB path. If it cannot construct the object for any reason, mmreader generates an error.

obj = mmreader(filename,'PropertyName',PropertyValue) constructs the object using options, specified as property name/value pairs. Property name/value pairs can be in any format that the set method supports: name/value string pairs, structures, or name/value cell array pairs.

Properties

vidObj = mmreader('varFrameRateFile.wmv');
lastFrame = read(vidObj, inf);
numFrames = vidObj.NumberOfFrames;

Methods

For backward compatibility, mmreader supports the following VideoReader methods:

Copy Semantics

Handle. To learn how handle classes affect copy operations, see Copying Objects in the MATLAB Programming Fundamentals documentation.

Examples

Construct an mmreader object for the demo movie file xylophone.mpg and view its properties:

xyloObj = mmreader('xylophone.mpg', 'Tag', 'My reader object');
get(xyloObj)

Read and play back the movie file xylophone.mpg:

xyloObj = mmreader('xylophone.mpg');

nFrames = xyloObj.NumberOfFrames;
vidHeight = xyloObj.Height;
vidWidth = xyloObj.Width;

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

% Read one frame at a time.
for k = 1 : nFrames
    mov(k).cdata = read(xyloObj, k);
end

% Size a figure based on the video's width and height.
hf = figure;
set(hf, 'position', [150 150 vidWidth vidHeight])

% Play back the movie once at the video's frame rate.
movie(hf, mov, 1, xyloObj.FrameRate);

See Also

mmfileinfo | VideoReader

How To

• Read Video Files