VideoReader: Unrecognized function or variable 'hasFrame'

I am following the VideoReader documentation from https://www.mathworks.com/help/matlab/ref/videoreader.html

When I try to run the example code using R2024a Update 5,

currAxes = axes;
v = VideoReader("xylophone_video.mp4");

while hasFrame(v)
    vidFrame = readFrame(v);
    image(vidFrame,"Parent",currAxes)
    currAxes.Visible = "off";
    pause(1/v.FrameRate)
end

the line with while hasFrame(v) throws an error: Unrecognized function or variable 'hasFrame'.

The VideoReader object was created, but the hasFrame(v) line does not work. Was support for this function removed? If so, what replaced it?

[Avni Agrawal]

Hi @Alexander Brandt,

Can you share OS version? Because it is working fine for me on windows 11 R2024a as well as MATLAB Online R2024a

[Walter Roberson]

For debugging purposes, try examining

methods(v)

[Alexander Brandt]

@Avni Agrawal I am running Windows 11 Pro, Version 10.0.22631 Build 22631. What update of R2024a are you using?

[Alexander Brandt]

@Walter Roberson It gives me:

Methods for class VideoWriter:

VideoWriter delete open set

close get saveobj writeVideo

Static methods:

getProfiles

Methods of VideoWriter inherited from handle

It doesn't list hasFrame as one of the methods for the class.

[Avni Agrawal]

MATLAB Version: 24.1.0.2537033 (R2024a)

Operating System: Microsoft Windows 11 Enterprise Version 10.0 (Build 22631)

Answer 1

[Avni Agrawal]

You are trying to access VideoWriter instead of VideoReader. Are you sure the code you are trying to run has VideoReader() but not VideoWriter() ?

Because, methods(v) is returning:

Methods for class VideoReader:

VideoReader hasFrame read saveobj

get inspect readFrame set

Static methods:

getFileFormats

[Alexander Brandt]

@Avni Agrawal That resolved it, thank you!