Why is VideoReader telling me the duration of every video is 0?

I am trying to use VideoReader to gather data about a video. Ultimatly what I want to do is define a time stamp and extract the frame that corresponds to that time frame. For some reason when I use VideoReader I get all of the usual data except for the Duration which always reads 0. Ive tried a few videos and they all read 0. Below is my code.

Edit: The video im trying to load is roughly an hour long

VideoName = "video.mp4";
V = VideoReader(VideoName);

VideoHeight = V.Height;
VideoWidth = V.Width;

VideoFrames = V.NumFrames;
VideoFrameRate = V.FrameRate;

VideoLength = VideoFrames/VideoFrameRate;

TargetTimeStamp = 0;
V.CurrentTime = TargetTimeStamp;

Frame = readFrame(V);

imshow(Frame)

Here is the output of VideoReader:

Duration	0	1×1	double
Name	'video.mp4'	1×38	char
Path	'C:\Users\'	1×46	char
BitsPerPixel	24	1×1	double
FrameRate	31.4136	1×1	double
Height	1080	1×1	double
NumFrames	2328	1×1	double
VideoFormat	'RGB24'	1×5	char
Width	1920	1×1	double
Tag	''	0×0	char
UserData	[ ]	0×0	double
CurrentTime	0.0318	1×1	double

[Stephen23]

"The video im trying to load is roughly an hour long "

The data implies the video is around 74 seconds long (although NumFrames may not be accurate for longer videos):

2328 / 31.4136 %  seconds

ans = 74.1080

Is it recorded with a variable frame rate? What OS are you using (MATLAB uses the OS's APIs for video conversion)?

What do tools like ffprobe or MediaInfo say about the duration and number of frames?

[Walter Roberson]

31.4136 is an odd-sounding frame rate.

[Mathieu NOE]

I suppose the OP wanted to say : The video im trying to load is roughly a minute long (and not an hour long)

otherwise the frame rate is super low

[Harald]

Hi,

I have tried with the doc example xylophone_video.mp4, and this shows a non-zero duration of 4.7.

Could you try the doc example to see if you also encounter the problem for this video, please?

If it works fine for the doc example, could you upload an example video so that we can try to reproduce the problem?

Best wishes,

Harald

[Bradley]

I moved all of my code over to a linux machine and got everything working. I was on windows and the video format was an MP4 file. it is infact 66 minutes long not a minute, I dont understand why this wasnt working on my windows machine, maybe it was an encoder issue im not sure. Thanks for the input everyone I was able to get everything working!

[Harald]

That's interesting, and I am happy for you! :)

As I wrote, it was working fine with me, and I am working on Windows. So, if you are still interested in making it work on Windows as well, please try what I suggested as an initial investigation.