How can I read a video with frame width and height as 6*8? Cannot read a single frame by using read() function

I am reading the attached video with Matlab R2021a, but I get an empty matrix result. However, this video can be played with PotPlayer or read by python code.

Matlab code:

file = VideoReader('tmpGetStiTimeFromFrametest.mov');
frm = read(file);

[Yang Liu]

file = VideoReader('tmpGetStiTimeFromFrametest.mov');
frm = read(file);

and the result frm is []

Answer 1

[Ananya Tewari]

Hi,

I tried to read the frames from the provided video but it seems there is some issue with the videofile itself. I also tried to open that in my Desktop but the video was not playing. You can try checking the videofile again and use the read().

At my end I used an example ".mov" videofile and it was working fine, attaching that here for your reference.

v = VideoReader("example.mov");
frm = read(v);

[Yang Liu]

Hello, great thanks for your answer. I wonder how my attached video perform in your desktop. I find that it is working fine in my desktop with Potplayer or some other video players except windows media player. I think it is windows media player that matters. Maybe because that the video frame is so small (6*8)?

By the way, my attached video is generated with ffmpeg cut from the one captured with a usb camera by

system(strcat('ffmpeg -i',32,myfile_name,32,'-vf crop=','8:6:1077:273',32,'-threads 5 -preset ultrafast -strict -2 ',32,output_file))

, but I don't think this can be the issue. If the result video frame size is set a bit larger(about 42*32), matlab can read it successfully.

[Walter Roberson]

On Mac, QuickTime Player does not complain about the file, but it only shows blanks.

VLC shows some actual content. It looks to me as if it is interpolating a lot on the display though.

[Yang Liu]

@Walter Roberson The video is just a fre pixels cropped from a 720p, 120 frameRate video by ffmpeg. There is no interpolation.

[Walter Roberson]

VLC is displaying at a lot larger than 6 x 8, and VLC is interpolating somehow.

That is, VLC knows the proper size of the video, but when it displays it in a larger window, it is not just replicating pixels; it is interpolating to a larger size when it displays. This is an issue with VLC.