Distorted frames at reading videos with large width using VideoReader()

Hello dear community,

In our project we have to read a wide screen video files (with some specific resolutions). At the begin I had some problems to read mp4-videos with such large resolutions at all. After I installed the K-Lite codec pack (17.1.2) it was possible to read the mp4-videos, but then I got some strange behavior in MATLAB by reading the single frames from these videos (see the attached screenshot).

To demonstrate this behavior I add source code snippet, so evreyone can run this code and see what happens.

The code generates mp4-video file, reads the generated video again and shows just the first frame. But the decoded frame looks distorted. If I increase video width just by 2px (7710px -> 7712px), the encoding is OK. If I increase the width once again (7712px -> 7714px) it looks distorted again. There is no problem to open and play these generated videos with VLC-Player, everything seems to be OK.

What am I doing wrong? Codec problems? Should I try other codecs?

Thank you for taking time to check/solve this problem :)

%% generate video
clear all; 

videoWidth  = 7712; % 7710 - NOK;  7712 - OK; 7714 - NOK; 7716 - OK;
videoHeight = 1000;
frameRate   = 5;
videoLength = 1; % in seconds

%% create image with some dummy content
img = uint8(zeros(videoHeight, videoWidth, 3));
value = 255;
img(  1:250  ,: ,1) = value;
img(251:500  ,: ,2) = value;
img(501:750  ,: ,3) = value;
img(751:1000 ,: ,:) = value;
img(:, 1000:2000 ,:) = 0;
img(500:600, :, :) = 0;
figNr = figure(1); set(figNr, 'Name', 'created image'); 
imshow(img);

%% create video
filename = ['TestVideo_' num2str(videoWidth) 'x' num2str(videoHeight) '.mp4'];
writer = VideoWriter(filename, 'MPEG-4');
disp('created file object');
writer.FrameRate = frameRate;
writer.Quality = 50;
open(writer);

totalFrames = writer.FrameRate * videoLength;

for i = 1:totalFrames
    writeVideo(writer, img);
    disp(['progress: ' num2str(floor(i * 100 / totalFrames)) '%']);
end

disp('all frames were written');
close(writer);

%% read the video file
% clearvars -except filename;

disp('read first frame from video file and show it');
reader = VideoReader(filename);
totalFrames = floor(reader.FrameRate * reader.Duration);
reader.CurrentTime = 0;
figNr = figure(2); set(figNr, 'NumberTitle', 2, 'Name', 'read frame');

nextFrame = reader.readFrame();
imshow(nextFrame);

disp('SCRIPT END!');