I am implementing a screen capture widget to create a video. The video was successfully created in MP4 format and I can view it in my app and then I posted it to my web. However, on the web, I cannot see the video preview, only when I download the video and view it on my phone can I see it. I think the problem is that there is some missing format that makes the video not playable on Https. Here is my code:

    final command = '-y -f image2 -i $imagesPath '
    '${fps != null ? "-r $fps" : ""} '
    '-vf "scale=2000:5000" '
    // '-vf "scale=iw*$scaleMultiplier:ih*$scaleMultiplier" '
    '-c:v mpeg4 -q:v $qValue -pix_fmt yuv420p -movflags +faststart $outputVideoPath';

I try to use libx264 nhưng bị báo lỗi