FFMPEG Video not working on Social Media Platforms (Flutter-FFMPEG) - flutter

Question

I am using Flutter-FFMPEG a Flutter library based on Mobile FFMPEG. I am creating a video from a list of .bmp images. The video works plays normally in devices media player on android or desktop.
But when I tried to share that video on social media like say Instagram it says file format not supported.
It didn't use to work on WhatsApp but after some googling, I made some changes and it works on WhatsApp and Youtube now but not on Instagram, Linkedin, etc.
void _runFFmpeg() async {
print('Run FFMPEG');
var dir = await getApplicationDocumentsDirectory();
var output = await getExternalStorageDirectory();
String videoSize = '$ImageWidth:$ImageSize';
print("${ImageWidth}x$ImageSize");
var arguments = [
"-y", // replace output file if it already exists
"-i", "${output.path}/frame_%d.bmp",
"-s", '${ImageWidth}x$ImageSize',
"-framerate", "30", // framrate
"-c:v", "libvpx",
'-ab', '128k',
'-ar', '44100',
'-strict', 'experimental',
"-vcodec", "libx264",
"-pixel_format", "yuv420p",
"-preset", "ultrafast",
"-tune", "animation",
"${output.path}/test.mp4"
];
await _flutterFFmpeg.executeWithArguments(arguments).then((rc) {
print('Process done with $rc');
});
The plugin I am using (Flutter-FFMPEG) didn't support libx264
I tried using '-profile:v' to baseline but that gives an error, saying Error setting profile to baseline.
Also, I tried to first make a .webm file and then convert that to mp4. I was also able to use '-profile:v' when converting .webm to mp4 and gave no error but the output video didn't work on Social Media platforms.

Answer 1

fixFFMPEG(int imageWidth, int imageSize) async {
print('Fix FFMPEG');
var output = await getExternalStorageDirectory();
var arguments2 = [
'-y',
// "-s",
// '${imageWidth}:$imageSize',
'-i',
'${output.path}/testNew.mp4',
"-framerate", "30", // framrate
"-vcodec", "h264",
"-c:v", "libx264rgb",
"-c:a", 'acc',
'-ab', '128k',
'-ar', '44100',
'-strict', 'experimental',
// '-c',
// 'copy',
// '-strict',
// '-2',
"-vprofile",
"baseline",
"-level",
"3.0",
"-an",
"-pixel_format", "yuv420p",
// '-vtag',
// 'avc1',
// "-vprofile",
// "baseline",
// "-level",
// "3.0",
// "-brand", "mp42",
'${output.path}/fixedvideo1.mp4'
];
// await _flutterFFmpeg
// .executeWithArguments(arguments2)
// .then((rc) => print("FFmpeg process2 exited with rc $rc"));
}