Hello I have use this code for video convert .mts to .mp4 with NReco.VideoConverter.LicenseKey
string fileNameonly = Path.GetFileNameWithoutExtension(Video.FileName);
string outputFileName = Path.ChangeExtension(Video.FileName, ".mp4");
//#pragma warning disable CS0618 // Type or member is obsolete
// Conversion.ToMp4(Video.FileName, outputFileName).Start();
//#pragma warning restore CS0618 // Type or member is obsolete
string filePath = fileNameonly + ".mp4";