some media can't convert , but no return value

[paniclp]

I find a media, call convert,but no any effect.
engine.Convert this function no return value.
so you couldn't know whether this convert is invalid or valid.
my code is:
var inputFile = new MediaFile { Filename = input };
string output = GetNewPathName(input);
var outputFile = new MediaFile { Filename = output };
try
{

            using (var engine = new Engine())
            {
                engine.ConvertProgressEvent += ConvertProgressEvent;
                engine.ConversionCompleteEvent += engine_ConversionCompleteEvent;
                
                engine.Convert(inputFile, outputFile);
            }
        }
        catch(Exception ex)
        {
        }

my file is:
https://user-images.githubusercontent.com/56712440/124778078-46fab280-df73-11eb-9ace-251be8653a1c.mp4
my email is [email protected]