filedatedelphiextractavi

Extract correct creation date from avi file

I am using Delphi 10 and Windows 10 Home Edition 64-bit. I have a video file called MVI_0640.AVI. The date shown in the File Explorer is 15/04/04 which corresponds to the Media Created Date in the Properties window.

I am using the following code to extract dates.

procedure TForm1.Button1Click(Sender: TObject);
var
  ADate: TDateTime;
  FlHandle: integer;
  MyData: TWin32FindData;
  FlTime: TFileTime;
  MySysTime: TSystemTime;
begin
  {get date using GetCreationTime}
  ADate := TFile.GetCreationTime(FlName);
  Memo1.Lines.Add('GetCreationTime ' + DateToStr(ADate));

  {get date using FileGetDate}
  FlHandle := FileOpen(FlName,fmOpenRead);
  ADate := FileDateToDateTime(FileGetDate(FlHandle));
  FileClose(FlHandle);
  Memo1.Lines.Add('FileGetDate ' + DateToStr(ADate));

  {get date using FindFirstFile}
  FindFirstFile(PChar(FlName), MyData);

  FlTime := MyData.ftCreationTime;
  FileTimeToSystemTime(FlTime, MySysTime);
  ADate := SystemTimeToDateTime(MySysTime);
  Memo1.Lines.Add('ftCreationTime ' + DateToStr(ADate));

  FlTime := MyData.ftLastAccessTime;
  FileTimeToSystemTime(FlTime, MySysTime);
  ADate := SystemTimeToDateTime(MySysTime);
  Memo1.Lines.Add('ftLastAccessTime ' + DateToStr(ADate));

  FlTime := MyData.ftLastWriteTime;
  FileTimeToSystemTime(FlTime, MySysTime);
  ADate := SystemTimeToDateTime(MySysTime);
  Memo1.Lines.Add('ftLastWriteTime ' + DateToStr(ADate));

end;

The result looks like this:

None of the dates reflect the Media Created Date. How can I extract it?

In answer to Tom Brunberg’s comment I attach an extract of the file taken with a hex editor. enter image description here

Solution

  • I found an answer to my question. Probably not very elegant or save but it does it's job. I tested it on more than 100 files and it worked without a problem. Here is my answer:

    function TForm1.GetAviMediaCreationDate(AFile: string): TDateTime;
var
  FS: TFileStream;
  NumOfChar: integer;
  i,d: integer;
  ABuffer: array of byte;
  AStr: string;
  DateStr: string;
  sdp: integer; //start date position
  dn,mn,yn: integer; //used to encode date
begin
  sdp := 0;
  FS := TFileStream.Create(AFile,fmOpenRead);
  NumOfChar := 400;
  SetLength(ABuffer,NumOfChar);
  FS.Read(Pointer(ABuffer)^, NumOfChar);
  {find IDIT}
  for i := 0 to NumOfChar-1 do
  begin
    AStr := Char(ABuffer[i]) +
            Char(ABuffer[i+1]) +
            Char(ABuffer[i+2]) +
            Char(ABuffer[i+3]);
    if AStr = 'IDIT' then sdp := i+7;
  end;
  {extract date}
  for d := 1 to 24 do
  DateStr := DateStr + Char(ABuffer[sdp+d]);
  {assemble TDateTime}
  //123456789 123456789 123456789
  //Sun Jun 28 10:13:39 2015
  dn := StrToInt(Copy(DateStr,9,2));
  mn := IndexText(Copy(DateStr,5,3),ShortMonthNames)+1;
  yn := StrToInt(Copy(DateStr,21,4));
  Result := EncodeDate(yn, mn, dn);
  FS.Free;
end;

procedure TForm1.Button2Click(Sender: TObject);
var
  ADate: TDateTime;
begin
  ADate := GetAviMediaCreationDate(FlName);
  Memo1.Lines.Add(DateToStr(ADate));
end;