ReNamer:Scripts:AVI video codec

Extract AVI video codec and insert it into the filename, as a suffix.

Tested

• ReNamer 5.50

Code

Author: prologician. Date: 3 Aug 2009.

The simple version of the script, which should work for most of the AVI files:

<syntaxhighlight lang="pascal"> var

 fourcc: string;

begin

 if WideSameText(WideExtractFileExt(FileName), '.avi') then
 begin
   fourcc := FileReadFragment(FilePath, 7*16, 4);
   FileName := WideExtractBaseName(FileName) +
     ' ' + fourcc + WideExtractFileExt(FileName);
 end

end. </source>

More complicated version, which is parsing internal AVI structures:

<syntaxhighlight lang="pascal"> function BigEndian(const bytestring: String): Integer; var

 i: Integer;

begin

 result := 0;
 for i := 1 to Length(bytestring) do
   result := result * $100 + ord(bytestring[i])

end;

function LittleEndian(const bytestring: String): Integer; var

 i: Integer;

begin

 result := 0;
 for i := Length(bytestring) downto 1 do
   result := result * $100 + ord(bytestring[i])

end;

function FileAssertString(var offset: integer; const actual: string): Boolean; begin

 result := (WideCompareStr(actual, FileReadFragment(FilePath, offset, length(actual))) = 0)
 offset := offset + length(actual)

end;

procedure FileSkip(var fileoffset: integer; const amount: integer); begin

 fileoffset := fileoffset + amount

end;

function IsStrhVids(offset: integer): Boolean; begin

 result := false;
 if not fileassertstring(offset, 'strl') then exit;
 if not fileassertstring(offset, 'strh') then exit;
 FileSkip(offset, 4); //Size of the strh chunk
 if not fileassertstring(offset, 'vids') then exit;
 result := true;

end;

var

 fourcc: string;
 fileptr: integer;
 streams: integer;
 chunksize: integer;
 i: integer;

begin

 if WideSameText(WideExtractFileExt(FileName), '.avi') then
 begin
   fileptr := 0;
   chunksize := 0;
   if not widefileexists(filepath) then exit;
   if not fileassertstring(fileptr, 'RIFF') then exit;
   FileSkip(fileptr, 4); //Size of the RIFF chunk (most of the file)
   if not fileassertstring(fileptr, 'AVI ') then exit;
   if not fileassertstring(fileptr, 'LIST') then exit;
   FileSkip(fileptr, 4); //Size of the list
   if not fileassertstring(fileptr, 'hdrl') then exit;
   if not fileassertstring(fileptr, 'avih') then exit;
   streams := LittleEndian(FileReadFragment(FilePath, fileptr + 28, 4));
   FileSkip(fileptr, LittleEndian(FileReadFragment(FilePath, fileptr, 4)) + 4); //Skip over the 'avih' chunk.

   for i := 1 to streams do
   begin
     FileSkip(fileptr, chunksize);
     if not fileassertstring(fileptr, 'LIST') then exit;
     chunksize := LittleEndian(FileReadFragment(FilePath, fileptr, 4));
     FileSkip(fileptr, 4); //Size of the list
     if IsStrhVids(fileptr) then
     begin
       fourcc := FileReadFragment(FilePath, fileptr + 16, 4);
       FileName := WideExtractBaseName(FileName) + ' ' + fourcc + WideExtractFileExt(FileName);
       exit
     end
   end
 end

end. </source>