PPMD Compress File

Demonstrates how to use the PPMD compression algorithm to compress a file. This code is capable of compressing any size file because the file data is compressed from input to output in a streaming mode. The output file does not contain any "PPMD" header -- it is purely PPMD compressed data.

Download Chilkat Compression ActiveX

uses
    Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
    Dialogs, StdCtrls,
    CHILKATCOMPRESSIONLib_TLB,
    OleCtrls;

...

procedure TForm1.Button1Click(Sender: TObject);
var
compress: TChilkatCompression;
success: Integer;

begin
compress := TChilkatCompression.Create(Self);

//  Any string argument automatically begins a 30-day trial.
success := compress.UnlockComponent('30-day trial');
if (success <> 1) then
  begin
    ShowMessage('Compression component unlock failed');
    Exit;
  end;

compress.Algorithm := 'ppmd';

success := compress.CompressFile('hamlet.xml','hamletPpmd.dat');
if (success <> 1) then
  begin
    ShowMessage(compress.LastErrorText);
    Exit;
  end;

//  Decompress back to the original:
success := compress.DecompressFile('hamletPpmd.dat','hamletInflated.xml');
if (success <> 1) then
  begin
    ShowMessage(compress.LastErrorText);
    Exit;
  end;

Memo1.Lines.Add('Success!');
end;