PPMD Compression: String to Compressed Bytes

Demonstrates how to compress a string to a compressed byte array using PPMD.

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;
strData: String;
i: Integer;
compressedBytes: Array of Byte;
strOriginal: String;

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';

//  Create a long string to compress.
strData := 'abcdefg1122334455667788';
strData := strData + #13#10;
for i := 0 to 99 do
  begin
    strData := strData + 'abcdefg1122334455667788';
    strData := strData + #13#10;
  end;

//  Depending on the programming language, the string
//  may be Unicode.  Tell the component to convert to
//  ansi (1-byte/char) prior to compression:
compress.Charset := 'ansi';

//  PPMD compress the string:
compressedBytes := compress.CompressString(strData);

//  Decompress back to the original:

strOriginal := compress.DecompressString(compressedBytes);

//  Display the uncompressed original:
Memo1.Lines.Add('--- Original ---');
Memo1.Lines.Add(strOriginal);
end;