154 lines
3.7 KiB
ObjectPascal
154 lines
3.7 KiB
ObjectPascal
{-----------------------------------------------------------------------------
|
|
The contents of this file are subject to the Mozilla Public License
|
|
Version 1.1 (the "License"); you may not use this file except in compliance
|
|
with the License. You may obtain a copy of the License at
|
|
http://www.mozilla.org/MPL/MPL-1.1.html
|
|
|
|
Software distributed under the License is distributed on an "AS IS" basis,
|
|
WITHOUT WARRANTY OF ANY KIND, either expressed or implied. See the License for
|
|
the specific language governing rights and limitations under the License.
|
|
|
|
The Original Code is: JvRle.PAS, released on 2001-02-28.
|
|
|
|
The Initial Developer of the Original Code is Sébastien Buysse [sbuysse att buypin dott com]
|
|
Portions created by Sébastien Buysse are Copyright (C) 2001 Sébastien Buysse.
|
|
All Rights Reserved.
|
|
|
|
Contributor(s): Michael Beck [mbeck att bigfoot dott com].
|
|
|
|
Last Modified: 2000-02-28
|
|
|
|
You may retrieve the latest version of this file at the Project JEDI's JVCL home page,
|
|
located at http://jvcl.sourceforge.net
|
|
|
|
Known Issues:
|
|
-----------------------------------------------------------------------------}
|
|
|
|
{$I JVCL.INC}
|
|
|
|
unit JvRle;
|
|
|
|
interface
|
|
|
|
uses
|
|
SysUtils, Classes;
|
|
|
|
// (rom) changed API for inclusion in JCL
|
|
|
|
procedure RleCompress(Stream: TStream);
|
|
procedure RleDecompress(Stream: TStream);
|
|
|
|
implementation
|
|
|
|
procedure RleCompress(Stream: TStream);
|
|
var
|
|
Count, Count2, Count3, I: Integer;
|
|
Buf1: array [0..1024] of Byte;
|
|
Buf2: array [0..60000] of Byte;
|
|
B: Byte;
|
|
Tmp: TMemoryStream;
|
|
begin
|
|
Tmp := TMemoryStream.Create;
|
|
Stream.Position := 0;
|
|
|
|
Count := 1024;
|
|
while Count = 1024 do
|
|
begin
|
|
Count := Stream.Read(Buf1, 1024);
|
|
Count2 := 0;
|
|
I := 0;
|
|
while I < Count do
|
|
begin
|
|
B := Buf1[I];
|
|
Count3 := 0;
|
|
while (Buf1[I] = B) and (I < Count) and (Count3 < $30) do
|
|
begin
|
|
Inc(I);
|
|
Inc(Count3);
|
|
end;
|
|
if (I = Count) and (Count3 in [2..$2F]) and (Count = 1024) then
|
|
Stream.Position := Stream.Position - Count3
|
|
else
|
|
begin
|
|
if Count3 = 1 then
|
|
begin
|
|
if (B and $C0) = $C0 then
|
|
begin
|
|
Buf2[Count2] := $C1;
|
|
Buf2[Count2 + 1] := B;
|
|
Inc(Count2, 2);
|
|
end
|
|
else
|
|
begin
|
|
Buf2[Count2] := B;
|
|
Inc(Count2);
|
|
end;
|
|
end
|
|
else
|
|
begin
|
|
Buf2[Count2] := Count3 or $C0;
|
|
Buf2[Count2 + 1] := B;
|
|
Inc(Count2, 2);
|
|
end;
|
|
end;
|
|
end;
|
|
Tmp.Write(Buf2, Count2);
|
|
end;
|
|
|
|
Tmp.Position := 0;
|
|
Stream.Size := 0;
|
|
Stream.CopyFrom(Tmp, Tmp.Size);
|
|
Tmp.Free;
|
|
end;
|
|
|
|
procedure RleDecompress(Stream: TStream);
|
|
var
|
|
Count, Count2, Count3, I: Integer;
|
|
Buf1: array [0..1024] of Byte;
|
|
Buf2: array [0..60000] of Byte;
|
|
B: Byte;
|
|
Tmp: TMemoryStream;
|
|
begin
|
|
Tmp := TMemoryStream.Create;
|
|
Stream.Position := 0;
|
|
|
|
Count := 1024;
|
|
while Count = 1024 do
|
|
begin
|
|
Count := Stream.Read(Buf1, 1024);
|
|
Count2 := 0;
|
|
I := 0;
|
|
while I < Count do
|
|
begin
|
|
if (Buf1[I] and $C0) = $C0 then
|
|
begin
|
|
if I = Count - 1 then
|
|
Stream.Position := Stream.Position - 1
|
|
else
|
|
begin
|
|
B := Buf1[I] and $3F;
|
|
Inc(I);
|
|
for Count3 := Count2 to Count2 + B - 1 do
|
|
Buf2[Count3] := Buf1[I];
|
|
Count2 := Count2 + B;
|
|
end;
|
|
end
|
|
else
|
|
begin
|
|
Buf2[Count2] := Buf1[I];
|
|
Inc(Count2);
|
|
end;
|
|
Inc(I);
|
|
end;
|
|
Tmp.Write(Buf2, Count2);
|
|
end;
|
|
|
|
Tmp.Position := 0;
|
|
Stream.Size := 0;
|
|
Stream.CopyFrom(Tmp, Tmp.Size);
|
|
Tmp.Free;
|
|
end;
|
|
|
|
end.
|
|
|