org.monte.media.ilbm
Class ILBMDecoder

java.lang.Object
  org.monte.media.ilbm.ILBMDecoder

All Implemented Interfaces:

IFFVisitor

public class ILBMDecoder
extends java.lang.Object
implements IFFVisitor

Creates Image objects by reading an IFF ILBM stream.

ILBM regular expression

 ILBM ::= "FORM" #{ "ILBM" BMHD [CMAP] [GRAB] [DEST] [SPRT] [CAMG] CRNG* CCRT* DRNG* [BODY] }

 BMHD ::= "BMHD" #{ BitMapHeader }
 CMAP ::= "CMAP" #{ (red green blue)* } [0]
 GRAB ::= "GRAB" #{ Point2D }
 DEST ::= "DEST" #{ DestMerge }
 SPRT ::= "SPRT" #{ SpritePrecedence }
 CAMG ::= "CAMG" #{ LONG }

 CRNG ::= "CRNG" #{ CRange }
 DRNG ::= "DRNG" #{ DRange }
 CCRT ::= "CCRT" #{ CycleInfo }
 BODY ::= "BODY" #{ UBYTE* } [0]
 

The token "#" represents a ckSize LONG count of the following braced data bytes. E.g., a BMHD's "#" should equal sizeof(BitMapHeader). Literal strings are shown in "quotes", [square bracket items] are optional, and "*" means 0 or more repetitions. A sometimes-needed pad byte is shown as "[0]".

Version:

1.8 2011-07-21 Treats CMAP specially if OCS chip set is detected.
1.7 2011-04-10 Generates gray-scale color table if no CMAP is provided. Adds support for CCRT color cycling.
1.6 2011-02-20 Adds method produceBitmaps().
1.5.1 2010-07-03 Improved performance of byterun1 decoder.
1.4 2010-01-22 Added support for DRNG color cycling.
1.3 2009-12-24 Added support for CRNG color cycling.
1.2 2004-05-20 Support for masking bitplane added. Removed enforcing of true colors (Apple fixed bugs in its Java VM).
1.1 2003-08-15 Enforcing True color for images. Due to bug in Java 1.3.1, 1.4.1 on Mac OS X 10.0 through 10.2.
1.0.2 2003-01-19 Conversion to JDK 1.3 continued.
1.0.1 2001-06-17 Conversion to JDK 1.3 in progress.
1.0 1999-10-19

Author:

Werner Randelshofer, Hausmatt 10, CH-6405 Immensee, Switzerland

Field Summary

protected static int	A2024_MONITOR_ID
protected java.util.ArrayList<BitmapImage>	bitmapSources
protected static int	BMHD_ID
protected int	bmhdCompression
protected int	bmhdHeight Raster width_ and heigth in pixels
protected int	bmhdMasking
protected int	bmhdNbPlanes Number of source bitplanes.
protected int	bmhdPageHeight Source "page" size in pixels.
protected int	bmhdPageWidth Source "page" size in pixels.
protected int	bmhdTransparentColor Transparent "color number" (sort of).
protected int	bmhdWidth Raster width_ and heigth in pixels
protected int	bmhdXAspect Pixel aspect, a ratio width : height
protected int	bmhdXPosition pixel position for this image
protected int	bmhdYAspect Pixel aspect, a ratio width : height
protected int	bmhdYPosition pixel position for this image
protected static int	BODY_ID
protected BitmapImage	bodyBitmap BODY data
protected int	camg Commodore Amiga Graphics Mode.
protected static int	CAMG_ID
protected int	camgMode CAMG Video display mode.
protected static int	CCRT_ID
protected static int	CMAP_ID
protected java.awt.image.ColorModel	cmapColorModel CMAP data.
protected static int	CMP_BYTE_RUN_1 ILBM BMHD chunk: compression algorithm.
protected static int	CMP_NONE ILBM BMHD chunk: compression algorithm.
protected static int	CMP_VERTICAL ILBM BMHD chunk: compression algorithm.
protected static int	CRNG_ID
protected static int	DBLNTSC_MONITOR_ID
protected static int	DBLPAL_MONITOR_ID
protected static int	DEFAULT_MONITOR_ID
protected static int	DRNG_ID
protected static int	EHB_MASK
protected static int	EURO36_MONITOR_ID
protected static int	EURO72_MONITOR_ID
protected static int	EXTRAHALFBRITE_KEY
protected static int	HAM_KEY
protected static int	HAM_MASK
protected static int	ILBM_ID Chunk ID's.
protected java.io.InputStream	inputStream Input stream to decode from.
protected java.net.URL	location URL to get the input stream from.
protected static int	MODE_DIRECT_COLORS
protected static int	MODE_EHB
protected static int	MODE_HAM6
protected static int	MODE_HAM8
protected static int	MODE_INDEXED_COLORS
protected static int	MONITOR_ID_MASK ILBM CAMG chunk: Mask and ID bits for CAMG ModeID.
protected static int	MSK_HAS_MASK ILBM BMHD chunk: masking technique.
protected static int	MSK_HAS_TRANSPARENT_COLOR ILBM BMHD chunk: masking technique.
protected static int	MSK_LASSO ILBM BMHD chunk: masking technique.
protected static int	MSK_NONE ILBM BMHD chunk: masking technique.
protected static int	NTSC_MONITOR_ID
protected static int	PAL_MONITOR_ID
protected java.util.Hashtable	properties Properties.
protected static int	PROTO_MONITOR_ID
protected java.util.ArrayList<ColorCyclingMemoryImageSource>	sources Stores all the ILBM pictures found during decoding as an instance of ColorCyclingMemoryImageSource.
protected static int	SUPER72_MONITOR_ID
protected static int	VDAT_ID
protected static int	VGA_MONITOR_ID

Constructor Summary

ILBMDecoder(java.io.InputStream in)
Constructors

ILBMDecoder(java.net.URL location)

Method Summary

protected void	decodeBMHD(IFFChunk chunk)
protected void	decodeBODY(IFFChunk chunk)
protected void	decodeCAMG(IFFChunk chunk) Decodes the CAMG Chunk.
protected ColorCycle	decodeCCRT(IFFChunk chunk) Decodes the color cycling range and timing chunk (ILBM CCRT).
protected void	decodeCMAP(IFFChunk chunk, boolean is4BitsPerChannel)
protected ColorCycle	decodeCRNG(IFFChunk chunk) Decodes the color range cycling (ILBM CRNG).
protected ColorCycle	decodeDRNG(IFFChunk chunk) Decodes the DPaint IV enhanced color cycle chunk (ILBM DRNG)
void	enterGroup(IFFChunk chunk)
void	leaveGroup(IFFChunk chunk)
java.util.ArrayList<ColorCyclingMemoryImageSource>	produce() Processes the input stream and creates a vector of ColorCyclingMemoryImageSource instances.
java.util.ArrayList<BitmapImage>	produceBitmaps() Processes the input stream and creates a vector of BitmapImages instances.
void	registerChunks(IFFParser iff)
static int	unpackByteRun1(byte[] in, byte[] out) ByteRun1 run decoder.
void	unpackVertical(byte[] in, BitmapImage bm) Vertical run decoder.
void	visitChunk(IFFChunk group, IFFChunk chunk)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

ILBM_ID

protected static final int ILBM_ID

Chunk ID's.

BMHD_ID

protected static final int BMHD_ID

CMAP_ID

protected static final int CMAP_ID

CAMG_ID

protected static final int CAMG_ID

CCRT_ID

protected static final int CCRT_ID

CRNG_ID

protected static final int CRNG_ID

DRNG_ID

protected static final int DRNG_ID

BODY_ID

protected static final int BODY_ID

VDAT_ID

protected static final int VDAT_ID

MONITOR_ID_MASK

protected static final int MONITOR_ID_MASK

ILBM CAMG chunk: Mask and ID bits for CAMG ModeID.

See Also:

Constant Field Values

DEFAULT_MONITOR_ID

protected static final int DEFAULT_MONITOR_ID

See Also:

Constant Field Values

NTSC_MONITOR_ID

protected static final int NTSC_MONITOR_ID

See Also:

Constant Field Values

PAL_MONITOR_ID

protected static final int PAL_MONITOR_ID

See Also:

Constant Field Values

VGA_MONITOR_ID

protected static final int VGA_MONITOR_ID

See Also:

Constant Field Values

A2024_MONITOR_ID

protected static final int A2024_MONITOR_ID

See Also:

Constant Field Values

PROTO_MONITOR_ID

protected static final int PROTO_MONITOR_ID

See Also:

Constant Field Values

EURO72_MONITOR_ID

protected static final int EURO72_MONITOR_ID

See Also:

Constant Field Values

EURO36_MONITOR_ID

protected static final int EURO36_MONITOR_ID

See Also:

Constant Field Values

SUPER72_MONITOR_ID

protected static final int SUPER72_MONITOR_ID

See Also:

Constant Field Values

DBLNTSC_MONITOR_ID

protected static final int DBLNTSC_MONITOR_ID

See Also:

Constant Field Values

DBLPAL_MONITOR_ID

protected static final int DBLPAL_MONITOR_ID

See Also:

Constant Field Values

MODE_INDEXED_COLORS

protected static final int MODE_INDEXED_COLORS

See Also:

Constant Field Values

MODE_DIRECT_COLORS

protected static final int MODE_DIRECT_COLORS

See Also:

Constant Field Values

MODE_EHB

protected static final int MODE_EHB

See Also:

Constant Field Values

MODE_HAM6

protected static final int MODE_HAM6

See Also:

Constant Field Values

MODE_HAM8

protected static final int MODE_HAM8

See Also:

Constant Field Values

HAM_MASK

protected static final int HAM_MASK

See Also:

Constant Field Values

EHB_MASK

protected static final int EHB_MASK

See Also:

Constant Field Values

HAM_KEY

protected static final int HAM_KEY

See Also:

Constant Field Values

EXTRAHALFBRITE_KEY

protected static final int EXTRAHALFBRITE_KEY

See Also:

Constant Field Values

MSK_NONE

protected static final int MSK_NONE

ILBM BMHD chunk: masking technique.

See Also:

Constant Field Values

MSK_HAS_MASK

protected static final int MSK_HAS_MASK

ILBM BMHD chunk: masking technique.

See Also:

Constant Field Values

MSK_HAS_TRANSPARENT_COLOR

protected static final int MSK_HAS_TRANSPARENT_COLOR

ILBM BMHD chunk: masking technique.

See Also:

Constant Field Values

MSK_LASSO

protected static final int MSK_LASSO

ILBM BMHD chunk: masking technique.

See Also:

Constant Field Values

CMP_NONE

protected static final int CMP_NONE

ILBM BMHD chunk: compression algorithm.

See Also:

Constant Field Values

CMP_BYTE_RUN_1

protected static final int CMP_BYTE_RUN_1

ILBM BMHD chunk: compression algorithm.

See Also:

Constant Field Values

CMP_VERTICAL

protected static final int CMP_VERTICAL

ILBM BMHD chunk: compression algorithm.

See Also:

Constant Field Values

inputStream

protected java.io.InputStream inputStream

Input stream to decode from.

location

protected java.net.URL location

URL to get the input stream from.

sources

protected java.util.ArrayList<ColorCyclingMemoryImageSource> sources

Stores all the ILBM pictures found during decoding as an instance of ColorCyclingMemoryImageSource.

bitmapSources

protected java.util.ArrayList<BitmapImage> bitmapSources

properties

protected java.util.Hashtable properties

Properties.

bmhdWidth

protected int bmhdWidth

Raster width_ and heigth in pixels

bmhdHeight

protected int bmhdHeight

Raster width_ and heigth in pixels

bmhdXPosition

protected int bmhdXPosition

pixel position for this image

bmhdYPosition

protected int bmhdYPosition

pixel position for this image

bmhdNbPlanes

protected int bmhdNbPlanes

Number of source bitplanes.

bmhdMasking

protected int bmhdMasking

bmhdCompression

protected int bmhdCompression

bmhdTransparentColor

protected int bmhdTransparentColor

Transparent "color number" (sort of).

bmhdXAspect

protected int bmhdXAspect

Pixel aspect, a ratio width : height

bmhdYAspect

protected int bmhdYAspect

Pixel aspect, a ratio width : height

bmhdPageWidth

protected int bmhdPageWidth

Source "page" size in pixels.

bmhdPageHeight

protected int bmhdPageHeight

Source "page" size in pixels.

camg

protected int camg

Commodore Amiga Graphics Mode.

camgMode

protected int camgMode

CAMG Video display mode.

cmapColorModel

protected java.awt.image.ColorModel cmapColorModel

CMAP data.

bodyBitmap

protected BitmapImage bodyBitmap

BODY data

Constructor Detail

ILBMDecoder

public ILBMDecoder(java.io.InputStream in)

Constructors

ILBMDecoder

public ILBMDecoder(java.net.URL location)

Method Detail

produce

public java.util.ArrayList<ColorCyclingMemoryImageSource> produce()
                                                           throws java.io.IOException

Processes the input stream and creates a vector of ColorCyclingMemoryImageSource instances.

Returns:

A vector of java.awt.img.ColorCyclingMemoryImageSource.

Throws:

java.io.IOException

produceBitmaps

public java.util.ArrayList<BitmapImage> produceBitmaps()
                                                throws java.io.IOException

Processes the input stream and creates a vector of BitmapImages instances.

Returns:

A vector of java.awt.img.ColorCyclingMemoryImageSource.

Throws:

java.io.IOException

registerChunks

public void registerChunks(IFFParser iff)

enterGroup

public void enterGroup(IFFChunk chunk)

Specified by:

enterGroup in interface IFFVisitor

leaveGroup

public void leaveGroup(IFFChunk chunk)

Specified by:

leaveGroup in interface IFFVisitor

visitChunk

public void visitChunk(IFFChunk group,
                       IFFChunk chunk)
                throws ParseException,
                       AbortException

Specified by:

visitChunk in interface IFFVisitor

Throws:

ParseException

AbortException

decodeBMHD

protected void decodeBMHD(IFFChunk chunk)
                   throws ParseException

Throws:

ParseException

decodeCAMG

protected void decodeCAMG(IFFChunk chunk)
                   throws ParseException

Decodes the CAMG Chunk. Requires data from BMHD Chunk.

Throws:

ParseException

decodeCMAP

protected void decodeCMAP(IFFChunk chunk,
                          boolean is4BitsPerChannel)
                   throws ParseException

Throws:

ParseException

decodeCCRT

protected ColorCycle decodeCCRT(IFFChunk chunk)
                         throws ParseException

Decodes the color cycling range and timing chunk (ILBM CCRT).

 enum {
     dontCycle = 0, forward = 1, backwards = -1
 } ccrtDirection;
 typedef struct {
   WORD enum ccrtDirection direction;  // 0=don't cycle, 1=forward, -1=backwards
   UBYTE start;      // range lower
   UBYTE end;        // range upper
   ULONG  seconds;    // seconds between cycling
   ULONG  microseconds; // msecs between cycling
   WORD  pad;        // future exp - store 0 here
 } ilbmColorCyclingRangeAndTimingChunk;
 

Throws:

ParseException

decodeCRNG

protected ColorCycle decodeCRNG(IFFChunk chunk)
                         throws ParseException

Decodes the color range cycling (ILBM CRNG).

 #define RNG_NORATE  36   // Dpaint uses this rate to mean non-active
  set {
  active = 1, reverse = 2
  } crngActive;

  // A CRange is store in a CRNG chunk.
  typedef struct {
  WORD  pad1;              // reserved for future use; store 0 here *
  WORD  rate;              // 60/sec=16384, 30/sec=8192, 1/sec=16384/60=273
  WORD set crngActive flags;     // bit0 set = active, bit 1 set = reverse
  UBYTE low; UBYTE high;         // lower and upper color registers selected
  } ilbmColorRegisterRangeChunk;
 

Throws:

ParseException

decodeDRNG

protected ColorCycle decodeDRNG(IFFChunk chunk)
                         throws ParseException

Decodes the DPaint IV enhanced color cycle chunk (ILBM DRNG)

The RNG_ACTIVE flag is set when the range is cyclable. A range should only have the RNG _ACTIVE if it:

1. contains at least one color register
2. has a defined rate
3. has more than one color and/or color register

 ILBM DRNG DPaint IV enhanced color cycle chunk
 --------------------------------------------

 set {
     RNG_ACTIVE=1,RNG_DP_RESERVED=4
 } drngFlags;

 /* True color cell * /
 typedef struct {
     UBYTE cell;
     UBYTE r;
     UBYTE g;
     UBYTE b;
 } ilbmDRNGDColor;

 /* Color register cell * /
 typedef struct {
     UBYTE cell;
     UBYTE index;
 } ilbmDRNGDIndex;

 /* DRNG chunk. * /
 typedef struct {
     UBYTE min; /* min cell value * /
     UBYTE max; /* max cell value * /
     UWORD rate; /* color cycling rate, 16384 = 60 steps/second * /
     UWORD set drngFlags flags; /* 1=RNG_ACTIVE, 4=RNG_DP_RESERVED * /
     UBYTE ntrue; /* number of DColorCell structs to follow * /
     UBYTE ntregs; /* number of DIndexCell structs to follow * /
     ilbmDRNGDColor[ntrue] trueColorCells;
     ilbmDRNGDIndex[ntregs] colorRegisterCells;
 } ilbmDRangeChunk;
 

Throws:

ParseException

decodeBODY

protected void decodeBODY(IFFChunk chunk)
                   throws ParseException

Throws:

ParseException

unpackByteRun1

public static int unpackByteRun1(byte[] in,
                                 byte[] out)
                          throws ParseException

ByteRun1 run decoder.

The run encoding scheme by byteRun1 is best described by pseudo code for the decoder Unpacker (called UnPackBits in the Macintosh toolbox.

 UnPacker:
  LOOP until produced the desired number of bytes
      Read the next source byte into n
      SELECT n FROM
          [0..127] => copy the next n+1 bytes literally
          [-1..-127] => replicate the next byte -n+1 times
          -128    => no operation
      ENDCASE;
   ENDLOOP;
 

Parameters:

in -

out -

Throws:

ParseException

unpackVertical

public void unpackVertical(byte[] in,
                           BitmapImage bm)
                    throws ParseException

Vertical run decoder.

Each plane is stored in a separate VDAT chunk.

A VDAT chunk consists of an id, a length, and a body.

 struct {
    uint16 id;  // The 4 ASCII characters "VDAT"
    uint16 length,
    byte[length] body
 }
 

The body consists of a command list and a data list.

 struct {
    uint16         cnt;        // Command count + 2
    uint8[cnt - 2] cmd;        // The commands
    uint16[]       data;       // Data words
 }
 

Pseudo code for the unpacker:

 UnPacker:
  Read cnt;
  LOOP cnt - 2 TIMES
      Read the next command byte into cmd
      SELECT cmd FROM
          0 =>
                  Read the next data word into n
                  Copy the next n data words literally
          1    =>
                  Read the next data word into n
                  Replicate the next data word n times
          [2..127] =>
                  Replicate the next data word cmd times
          [-1..-128] =>
                  Copy the next -cmd data words literally
      ENDCASE;
      IF end of data reached THEN EXIT END;
   ENDLOOP;
 

Throws:

ParseException