Class VP8LDecoder

java.lang.Object

com.twelvemonkeys.imageio.plugins.webp.lossless.VP8LDecoder

public final class VP8LDecoder
extends Object

VP8LDecoder.

Field Summary

Fields

Modifier and Type	Field	Description
private static final byte[]	DISTANCES	Used for decoding backward references Upper 4Bits are y distance, lower 4 Bits are 8 minus x distance
private final ImageInputStream	imageInput
private final LSBBitReader	lsbBitReader

Constructor Summary

Constructors

Constructor	Description
VP8LDecoder(ImageInputStream imageInput, boolean debug)

Method Summary

Modifier and Type	Method	Description
static void	copyIntoRasterWithParams(Raster srcRaster, WritableRaster dstRaster, ImageReadParam param)	Copy a source raster into a destination raster with optional settings applied.
private WritableRaster	createDecodeRaster(WritableRaster raster, ImageReadParam param, Rectangle bounds)
private int	decodeBwRef(WritableRaster raster, ColorCache colorCache, int width, HuffmanCodeGroup curCodeGroup, byte[] rgba, short code, int x, int y)
private void	decodeCached(WritableRaster raster, ColorCache colorCache, byte[] rgba, int y, int x, short code)
private void	decodeImage(WritableRaster raster, HuffmanInfo huffmanInfo, ColorCache colorCache)
private void	decodeLiteral(WritableRaster raster, ColorCache colorCache, HuffmanCodeGroup curCodeGroup, byte[] rgba, int y, int x, short code)
private int	lz77decode(int prefixCode)
private HuffmanInfo	readHuffmanCodes(int xSize, int ySize, int colorCacheBits, boolean readMetaCodes)
private int	readTransform(int xSize, int ySize, List<Transform> transforms)
void	readVP8Lossless(WritableRaster raster, boolean topLevel, ImageReadParam param, int width, int height)
private static int	subSampleSize(int size, int samplingBits)

Methods inherited from class Object

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

Field Details

DISTANCES

private static final byte[] DISTANCES

Used for decoding backward references Upper 4Bits are y distance, lower 4 Bits are 8 minus x distance

imageInput

private final ImageInputStream imageInput

lsbBitReader

private final LSBBitReader lsbBitReader

Constructor Details

VP8LDecoder

public VP8LDecoder(ImageInputStream imageInput,
 boolean debug)

Method Details

readVP8Lossless

public void readVP8Lossless(WritableRaster raster,
 boolean topLevel,
 ImageReadParam param,
 int width,
 int height)
                     throws IOException

Throws:

IOException

createDecodeRaster

private WritableRaster createDecodeRaster(WritableRaster raster,
 ImageReadParam param,
 Rectangle bounds)

copyIntoRasterWithParams

public static void copyIntoRasterWithParams(Raster srcRaster,
 WritableRaster dstRaster,
 ImageReadParam param)

Copy a source raster into a destination raster with optional settings applied.

decodeImage

private void decodeImage(WritableRaster raster,
 HuffmanInfo huffmanInfo,
 ColorCache colorCache)
                  throws IOException

Throws:

IOException

decodeCached

private void decodeCached(WritableRaster raster,
 ColorCache colorCache,
 byte[] rgba,
 int y,
 int x,
 short code)

decodeLiteral

private void decodeLiteral(WritableRaster raster,
 ColorCache colorCache,
 HuffmanCodeGroup curCodeGroup,
 byte[] rgba,
 int y,
 int x,
 short code)
                    throws IOException

Throws:

IOException

decodeBwRef

private int decodeBwRef(WritableRaster raster,
 ColorCache colorCache,
 int width,
 HuffmanCodeGroup curCodeGroup,
 byte[] rgba,
 short code,
 int x,
 int y)
                 throws IOException

Throws:

IOException

lz77decode

private int lz77decode(int prefixCode)
                throws IOException

Throws:

IOException

readTransform

private int readTransform(int xSize,
 int ySize,
 List<Transform> transforms)
                   throws IOException

Throws:

IOException

readHuffmanCodes

private HuffmanInfo readHuffmanCodes(int xSize,
 int ySize,
 int colorCacheBits,
 boolean readMetaCodes)
                              throws IOException

Throws:

IOException

subSampleSize

private static int subSampleSize(int size,
 int samplingBits)