| /* EncodeRLE4.java -- |
| Copyright (C) 2006 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package gnu.javax.imageio.bmp; |
| |
| import java.awt.image.BufferedImage; |
| import java.awt.image.PixelGrabber; |
| import java.io.IOException; |
| import java.nio.BufferUnderflowException; |
| import java.nio.ByteBuffer; |
| |
| import javax.imageio.IIOImage; |
| import javax.imageio.ImageWriteParam; |
| import javax.imageio.metadata.IIOMetadata; |
| import javax.imageio.stream.ImageOutputStream; |
| |
| public class EncodeRLE4 |
| extends BMPEncoder |
| { |
| protected BMPInfoHeader infoHeader; |
| protected BMPFileHeader fileHeader; |
| protected long offset; |
| |
| /** |
| * RLE control codes |
| */ |
| private static final byte ESCAPE = (byte)0; |
| private static final byte EOL = (byte)0; // end of line |
| private static final byte EOB = (byte)1; // end of bitmap |
| private static final byte DELTA = (byte)2; // delta |
| |
| /** |
| * Constructs an instance of this class. |
| * |
| * @param fh - the file header to use. |
| * @param ih - the info header to use. |
| */ |
| public EncodeRLE4(BMPFileHeader fh, BMPInfoHeader ih) |
| { |
| super(); |
| fileHeader = fh; |
| infoHeader = ih; |
| offset = BMPFileHeader.SIZE + BMPInfoHeader.SIZE; |
| } |
| |
| /** |
| * The image encoder. |
| * |
| * @param o - the image output stream |
| * @param streamMetadata - metadata associated with this stream, or |
| * null |
| * @param image - an IIOImage containing image data. |
| * @param param - image writing parameters, or null |
| * @exception IOException if a write error occurs |
| */ |
| public void encode(ImageOutputStream o, IIOMetadata streamMetadata, |
| IIOImage image, ImageWriteParam param) throws IOException |
| { |
| int size; |
| int value; |
| int j; |
| int rowCount; |
| int rowIndex; |
| int lastRowIndex; |
| int[] bitmap; |
| size = (infoHeader.biWidth * infoHeader.biHeight) - 1; |
| rowCount = 1; |
| rowIndex = size - infoHeader.biWidth; |
| lastRowIndex = rowIndex; |
| ByteBuffer buf = ByteBuffer.allocate(size); |
| try |
| { |
| bitmap = new int[infoHeader.biWidth * infoHeader.biHeight]; |
| PixelGrabber pg = new PixelGrabber((BufferedImage) image.getRenderedImage(), |
| 0, 0, infoHeader.biWidth, |
| infoHeader.biHeight, bitmap, 0, |
| infoHeader.biWidth); |
| pg.grabPixels(); |
| |
| for (j = 0; j < size; j++) |
| { |
| value = bitmap[rowIndex]; |
| buf.put((byte) (value & 0xFF)); |
| |
| if (rowCount == infoHeader.biWidth) |
| { |
| rowCount = 1; |
| rowIndex = lastRowIndex - infoHeader.biWidth; |
| lastRowIndex = rowIndex; |
| } |
| else |
| rowCount++; |
| rowIndex++; |
| } |
| |
| buf.flip(); |
| o.write(uncompress(infoHeader.biWidth, infoHeader.biHeight, buf)); |
| } |
| catch (Exception wb) |
| { |
| wb.printStackTrace(); |
| } |
| } |
| |
| /** |
| * Uncompresses the image stored in the buffer. |
| * |
| * @param w - the width of the image |
| * @param h - the height of the image |
| * @param buf - the ByteBuffer containing the pixel values. |
| * @return byte array containing the uncompressed image |
| * @throws IOException if an error is encountered while reading |
| * buffer. |
| */ |
| private byte[] uncompress(int w, int h, ByteBuffer buf) |
| throws IOException |
| { |
| byte[] cmd = new byte[2]; |
| byte[] data = new byte[w * h >> 1]; |
| int offIn = 0; |
| int x = 0, y = 0; |
| |
| w += (w & 1); |
| w = w >> 1; |
| |
| try |
| { |
| while (((x >> 1) + y * w) < w * h) |
| { |
| try |
| { |
| buf.get(cmd); |
| } |
| catch (BufferUnderflowException e) |
| { |
| throw new IOException("Error reading compressed data."); |
| } |
| |
| if (cmd[0] == ESCAPE) |
| { |
| switch (cmd[1]) |
| { |
| case EOB: |
| return data; |
| case EOL: |
| x = 0; |
| y++; |
| break; |
| case DELTA: |
| try |
| { |
| buf.get(cmd); |
| } |
| catch (BufferUnderflowException e) |
| { |
| throw new IOException("Error reading compressed data."); |
| } |
| |
| int dx = cmd[0] & (0xFF); |
| int dy = cmd[1] & (0xFF); |
| x += dx; |
| y += dy; |
| break; |
| |
| default: |
| int length = cmd[1] & (0xFF); |
| |
| int bytesize = length; |
| bytesize += (bytesize & 1); |
| bytesize >>= 1; |
| bytesize += (bytesize & 1); |
| |
| byte[] run = new byte[bytesize]; |
| try |
| { |
| buf.get(run); |
| } |
| catch (BufferUnderflowException e) |
| { |
| throw new IOException("Error reading compressed data."); |
| } |
| |
| if ((x & 1) == 0) |
| { |
| length += (length & 1); |
| length >>= 1; |
| System.arraycopy(run, 0, data, |
| ((x >> 1) + w * (h - y - 1)), length); |
| } |
| else |
| { |
| for (int i = 0; i < length; i++) |
| { |
| if ((i & 1) == 0) |
| data[((x + i) >> 1) + w * (h - y - 1)] |= ((run[i >> 1] & 0xF0) >> 4); |
| else |
| data[((x + i) >> 1) + w * (h - y - 1)] |= ((run[i >> 1] & 0x0F) << 4); |
| } |
| } |
| x += cmd[1] & (0xFF); |
| break; |
| } |
| } |
| else |
| { |
| int length = cmd[0] & (0xFF); |
| if ((x & 1) == 0) |
| { |
| length += (length & 1); |
| length >>= 1; |
| for (int i = 0; i < length; i++) |
| data[(h - y - 1) * w + i + (x >> 1)] = cmd[1]; |
| } |
| else |
| { |
| for (int i = 0; i < length; i++) |
| { |
| if ((i & 1) == 0) |
| data[((x + i) >> 1) + w * (h - y - 1)] |= ((cmd[1] & 0xF0) >> 4); |
| else |
| data[((x + i) >> 1) + w * (h - y - 1)] |= ((cmd[1] & 0x0F) << 4); |
| } |
| } |
| x += cmd[0] & (0xFF); |
| } |
| } |
| return data; |
| } |
| catch (ArrayIndexOutOfBoundsException e) |
| { |
| throw new BMPException("Invalid RLE data."); |
| } |
| } |
| } |