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      1 /*
      2  * Copyright (C)2011, 2013-2015 D. R. Commander.  All Rights Reserved.
      3  * Copyright (C)2015 Viktor Szathmry.  All Rights Reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions are met:
      7  *
      8  * - Redistributions of source code must retain the above copyright notice,
      9  *   this list of conditions and the following disclaimer.
     10  * - Redistributions in binary form must reproduce the above copyright notice,
     11  *   this list of conditions and the following disclaimer in the documentation
     12  *   and/or other materials provided with the distribution.
     13  * - Neither the name of the libjpeg-turbo Project nor the names of its
     14  *   contributors may be used to endorse or promote products derived from this
     15  *   software without specific prior written permission.
     16  *
     17  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS",
     18  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
     21  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     22  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     23  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     24  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     25  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     26  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     27  * POSSIBILITY OF SUCH DAMAGE.
     28  */
     29 
     30 package org.libjpegturbo.turbojpeg;
     31 
     32 /**
     33  * TurboJPEG lossless transformer
     34  */
     35 public class TJTransformer extends TJDecompressor {
     36 
     37   /**
     38    * Create a TurboJPEG lossless transformer instance.
     39    */
     40   public TJTransformer() throws TJException {
     41     init();
     42   }
     43 
     44   /**
     45    * Create a TurboJPEG lossless transformer instance and associate the JPEG
     46    * image stored in <code>jpegImage</code> with the newly created instance.
     47    *
     48    * @param jpegImage JPEG image buffer (size of the JPEG image is assumed to
     49    * be the length of the array.)  This buffer is not modified.
     50    */
     51   public TJTransformer(byte[] jpegImage) throws TJException {
     52     init();
     53     setSourceImage(jpegImage, jpegImage.length);
     54   }
     55 
     56   /**
     57    * Create a TurboJPEG lossless transformer instance and associate the JPEG
     58    * image of length <code>imageSize</code> bytes stored in
     59    * <code>jpegImage</code> with the newly created instance.
     60    *
     61    * @param jpegImage JPEG image buffer.  This buffer is not modified.
     62    *
     63    * @param imageSize size of the JPEG image (in bytes)
     64    */
     65   public TJTransformer(byte[] jpegImage, int imageSize) throws TJException {
     66     init();
     67     setSourceImage(jpegImage, imageSize);
     68   }
     69 
     70   /**
     71    * Losslessly transform the JPEG image associated with this transformer
     72    * instance into one or more JPEG images stored in the given destination
     73    * buffers.  Lossless transforms work by moving the raw coefficients from one
     74    * JPEG image structure to another without altering the values of the
     75    * coefficients.  While this is typically faster than decompressing the
     76    * image, transforming it, and re-compressing it, lossless transforms are not
     77    * free.  Each lossless transform requires reading and performing Huffman
     78    * decoding on all of the coefficients in the source image, regardless of the
     79    * size of the destination image.  Thus, this method provides a means of
     80    * generating multiple transformed images from the same source or of applying
     81    * multiple transformations simultaneously, in order to eliminate the need to
     82    * read the source coefficients multiple times.
     83    *
     84    * @param dstBufs an array of image buffers.  <code>dstbufs[i]</code> will
     85    * receive a JPEG image that has been transformed using the parameters in
     86    * <code>transforms[i]</code>.  Use {@link TJ#bufSize} to determine the
     87    * maximum size for each buffer based on the transformed or cropped width and
     88    * height and the level of subsampling used in the source image.
     89    *
     90    * @param transforms an array of {@link TJTransform} instances, each of
     91    * which specifies the transform parameters and/or cropping region for the
     92    * corresponding transformed output image
     93    *
     94    * @param flags the bitwise OR of one or more of
     95    * {@link TJ#FLAG_BOTTOMUP TJ.FLAG_*}
     96    */
     97   public void transform(byte[][] dstBufs, TJTransform[] transforms,
     98                         int flags) throws TJException {
     99     if (jpegBuf == null)
    100       throw new IllegalStateException("JPEG buffer not initialized");
    101     transformedSizes = transform(jpegBuf, jpegBufSize, dstBufs, transforms,
    102                                  flags);
    103   }
    104 
    105   /**
    106    * Losslessly transform the JPEG image associated with this transformer
    107    * instance and return an array of {@link TJDecompressor} instances, each of
    108    * which has a transformed JPEG image associated with it.
    109    *
    110    * @param transforms an array of {@link TJTransform} instances, each of
    111    * which specifies the transform parameters and/or cropping region for the
    112    * corresponding transformed output image
    113    *
    114    * @return an array of {@link TJDecompressor} instances, each of
    115    * which has a transformed JPEG image associated with it.
    116    *
    117    * @param flags the bitwise OR of one or more of
    118    * {@link TJ#FLAG_BOTTOMUP TJ.FLAG_*}
    119    */
    120   public TJDecompressor[] transform(TJTransform[] transforms, int flags)
    121                                     throws TJException {
    122     byte[][] dstBufs = new byte[transforms.length][];
    123     if (jpegWidth < 1 || jpegHeight < 1)
    124       throw new IllegalStateException("JPEG buffer not initialized");
    125     for (int i = 0; i < transforms.length; i++) {
    126       int w = jpegWidth, h = jpegHeight;
    127       if ((transforms[i].options & TJTransform.OPT_CROP) != 0) {
    128         if (transforms[i].width != 0) w = transforms[i].width;
    129         if (transforms[i].height != 0) h = transforms[i].height;
    130       }
    131       dstBufs[i] = new byte[TJ.bufSize(w, h, jpegSubsamp)];
    132     }
    133     TJDecompressor[] tjd = new TJDecompressor[transforms.length];
    134     transform(dstBufs, transforms, flags);
    135     for (int i = 0; i < transforms.length; i++)
    136       tjd[i] = new TJDecompressor(dstBufs[i], transformedSizes[i]);
    137     return tjd;
    138   }
    139 
    140   /**
    141    * Returns an array containing the sizes of the transformed JPEG images
    142    * generated by the most recent transform operation.
    143    *
    144    * @return an array containing the sizes of the transformed JPEG images
    145    * generated by the most recent transform operation.
    146    */
    147   public int[] getTransformedSizes() {
    148     if (transformedSizes == null)
    149       throw new IllegalStateException("No image has been transformed yet");
    150     return transformedSizes;
    151   }
    152 
    153   private native void init() throws TJException;
    154 
    155   private native int[] transform(byte[] srcBuf, int srcSize, byte[][] dstBufs,
    156     TJTransform[] transforms, int flags) throws TJException;
    157 
    158   static {
    159     TJLoader.load();
    160   }
    161 
    162   private int[] transformedSizes = null;
    163 }
    164