tjGetScaledSize() would never be able to accommodate scaling factors > 1, so replace it with a function that returns a list of fractional scaling factors that TurboJPEG supports.

git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@477 632fc199-4ca6-4c93-a231-07263d6284db

java/TJUnitTest.java

@@ -253,14 +253,14 @@ public class TJUnitTest {
 	}
 
 	private static int checkbuf(byte [] buf, int w, int pitch, int h, int pf,
-		int subsamp, int scalefactor, int flags) throws Exception
+		int subsamp, int scale_num, int scale_denom, int flags) throws Exception
 	{
 		int roffset=TJ.getRedShift(pf)/8;
 		int goffset=TJ.getGreenShift(pf)/8;
 		int boffset=TJ.getBlueShift(pf)/8;
 		int ps=TJ.getPixelSize(pf);
 		int i, _i, j, retval=1;
-		int halfway=16/scalefactor, blocksize=8/scalefactor;
+		int halfway=16*scale_num/scale_denom, blocksize=8*scale_num/scale_denom;
 
 		try
 		{
@@ -350,13 +350,13 @@ public class TJUnitTest {
 	}
 
 	private static int checkintbuf(int [] buf, int w, int pitch, int h, int pf,
-		int subsamp, int scalefactor, int flags) throws Exception
+		int subsamp, int scale_num, int scale_denom, int flags) throws Exception
 	{
 		int rshift=TJ.getRedShift(pf);
 		int gshift=TJ.getGreenShift(pf);
 		int bshift=TJ.getBlueShift(pf);
 		int i, _i, j, retval=1;
-		int halfway=16/scalefactor, blocksize=8/scalefactor;
+		int halfway=16*scale_num/scale_denom, blocksize=8*scale_num/scale_denom;
 
 		try
 		{
@@ -448,7 +448,7 @@ public class TJUnitTest {
 	}
 
 	private static int checkimg(BufferedImage img, int pf,
-		int subsamp, int scalefactor, int flags) throws Exception
+		int subsamp, int scale_num, int scale_denom, int flags) throws Exception
 	{
 		WritableRaster wr=img.getRaster();
 		int imgtype=img.getType();
@@ -461,7 +461,7 @@ public class TJUnitTest {
 			DataBufferInt db=(DataBufferInt)wr.getDataBuffer();
 			int [] buf = db.getData();
 			return checkintbuf(buf, img.getWidth(), pitch, img.getHeight(), pf,
-				subsamp, scalefactor, flags);
+				subsamp, scale_num, scale_denom, flags);
 		}
 		else
 		{
@@ -471,7 +471,7 @@ public class TJUnitTest {
 			DataBufferByte db=(DataBufferByte)wr.getDataBuffer();
 			byte [] buf = db.getData();
 			return checkbuf(buf, img.getWidth(), pitch, img.getHeight(), pf, subsamp,
-				scalefactor, flags);
+				scale_num, scale_denom, flags);
 		}
 	}
 
@@ -681,12 +681,12 @@ public class TJUnitTest {
 
 	private static void _gentestbmp(TJDecompressor tjd, byte [] jpegbuf,
 		int jpegsize, int w, int h, int pf, String basefilename, int subsamp,
-		int flags, int scalefactor) throws Exception
+		int flags, int scale_num, int scale_denom) throws Exception
 	{
 		String pixformat, tempstr;  int _hdrw=0, _hdrh=0, _hdrsubsamp=-1;
 		double t;
-		int scaledw=(w+scalefactor-1)/scalefactor;
-		int scaledh=(h+scalefactor-1)/scalefactor;
+		int scaledw=(w*scale_num+scale_denom-1)/scale_denom;
+		int scaledh=(h*scale_num+scale_denom-1)/scale_denom;
 		int temp1, temp2;
 		BufferedImage img=null;  byte [] bmpbuf=null;
 
@@ -701,7 +701,8 @@ public class TJUnitTest {
 			System.out.print(pixformat+" ");
 			if((flags&TJ.BOTTOMUP)!=0) System.out.print("Bottom-Up ");
 			else System.out.print("Top-Down  ");
-			if(scalefactor!=1) System.out.print("1/"+scalefactor+" ... ");
+			if(scale_num!=1 || scale_denom!=1)
+				System.out.print(scale_num+"/"+scale_denom+" ... ");
 			else System.out.print("... ");
 		}
 
@@ -728,7 +729,7 @@ public class TJUnitTest {
 		{
 			tempstr=basefilename+"_dec_"+pixformat+"_"
 				+(((flags&TJ.BOTTOMUP)!=0)? "BU":"TD")+"_"+_subnames[subsamp]
-				+"_"+scalefactor+"x"+".png";
+				+"_"+(double)scale_num/(double)scale_denom+"x"+".png";
 			File file=new File(tempstr);
 			ImageIO.write(img, "png", file);
 		}
@@ -741,9 +742,9 @@ public class TJUnitTest {
 		}
 		else
 		{
-			if((bi && checkimg(img, pf, subsamp, scalefactor, flags)==1)
+			if((bi && checkimg(img, pf, subsamp, scale_num, scale_denom, flags)==1)
 				|| (!bi && checkbuf(bmpbuf, scaledw, scaledw*TJ.getPixelSize(pf),
-					scaledh, pf, subsamp, scalefactor, flags)==1))
+					scaledh, pf, subsamp, scale_num, scale_denom, flags)==1))
 				System.out.print("Passed.");
 			else
 			{
@@ -760,13 +761,14 @@ public class TJUnitTest {
 		int i;
 		if((subsamp==TJ.SAMP_444 || subsamp==TJ.SAMP_GRAY) && yuv==0)
 		{
-			for(i=1; i<=8; i*=2)
+			TJ.ScalingFactor sf []=TJ.getScalingFactors();
+			for(i=0; i<sf.length; i++)
 				_gentestbmp(tjd, jpegbuf, jpegsize, w, h, pf, basefilename, subsamp,
-					flags, i);
+					flags, sf[i].num, sf[i].denom);
 		}
 		else
 			_gentestbmp(tjd, jpegbuf, jpegsize, w, h, pf, basefilename, subsamp,
-				flags, 1);
+				flags, 1, 1);
 		System.out.print("\n");
 	}
 

java/org/libjpegturbo/turbojpeg/TJ.java

@@ -30,6 +30,11 @@ package org.libjpegturbo.turbojpeg;
 
 final public class TJ {
 
+  final public class ScalingFactor {
+    public int num = 1;
+    public int denom = 1;
+  };
+
   // Chrominance subsampling options
   final public static int
     NUMSAMPOPT = 4,
@@ -105,6 +110,9 @@ final public class TJ {
     int subsamp)
     throws Exception;
 
+  public native final static ScalingFactor [] getScalingFactors()
+    throws Exception;
+
   static {
     System.loadLibrary("turbojpeg");
   }

java/org/libjpegturbo/turbojpeg/TJDecompressor.java

@@ -76,8 +76,19 @@ public class TJDecompressor {
       throw new Exception("JPEG buffer not initialized");
     if(desiredWidth < 0 || desiredHeight < 0)
       throw new Exception("Invalid argument in getScaledWidth()");
-    return getScaledWidth(jpegWidth, jpegHeight, desiredWidth,
-      desiredHeight);
+    TJ.ScalingFactor sf [] = TJ.getScalingFactors();
+    if(desiredWidth == 0) desiredWidth = jpegWidth;
+    if(desiredHeight == 0) desiredHeight = jpegHeight;
+    int scaledWidth = jpegWidth, scaledHeight = jpegHeight;
+    for(int i=0; i<sf.length; i++) {
+      scaledWidth = (jpegWidth * sf[i].num + sf[i].denom - 1) / sf[i].denom;
+      scaledHeight = (jpegHeight * sf[i].num + sf[i].denom - 1) / sf[i].denom;
+      if(scaledWidth <= desiredWidth && scaledHeight <= desiredHeight)
+        break;
+    }
+    if(scaledWidth > desiredWidth || scaledHeight > desiredHeight)
+      throw new Exception("Could not scale down to desired image dimensions");
+    return scaledWidth;
   }
 
   public int getScaledHeight(int desiredWidth, int desiredHeight)
@@ -86,8 +97,19 @@ public class TJDecompressor {
       throw new Exception("JPEG buffer not initialized");
     if(desiredWidth < 0 || desiredHeight < 0)
       throw new Exception("Invalid argument in getScaledHeight()");
-    return getScaledHeight(jpegWidth, jpegHeight, desiredWidth,
-      desiredHeight);
+    TJ.ScalingFactor sf [] = TJ.getScalingFactors();
+    if(desiredWidth == 0) desiredWidth = jpegWidth;
+    if(desiredHeight == 0) desiredHeight = jpegHeight;
+    int scaledWidth = jpegWidth, scaledHeight = jpegHeight;
+    for(int i=0; i<sf.length; i++) {
+      scaledWidth = (jpegWidth * sf[i].num + sf[i].denom - 1) / sf[i].denom;
+      scaledHeight = (jpegHeight * sf[i].num + sf[i].denom - 1) / sf[i].denom;
+      if(scaledWidth <= desiredWidth && scaledHeight <= desiredHeight)
+        break;
+    }
+    if(scaledWidth > desiredWidth || scaledHeight > desiredHeight)
+      throw new Exception("Could not scale down to desired image dimensions");
+    return scaledHeight;
   }
 
   public void decompress(byte [] dstBuf, int desiredWidth, int pitch,
@@ -224,12 +246,6 @@ public class TJDecompressor {
     int flags)
     throws Exception;
 
-  private native int getScaledWidth(int jpegWidth, int jpegHeight,
-    int desiredWidth, int desiredHeight) throws Exception;
-
-  private native int getScaledHeight(int jpegWidth, int jpegHeight,
-    int desiredWidth, int desiredHeight) throws Exception;
-
   static {
     System.loadLibrary("turbojpeg");
   }

java/org_libjpegturbo_turbojpeg_TJ.h

@@ -61,6 +61,14 @@ JNIEXPORT jint JNICALL Java_org_libjpegturbo_turbojpeg_TJ_bufSize
 JNIEXPORT jint JNICALL Java_org_libjpegturbo_turbojpeg_TJ_bufSizeYUV
   (JNIEnv *, jclass, jint, jint, jint);
 
+/*
+ * Class:     org_libjpegturbo_turbojpeg_TJ
+ * Method:    getScalingFactors
+ * Signature: ()[Lorg/libjpegturbo/turbojpeg/TJ/ScalingFactor;
+ */
+JNIEXPORT jobjectArray JNICALL Java_org_libjpegturbo_turbojpeg_TJ_getScalingFactors
+  (JNIEnv *, jclass);
+
 #ifdef __cplusplus
 }
 #endif

java/org_libjpegturbo_turbojpeg_TJDecompressor.h

@@ -55,22 +55,6 @@ JNIEXPORT void JNICALL Java_org_libjpegturbo_turbojpeg_TJDecompressor_decompress
 JNIEXPORT void JNICALL Java_org_libjpegturbo_turbojpeg_TJDecompressor_decompressToYUV
   (JNIEnv *, jobject, jbyteArray, jint, jbyteArray, jint);
 
-/*
- * Class:     org_libjpegturbo_turbojpeg_TJDecompressor
- * Method:    getScaledWidth
- * Signature: (IIII)I
- */
-JNIEXPORT jint JNICALL Java_org_libjpegturbo_turbojpeg_TJDecompressor_getScaledWidth
-  (JNIEnv *, jobject, jint, jint, jint, jint);
-
-/*
- * Class:     org_libjpegturbo_turbojpeg_TJDecompressor
- * Method:    getScaledHeight
- * Signature: (IIII)I
- */
-JNIEXPORT jint JNICALL Java_org_libjpegturbo_turbojpeg_TJDecompressor_getScaledHeight
-  (JNIEnv *, jobject, jint, jint, jint, jint);
-
 #ifdef __cplusplus
 }
 #endif