WebP source subsampling.

imageio/imageio-webp/src/main/java/com/twelvemonkeys/imageio/plugins/webp/WebPImageReader.java

@@ -428,7 +428,7 @@ final class WebPImageReader extends ImageReaderBase {
     }
 
     private void readVP8Lossless(final WritableRaster raster, final ImageReadParam param) throws IOException {
-        VP8LDecoder decoder = new VP8LDecoder(imageInput);
+        VP8LDecoder decoder = new VP8LDecoder(imageInput, DEBUG);
         decoder.readVP8Lossless(raster, true);
     }
 
@@ -443,7 +443,6 @@ final class WebPImageReader extends ImageReaderBase {
         });
 
         if (!frame.decode(raster, param)) {
-            // TODO: Does this make any sense? Only happens if frame type is not still (0)
             processWarningOccurred("Nothing to decode");
         }
     }

imageio/imageio-webp/src/main/java/com/twelvemonkeys/imageio/plugins/webp/lossless/VP8LDecoder.java

@@ -41,7 +41,7 @@ import java.util.ArrayList;
 import java.util.List;
 
 import static com.twelvemonkeys.imageio.plugins.webp.RasterUtils.asByteRaster;
-import static java.lang.Math.abs;
+import static java.lang.Math.*;
 
 /**
  * VP8LDecoder.
@@ -49,14 +49,13 @@ import static java.lang.Math.abs;
  * @author <a href="mailto:harald.kuhr@gmail.com">Harald Kuhr</a>
  */
 public final class VP8LDecoder {
-
     private final ImageInputStream imageInput;
     private final LSBBitReader lsbBitReader;
 
     private final List<Transform> transforms = new ArrayList<>();
     private ColorCache colorCache;
 
-    public VP8LDecoder(final ImageInputStream imageInput) {
+    public VP8LDecoder(final ImageInputStream imageInput, final boolean debug) {
         this.imageInput = imageInput;
         lsbBitReader = new LSBBitReader(imageInput);
     }
@@ -275,7 +274,7 @@ public final class VP8LDecoder {
 
     // Clamp the input value between 0 and 255.
     private static int clamp(final int a) {
-        return a < 0 ? 0 : a > 255 ? 255 : a;
+        return max(0, min(a, 255));
     }
 
     private static int clampAddSubtractFull(final int a, final int b, final int c) {

imageio/imageio-webp/src/main/java/com/twelvemonkeys/imageio/plugins/webp/vp8/Globals.java

@@ -499,8 +499,7 @@ final class Globals {
 		for (int i = 0; i < vp8DefaultCoefProbs.length; i++)
 			for (int j = 0; j < vp8DefaultCoefProbs[0].length; j++)
 				for (int k = 0; k < vp8DefaultCoefProbs[0][0].length; k++)
-					for (int l = 0; l < vp8DefaultCoefProbs[0][0][0].length; l++)
+						r[i][j][k] = vp8DefaultCoefProbs[i][j][k].clone();
-						r[i][j][k][l] = vp8DefaultCoefProbs[i][j][k][l];
 		return r;
 	}
 

imageio/imageio-webp/src/main/java/com/twelvemonkeys/imageio/plugins/webp/vp8/LoopFilter.java

@@ -145,16 +145,6 @@ final class LoopFilter {
         return abs(p1 - p0) > threshold || abs(q1 - q0) > threshold;
     }
 
-//     public static void loopFilter(VP8Frame frame) {
-//         if (frame.getFilterType() == 2) {
-//             loopFilterUV(frame);
-//             loopFilterY(frame);
-//         }
-//         else if (frame.getFilterType() == 1) {
-//             loopFilterSimple(frame);
-//         }
-//     }
-
     static void loopFilterBlock(final MacroBlock cmb, final MacroBlock lmb, final MacroBlock tmb, int frameType, boolean simpleFilter, int sharpness) {
         if (simpleFilter) {
             loopFilterSimpleBlock(cmb, lmb, tmb, sharpness);
@@ -165,23 +155,7 @@ final class LoopFilter {
         }
     }
 
-
-    private static void loopFilterSimple(VP8Frame frame) {
-        for (int y = 0; y < frame.getMacroBlockRows(); y++) {
-//            frame.fireLFProgressUpdate((100.0f * ((float) (y + 1) / (float) (frame
-//                    .getMacroBlockRows()))));
-            for (int x = 0; x < frame.getMacroBlockCols(); x++) {
-                loopFilterSimpleBlock(frame.getMacroBlock(x, y),
-                        x > 0 ? frame.getMacroBlock(x - 1, y) : null,
-                        y > 0 ? frame.getMacroBlock(x, y - 1) : null,
-                        frame.getSharpnessLevel());
-            }
-        }
-    }
-
     static void loopFilterSimpleBlock(final MacroBlock cmb, final MacroBlock lmb, final MacroBlock tmb, final int sharpnessLevel) {
-        // System.out.println("x: "+x+" y: "+y);
-//         MacroBlock bmb = frame.getMacroBlock(x, y); // TODO: Same..?
         int loop_filter_level = cmb.getFilterLevel();
         if (loop_filter_level != 0) {
             int interior_limit = cmb.getFilterLevel();
@@ -277,18 +251,6 @@ final class LoopFilter {
         }
     }
 
-    private static void loopFilterUV(VP8Frame frame) {
-        for (int y = 0; y < frame.getMacroBlockRows(); y++) {
-            for (int x = 0; x < frame.getMacroBlockCols(); x++) {
-                loopFilterUVBlock(frame.getMacroBlock(x, y),
-                        x > 0 ? frame.getMacroBlock(x - 1, y) : null,
-                        y > 0 ? frame.getMacroBlock(x, y - 1) : null,
-                        frame.getSharpnessLevel(), frame.getFrameType()
-                );
-            }
-        }
-    }
-
     static void loopFilterUVBlock(final MacroBlock cmb, final MacroBlock lmb, final MacroBlock tmb, final int sharpnessLevel, final int frameType) {
         int loop_filter_level = cmb.getFilterLevel();
         if (loop_filter_level != 0) {
@@ -407,17 +369,6 @@ final class LoopFilter {
         }
     }
 
-    private static void loopFilterY(VP8Frame frame) {
-        for (int y = 0; y < frame.getMacroBlockRows(); y++) {
-            for (int x = 0; x < frame.getMacroBlockCols(); x++) {
-                loopFilterYBlock(frame.getMacroBlock(x, y),
-                        x > 0 ? frame.getMacroBlock(x - 1, y) : null,
-                        y > 0 ? frame.getMacroBlock(x, y - 1) : null,
-                        frame.getSharpnessLevel(), frame.getFrameType());
-            }
-        }
-    }
-
     static void loopFilterYBlock(final MacroBlock cmb, final MacroBlock lmb, final MacroBlock tmb, final int sharpnessLevel, final int frameType) {
         int loop_filter_level = cmb.getFilterLevel();
 
@@ -587,9 +538,6 @@ final class LoopFilter {
         if ((abs(seg.P0 - seg.Q0) * 2 + abs(seg.P1 - seg.Q1) / 2) <= edge_limit) {
             common_adjust(true, seg); // use outer taps
         }
-        else {
-            // TODO?
-        }
     }
 
     private static void subblock_filter(int hev_threshold, // detect high edge variance
@@ -605,9 +553,6 @@ final class LoopFilter {
                 seg.P1 = s2u(p1 + a);
             }
         }
-        else {
-            // TODO?
-        }
     }
 
     /* Convert pixel value (0 <= v <= 255) to an 8-bit signed number. */

imageio/imageio-webp/src/main/java/com/twelvemonkeys/imageio/plugins/webp/vp8/SubBlock.java

@@ -236,7 +236,6 @@ final class SubBlock {
     }
 
     public SubBlock getAbove() {
-
         return above;
     }
 
@@ -247,6 +246,7 @@ final class SubBlock {
                 && plane == Plane.Y1) {
             r = r + "\n  " + Globals.getSubBlockModeAsString(mode);
         }
+
         return r;
     }
 
@@ -260,12 +260,10 @@ final class SubBlock {
     }
 
     public int[][] getDiff() {
-
         return diff;
     }
 
     public SubBlock getLeft() {
-
         return left;
     }
 

imageio/imageio-webp/src/main/java/com/twelvemonkeys/imageio/plugins/webp/vp8/VP8Frame.java

@@ -1060,22 +1060,24 @@ public final class VP8Frame {
     private final byte[] rgb = new byte[4]; // Allow decoding into RGBA, leaving the alpha out.
 
     private void copyBlock(final MacroBlock macroBlock, final WritableRaster byteRGBRaster, final ImageReadParam param) {
-        // TODO: Consider doing YCbCr -> RGB in reader instead, or pass a flag to allow readRaster reading direct YUV/YCbCr values
+        int sourceYSubsampling = param != null ? param.getSourceYSubsampling() : 1;
+        int sourceXSubsampling = param != null ? param.getSourceXSubsampling() : 1;
 
         // We might be copying into a smaller raster
         int yStart = macroBlock.getY() * 16;
-        int yEnd = Math.min(16, byteRGBRaster.getHeight() - yStart);
+        int yEnd = Math.min(16, byteRGBRaster.getHeight() * sourceYSubsampling - yStart);
         int xStart = macroBlock.getX() * 16;
-        int xEnd = Math.min(16, byteRGBRaster.getWidth() - xStart);
+        int xEnd = Math.min(16, byteRGBRaster.getWidth() * sourceXSubsampling - xStart);
 
-        for (int y = 0; y < yEnd; y++) {
+        for (int y = 0; y < yEnd; y += sourceYSubsampling) {
-            for (int x = 0; x < xEnd; x++) {
+            for (int x = 0; x < xEnd; x += sourceXSubsampling) {
                 yuv[0] = (byte) macroBlock.getSubBlock(SubBlock.Plane.Y1, x / 4, y / 4).getDest()[x % 4][y % 4];
                 yuv[1] = (byte) macroBlock.getSubBlock(SubBlock.Plane.U, (x / 2) / 4, (y / 2) / 4).getDest()[(x / 2) % 4][(y / 2) % 4];
                 yuv[2] = (byte) macroBlock.getSubBlock(SubBlock.Plane.V, (x / 2) / 4, (y / 2) / 4).getDest()[(x / 2) % 4][(y / 2) % 4];
 
+                // TODO: Consider doing YCbCr -> RGB in reader instead, or pass a flag to allow readRaster reading direct YUV/YCbCr values
                 convertYCbCr2RGB(yuv, rgb, 0);
-                byteRGBRaster.setDataElements(xStart + x, yStart + y, rgb);
+                byteRGBRaster.setDataElements((xStart + x) / sourceXSubsampling, (yStart + y) / sourceYSubsampling, rgb);
             }
         }
     }