1 files changed, 80 insertions, 0 deletions
diff --git a/gallerycommon/src/com/android/gallery3d/jpegstream/StreamUtils.java b/gallerycommon/src/com/android/gallery3d/jpegstream/StreamUtils.java
new file mode 100644
index 000000000..abd8f681e
--- /dev/null
+++ b/gallerycommon/src/com/android/gallery3d/jpegstream/StreamUtils.java
@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.gallery3d.jpegstream;
+
+import java.nio.ByteOrder;
+
+public class StreamUtils {
+
+    private StreamUtils() {
+    }
+
+    /**
+     * Copies the input byte array into the output int array with the given
+     * endianness. If input is not a multiple of 4, ignores the last 1-3 bytes
+     * and returns true.
+     */
+    public static boolean byteToIntArray(int[] output, byte[] input, ByteOrder endianness) {
+        int length = input.length - (input.length % 4);
+        if (output.length * 4 < length) {
+            throw new ArrayIndexOutOfBoundsException("Output array is too short to hold input");
+        }
+        if (endianness == ByteOrder.BIG_ENDIAN) {
+            for (int i = 0, j = 0; i < output.length; i++, j += 4) {
+                output[i] = ((input[j] & 0xFF) << 24) | ((input[j + 1] & 0xFF) << 16)
+                        | ((input[j + 2] & 0xFF) << 8) | ((input[j + 3] & 0xFF));
+            }
+        } else {
+            for (int i = 0, j = 0; i < output.length; i++, j += 4) {
+                output[i] = ((input[j + 3] & 0xFF) << 24) | ((input[j + 2] & 0xFF) << 16)
+                        | ((input[j + 1] & 0xFF) << 8) | ((input[j] & 0xFF));
+            }
+        }
+        return input.length % 4 != 0;
+    }
+
+    public static int[] byteToIntArray(byte[] input, ByteOrder endianness) {
+        int[] output = new int[input.length / 4];
+        byteToIntArray(output, input, endianness);
+        return output;
+    }
+
+    /**
+     * Uses native endianness.
+     */
+    public static int[] byteToIntArray(byte[] input) {
+        return byteToIntArray(input, ByteOrder.nativeOrder());
+    }
+
+    /**
+     * Returns the number of bytes in a pixel for a given format defined in
+     * JpegConfig.
+     */
+    public static int pixelSize(int format) {
+        switch (format) {
+            case JpegConfig.FORMAT_ABGR:
+            case JpegConfig.FORMAT_RGBA:
+                return 4;
+            case JpegConfig.FORMAT_RGB:
+                return 3;
+            case JpegConfig.FORMAT_GRAYSCALE:
+                return 1;
+            default:
+                return -1;
+        }
+    }
+}