Import LappedTransform and friends.

Add code for doing block-based frequency domain processing. Developed
and reviewed in isolation. Corresponding export CL:
https://chromereviews.googleplex.com/95187013/

R=bercic@google.com, kjellander@webrtc.org, turaj@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/31539004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@7359 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/system_wrappers/interface/aligned_array.h b/webrtc/system_wrappers/interface/aligned_array.h
new file mode 100644
index 0000000..4b5c276
--- /dev/null
+++ b/webrtc/system_wrappers/interface/aligned_array.h
@@ -0,0 +1,89 @@
+/*
+ *  Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_SYSTEM_WRAPPERS_INTERFACE_ALIGNED_ARRAY_
+#define WEBRTC_SYSTEM_WRAPPERS_INTERFACE_ALIGNED_ARRAY_
+
+#include "webrtc/base/checks.h"
+#include "webrtc/system_wrappers/interface/aligned_malloc.h"
+
+namespace webrtc {
+
+// Wrapper class for aligned arrays. Every row (and the first dimension) are
+// aligned to the given byte alignment.
+template<typename T> class AlignedArray {
+ public:
+  AlignedArray(int rows, int cols, int alignment)
+      : rows_(rows),
+        cols_(cols),
+        alignment_(alignment) {
+    CHECK_GT(alignment_, 0);
+    head_row_ = static_cast<T**>(AlignedMalloc(rows_ * sizeof(*head_row_),
+                                               alignment_));
+    for (int i = 0; i < rows_; ++i) {
+      head_row_[i] = static_cast<T*>(AlignedMalloc(cols_ * sizeof(**head_row_),
+                                                   alignment_));
+    }
+  }
+
+  ~AlignedArray() {
+    for (int i = 0; i < rows_; ++i) {
+      AlignedFree(head_row_[i]);
+    }
+    AlignedFree(head_row_);
+  }
+
+  T* const* Array() {
+    return head_row_;
+  }
+
+  const T* const* Array() const {
+    return head_row_;
+  }
+
+  T* Row(int row) {
+    CHECK_LE(row, rows_);
+    return head_row_[row];
+  }
+
+  const T* Row(int row) const {
+    CHECK_LE(row, rows_);
+    return head_row_[row];
+  }
+
+  T& At(int row, int col) {
+    CHECK_LE(col, cols_);
+    return Row(row)[col];
+  }
+
+  const T& At(int row, int col) const {
+    CHECK_LE(col, cols_);
+    return Row(row)[col];
+  }
+
+  int rows() const {
+    return rows_;
+  }
+
+  int cols() const {
+    return cols_;
+  }
+
+ private:
+  int rows_;
+  int cols_;
+  int alignment_;
+  T** head_row_;
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_SYSTEM_WRAPPERS_INTERFACE_ALIGNED_ARRAY_
+