Import aom library

This is the reference implementation for the Alliance for Open Media's av1 video code.

The commit used was 4d668d7feb1f8abd809d1bca0418570a7f142a36.

third_party/aom/av1/common/common.h

@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2016, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+
+#ifndef AV1_COMMON_COMMON_H_
+#define AV1_COMMON_COMMON_H_
+
+/* Interface header for common constant data structures and lookup tables */
+
+#include <assert.h>
+
+#include "aom_dsp/aom_dsp_common.h"
+#include "aom_mem/aom_mem.h"
+#include "aom/aom_integer.h"
+#include "aom_ports/bitops.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define PI 3.141592653589793238462643383279502884
+
+// Only need this for fixed-size arrays, for structs just assign.
+#define av1_copy(dest, src)              \
+  {                                      \
+    assert(sizeof(dest) == sizeof(src)); \
+    memcpy(dest, src, sizeof(src));      \
+  }
+
+// Use this for variably-sized arrays.
+#define av1_copy_array(dest, src, n)           \
+  {                                            \
+    assert(sizeof(*(dest)) == sizeof(*(src))); \
+    memcpy(dest, src, n * sizeof(*(src)));     \
+  }
+
+#define av1_zero(dest) memset(&(dest), 0, sizeof(dest))
+#define av1_zero_array(dest, n) memset(dest, 0, n * sizeof(*(dest)))
+
+static INLINE int get_unsigned_bits(unsigned int num_values) {
+  return num_values > 0 ? get_msb(num_values) + 1 : 0;
+}
+
+#define CHECK_MEM_ERROR(cm, lval, expr) \
+  AOM_CHECK_MEM_ERROR(&cm->error, lval, expr)
+// TODO(yaowu: validate the usage of these codes or develop new ones.)
+#define AV1_SYNC_CODE_0 0x49
+#define AV1_SYNC_CODE_1 0x83
+#define AV1_SYNC_CODE_2 0x43
+
+#define AOM_FRAME_MARKER 0x2
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif  // AV1_COMMON_COMMON_H_