Cosmetic: include guard, fwd txfm test, rtc sample

- Fix include guard for av1_fwd_txfm2d_hwy.h
- Add `constexpr` to constant arrays in av1_fwd_txfm2d_test.cc
- Fix a typo in svc_encoder_rtc.cc

Change-Id: Id8499b8e272fbd533cbb8f94fee6a5c0f6540b2e
diff --git a/av1/encoder/av1_fwd_txfm2d_hwy.h b/av1/encoder/av1_fwd_txfm2d_hwy.h
index 3cccc88..65a3668 100644
--- a/av1/encoder/av1_fwd_txfm2d_hwy.h
+++ b/av1/encoder/av1_fwd_txfm2d_hwy.h
@@ -9,8 +9,8 @@
  * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
  */
 
-#ifndef AOM_AV1_AV1_FWD_TXFM2D_HWY_H_
-#define AOM_AV1_AV1_FWD_TXFM2D_HWY_H_
+#ifndef AOM_AV1_ENCODER_AV1_FWD_TXFM2D_HWY_H_
+#define AOM_AV1_ENCODER_AV1_FWD_TXFM2D_HWY_H_
 
 #include <stdint.h>
 
@@ -2554,4 +2554,4 @@
                                                  txfm_param);                  \
   }
 
-#endif  // AOM_AV1_AV1_FWD_TXFM2D_HWY_H_
+#endif  // AOM_AV1_ENCODER_AV1_FWD_TXFM2D_HWY_H_
diff --git a/examples/svc_encoder_rtc.cc b/examples/svc_encoder_rtc.cc
index a536607..7509fa6 100644
--- a/examples/svc_encoder_rtc.cc
+++ b/examples/svc_encoder_rtc.cc
@@ -1784,7 +1784,7 @@
   memset(&roi.delta_q, 0, sizeof(roi.delta_q));
   memset(&roi.delta_lf, 0, sizeof(roi.delta_lf));
   memset(roi.ref_frame, -1, sizeof(roi.ref_frame));
-  // Set ROI map to be 1 (segment #1) in middle squere of image,
+  // Set ROI map to be 1 (segment #1) in middle square of image,
   // 0 elsewhere.
   roi.enabled = 1;
   roi.roi_map = (uint8_t *)calloc(roi.rows * roi.cols, sizeof(*roi.roi_map));
diff --git a/test/av1_fwd_txfm2d_test.cc b/test/av1_fwd_txfm2d_test.cc
index 8bdcc20..3329bd8 100644
--- a/test/av1_fwd_txfm2d_test.cc
+++ b/test/av1_fwd_txfm2d_test.cc
@@ -142,7 +142,7 @@
   int lr_flip_;  // flip left to right
 };
 
-static double avg_error_ls[TX_SIZES_ALL] = {
+static constexpr double avg_error_ls[TX_SIZES_ALL] = {
   0.5,   // 4x4 transform
   0.5,   // 8x8 transform
   1.2,   // 16x16 transform
@@ -164,7 +164,7 @@
   4.7,   // 64x16 transform
 };
 
-static double max_error_ls[TX_SIZES_ALL] = {
+static constexpr double max_error_ls[TX_SIZES_ALL] = {
   3,    // 4x4 transform
   5,    // 8x8 transform
   11,   // 16x16 transform
@@ -443,7 +443,7 @@
 using ::testing::ValuesIn;
 
 #if AOM_ARCH_X86 && HAVE_SSE2
-static TX_SIZE fwd_txfm_for_sse2[] = {
+static constexpr TX_SIZE fwd_txfm_for_sse2[] = {
   TX_4X4,
   TX_8X8,
   TX_16X16,
@@ -471,11 +471,11 @@
 #endif  // AOM_ARCH_X86 && HAVE_SSE2
 
 #if HAVE_SSE4_1
-static TX_SIZE fwd_txfm_for_sse41[] = { TX_4X4,   TX_8X8,   TX_16X16, TX_32X32,
-                                        TX_64X64, TX_4X8,   TX_8X4,   TX_8X16,
-                                        TX_16X8,  TX_16X32, TX_32X16, TX_32X64,
-                                        TX_64X32, TX_4X16,  TX_16X4,  TX_8X32,
-                                        TX_32X8,  TX_16X64, TX_64X16 };
+static constexpr TX_SIZE fwd_txfm_for_sse41[] = {
+  TX_4X4,  TX_8X8,  TX_16X16, TX_32X32, TX_64X64, TX_4X8,   TX_8X4,
+  TX_8X16, TX_16X8, TX_16X32, TX_32X16, TX_32X64, TX_64X32, TX_4X16,
+  TX_16X4, TX_8X32, TX_32X8,  TX_16X64, TX_64X16
+};
 
 INSTANTIATE_TEST_SUITE_P(SSE4_1, AV1FwdTxfm2dTest,
                          Combine(ValuesIn(fwd_txfm_for_sse41),
@@ -483,7 +483,7 @@
 #endif  // HAVE_SSE4_1
 
 #if HAVE_AVX2
-static TX_SIZE fwd_txfm_for_avx2[] = {
+static constexpr TX_SIZE fwd_txfm_for_avx2[] = {
   TX_4X4,  TX_8X8,  TX_16X16, TX_32X32, TX_64X64, TX_4X8,   TX_8X4,
   TX_8X16, TX_16X8, TX_16X32, TX_32X16, TX_32X64, TX_64X32, TX_4X16,
   TX_16X4, TX_8X32, TX_32X8,  TX_16X64, TX_64X16,
@@ -495,7 +495,7 @@
 #endif  // HAVE_AVX2
 
 #if CONFIG_HIGHWAY && HAVE_AVX512
-static TX_SIZE fwd_txfm_for_avx512[] = {
+static constexpr TX_SIZE fwd_txfm_for_avx512[] = {
   TX_4X4,  TX_8X8,  TX_16X16, TX_32X32, TX_64X64, TX_4X8,   TX_8X4,
   TX_8X16, TX_16X8, TX_16X32, TX_32X16, TX_32X64, TX_64X32, TX_4X16,
   TX_16X4, TX_8X32, TX_32X8,  TX_16X64, TX_64X16,
@@ -508,11 +508,11 @@
 
 #if HAVE_NEON
 
-static TX_SIZE fwd_txfm_for_neon[] = { TX_4X4,   TX_8X8,   TX_16X16, TX_32X32,
-                                       TX_64X64, TX_4X8,   TX_8X4,   TX_8X16,
-                                       TX_16X8,  TX_16X32, TX_32X16, TX_32X64,
-                                       TX_64X32, TX_4X16,  TX_16X4,  TX_8X32,
-                                       TX_32X8,  TX_16X64, TX_64X16 };
+static constexpr TX_SIZE fwd_txfm_for_neon[] = {
+  TX_4X4,  TX_8X8,  TX_16X16, TX_32X32, TX_64X64, TX_4X8,   TX_8X4,
+  TX_8X16, TX_16X8, TX_16X32, TX_32X16, TX_32X64, TX_64X32, TX_4X16,
+  TX_16X4, TX_8X32, TX_32X8,  TX_16X64, TX_64X16
+};
 
 INSTANTIATE_TEST_SUITE_P(NEON, AV1FwdTxfm2dTest,
                          Combine(ValuesIn(fwd_txfm_for_neon),
@@ -666,7 +666,7 @@
 using ::testing::ValuesIn;
 
 #if HAVE_SSE4_1
-static TX_SIZE Highbd_fwd_txfm_for_sse4_1[] = {
+static constexpr TX_SIZE Highbd_fwd_txfm_for_sse4_1[] = {
   TX_4X4,  TX_8X8,  TX_16X16, TX_32X32, TX_64X64, TX_4X8,   TX_8X4,
   TX_8X16, TX_16X8, TX_16X32, TX_32X16, TX_32X64, TX_64X32,
 #if !CONFIG_REALTIME_ONLY
@@ -679,8 +679,9 @@
                                  Values(av1_highbd_fwd_txfm)));
 #endif  // HAVE_SSE4_1
 #if HAVE_AVX2
-static TX_SIZE Highbd_fwd_txfm_for_avx2[] = { TX_8X8,   TX_16X16, TX_32X32,
-                                              TX_64X64, TX_8X16,  TX_16X8 };
+static constexpr TX_SIZE Highbd_fwd_txfm_for_avx2[] = { TX_8X8,   TX_16X16,
+                                                        TX_32X32, TX_64X64,
+                                                        TX_8X16,  TX_16X8 };
 
 INSTANTIATE_TEST_SUITE_P(AVX2, AV1HighbdFwdTxfm2dTest,
                          Combine(ValuesIn(Highbd_fwd_txfm_for_avx2),
@@ -688,7 +689,7 @@
 #endif  // HAVE_AVX2
 
 #if HAVE_NEON
-static TX_SIZE Highbd_fwd_txfm_for_neon[] = {
+static constexpr TX_SIZE Highbd_fwd_txfm_for_neon[] = {
   TX_4X4,  TX_8X8,  TX_16X16, TX_32X32, TX_64X64, TX_4X8,   TX_8X4,
   TX_8X16, TX_16X8, TX_16X32, TX_32X16, TX_32X64, TX_64X32,
 #if !CONFIG_REALTIME_ONLY