Add NV12ToNV24 and NV16ToNV24

These are bi-planar convert functions to scale UV plane to Y plane's size using (bi)linear filter.

libyuv_unittest --gtest_filter=*ToNV24*

R=fbarchard@chromium.org

Change-Id: I3d98f833feeef00af3c903ac9ad0e41bdcbcb51f
Bug: libyuv:872
Reviewed-on: https://chromium-review.googlesource.com/c/libyuv/libyuv/+/2682152
Reviewed-by: Frank Barchard <fbarchard@chromium.org>

1 files changed, 50 insertions, 0 deletions

diff --git a/source/scale_common.cc b/source/scale_common.cc
index 8d41c03d..4af84321 100644
--- a/source/scale_common.cc
+++ b/source/scale_common.cc
@@ -1200,6 +1200,56 @@ void ScaleUVRowDownEvenBox_C(const uint8_t* src_uv,
   }
 }
 
+void ScaleUVRowUp2_Linear_C(const uint8_t* src_ptr,
+                            uint8_t* dst_ptr,
+                            int dst_width) {
+  int src_width = dst_width >> 1;
+  int x;
+  assert((dst_width % 2 == 0) && (dst_width >= 0));
+  for (x = 0; x < src_width; ++x) {
+    dst_ptr[4 * x + 0] =
+        (src_ptr[2 * x + 0] * 3 + src_ptr[2 * x + 2] * 1 + 2) >> 2;
+    dst_ptr[4 * x + 1] =
+        (src_ptr[2 * x + 1] * 3 + src_ptr[2 * x + 3] * 1 + 2) >> 2;
+    dst_ptr[4 * x + 2] =
+        (src_ptr[2 * x + 0] * 1 + src_ptr[2 * x + 2] * 3 + 2) >> 2;
+    dst_ptr[4 * x + 3] =
+        (src_ptr[2 * x + 1] * 1 + src_ptr[2 * x + 3] * 3 + 2) >> 2;
+  }
+}
+
+void ScaleUVRowUp2_Bilinear_C(const uint8_t* src_ptr,
+                              ptrdiff_t src_stride,
+                              uint8_t* dst_ptr,
+                              ptrdiff_t dst_stride,
+                              int dst_width) {
+  const uint8_t* s = src_ptr;
+  const uint8_t* t = src_ptr + src_stride;
+  uint8_t* d = dst_ptr;
+  uint8_t* e = dst_ptr + dst_stride;
+  int src_width = dst_width >> 1;
+  int x;
+  assert((dst_width % 2 == 0) && (dst_width >= 0));
+  for (x = 0; x < src_width; ++x) {
+    d[4 * x + 0] = (s[2 * x + 0] * 9 + s[2 * x + 2] * 3 + t[2 * x + 0] * 3 +
+                    t[2 * x + 2] * 1 + 8) >> 4;
+    d[4 * x + 1] = (s[2 * x + 1] * 9 + s[2 * x + 3] * 3 + t[2 * x + 1] * 3 +
+                    t[2 * x + 3] * 1 + 8) >> 4;
+    d[4 * x + 2] = (s[2 * x + 0] * 3 + s[2 * x + 2] * 9 + t[2 * x + 0] * 1 +
+                    t[2 * x + 2] * 3 + 8) >> 4;
+    d[4 * x + 3] = (s[2 * x + 1] * 3 + s[2 * x + 3] * 9 + t[2 * x + 1] * 1 +
+                    t[2 * x + 3] * 3 + 8) >> 4;
+    e[4 * x + 0] = (s[2 * x + 0] * 3 + s[2 * x + 2] * 1 + t[2 * x + 0] * 9 +
+                    t[2 * x + 2] * 3 + 8) >> 4;
+    e[4 * x + 1] = (s[2 * x + 1] * 3 + s[2 * x + 3] * 1 + t[2 * x + 1] * 9 +
+                    t[2 * x + 3] * 3 + 8) >> 4;
+    e[4 * x + 2] = (s[2 * x + 0] * 1 + s[2 * x + 2] * 3 + t[2 * x + 0] * 3 +
+                    t[2 * x + 2] * 9 + 8) >> 4;
+    e[4 * x + 3] = (s[2 * x + 1] * 1 + s[2 * x + 3] * 3 + t[2 * x + 1] * 3 +
+                    t[2 * x + 3] * 9 + 8) >> 4;
+  }
+}
+
 // Scales a single row of pixels using point sampling.
 void ScaleUVCols_C(uint8_t* dst_uv,
                    const uint8_t* src_uv,