Add SplitUVPlanes and MergeUVPlanes

source/convert.cc

 /*
  *  Copyright 2011 The LibYuv 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.
  */
 
@@ skipping 208 matching lines @@
     CopyRow(src, dst, width);
     CopyRow(src + src_stride_0, dst + dst_stride, width);
     src += src_stride_0 + src_stride_1;
     dst += dst_stride * 2;
   }
   if (height & 1) {
     CopyRow(src, dst, width);
   }
 }
 
-// Support function for NV12 etc UV channels.
-// Width and height are plane sizes (typically half pixel width).

[fbarchard1, 2016/08/24 17:42:24]

keep this comment.

-static void SplitUVPlane(const uint8* src_uv, int src_stride_uv,
-                         uint8* dst_u, int dst_stride_u,
-                         uint8* dst_v, int dst_stride_v,
-                         int width, int height) {
-  int y;
-  void (*SplitUVRow)(const uint8* src_uv, uint8* dst_u, uint8* dst_v,
-                     int width) = SplitUVRow_C;
+LIBYUV_API
+int SplitUVPlane(const uint8* src_uv, int src_stride_uv,
+                 uint8* dst_u, int dst_stride_u,
+                 uint8* dst_v, int dst_stride_v,
+                 int width, int height) {
+  if (!src_uv || !dst_u || !dst_v || width <= 0 || height == 0) {
+    return -1;
+  }
   // Negative height means invert the image.
   if (height < 0) {
     height = -height;
     dst_u = dst_u + (height - 1) * dst_stride_u;
     dst_v = dst_v + (height - 1) * dst_stride_v;
     dst_stride_u = -dst_stride_u;
     dst_stride_v = -dst_stride_v;
   }
   // Coalesce rows.
   if (src_stride_uv == width * 2 &&
       dst_stride_u == width &&
       dst_stride_v == width) {
     width *= height;
     height = 1;
     src_stride_uv = dst_stride_u = dst_stride_v = 0;
   }
-#if defined(HAS_SPLITUVROW_SSE2)
-  if (TestCpuFlag(kCpuHasSSE2)) {
-    SplitUVRow = SplitUVRow_Any_SSE2;
-    if (IS_ALIGNED(width, 16)) {
-      SplitUVRow = SplitUVRow_SSE2;
-    }
-  }
-#endif
-#if defined(HAS_SPLITUVROW_AVX2)
-  if (TestCpuFlag(kCpuHasAVX2)) {
-    SplitUVRow = SplitUVRow_Any_AVX2;
-    if (IS_ALIGNED(width, 32)) {
-      SplitUVRow = SplitUVRow_AVX2;
-    }
-  }
-#endif
-#if defined(HAS_SPLITUVROW_NEON)
-  if (TestCpuFlag(kCpuHasNEON)) {
-    SplitUVRow = SplitUVRow_Any_NEON;
-    if (IS_ALIGNED(width, 16)) {
-      SplitUVRow = SplitUVRow_NEON;
-    }
-  }
-#endif
-#if defined(HAS_SPLITUVROW_DSPR2)
-  if (TestCpuFlag(kCpuHasDSPR2) &&
-      IS_ALIGNED(dst_u, 4) && IS_ALIGNED(dst_stride_u, 4) &&
-      IS_ALIGNED(dst_v, 4) && IS_ALIGNED(dst_stride_v, 4)) {
-    SplitUVRow = SplitUVRow_Any_DSPR2;
-    if (IS_ALIGNED(width, 16)) {
-      SplitUVRow = SplitUVRow_DSPR2;
-    }
-  }
-#endif
+  SplitUVRowFunction SplitUVRow = GetOptimizedSplitUVRowFunction(
+      src_uv, src_stride_uv, dst_u, dst_stride_u, dst_v, dst_stride_v, width);
 
-  for (y = 0; y < height; ++y) {
+  for (int y = 0; y < height; ++y) {

[fbarchard1, 2016/08/24 17:42:24]

int y needs to be declared at top of function for c89 compatibility.

     // Copy a row of UV.
     SplitUVRow(src_uv, dst_u, dst_v, width);
     dst_u += dst_stride_u;
     dst_v += dst_stride_v;
     src_uv += src_stride_uv;
   }
+  return 0;
 }
 
 // Support converting from FOURCC_M420
 // Useful for bandwidth constrained transports like USB 1.0 and 2.0 and for
 // easy conversion to I420.
 // M420 format description:
 // M420 is row biplanar 420: 2 rows of Y and 1 row of UV.
 // Chroma is half width / half height. (420)
 // src_stride_m420 is row planar. Normally this will be the width in pixels.
 //   The UV plane is half width, but 2 values, so src_stride_m420 applies to
@@ skipping 1177 matching lines @@
     dst_u += dst_stride_u;
     dst_v += dst_stride_v;
   }
   return 0;
 }
 
 #ifdef __cplusplus
 }  // extern "C"
 }  // namespace libyuv
 #endif