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 22 matching lines @@
                       const uint8* src_v, int src_stride_v,
                       uint8* dst_y, int dst_stride_y,
                       uint8* dst_u, int dst_stride_u,
                       uint8* dst_v, int dst_stride_v,
                       int src_y_width, int src_y_height,
                       int src_uv_width, int src_uv_height) {
   const int dst_y_width = Abs(src_y_width);
   const int dst_y_height = Abs(src_y_height);
   const int dst_uv_width = SUBSAMPLE(dst_y_width, 1, 1);
   const int dst_uv_height = SUBSAMPLE(dst_y_height, 1, 1);
-  if (src_y_width == 0 || src_y_height == 0 ||
-      src_uv_width == 0 || src_uv_height == 0) {
+  if (src_uv_width == 0 || src_uv_height == 0) {
     return -1;
   }
-  // TODO(fbarchard): support NULL for dst_y
-  ScalePlane(src_y, src_stride_y, src_y_width, src_y_height,
-             dst_y, dst_stride_y, dst_y_width, dst_y_height,
-             kFilterBilinear);
+  if (dst_y) {
+    ScalePlane(src_y, src_stride_y, src_y_width, src_y_height,
+               dst_y, dst_stride_y, dst_y_width, dst_y_height,
+               kFilterBilinear);
+  }
   ScalePlane(src_u, src_stride_u, src_uv_width, src_uv_height,
              dst_u, dst_stride_u, dst_uv_width, dst_uv_height,
              kFilterBilinear);
   ScalePlane(src_v, src_stride_v, src_uv_width, src_uv_height,
              dst_v, dst_stride_v, dst_uv_width, dst_uv_height,
              kFilterBilinear);
   return 0;
 }
 
 // Copy I420 with optional flipping
@@ skipping 161 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).
-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;
-  // 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
-
-  for (y = 0; y < height; ++y) {
-    // 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;
-  }
-}
-
 // 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
 //   this as well as the two Y planes.
 static int X420ToI420(const uint8* src_y,
                       int src_stride_y0, int src_stride_y1,
                       const uint8* src_uv, int src_stride_uv,
                       uint8* dst_y, int dst_stride_y,
                       uint8* dst_u, int dst_stride_u,
                       uint8* dst_v, int dst_stride_v,
                       int width, int height) {
   int halfwidth = (width + 1) >> 1;
   int halfheight = (height + 1) >> 1;
   if (!src_uv || !dst_u || !dst_v ||
       width <= 0 || height == 0) {
     return -1;
   }
   // Negative height means invert the image.
   if (height < 0) {
     height = -height;
     halfheight = (height + 1) >> 1;
-    dst_y = dst_y + (height - 1) * dst_stride_y;
+    if (dst_y) {
+      dst_y = dst_y + (height - 1) * dst_stride_y;
+    }
     dst_u = dst_u + (halfheight - 1) * dst_stride_u;
     dst_v = dst_v + (halfheight - 1) * dst_stride_v;
     dst_stride_y = -dst_stride_y;
     dst_stride_u = -dst_stride_u;
     dst_stride_v = -dst_stride_v;
   }
   // Coalesce rows.
   if (src_stride_y0 == width &&
       src_stride_y1 == width &&
       dst_stride_y == width) {
@@ skipping 1147 matching lines @@
     dst_u += dst_stride_u;
     dst_v += dst_stride_v;
   }
   return 0;
 }
 
 #ifdef __cplusplus
 }  // extern "C"
 }  // namespace libyuv
 #endif