API for deinterlacing YUV420 output on Android

source/row_common.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 970 matching lines @@
 #define UB -128 /* max(-128, round(-2.018 * 64)) */
 #define UG 25 /* round(0.391 * 64) */
 #define VG 52 /* round(0.813 * 64) */
 #define VR -102 /* round(-1.596 * 64) */
 
 // Bias values to subtract 16 from Y and 128 from U and V.
 #define BB (UB * 128            + YGB)
 #define BG (UG * 128 + VG * 128 + YGB)
 #define BR            (VR * 128 + YGB)
 
-#if defined(__aarch64__)
+#if defined(__aarch64__)  // 64 bit arm
 const YuvConstants SIMD_ALIGNED(kYuvI601Constants) = {
   { -UB, -VR, -UB, -VR, -UB, -VR, -UB, -VR },
   { -UB, -VR, -UB, -VR, -UB, -VR, -UB, -VR },
   { UG, VG, UG, VG, UG, VG, UG, VG },
   { UG, VG, UG, VG, UG, VG, UG, VG },
   { BB, BG, BR, 0, 0, 0, 0, 0 },
   { 0x0101 * YG, 0, 0, 0 }
 };
 const YuvConstants SIMD_ALIGNED(kYvuI601Constants) = {
   { -VR, -UB, -VR, -UB, -VR, -UB, -VR, -UB },
   { -VR, -UB, -VR, -UB, -VR, -UB, -VR, -UB },
   { VG, UG, VG, UG, VG, UG, VG, UG },
   { VG, UG, VG, UG, VG, UG, VG, UG },
   { BR, BG, BB, 0, 0, 0, 0, 0 },
   { 0x0101 * YG, 0, 0, 0 }
 };
-#elif defined(__arm__)
+#elif defined(__arm__)  // 32 bit arm
 const YuvConstants SIMD_ALIGNED(kYuvI601Constants) = {
   { -UB, -UB, -UB, -UB, -VR, -VR, -VR, -VR, 0, 0, 0, 0, 0, 0, 0, 0 },
   { UG, UG, UG, UG, VG, VG, VG, VG, 0, 0, 0, 0, 0, 0, 0, 0 },
   { BB, BG, BR, 0, 0, 0, 0, 0 },
   { 0x0101 * YG, 0, 0, 0 }
 };
 const YuvConstants SIMD_ALIGNED(kYvuI601Constants) = {
   { -VR, -VR, -VR, -VR, -UB, -UB, -UB, -UB, 0, 0, 0, 0, 0, 0, 0, 0 },
   { VG, VG, VG, VG, UG, UG, UG, UG, 0, 0, 0, 0, 0, 0, 0, 0 },
   { BR, BG, BB, 0, 0, 0, 0, 0 },
@@ skipping 238 matching lines @@
   int ug = yuvconstants->kUVToG[0];
   int vg = yuvconstants->kUVToG[1];
   int vr = yuvconstants->kUVToR[1];
   int bb = yuvconstants->kUVBiasB[0];
   int bg = yuvconstants->kUVBiasG[0];
   int br = yuvconstants->kUVBiasR[0];
   int yg = yuvconstants->kYToRgb[0];
 #endif
 
   uint32 y1 = (uint32)(y * 0x0101 * yg) >> 16;
-  *b = Clamp((int32)(-(u * ub         ) + y1 + bb) >> 6);
+  *b = Clamp((int32)(-(u * ub)          + y1 + bb) >> 6);
   *g = Clamp((int32)(-(u * ug + v * vg) + y1 + bg) >> 6);
-  *r = Clamp((int32)(-(         v * vr) + y1 + br) >> 6);
+  *r = Clamp((int32)         (-(v * vr) + y1 + br) >> 6);
 }
 
 // Y contribution to R,G,B.  Scale and bias.
 #define YG 18997 /* round(1.164 * 64 * 256 * 256 / 257) */
 #define YGB -1160 /* 1.164 * 64 * -16 + 64 / 2 */
 
 // C reference code that mimics the YUV assembly.
 static __inline void YPixel(uint8 y, uint8* b, uint8* g, uint8* r) {
   uint32 y1 = (uint32)(y * 0x0101 * YG) >> 16;
   *b = Clamp((int32)(y1 + YGB) >> 6);
@@ skipping 880 matching lines @@
   int x;
   for (x = 0; x < width; ++x) {
     dst_uv[x] = (src_uv[x] + src_uv[src_uv_stride + x] + 1) >> 1;
   }
 }
 
 // C version 2x2 -> 2x1.
 void InterpolateRow_C(uint8* dst_ptr, const uint8* src_ptr,
                       ptrdiff_t src_stride,
                       int width, int source_y_fraction) {
-  int y1_fraction = source_y_fraction ;
+  int y1_fraction = source_y_fraction;
   int y0_fraction = 256 - y1_fraction;
   const uint8* src_ptr1 = src_ptr + src_stride;
   int x;
   if (y1_fraction == 0) {
     memcpy(dst_ptr, src_ptr, width);
     return;
   }
   if (y1_fraction == 128) {
     HalfRow_C(src_ptr, src_stride, dst_ptr, width);
     return;
@@ skipping 437 matching lines @@
     dst_rgb565 += twidth * 2;
     width -= twidth;
   }
 }
 #endif
 
 #ifdef __cplusplus
 }  // extern "C"
 }  // namespace libyuv
 #endif