adding the start of a neon based yuv2rgb routine - very ugly and rough

android/android-jni/jni/yuv2rgb_neon.c

+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+#include "yuv420sp2rgb.h"
+#include <arm_neon.h>
+#include <stdlib.h>
+
+/* this source file should only be compiled by Android.mk when targeting
+ * the armeabi-v7a ABI, and should be built in NEON mode
+ */
+void fir_filter_neon_intrinsics(short *output, const short* input, const short* kernel, int width, int kernelSize)
+{
+#if 1
+  int nn, offset = -kernelSize / 2;
+
+  for (nn = 0; nn < width; nn++)
+  {
+    int mm, sum = 0;
+    int32x4_t sum_vec = vdupq_n_s32(0);
+    for (mm = 0; mm < kernelSize / 4; mm++)
+    {
+      int16x4_t kernel_vec = vld1_s16(kernel + mm * 4);
+      int16x4_t input_vec = vld1_s16(input + (nn + offset + mm * 4));
+      sum_vec = vmlal_s16(sum_vec, kernel_vec, input_vec);
+    }
+
+    sum += vgetq_lane_s32(sum_vec, 0);
+    sum += vgetq_lane_s32(sum_vec, 1);
+    sum += vgetq_lane_s32(sum_vec, 2);
+    sum += vgetq_lane_s32(sum_vec, 3);
+
+    if (kernelSize & 3)
+    {
+      for (mm = kernelSize - (kernelSize & 3); mm < kernelSize; mm++)
+        sum += kernel[mm] * input[nn + offset + mm];
+    }
+
+    output[nn] = (short)((sum + 0x8000) >> 16);
+  }
+#else /* for comparison purposes only */
+  int nn, offset = -kernelSize/2;
+  for (nn = 0; nn < width; nn++)
+  {
+    int sum = 0;
+    int mm;
+    for (mm = 0; mm < kernelSize; mm++)
+    {
+      sum += kernel[mm]*input[nn+offset+mm];
+    }
+    output[n] = (short)((sum + 0x8000) >> 16);
+  }
+#endif
+}
+
+/*
+ YUV 4:2:0 image with a plane of 8 bit Y samples followed by an interleaved
+ U/V plane containing 8 bit 2x2 subsampled chroma samples.
+ except the interleave order of U and V is reversed.
+
+ H V
+ Y Sample Period      1 1
+ U (Cb) Sample Period 2 2
+ V (Cr) Sample Period 2 2
+ */
+
+/*
+ size of a char:
+ find . -name limits.h -exec grep CHAR_BIT {} \;
+ */
+
+#ifndef max
+#define max(a,b) ({typeof(a) _a = (a); typeof(b) _b = (b); _a > _b ? _a : _b; })
+#define min(a,b) ({typeof(a) _a = (a); typeof(b) _b = (b); _a < _b ? _a : _b; })
+#endif
+
+#define bytes_per_pixel 2
+#define LOAD_Y(i,j) (pY + i * width + j)
+#define LOAD_V(i,j) (pUV + (i / 2) * width + bytes_per_pixel * (j / 2))
+#define LOAD_U(i,j) (pUV + (i / 2) * width + bytes_per_pixel * (j / 2)+1)
+
+const uint8_t ZEROS[8] = {220,220, 220, 220, 220, 220, 220, 220};
+const uint8_t Y_SUBS[8] = {16, 16, 16, 16, 16, 16, 16, 16};
+const uint8_t UV_SUBS[8] = {128, 128, 128, 128, 128, 128, 128, 128};
+
+const uint32_t UV_MULS[] = {833, 400, 833, 400};
+
+void color_convert_common(unsigned char *pY, unsigned char *pUV, int width, int height, unsigned char *buffer, int grey)
+{
+
+  int i, j;
+  int nR, nG, nB;
+  int nY, nU, nV;
+  unsigned char *out = buffer;
+  int offset = 0;
+
+  uint8x8_t Y_SUBvec = vld1_u8(Y_SUBS);
+  uint8x8_t UV_SUBvec = vld1_u8(UV_SUBS); // v,u,v,u v,u,v,u
+  uint32x4_t UV_MULSvec = vld1q_u32(UV_MULS);
+  uint8x8_t ZEROSvec =vld1_u8(ZEROS);
+
+  uint32_t UVvec_int[8];
+  if (grey)
+  {
+    memcpy(out, pY, width * height * sizeof(unsigned char));
+  }
+  else
+    // YUV 4:2:0
+    for (i = 0; i < height; i++)
+    {
+      for (j = 0; j < width; j += 8)
+      {
+        //        nY = *(pY + i * width + j);
+        //        nV = *(pUV + (i / 2) * width + bytes_per_pixel * (j / 2));
+        //        nU = *(pUV + (i / 2) * width + bytes_per_pixel * (j / 2) + 1);
+
+        uint8x8_t nYvec = vld1_u8(LOAD_Y(i,j));
+        uint8x8_t nUVvec = vld1_u8(LOAD_V(i,j)); // v,u,v,u v,u,v,u
+
+        nYvec = vmul_u8(nYvec, vcle_u8(nYvec,ZEROSvec));
+
+        // Yuv Convert
+        //        nY -= 16;
+        //        nU -= 128;
+        //        nV -= 128;
+
+        //        nYvec = vsub_u8(nYvec, Y_SUBvec);
+        //        nUVvec = vsub_u8(nYvec, UV_SUBvec);
+
+        uint16x8_t nYvec16 = vmovl_u8(vsub_u8(nYvec, Y_SUBvec));
+        uint16x8_t nUVvec16 = vmovl_u8(vsub_u8(nYvec, UV_SUBvec));
+
+        uint16x4_t Y_low4 = vget_low_u16(nYvec16);
+        uint16x4_t Y_high4 = vget_high_u16(nYvec16);
+        uint16x4_t UV_low4 = vget_low_u16(nUVvec16);
+        uint16x4_t UV_high4 = vget_high_u16(nUVvec16);
+
+        uint32x4_t UV_low4_int = vmovl_u16(UV_low4);
+        uint32x4_t UV_high4_int = vmovl_u16(UV_high4);
+
+        uint32x4_t Y_low4_int = vmull_n_u16(Y_low4, 1192);
+        uint32x4_t Y_high4_int = vmull_n_u16(Y_high4, 1192);
+
+        uint32x4x2_t UV_uzp = vuzpq_u32(UV_low4_int, UV_high4_int);
+
+        uint32x2_t Vl = vget_low_u32(UV_uzp.val[0]);// vld1_u32(UVvec_int);
+        uint32x2_t Vh = vget_high_u32(UV_uzp.val[0]);//vld1_u32(UVvec_int + 2);
+
+        uint32x2x2_t Vll_ = vzip_u32(Vl, Vl);
+        uint32x4_t* Vll = (uint32x4_t*)(&Vll_);
+
+        uint32x2x2_t Vhh_ = vzip_u32(Vh, Vh);
+        uint32x4_t* Vhh = (uint32x4_t*)(&Vhh_);
+
+        uint32x2_t Ul =  vget_low_u32(UV_uzp.val[1]);
+        uint32x2_t Uh =  vget_high_u32(UV_uzp.val[1]);
+
+        uint32x2x2_t Ull_ = vzip_u32(Ul, Ul);
+        uint32x4_t* Ull = (uint32x4_t*)(&Ull_);
+
+        uint32x2x2_t Uhh_ = vzip_u32(Uh, Uh);
+        uint32x4_t* Uhh = (uint32x4_t*)(&Uhh_);
+
+        uint32x4_t B_int_low = vmlaq_n_u32(Y_low4_int, *Ull, 2066); //multiply by scalar accum
+        uint32x4_t B_int_high = vmlaq_n_u32(Y_high4_int, *Uhh, 2066); //multiply by scalar accum
+        uint32x4_t G_int_low = vsubq_u32(Y_low4_int, vmlaq_n_u32(vmulq_n_u32(*Vll, 833), *Ull, 400));
+        uint32x4_t G_int_high = vsubq_u32(Y_high4_int, vmlaq_n_u32(vmulq_n_u32(*Vhh, 833), *Uhh, 400));
+        uint32x4_t R_int_low = vmlaq_n_u32(Y_low4_int, *Vll, 1634); //multiply by scalar accum
+        uint32x4_t R_int_high = vmlaq_n_u32(Y_high4_int, *Vhh, 1634); //multiply by scalar accum
+
+        B_int_low = vshrq_n_u32 (B_int_low, 10);
+        B_int_high = vshrq_n_u32 (B_int_high, 10);
+        G_int_low = vshrq_n_u32 (G_int_low, 10);
+        G_int_high = vshrq_n_u32 (G_int_high, 10);
+        R_int_low = vshrq_n_u32 (R_int_low, 10);
+        R_int_high = vshrq_n_u32 (R_int_high, 10);
+
+
+        uint8x8x3_t RGB;
+        RGB.val[0] = vmovn_u16(vcombine_u16(vqmovn_u32 (R_int_low),vqmovn_u32 (R_int_high)));
+        RGB.val[1] = vmovn_u16(vcombine_u16(vqmovn_u32 (G_int_low),vqmovn_u32 (G_int_high)));
+        RGB.val[2] = vmovn_u16(vcombine_u16(vqmovn_u32 (B_int_low),vqmovn_u32 (B_int_high)));
+
+        vst3_u8 (out+i*width*3 + j*3, RGB);
+      }
+    }
+
+}
+