/*
 *  Copyright (c) 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.
 */

#include "libyuv/planar_functions.h"
#include "libyuv/rotate.h"
#include "rotate_priv.h"

#include "libyuv/cpu_id.h"

namespace libyuv {

#if (defined(WIN32) || defined(__x86_64__) || defined(__i386__)) \
    && !defined(COVERAGE_ENABLED) && !defined(TARGET_IPHONE_SIMULATOR)
#if defined(_MSC_VER)
#define TALIGN16(t, var) static __declspec(align(16)) t _ ## var
#else
#define TALIGN16(t, var) t var __attribute__((aligned(16)))
#endif
// Shuffle table for reversing the bytes.
extern "C" TALIGN16(const uint8, kShuffleReverse[16]) =
  { 15u, 14u, 13u, 12u, 11u, 10u, 9u, 8u, 7u, 6u, 5u, 4u, 3u, 2u, 1u, 0u };
// Shuffle table for reversing the bytes of UV channels.
extern "C" TALIGN16(const uint8, kShuffleReverseUV[16]) =
  { 14u, 12u, 10u, 8u, 6u, 4u, 2u, 0u, 15u, 13u, 11u, 9u, 7u, 5u, 3u, 1u };
#endif

typedef void (*reverse_uv_func)(const uint8*, uint8*, uint8*, int);
typedef void (*reverse_func)(const uint8*, uint8*, int);
typedef void (*rotate_uv_wx8_func)(const uint8*, int,
                                   uint8*, int,
                                   uint8*, int, int);
typedef void (*rotate_uv_wxh_func)(const uint8*, int,
                                   uint8*, int,
                                   uint8*, int, int, int);
typedef void (*rotate_wx8_func)(const uint8*, int, uint8*, int, int);
typedef void (*rotate_wxh_func)(const uint8*, int, uint8*, int, int, int);

#ifdef __ARM_NEON__
extern "C" {
void RestoreRegisters_NEON(unsigned long long *restore);
void SaveRegisters_NEON(unsigned long long *store);
#define HAS_REVERSE_LINE_NEON
void ReverseLine_NEON(const uint8* src, uint8* dst, int width);
#define HAS_REVERSE_LINE_UV_NEON
void ReverseLineUV_NEON(const uint8* src,
                        uint8* dst_a, uint8* dst_b,
                        int width);
#define HAS_TRANSPOSE_WX8_NEON
void TransposeWx8_NEON(const uint8* src, int src_stride,
                       uint8* dst, int dst_stride, int width);
#define HAS_TRANSPOSE_UVWX8_NEON
void TransposeUVWx8_NEON(const uint8* src, int src_stride,
                         uint8* dst_a, int dst_stride_a,
                         uint8* dst_b, int dst_stride_b,
                         int width);
}  // extern "C"
#endif

#if defined(WIN32) && !defined(COVERAGE_ENABLED)
#define HAS_TRANSPOSE_WX8_SSSE3
__declspec(naked)
static void TransposeWx8_SSSE3(const uint8* src, int src_stride,
                               uint8* dst, int dst_stride, int width) {
__asm {
    push      edi
    push      esi
    push      ebp
    mov       eax, [esp + 12 + 4]   // src
    mov       edi, [esp + 12 + 8]   // src_stride
    mov       edx, [esp + 12 + 12]  // dst
    mov       esi, [esp + 12 + 16]  // dst_stride
    mov       ecx, [esp + 12 + 20]  // width
 convertloop :
    // Read in the data from the source pointer.
    // First round of bit swap.
    movq      xmm0, qword ptr [eax]
    lea       ebp, [eax + 8]
    movq      xmm1, qword ptr [eax + edi]
    lea       eax, [eax + 2 * edi]
    punpcklbw xmm0, xmm1
    movq      xmm2, qword ptr [eax]
    movdqa    xmm1, xmm0
    palignr   xmm1, xmm1, 8
    movq      xmm3, qword ptr [eax + edi]
    lea       eax, [eax + 2 * edi]
    punpcklbw xmm2, xmm3
    movdqa    xmm3, xmm2
    movq      xmm4, qword ptr [eax]
    palignr   xmm3, xmm3, 8
    movq      xmm5, qword ptr [eax + edi]
    punpcklbw xmm4, xmm5
    lea       eax, [eax + 2 * edi]
    movdqa    xmm5, xmm4
    movq      xmm6, qword ptr [eax]
    palignr   xmm5, xmm5, 8
    movq      xmm7, qword ptr [eax + edi]
    punpcklbw xmm6, xmm7
    mov       eax, ebp
    movdqa    xmm7, xmm6
    palignr   xmm7, xmm7, 8
    // Second round of bit swap.
    punpcklwd xmm0, xmm2
    punpcklwd xmm1, xmm3
    movdqa    xmm2, xmm0
    movdqa    xmm3, xmm1
    palignr   xmm2, xmm2, 8
    palignr   xmm3, xmm3, 8
    punpcklwd xmm4, xmm6
    punpcklwd xmm5, xmm7
    movdqa    xmm6, xmm4
    movdqa    xmm7, xmm5
    palignr   xmm6, xmm6, 8
    palignr   xmm7, xmm7, 8
    // Third round of bit swap.
    // Write to the destination pointer. 
    punpckldq xmm0, xmm4
    movq      qword ptr [edx], xmm0
    movdqa    xmm4, xmm0
    palignr   xmm4, xmm4, 8
    movq      qword ptr [edx + esi], xmm4
    lea       edx, [edx + 2 * esi]
    punpckldq xmm2, xmm6
    movdqa    xmm6, xmm2
    palignr   xmm6, xmm6, 8
    movq      qword ptr [edx], xmm2
    punpckldq xmm1, xmm5
    movq      qword ptr [edx + esi], xmm6
    lea       edx, [edx + 2 * esi]
    movdqa    xmm5, xmm1
    movq      qword ptr [edx], xmm1
    palignr   xmm5, xmm5, 8
    punpckldq xmm3, xmm7
    movq      qword ptr [edx + esi], xmm5
    lea       edx, [edx + 2 * esi]
    movq      qword ptr [edx], xmm3
    movdqa    xmm7, xmm3
    palignr   xmm7, xmm7, 8
    movq      qword ptr [edx + esi], xmm7
    lea       edx, [edx + 2 * esi]
    sub       ecx, 8
    ja        convertloop
    
    pop       ebp
    pop       esi
    pop       edi
    ret
  }
}

#elif (defined(__i386__) || defined(__x86_64__)) && \
    !defined(COVERAGE_ENABLED) && !defined(TARGET_IPHONE_SIMULATOR)
#define HAS_TRANSPOSE_WX8_SSSE3
static void TransposeWx8_SSSE3(const uint8* src, int src_stride,
                               uint8* dst, int dst_stride, int width) {
  asm volatile(
"1:"
  // Read in the data from the source pointer.
  // First round of bit swap.
  "movq       (%0),%%xmm0\n"
  "movq       (%0,%3),%%xmm1\n"
  "lea        (%0,%3,2),%0\n"
  "punpcklbw  %%xmm1,%%xmm0\n"
  "movq       (%0),%%xmm2\n"
  "movdqa     %%xmm0,%%xmm1\n"
  "palignr    $0x8,%%xmm1,%%xmm1\n"
  "movq       (%0,%3),%%xmm3\n"
  "lea        (%0,%3,2),%0\n"
  "punpcklbw  %%xmm3,%%xmm2\n"
  "movdqa     %%xmm2,%%xmm3\n"
  "movq       (%0),%%xmm4\n"
  "palignr    $0x8,%%xmm3,%%xmm3\n"
  "movq       (%0,%3),%%xmm5\n"
  "lea        (%0,%3,2),%0\n"
  "punpcklbw  %%xmm5,%%xmm4\n"
  "movdqa     %%xmm4,%%xmm5\n"
  "movq       (%0),%%xmm6\n"
  "palignr    $0x8,%%xmm5,%%xmm5\n"
  "movq       (%0,%3),%%xmm7\n"
  "lea        (%0,%3,2),%0\n"
  "punpcklbw  %%xmm7,%%xmm6\n"
  "neg        %3\n"
  "movdqa     %%xmm6,%%xmm7\n"
  "lea        0x8(%0,%3,8),%0\n"
  "palignr    $0x8,%%xmm7,%%xmm7\n"
  "neg        %3\n"
   // Second round of bit swap.
  "punpcklwd  %%xmm2,%%xmm0\n"
  "punpcklwd  %%xmm3,%%xmm1\n"
  "movdqa     %%xmm0,%%xmm2\n"
  "movdqa     %%xmm1,%%xmm3\n"
  "palignr    $0x8,%%xmm2,%%xmm2\n"
  "palignr    $0x8,%%xmm3,%%xmm3\n"
  "punpcklwd  %%xmm6,%%xmm4\n"
  "punpcklwd  %%xmm7,%%xmm5\n"
  "movdqa     %%xmm4,%%xmm6\n"
  "movdqa     %%xmm5,%%xmm7\n"
  "palignr    $0x8,%%xmm6,%%xmm6\n"
  "palignr    $0x8,%%xmm7,%%xmm7\n"
  // Third round of bit swap.
  // Write to the destination pointer. 
  "punpckldq  %%xmm4,%%xmm0\n"
  "movq       %%xmm0,(%1)\n"
  "movdqa     %%xmm0,%%xmm4\n"
  "palignr    $0x8,%%xmm4,%%xmm4\n"
  "movq       %%xmm4,(%1,%4)\n"
  "lea        (%1,%4,2),%1\n"
  "punpckldq  %%xmm6,%%xmm2\n"
  "movdqa     %%xmm2,%%xmm6\n"
  "movq       %%xmm2,(%1)\n"
  "palignr    $0x8,%%xmm6,%%xmm6\n"
  "punpckldq  %%xmm5,%%xmm1\n"
  "movq       %%xmm6,(%1,%4)\n"
  "lea        (%1,%4,2),%1\n"
  "movdqa     %%xmm1,%%xmm5\n"
  "movq       %%xmm1,(%1)\n"
  "palignr    $0x8,%%xmm5,%%xmm5\n"
  "movq       %%xmm5,(%1,%4)\n"
  "lea        (%1,%4,2),%1\n"
  "punpckldq  %%xmm7,%%xmm3\n"
  "movq       %%xmm3,(%1)\n"
  "movdqa     %%xmm3,%%xmm7\n"
  "palignr    $0x8,%%xmm7,%%xmm7\n"
  "movq       %%xmm7,(%1,%4)\n"
  "lea        (%1,%4,2),%1\n"
  "sub        $0x8,%2\n"
  "ja         1b\n"
  : "+r"(src),    // %0
    "+r"(dst),    // %1
    "+r"(width)   // %2
  : "r"(static_cast<intptr_t>(src_stride)),  // %3
    "r"(static_cast<intptr_t>(dst_stride))   // %4
  : "memory"
);
}

#endif

static void TransposeWx8_C(const uint8* src, int src_stride,
                           uint8* dst, int dst_stride,
                           int w) {
  int i, j;
  for (i = 0; i < w; ++i)
    for (j = 0; j < 8; ++j)
      dst[i * dst_stride + j] = src[j * src_stride + i];
}

static void TransposeWxH_C(const uint8* src, int src_stride,
                           uint8* dst, int dst_stride,
                           int width, int height) {
  int i, j;
  for (i = 0; i < width; ++i)
    for (j = 0; j < height; ++j)
      dst[i * dst_stride + j] = src[j * src_stride + i];
}

void TransposePlane(const uint8* src, int src_stride,
                    uint8* dst, int dst_stride,
                    int width, int height) {
  int i = height;
  rotate_wx8_func TransposeWx8;
  rotate_wxh_func TransposeWxH;

#if defined(HAS_TRANSPOSE_WX8_NEON)
  if (libyuv::TestCpuFlag(libyuv::kCpuHasNEON) &&
      (width % 8 == 0) &&
      IS_ALIGNED(src, 16) && (src_stride % 8 == 0) &&
      IS_ALIGNED(dst, 16) && (dst_stride % 8 == 0)) {
    TransposeWx8 = TransposeWx8_NEON;
    TransposeWxH = TransposeWxH_C;
  } else
#endif
#if defined(HAS_TRANSPOSE_WX8_SSSE3)
  if (libyuv::TestCpuFlag(libyuv::kCpuHasSSSE3) &&
      (width % 8 == 0) &&
      IS_ALIGNED(src, 16) && (src_stride % 8 == 0) &&
      IS_ALIGNED(dst, 16) && (dst_stride % 8 == 0)) {
    TransposeWx8 = TransposeWx8_SSSE3;
    TransposeWxH = TransposeWxH_C;
  } else
#endif
  {
    TransposeWx8 = TransposeWx8_C;
    TransposeWxH = TransposeWxH_C;
  }

  // work across the source in 8x8 tiles
  while (i >= 8) {
    TransposeWx8(src, src_stride, dst, dst_stride, width);

    src += 8 * src_stride;    // go down 8 rows
    dst += 8;                 // move over 8 columns
    i   -= 8;
  }

  TransposeWxH(src, src_stride, dst, dst_stride, width, i);
}

void RotatePlane90(const uint8* src, int src_stride,
                   uint8* dst, int dst_stride,
                   int width, int height) {
  // Rotate by 90 is a transpose with the source read
  // from bottom to top.  So set the source pointer to the end
  // of the buffer and flip the sign of the source stride.
  src += src_stride * (height - 1);
  src_stride = -src_stride;

  TransposePlane(src, src_stride, dst, dst_stride, width, height);
}

void RotatePlane270(const uint8* src, int src_stride,
                    uint8* dst, int dst_stride,
                    int width, int height) {
  // Rotate by 270 is a transpose with the destination written
  // from bottom to top.  So set the destination pointer to the end
  // of the buffer and flip the sign of the destination stride.
  dst += dst_stride * (width - 1);
  dst_stride = -dst_stride;

  TransposePlane(src, src_stride, dst, dst_stride, width, height);
}

static void ReverseLine_C(const uint8* src, uint8* dst, int width) {
  int i;
  src += width;
  for (i = 0; i < width; ++i) {
    --src;
    dst[i] = src[0];
  }
}

#if defined(WIN32) && !defined(COVERAGE_ENABLED)
#define HAS_REVERSE_LINE_SSSE3
__declspec(naked)
static void ReverseLine_SSSE3(const uint8* src, uint8* dst, int width) {
__asm {
    mov       eax, [esp + 4]   // src
    mov       edx, [esp + 8]   // dst
    mov       ecx, [esp + 12]  // width
    movdqa    xmm7, _kShuffleReverse
    lea       eax, [eax + ecx - 16]
 convertloop :
    movdqa    xmm0, [eax]
    lea       eax, [eax - 16]
    pshufb    xmm0, xmm7
    movdqa    [edx], xmm0
    lea       edx, [edx + 16]
    sub       ecx, 16
    ja        convertloop
    ret
  }
}

#elif (defined(__i386__) || defined(__x86_64__)) && \
    !defined(COVERAGE_ENABLED) && !defined(TARGET_IPHONE_SIMULATOR)
#define HAS_REVERSE_LINE_SSSE3
static void ReverseLine_SSSE3(const uint8* src, uint8* dst, int width) {
  intptr_t temp_width = static_cast<intptr_t>(width);
  asm volatile(
  "movdqa     (%3),%%xmm7\n"
  "lea        -0x10(%0,%2,1),%0\n"
"1:"
  "movdqa     (%0),%%xmm0\n"
  "lea        -0x10(%0),%0\n"
  "pshufb     %%xmm7,%%xmm0\n"
  "movdqa     %%xmm0,(%1)\n"
  "lea        0x10(%1),%1\n"
  "sub        $0x10,%2\n"
  "ja         1b\n"
  : "+r"(src),    // %0
    "+r"(dst),    // %1
    "+r"(temp_width)   // %2
  : "r"(kShuffleReverse)   // %3
  : "memory"
);
}
#endif

void RotatePlane180(const uint8* src, int src_stride,
                    uint8* dst, int dst_stride,
                    int width, int height) {
  int i;
  reverse_func ReverseLine;

#if defined(HAS_REVERSE_LINE_NEON)
  if (libyuv::TestCpuFlag(libyuv::kCpuHasNEON) &&
      (width % 16 == 0) &&
      IS_ALIGNED(src, 16) && (src_stride % 16 == 0) &&
      IS_ALIGNED(dst, 16) && (dst_stride % 16 == 0)) {
    ReverseLine = ReverseLine_NEON;
  } else
#endif
#if defined(HAS_REVERSE_LINE_SSSE3)
  if (libyuv::TestCpuFlag(libyuv::kCpuHasSSSE3) &&
      (width % 16 == 0) &&
      IS_ALIGNED(src, 16) && (src_stride % 16 == 0) &&
      IS_ALIGNED(dst, 16) && (dst_stride % 16 == 0)) {
    ReverseLine = ReverseLine_SSSE3;
  } else
#endif
  {
    ReverseLine = ReverseLine_C;
  }
  // Rotate by 180 is a mirror with the destination
  // written in reverse.
  dst += dst_stride * (height - 1);

  for (i = 0; i < height; ++i) {
    ReverseLine(src, dst, width);

    src += src_stride;
    dst -= dst_stride;
  }
}

static void TransposeUVWx8_C(const uint8* src, int src_stride,
                             uint8* dst_a, int dst_stride_a,
                             uint8* dst_b, int dst_stride_b,
                             int w) {
  int i, j;
  for (i = 0; i < w * 2; i += 2)
    for (j = 0; j < 8; ++j) {
      dst_a[j + ((i >> 1) * dst_stride_a)] = src[i + (j * src_stride)];
      dst_b[j + ((i >> 1) * dst_stride_b)] = src[i + (j * src_stride) + 1];
    }
}

static void TransposeUVWxH_C(const uint8* src, int src_stride,
                             uint8* dst_a, int dst_stride_a,
                             uint8* dst_b, int dst_stride_b,
                             int w, int h) {
  int i, j;
  for (i = 0; i < w*2; i += 2)
    for (j = 0; j < h; ++j) {
      dst_a[j + ((i >> 1) * dst_stride_a)] = src[i + (j * src_stride)];
      dst_b[j + ((i >> 1) * dst_stride_b)] = src[i + (j * src_stride) + 1];
    }
}

void TransposeUV(const uint8* src, int src_stride,
                 uint8* dst_a, int dst_stride_a,
                 uint8* dst_b, int dst_stride_b,
                 int width, int height) {
  int i = height;
  rotate_uv_wx8_func TransposeWx8;
  rotate_uv_wxh_func TransposeWxH;

#if defined(HAS_TRANSPOSE_UVWX8_NEON)
  if (libyuv::TestCpuFlag(libyuv::kCpuHasNEON) &&
      (width % 8 == 0) &&
      IS_ALIGNED(src, 16) && (src_stride % 8 == 0) &&
      IS_ALIGNED(dst_a, 16) && (dst_stride_a % 8 == 0) &&
      IS_ALIGNED(dst_b, 16) && (dst_stride_b % 8 == 0)) {
    unsigned long long store_reg[8];
    SaveRegisters_NEON(store_reg);
    TransposeWx8 = TransposeUVWx8_NEON;
    TransposeWxH = TransposeUVWxH_C;
  } else
#endif
#if defined(HAS_TRANSPOSE_UVWX8_SSE2)
  if (libyuv::TestCpuFlag(libyuv::kCpuHasSSE2) &&
      (width % 8 == 0) &&
      IS_ALIGNED(src, 16) && (src_stride % 8 == 0) &&
      IS_ALIGNED(dst_a, 16) && (dst_stride_a % 8 == 0) &&
      IS_ALIGNED(dst_b, 16) && (dst_stride_b % 8 == 0)) {
    TransposeWx8 = TransposeUVWx8_SSE2;
    TransposeWxH = TransposeUVWxH_C;
  } else
#endif
  {
    TransposeWx8 = TransposeUVWx8_C;
    TransposeWxH = TransposeUVWxH_C;
  }

  // work through the source in 8x8 tiles
  while (i >= 8) {
    TransposeWx8(src, src_stride,
                 dst_a, dst_stride_a,
                 dst_b, dst_stride_b,
                 width);

    src   += 8 * src_stride;    // go down 8 rows
    dst_a += 8;                 // move over 8 columns
    dst_b += 8;                 // move over 8 columns
    i     -= 8;
  }

  TransposeWxH(src, src_stride,
               dst_a, dst_stride_a,
               dst_b, dst_stride_b,
               width, i);

#if defined(HAS_TRANSPOSE_UVWX8_NEON)
  if (libyuv::TestCpuFlag(libyuv::kCpuHasNEON)) {
    RestoreRegisters_NEON(store_reg);
  }
#endif
}

void RotateUV90(const uint8* src, int src_stride,
                uint8* dst_a, int dst_stride_a,
                uint8* dst_b, int dst_stride_b,
                int width, int height) {
  src += src_stride * (height - 1);
  src_stride = -src_stride;

  TransposeUV(src, src_stride,
              dst_a, dst_stride_a,
              dst_b, dst_stride_b,
              width, height);
}

void RotateUV270(const uint8* src, int src_stride,
                 uint8* dst_a, int dst_stride_a,
                 uint8* dst_b, int dst_stride_b,
                 int width, int height) {
  dst_a += dst_stride_a * (width - 1);
  dst_b += dst_stride_b * (width - 1);
  dst_stride_a = -dst_stride_a;
  dst_stride_b = -dst_stride_b;

  TransposeUV(src, src_stride,
              dst_a, dst_stride_a,
              dst_b, dst_stride_b,
              width, height);
}

#if defined(WIN32) && !defined(COVERAGE_ENABLED)
#define HAS_REVERSE_LINE_UV_SSSE3
__declspec(naked)
void ReverseLineUV_SSSE3(const uint8* src,
                         uint8* dst_a, uint8* dst_b,
                         int width) {
__asm {
    push      edi
    mov       eax, [esp + 4 + 4]   // src
    mov       edx, [esp + 4 + 8]   // dst_a
    mov       edi, [esp + 4 + 12]  // dst_b
    mov       ecx, [esp + 4 + 16]  // width
    movdqa    xmm7, _kShuffleReverseUV
    lea       eax, [eax + 2 * ecx - 16]

 convertloop :
    movdqa    xmm0, [eax]
    lea       eax, [eax - 16]
    pshufb    xmm0, xmm7
    movlpd    qword ptr [edx], xmm0
    lea       edx, [edx + 8]
    movhpd    qword ptr [edi], xmm0
    lea       edi, [edi + 8]
    sub       ecx, 8
    ja        convertloop
    pop       edi
    ret
  }
}

#elif (defined(__i386__) || defined(__x86_64__)) && \
    !defined(COVERAGE_ENABLED) && !defined(TARGET_IPHONE_SIMULATOR)
#define HAS_REVERSE_LINE_UV_SSSE3
void ReverseLineUV_SSSE3(const uint8* src,
                         uint8* dst_a, uint8* dst_b,
                         int width) {
  intptr_t temp_width = static_cast<intptr_t>(width);
  asm volatile(
  "movdqa     (%4),%%xmm7\n"
  "lea        -0x10(%0,%3,2),%0\n"
"1:"
  "movdqa     (%0),%%xmm0\n"
  "lea        -0x10(%0),%0\n"
  "pshufb     %%xmm7,%%xmm0\n"
  "movlpd     %%xmm0,(%1)\n"
  "lea        0x8(%1),%1\n"
  "movhpd     %%xmm0,(%2)\n"
  "lea        0x8(%2),%2\n"
  "sub        $0x8,%3\n"
  "ja         1b\n"
  : "+r"(src),      // %0
    "+r"(dst_a),    // %1
    "+r"(dst_b),    // %2
    "+r"(temp_width)     // %3
  : "r"(kShuffleReverseUV)  // %4
  : "memory"
);
}
#endif

static void ReverseLineUV_C(const uint8* src,
                            uint8* dst_a, uint8* dst_b,
                            int width) {
  int i;
  src += width << 1;
  for (i = 0; i < width; ++i) {
    src -= 2;
    dst_a[i] = src[0];
    dst_b[i] = src[1];
  }
}

void RotateUV180(const uint8* src, int src_stride,
                 uint8* dst_a, int dst_stride_a,
                 uint8* dst_b, int dst_stride_b,
                 int width, int height) {
  int i;
  reverse_uv_func ReverseLine;

  // TODO(frkoenig) : do processor detection here.
#if defined(HAS_REVERSE_LINE_UV_NEON)
  if (libyuv::TestCpuFlag(libyuv::kCpuHasNEON) &&
      (width % 16 == 0) &&
      IS_ALIGNED(src, 16) && (src_stride % 16 == 0) &&
      IS_ALIGNED(dst_a, 16) && (dst_stride_a % 8 == 0) &&
      IS_ALIGNED(dst_b, 16) && (dst_stride_b % 8 == 0) ) {
    ReverseLine = ReverseLineUV_NEON;
  } else
#endif
#if defined(HAS_REVERSE_LINE_UV_SSSE3)
  if (libyuv::TestCpuFlag(libyuv::kCpuHasSSSE3) &&
      (width % 16 == 0) &&
      IS_ALIGNED(src, 16) && (src_stride % 16 == 0) &&
      IS_ALIGNED(dst_a, 16) && (dst_stride_a % 8 == 0) &&
      IS_ALIGNED(dst_b, 16) && (dst_stride_b % 8 == 0) ) {
    ReverseLine = ReverseLineUV_SSSE3;
  } else
#endif
  {
    ReverseLine = ReverseLineUV_C;
  }

  dst_a += dst_stride_a * (height - 1);
  dst_b += dst_stride_b * (height - 1);

  for (i = 0; i < height; ++i) {
    ReverseLine(src, dst_a, dst_b, width);

    src   += src_stride;      // down one line at a time
    dst_a -= dst_stride_a;    // nominally up one line at a time
    dst_b -= dst_stride_b;    // nominally up one line at a time
  }
}

int I420Rotate(const uint8* src_y, int src_stride_y,
               const uint8* src_u, int src_stride_u,
               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 width, int height,
               RotationMode mode) {
  int halfwidth = (width + 1) >> 1;
  int halfheight = (height + 1) >> 1;

  // Negative height means invert the image.
  if (height < 0) {
    height = -height;
    halfheight = (height + 1) >> 1;
    src_y = src_y + (height - 1) * src_stride_y;
    src_u = src_u + (halfheight - 1) * src_stride_u;
    src_v = src_v + (halfheight - 1) * src_stride_v;
    src_stride_y = -src_stride_y;
    src_stride_u = -src_stride_u;
    src_stride_v = -src_stride_v;
  }

  switch (mode) {
    case kRotateNone:
      // copy frame
      return I420Copy(src_y, src_stride_y,
                      src_u, src_stride_u,
                      src_v, src_stride_v,
                      dst_y, dst_stride_y,
                      dst_u, dst_stride_u,
                      dst_v, dst_stride_v,
                      width, height);
    case kRotateClockwise:
      RotatePlane90(src_y, src_stride_y,
                    dst_y, dst_stride_y,
                    width, height);
      RotatePlane90(src_u, src_stride_u,
                    dst_u, dst_stride_u,
                    halfwidth, halfheight);
      RotatePlane90(src_v, src_stride_v,
                    dst_v, dst_stride_v,
                    halfwidth, halfheight);
      return 0;
    case kRotateCounterClockwise:
      RotatePlane270(src_y, src_stride_y,
                     dst_y, dst_stride_y,
                     width, height);
      RotatePlane270(src_u, src_stride_u,
                     dst_u, dst_stride_u,
                     halfwidth, halfheight);
      RotatePlane270(src_v, src_stride_v,
                     dst_v, dst_stride_v,
                     halfwidth, halfheight);
      return 0;
    case kRotate180:
      RotatePlane180(src_y, src_stride_y,
                     dst_y, dst_stride_y,
                     width, height);
      RotatePlane180(src_u, src_stride_u,
                     dst_u, dst_stride_u,
                     halfwidth, halfheight);
      RotatePlane180(src_v, src_stride_v,
                     dst_v, dst_stride_v,
                     halfwidth, halfheight);
      return 0;
    default:
      break;
  }
  return -1;
}

int NV12ToI420Rotate(const uint8* src_y, int src_stride_y,
                     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,
                     RotationMode mode) {
  int halfwidth = (width + 1) >> 1;
  int halfheight = (height + 1) >> 1;

  // Negative height means invert the image.
  if (height < 0) {
    height = -height;
    halfheight = (height + 1) >> 1;
    src_y = src_y + (height - 1) * src_stride_y;
    src_uv = src_uv + (halfheight - 1) * src_stride_uv;
    src_stride_y = -src_stride_y;
    src_stride_uv = -src_stride_uv;
  }

  switch (mode) {
    case kRotateNone:
      // copy frame
      return NV12ToI420(src_y, src_uv, src_stride_y,
                        dst_y, dst_stride_y,
                        dst_u, dst_stride_u,
                        dst_v, dst_stride_v,
                        width, height);
    case kRotateClockwise:
      RotatePlane90(src_y, src_stride_y,
                    dst_y, dst_stride_y,
                    width, height);
      RotateUV90(src_uv, src_stride_uv,
                 dst_u, dst_stride_u,
                 dst_v, dst_stride_v,
                 halfwidth, halfheight);
      return 0;
    case kRotateCounterClockwise:
      RotatePlane270(src_y, src_stride_y,
                     dst_y, dst_stride_y,
                     width, height);
      RotateUV270(src_uv, src_stride_uv,
                  dst_u, dst_stride_u,
                  dst_v, dst_stride_v,
                  halfwidth, halfheight);
      return 0;
    case kRotate180:
      RotatePlane180(src_y, src_stride_y,
                     dst_y, dst_stride_y,
                     width, height);
      RotateUV180(src_uv, src_stride_uv,
                  dst_u, dst_stride_u,
                  dst_v, dst_stride_v,
                  halfwidth, halfheight);
      return 0;
    default:
      break;
  }
  return -1;
}

}  // namespace libyuv