// Copyright 2022 Google Inc. All Rights Reserved.

//

// Use of this source code is governed by a BSD-style license

// that can be found in the COPYING 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.

// -----------------------------------------------------------------------------

//

// Speed-critical functions for Sharp YUV.

//

// Author: Skal (pascal.massimino@gmail.com)

#include "sharpyuv/sharpyuv_dsp.h"

#include <assert.h>

#include <stdlib.h>

#include "sharpyuv/sharpyuv_cpu.h"

#include "src/webp/types.h"

//-----------------------------------------------------------------------------

#if !WEBP_NEON_OMIT_C_CODE

static uint16_t clip(int v, int max) {

  return (v < 0) ? 0 : (v > max) ? max : (uint16_t)v;

}

static uint64_t SharpYuvUpdateY_C(const uint16_t* ref, const uint16_t* src,

                                  uint16_t* dst, int len, int bit_depth) {

  uint64_t diff = 0;

  int i;

  const int max_y = (1 << bit_depth) - 1;

  for (i = 0; i < len; ++i) {

    const int diff_y = ref[i] - src[i];

    const int new_y = (int)dst[i] + diff_y;

    dst[i] = clip(new_y, max_y);

    diff += (uint64_t)abs(diff_y);

  }

  return diff;

}

static void SharpYuvUpdateRGB_C(const int16_t* ref, const int16_t* src,

                                int16_t* dst, int len) {

  int i;

  for (i = 0; i < len; ++i) {

    const int diff_uv = ref[i] - src[i];

    dst[i] += diff_uv;

  }

}

static void SharpYuvFilterRow_C(const int16_t* A, const int16_t* B, int len,

                                const uint16_t* best_y, uint16_t* out,

                                int bit_depth) {

  int i;

  const int max_y = (1 << bit_depth) - 1;

  for (i = 0; i < len; ++i, ++A, ++B) {

    const int v0 = (A[0] * 9 + A[1] * 3 + B[0] * 3 + B[1] + 8) >> 4;

    const int v1 = (A[1] * 9 + A[0] * 3 + B[1] * 3 + B[0] + 8) >> 4;

    out[2 * i + 0] = clip(best_y[2 * i + 0] + v0, max_y);

    out[2 * i + 1] = clip(best_y[2 * i + 1] + v1, max_y);

  }

}

#endif  // !WEBP_NEON_OMIT_C_CODE

//-----------------------------------------------------------------------------

uint64_t (*SharpYuvUpdateY)(const uint16_t* src, const uint16_t* ref,

                            uint16_t* dst, int len, int bit_depth);

void (*SharpYuvUpdateRGB)(const int16_t* src, const int16_t* ref, int16_t* dst,

                          int len);

void (*SharpYuvFilterRow)(const int16_t* A, const int16_t* B, int len,

                          const uint16_t* best_y, uint16_t* out, int bit_depth);

extern VP8CPUInfo SharpYuvGetCPUInfo;

extern void InitSharpYuvSSE2(void);

extern void InitSharpYuvNEON(void);

void SharpYuvInitDsp(void) {

#if !WEBP_NEON_OMIT_C_CODE

  SharpYuvUpdateY = SharpYuvUpdateY_C;

  SharpYuvUpdateRGB = SharpYuvUpdateRGB_C;

  SharpYuvFilterRow = SharpYuvFilterRow_C;

#endif

  if (SharpYuvGetCPUInfo != NULL) {

#if defined(WEBP_HAVE_SSE2)

    if (SharpYuvGetCPUInfo(kSSE2)) {

      InitSharpYuvSSE2();

    }

#endif  // WEBP_HAVE_SSE2

  }

#if defined(WEBP_HAVE_NEON)

  if (WEBP_NEON_OMIT_C_CODE ||

      (SharpYuvGetCPUInfo != NULL && SharpYuvGetCPUInfo(kNEON))) {

    InitSharpYuvNEON();

  }

#endif  // WEBP_HAVE_NEON

  assert(SharpYuvUpdateY != NULL);

  assert(SharpYuvUpdateRGB != NULL);

  assert(SharpYuvFilterRow != NULL);

}