media/base/simd/convert_rgb_to_yuv

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This source file includes following definitions.
Clamp
RGBToY
RGBToU
RGBToV
ConvertRGBToYUV_V2H2
ConvertRGBToYUV_V2H1
ConvertRGBToYUV_V1H2
ConvertRGBToYUV_V1H1
ConvertRGB32ToYUVRow_SSE2
ConvertRGB32ToYUV_SSE2
ConvertRGB32ToYUV_SSE2_Reference
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "build/build_config.h"
#include "media/base/simd/convert_rgb_to_yuv.h"
#include "media/base/simd/yuv_to_rgb_table.h"

#if defined(COMPILER_MSVC)
#include <intrin.h>
#else
#include <mmintrin.h>
#include <emmintrin.h>
#endif

namespace media {

#define FIX_SHIFT 12
#define FIX(x) ((x) * (1 << FIX_SHIFT))

// Define a convenient macro to do static cast.
#define INT16_FIX(x) static_cast<int16>(FIX(x))

// Android's pixel layout is RGBA, while other platforms
// are BGRA.
#if defined(OS_ANDROID)
SIMD_ALIGNED(const int16 ConvertRGBAToYUV_kTable[8 * 3]) = {
  INT16_FIX(0.257), INT16_FIX(0.504), INT16_FIX(0.098), 0,
  INT16_FIX(0.257), INT16_FIX(0.504), INT16_FIX(0.098), 0,
  -INT16_FIX(0.148), -INT16_FIX(0.291), INT16_FIX(0.439), 0,
  -INT16_FIX(0.148), -INT16_FIX(0.291), INT16_FIX(0.439), 0,
  INT16_FIX(0.439), -INT16_FIX(0.368), -INT16_FIX(0.071), 0,
  INT16_FIX(0.439), -INT16_FIX(0.368), -INT16_FIX(0.071), 0,
};
#else
SIMD_ALIGNED(const int16 ConvertRGBAToYUV_kTable[8 * 3]) = {
  INT16_FIX(0.098), INT16_FIX(0.504), INT16_FIX(0.257), 0,
  INT16_FIX(0.098), INT16_FIX(0.504), INT16_FIX(0.257), 0,
  INT16_FIX(0.439), -INT16_FIX(0.291), -INT16_FIX(0.148), 0,
  INT16_FIX(0.439), -INT16_FIX(0.291), -INT16_FIX(0.148), 0,
  -INT16_FIX(0.071), -INT16_FIX(0.368), INT16_FIX(0.439), 0,
  -INT16_FIX(0.071), -INT16_FIX(0.368), INT16_FIX(0.439), 0,
};
#endif

#undef INT16_FIX

// This is the final offset for the conversion from signed yuv values to
// unsigned values. It is arranged so that offset of 16 is applied to Y
// components and 128 is added to UV components for 2 pixels.
SIMD_ALIGNED(const int32 kYOffset[4]) = {16, 16, 16, 16};

static inline int Clamp(int value) {
  if (value < 0)
    return 0;
  if (value > 255)
    return 255;
  return value;
}

static inline int RGBToY(int r, int g, int b) {
  int y = ConvertRGBAToYUV_kTable[0] * b +
      ConvertRGBAToYUV_kTable[1] * g +
      ConvertRGBAToYUV_kTable[2] * r;
  y >>= FIX_SHIFT;
  return Clamp(y + 16);
}

static inline int RGBToU(int r, int g, int b, int shift) {
  int u = ConvertRGBAToYUV_kTable[8] * b +
      ConvertRGBAToYUV_kTable[9] * g +
      ConvertRGBAToYUV_kTable[10] * r;
  u >>= FIX_SHIFT + shift;
  return Clamp(u + 128);
}

static inline int RGBToV(int r, int g, int b, int shift) {
  int v = ConvertRGBAToYUV_kTable[16] * b +
      ConvertRGBAToYUV_kTable[17] * g +
      ConvertRGBAToYUV_kTable[18] * r;
  v >>= FIX_SHIFT + shift;
  return Clamp(v + 128);
}

#define CONVERT_Y(rgb_buf, y_buf) \
  b = *rgb_buf++; \
  g = *rgb_buf++; \
  r = *rgb_buf++; \
  ++rgb_buf;      \
  sum_b += b;     \
  sum_g += g;     \
  sum_r += r;     \
  *y_buf++ = RGBToY(r, g, b);

static inline void ConvertRGBToYUV_V2H2(const uint8* rgb_buf_1,
                                        const uint8* rgb_buf_2,
                                        uint8* y_buf_1,
                                        uint8* y_buf_2,
                                        uint8* u_buf,
                                        uint8* v_buf) {
  int sum_b = 0;
  int sum_g = 0;
  int sum_r = 0;
  int r, g, b;



  CONVERT_Y(rgb_buf_1, y_buf_1);
  CONVERT_Y(rgb_buf_1, y_buf_1);
  CONVERT_Y(rgb_buf_2, y_buf_2);
  CONVERT_Y(rgb_buf_2, y_buf_2);
  *u_buf++ = RGBToU(sum_r, sum_g, sum_b, 2);
  *v_buf++ = RGBToV(sum_r, sum_g, sum_b, 2);
}

static inline void ConvertRGBToYUV_V2H1(const uint8* rgb_buf_1,
                                        const uint8* rgb_buf_2,
                                        uint8* y_buf_1,
                                        uint8* y_buf_2,
                                        uint8* u_buf,
                                        uint8* v_buf) {
  int sum_b = 0;
  int sum_g = 0;
  int sum_r = 0;
  int r, g, b;

  CONVERT_Y(rgb_buf_1, y_buf_1);
  CONVERT_Y(rgb_buf_2, y_buf_2);
  *u_buf++ = RGBToU(sum_r, sum_g, sum_b, 1);
  *v_buf++ = RGBToV(sum_r, sum_g, sum_b, 1);
}

static inline void ConvertRGBToYUV_V1H2(const uint8* rgb_buf,
                                       uint8* y_buf,
                                       uint8* u_buf,
                                       uint8* v_buf) {
  int sum_b = 0;
  int sum_g = 0;
  int sum_r = 0;
  int r, g, b;

  CONVERT_Y(rgb_buf, y_buf);
  CONVERT_Y(rgb_buf, y_buf);
  *u_buf++ = RGBToU(sum_r, sum_g, sum_b, 1);
  *v_buf++ = RGBToV(sum_r, sum_g, sum_b, 1);
}

static inline void ConvertRGBToYUV_V1H1(const uint8* rgb_buf,
                                       uint8* y_buf,
                                       uint8* u_buf,
                                       uint8* v_buf) {
  int sum_b = 0;
  int sum_g = 0;
  int sum_r = 0;
  int r, g, b;

  CONVERT_Y(rgb_buf, y_buf);
  *u_buf++ = RGBToU(r, g, b, 0);
  *v_buf++ = RGBToV(r, g, b, 0);
}

static void ConvertRGB32ToYUVRow_SSE2(const uint8* rgb_buf_1,
                                      const uint8* rgb_buf_2,
                                      uint8* y_buf_1,
                                      uint8* y_buf_2,
                                      uint8* u_buf,
                                      uint8* v_buf,
                                      int width) {
  while (width >= 4) {
    // Name for the Y pixels:
    // Row 1: a b c d
    // Row 2: e f g h
    //
    // First row 4 pixels.
    __m128i rgb_row_1 = _mm_loadu_si128(
        reinterpret_cast<const __m128i*>(rgb_buf_1));
    __m128i zero_1 = _mm_xor_si128(rgb_row_1, rgb_row_1);

    __m128i y_table = _mm_load_si128(
        reinterpret_cast<const __m128i*>(ConvertRGBAToYUV_kTable));

    __m128i rgb_a_b = _mm_unpackhi_epi8(rgb_row_1, zero_1);
    rgb_a_b = _mm_madd_epi16(rgb_a_b, y_table);

    __m128i rgb_c_d = _mm_unpacklo_epi8(rgb_row_1, zero_1);
    rgb_c_d = _mm_madd_epi16(rgb_c_d, y_table);

    // Do a crazh shuffle so that we get:
    //  v------------ Multiply Add
    // BG: a b c d
    // A0: a b c d
    __m128i bg_abcd = _mm_castps_si128(
        _mm_shuffle_ps(
            _mm_castsi128_ps(rgb_c_d),
            _mm_castsi128_ps(rgb_a_b),
            (3 << 6) | (1 << 4) | (3 << 2) | 1));
    __m128i r_abcd = _mm_castps_si128(
        _mm_shuffle_ps(
            _mm_castsi128_ps(rgb_c_d),
            _mm_castsi128_ps(rgb_a_b),
            (2 << 6) | (2 << 2)));
    __m128i y_abcd = _mm_add_epi32(bg_abcd, r_abcd);

    // Down shift back to 8bits range.
    __m128i y_offset = _mm_load_si128(
        reinterpret_cast<const __m128i*>(kYOffset));
    y_abcd = _mm_srai_epi32(y_abcd, FIX_SHIFT);
    y_abcd = _mm_add_epi32(y_abcd, y_offset);
    y_abcd = _mm_packs_epi32(y_abcd, y_abcd);
    y_abcd = _mm_packus_epi16(y_abcd, y_abcd);
    *reinterpret_cast<uint32*>(y_buf_1) = _mm_cvtsi128_si32(y_abcd);
    y_buf_1 += 4;

    // Second row 4 pixels.
    __m128i rgb_row_2 = _mm_loadu_si128(
        reinterpret_cast<const __m128i*>(rgb_buf_2));
    __m128i zero_2 = _mm_xor_si128(rgb_row_2, rgb_row_2);
    __m128i rgb_e_f = _mm_unpackhi_epi8(rgb_row_2, zero_2);
    __m128i rgb_g_h = _mm_unpacklo_epi8(rgb_row_2, zero_2);

    // Add two rows together.
    __m128i rgb_ae_bf =
        _mm_add_epi16(_mm_unpackhi_epi8(rgb_row_1, zero_2), rgb_e_f);
    __m128i rgb_cg_dh =
        _mm_add_epi16(_mm_unpacklo_epi8(rgb_row_1, zero_2), rgb_g_h);

    // Multiply add like the previous row.
    rgb_e_f = _mm_madd_epi16(rgb_e_f, y_table);
    rgb_g_h = _mm_madd_epi16(rgb_g_h, y_table);

    __m128i bg_efgh = _mm_castps_si128(
        _mm_shuffle_ps(_mm_castsi128_ps(rgb_g_h),
                       _mm_castsi128_ps(rgb_e_f),
                       (3 << 6) | (1 << 4) | (3 << 2) | 1));
    __m128i r_efgh = _mm_castps_si128(
        _mm_shuffle_ps(_mm_castsi128_ps(rgb_g_h),
                       _mm_castsi128_ps(rgb_e_f),
                       (2 << 6) | (2 << 2)));
    __m128i y_efgh = _mm_add_epi32(bg_efgh, r_efgh);
    y_efgh = _mm_srai_epi32(y_efgh, FIX_SHIFT);
    y_efgh = _mm_add_epi32(y_efgh, y_offset);
    y_efgh = _mm_packs_epi32(y_efgh, y_efgh);
    y_efgh = _mm_packus_epi16(y_efgh, y_efgh);
    *reinterpret_cast<uint32*>(y_buf_2) = _mm_cvtsi128_si32(y_efgh);
    y_buf_2 += 4;

    __m128i rgb_ae_cg = _mm_castps_si128(
        _mm_shuffle_ps(_mm_castsi128_ps(rgb_cg_dh),
                       _mm_castsi128_ps(rgb_ae_bf),
                       (3 << 6) | (2 << 4) | (3 << 2) | 2));
    __m128i rgb_bf_dh = _mm_castps_si128(
        _mm_shuffle_ps(_mm_castsi128_ps(rgb_cg_dh),
                       _mm_castsi128_ps(rgb_ae_bf),
                       (1 << 6) | (1 << 2)));

    // This is a 2x2 subsampling for 2 pixels.
    __m128i rgb_abef_cdgh = _mm_add_epi16(rgb_ae_cg, rgb_bf_dh);

    // Do a multiply add with U table.
    __m128i u_a_b = _mm_madd_epi16(
        rgb_abef_cdgh,
        _mm_load_si128(
            reinterpret_cast<const __m128i*>(ConvertRGBAToYUV_kTable + 8)));
    u_a_b = _mm_add_epi32(_mm_shuffle_epi32(u_a_b, ((3 << 2) | 1)),
                          _mm_shuffle_epi32(u_a_b, (2 << 2)));
    // Right shift 14 because of 12 from fixed point and 2 from subsampling.
    u_a_b = _mm_srai_epi32(u_a_b, FIX_SHIFT + 2);
    __m128i uv_offset = _mm_slli_epi32(y_offset, 3);
    u_a_b = _mm_add_epi32(u_a_b, uv_offset);
    u_a_b = _mm_packs_epi32(u_a_b, u_a_b);
    u_a_b = _mm_packus_epi16(u_a_b, u_a_b);
    *reinterpret_cast<uint16*>(u_buf) = _mm_extract_epi16(u_a_b, 0);
    u_buf += 2;

    __m128i v_a_b = _mm_madd_epi16(
        rgb_abef_cdgh,
        _mm_load_si128(
            reinterpret_cast<const __m128i*>(ConvertRGBAToYUV_kTable + 16)));
    v_a_b = _mm_add_epi32(_mm_shuffle_epi32(v_a_b, ((3 << 2) | 1)),
                          _mm_shuffle_epi32(v_a_b, (2 << 2)));
    v_a_b = _mm_srai_epi32(v_a_b, FIX_SHIFT + 2);
    v_a_b = _mm_add_epi32(v_a_b, uv_offset);
    v_a_b = _mm_packs_epi32(v_a_b, v_a_b);
    v_a_b = _mm_packus_epi16(v_a_b, v_a_b);
    *reinterpret_cast<uint16*>(v_buf) = _mm_extract_epi16(v_a_b, 0);
    v_buf += 2;

    rgb_buf_1 += 16;
    rgb_buf_2 += 16;

    // Move forward by 4 pixels.
    width -= 4;
  }

  // Just use C code to convert the remaining pixels.
  if (width >= 2) {
    ConvertRGBToYUV_V2H2(rgb_buf_1, rgb_buf_2, y_buf_1, y_buf_2, u_buf, v_buf);
    rgb_buf_1 += 8;
    rgb_buf_2 += 8;
    y_buf_1 += 2;
    y_buf_2 += 2;
    ++u_buf;
    ++v_buf;
    width -= 2;
  }

  if (width)
    ConvertRGBToYUV_V2H1(rgb_buf_1, rgb_buf_2, y_buf_1, y_buf_2, u_buf, v_buf);
}

extern void ConvertRGB32ToYUV_SSE2(const uint8* rgbframe,
                                   uint8* yplane,
                                   uint8* uplane,
                                   uint8* vplane,
                                   int width,
                                   int height,
                                   int rgbstride,
                                   int ystride,
                                   int uvstride) {
  while (height >= 2) {
    ConvertRGB32ToYUVRow_SSE2(rgbframe,
                              rgbframe + rgbstride,
                              yplane,
                              yplane + ystride,
                              uplane,
                              vplane,
                              width);
    rgbframe += 2 * rgbstride;
    yplane += 2 * ystride;
    uplane += uvstride;
    vplane += uvstride;
    height -= 2;
  }

  if (!height)
    return;

  // Handle the last row.
  while (width >= 2) {
    ConvertRGBToYUV_V1H2(rgbframe, yplane, uplane, vplane);
    rgbframe += 8;
    yplane += 2;
    ++uplane;
    ++vplane;
    width -= 2;
  }

  if (width)
    ConvertRGBToYUV_V1H1(rgbframe, yplane, uplane, vplane);
}

void ConvertRGB32ToYUV_SSE2_Reference(const uint8* rgbframe,
                                      uint8* yplane,
                                      uint8* uplane,
                                      uint8* vplane,
                                      int width,
                                      int height,
                                      int rgbstride,
                                      int ystride,
                                      int uvstride) {
  while (height >= 2) {
    int i = 0;

    // Convert a 2x2 block.
    while (i + 2 <= width) {
      ConvertRGBToYUV_V2H2(rgbframe + i * 4,
                           rgbframe + rgbstride + i * 4,
                           yplane + i,
                           yplane + ystride + i,
                           uplane + i / 2,
                           vplane + i / 2);
      i += 2;
    }

    // Convert the last pixel of two rows.
    if (i < width) {
      ConvertRGBToYUV_V2H1(rgbframe + i * 4,
                           rgbframe + rgbstride + i * 4,
                           yplane + i,
                           yplane + ystride + i,
                           uplane + i / 2,
                           vplane + i / 2);
    }

    rgbframe += 2 * rgbstride;
    yplane += 2 * ystride;
    uplane += uvstride;
    vplane += uvstride;
    height -= 2;
  }

  if (!height)
    return;

  // Handle the last row.
  while (width >= 2) {
    ConvertRGBToYUV_V1H2(rgbframe, yplane, uplane, vplane);
    rgbframe += 8;
    yplane += 2;
    ++uplane;
    ++vplane;
    width -= 2;
  }

  // Handle the last pixel in the last row.
  if (width)
    ConvertRGBToYUV_V1H1(rgbframe, yplane, uplane, vplane);
}

}  // namespace media
/* [<][>][^][v][top][bottom][index][help] */
root/media/base/simd/convert_rgb_to_yuv_sse2.cc

DEFINITIONS
