// Copyright (c) 2009 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 "media/base/yuv_row.h"

// Enable bilinear filtering by turning on the following macro.
//  #define MEDIA_BILINEAR_FILTER 1

#ifdef _DEBUG
#include "base/logging.h"
#else
#define DCHECK(a)
#endif

namespace media {

// Reference version of YUV converter.
static const int kClipTableSize = 256;
static const int kClipOverflow = 256;

static uint8 g_rgb_clip_table[kClipOverflow +
                              kClipTableSize +
                              kClipOverflow] = {
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  // 256 underflow values
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  // clipped to 0.
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,  // Unclipped values.
  0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
  0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
  0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F,
  0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
  0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F,
  0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
  0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0x3F,
  0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
  0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F,
  0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57,
  0x58, 0x59, 0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F,
  0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
  0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F,
  0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
  0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F,
  0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
  0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E, 0x8F,
  0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97,
  0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D, 0x9E, 0x9F,
  0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7,
  0xA8, 0xA9, 0xAA, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF,
  0xB0, 0xB1, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, 0xB7,
  0xB8, 0xB9, 0xBA, 0xBB, 0xBC, 0xBD, 0xBE, 0xBF,
  0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7,
  0xC8, 0xC9, 0xCA, 0xCB, 0xCC, 0xCD, 0xCE, 0xCF,
  0xD0, 0xD1, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6, 0xD7,
  0xD8, 0xD9, 0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF,
  0xE0, 0xE1, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7,
  0xE8, 0xE9, 0xEA, 0xEB, 0xEC, 0xED, 0xEE, 0xEF,
  0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7,
  0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,  // 256 overflow values
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,  // clipped to 255.
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
};

// Clip an rgb channel value to 0..255 range.
// Source is signed fixed point 8.8.
// Table allows for values to underflow or overflow by 128.
// Therefore source range is -128 to 384.
// Output clips to unsigned 0 to 255.
static inline uint32 clip(int32 value) {
  DCHECK(((value >> 8) + kClipOverflow) >= 0);
  DCHECK(((value >> 8) + kClipOverflow) <
         (kClipOverflow + kClipTableSize + kClipOverflow));
  return static_cast<uint32>(g_rgb_clip_table[((value) >> 8) + kClipOverflow]);
}

static inline void YuvPixel(uint8 y,
                            uint8 u,
                            uint8 v,
                            uint8* rgb_buf) {
  int32 d = static_cast<int32>(u) - 128;
  int32 e = static_cast<int32>(v) - 128;

  int32 cb =   (516 * d + 128);
  int32 cg = (- 100 * d - 208 * e + 128);
  int32 cr =             (409 * e + 128);

  int32 C298a = ((static_cast<int32>(y) - 16) * 298 + 128);
  *reinterpret_cast<uint32*>(rgb_buf) = (clip(C298a + cb)) |
                                        (clip(C298a + cg) << 8) |
                                        (clip(C298a + cr) << 16) |
                                        (0xff000000);
}

void FastConvertYUVToRGB32Row(const uint8* y_buf,
                              const uint8* u_buf,
                              const uint8* v_buf,
                              uint8* rgb_buf,
                              int width) {
  for (int32 x = 0; x < static_cast<int32>(width); x += 2) {
    uint8 u = u_buf[x >> 1];
    uint8 v = v_buf[x >> 1];
    uint8 y0 = y_buf[x];
    uint8 y1 = y_buf[x + 1];
    YuvPixel(y0, u, v, rgb_buf);
    YuvPixel(y1, u, v, rgb_buf + 4);

    rgb_buf += 8;  // Advance 2 pixels.
  }
}

// 28.4 fixed point is used.  A shift by 4 isolates the integer.
// A shift by 5 is used to further subsample the chrominence channels.
// & 15 isolates the fixed point fraction.  >> 2 to get the upper 2 bits,
// for 1/4 pixel accurate interpolation.
void ScaleYUVToRGB32Row(const uint8* y_buf,
                        const uint8* u_buf,
                        const uint8* v_buf,
                        uint8* rgb_buf,
                        int width,
                        int scaled_dx) {
  int scaled_x = 0;
  for (int32 x = 0; x < width; ++x) {
    uint8 u = u_buf[scaled_x >> 5];
    uint8 v = v_buf[scaled_x >> 5];
    uint8 y0 = y_buf[scaled_x >> 4];
    YuvPixel(y0, u, v, rgb_buf);
    rgb_buf += 4;
    scaled_x += scaled_dx;
  }
}

}  // namespace media