// 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.

// This webpage shows layout of YV12 and other YUV formats
// http://www.fourcc.org/yuv.php
// The actual conversion is best described here
// http://en.wikipedia.org/wiki/YUV
// An article on optimizing YUV conversion using tables instead of multiplies
// http://lestourtereaux.free.fr/papers/data/yuvrgb.pdf
//
// YV12 is a full plane of Y and a half height, half width chroma planes
// YV16 is a full plane of Y and a full height, half width chroma planes
//
// ARGB pixel format is output, which on little endian is stored as BGRA.
// The alpha is set to 255, allowing the application to use RGBA or RGB32.

#include "media/base/yuv_convert.h"

#include "base/cpu.h"
#include "base/logging.h"
#include "base/memory/scoped_ptr.h"
#include "build/build_config.h"
#include "media/base/simd/convert_rgb_to_yuv.h"
#include "media/base/simd/convert_yuv_to_rgb.h"
#include "media/base/simd/filter_yuv.h"

#if defined(ARCH_CPU_X86_FAMILY)
#if defined(COMPILER_MSVC)
#include <intrin.h>
#else
#include <mmintrin.h>
#endif
#endif

namespace media {

static FilterYUVRowsProc ChooseFilterYUVRowsProc() {
#if defined(ARCH_CPU_X86_FAMILY)
  base::CPU cpu;
  if (cpu.has_sse2())
    return &FilterYUVRows_SSE2;
  if (cpu.has_mmx())
    return &FilterYUVRows_MMX;
#endif
  return &FilterYUVRows_C;
}

static ConvertYUVToRGB32RowProc ChooseConvertYUVToRGB32RowProc() {
#if defined(ARCH_CPU_X86_FAMILY)
  base::CPU cpu;
  if (cpu.has_sse())
    return &ConvertYUVToRGB32Row_SSE;
  if (cpu.has_mmx())
    return &ConvertYUVToRGB32Row_MMX;
#endif
  return &ConvertYUVToRGB32Row_C;
}

static ScaleYUVToRGB32RowProc ChooseScaleYUVToRGB32RowProc() {
#if defined(ARCH_CPU_X86_64)
  // Use 64-bits version if possible.
  return &ScaleYUVToRGB32Row_SSE2_X64;
#elif defined(ARCH_CPU_X86_FAMILY)
  base::CPU cpu;
  // Choose the best one on 32-bits system.
  if (cpu.has_sse())
    return &ScaleYUVToRGB32Row_SSE;
  if (cpu.has_mmx())
    return &ScaleYUVToRGB32Row_MMX;
#endif  // defined(ARCH_CPU_X86_64)
  return &ScaleYUVToRGB32Row_C;
}

static ScaleYUVToRGB32RowProc ChooseLinearScaleYUVToRGB32RowProc() {
#if defined(ARCH_CPU_X86_64)
  // Use 64-bits version if possible.
  return &LinearScaleYUVToRGB32Row_MMX_X64;
#elif defined(ARCH_CPU_X86_FAMILY)
  base::CPU cpu;
  // 32-bits system.
  if (cpu.has_sse())
    return &LinearScaleYUVToRGB32Row_SSE;
  if (cpu.has_mmx())
    return &LinearScaleYUVToRGB32Row_MMX;
#endif  // defined(ARCH_CPU_X86_64)
  return &LinearScaleYUVToRGB32Row_C;
}

// Empty SIMD registers state after using them.
void EmptyRegisterState() {
#if defined(ARCH_CPU_X86_FAMILY)
  static bool checked = false;
  static bool has_mmx = false;
  if (!checked) {
    base::CPU cpu;
    has_mmx = cpu.has_mmx();
    checked = true;
  }
  if (has_mmx)
    _mm_empty();
#endif
}

// 16.16 fixed point arithmetic
const int kFractionBits = 16;
const int kFractionMax = 1 << kFractionBits;
const int kFractionMask = ((1 << kFractionBits) - 1);

// Scale a frame of YUV to 32 bit ARGB.
void ScaleYUVToRGB32(const uint8* y_buf,
                     const uint8* u_buf,
                     const uint8* v_buf,
                     uint8* rgb_buf,
                     int source_width,
                     int source_height,
                     int width,
                     int height,
                     int y_pitch,
                     int uv_pitch,
                     int rgb_pitch,
                     YUVType yuv_type,
                     Rotate view_rotate,
                     ScaleFilter filter) {
  static FilterYUVRowsProc filter_proc = NULL;
  static ConvertYUVToRGB32RowProc convert_proc = NULL;
  static ScaleYUVToRGB32RowProc scale_proc = NULL;
  static ScaleYUVToRGB32RowProc linear_scale_proc = NULL;

  if (!filter_proc)
    filter_proc = ChooseFilterYUVRowsProc();
  if (!convert_proc)
    convert_proc = ChooseConvertYUVToRGB32RowProc();
  if (!scale_proc)
    scale_proc = ChooseScaleYUVToRGB32RowProc();
  if (!linear_scale_proc)
    linear_scale_proc = ChooseLinearScaleYUVToRGB32RowProc();

  // Handle zero sized sources and destinations.
  if ((yuv_type == YV12 && (source_width < 2 || source_height < 2)) ||
      (yuv_type == YV16 && (source_width < 2 || source_height < 1)) ||
      width == 0 || height == 0)
    return;

  // 4096 allows 3 buffers to fit in 12k.
  // Helps performance on CPU with 16K L1 cache.
  // Large enough for 3830x2160 and 30" displays which are 2560x1600.
  const int kFilterBufferSize = 4096;
  // Disable filtering if the screen is too big (to avoid buffer overflows).
  // This should never happen to regular users: they don't have monitors
  // wider than 4096 pixels.
  // TODO(fbarchard): Allow rotated videos to filter.
  if (source_width > kFilterBufferSize || view_rotate)
    filter = FILTER_NONE;

  unsigned int y_shift = yuv_type;
  // Diagram showing origin and direction of source sampling.
  // ->0   4<-
  // 7       3
  //
  // 6       5
  // ->1   2<-
  // Rotations that start at right side of image.
  if ((view_rotate == ROTATE_180) ||
      (view_rotate == ROTATE_270) ||
      (view_rotate == MIRROR_ROTATE_0) ||
      (view_rotate == MIRROR_ROTATE_90)) {
    y_buf += source_width - 1;
    u_buf += source_width / 2 - 1;
    v_buf += source_width / 2 - 1;
    source_width = -source_width;
  }
  // Rotations that start at bottom of image.
  if ((view_rotate == ROTATE_90) ||
      (view_rotate == ROTATE_180) ||
      (view_rotate == MIRROR_ROTATE_90) ||
      (view_rotate == MIRROR_ROTATE_180)) {
    y_buf += (source_height - 1) * y_pitch;
    u_buf += ((source_height >> y_shift) - 1) * uv_pitch;
    v_buf += ((source_height >> y_shift) - 1) * uv_pitch;
    source_height = -source_height;
  }

  int source_dx = source_width * kFractionMax / width;

  if ((view_rotate == ROTATE_90) ||
      (view_rotate == ROTATE_270)) {
    int tmp = height;
    height = width;
    width = tmp;
    tmp = source_height;
    source_height = source_width;
    source_width = tmp;
    int source_dy = source_height * kFractionMax / height;
    source_dx = ((source_dy >> kFractionBits) * y_pitch) << kFractionBits;
    if (view_rotate == ROTATE_90) {
      y_pitch = -1;
      uv_pitch = -1;
      source_height = -source_height;
    } else {
      y_pitch = 1;
      uv_pitch = 1;
    }
  }

  // Need padding because FilterRows() will write 1 to 16 extra pixels
  // after the end for SSE2 version.
  uint8 yuvbuf[16 + kFilterBufferSize * 3 + 16];
  uint8* ybuf =
      reinterpret_cast<uint8*>(reinterpret_cast<uintptr_t>(yuvbuf + 15) & ~15);
  uint8* ubuf = ybuf + kFilterBufferSize;
  uint8* vbuf = ubuf + kFilterBufferSize;

  // TODO(fbarchard): Fixed point math is off by 1 on negatives.

  // We take a y-coordinate in [0,1] space in the source image space, and
  // transform to a y-coordinate in [0,1] space in the destination image space.
  // Note that the coordinate endpoints lie on pixel boundaries, not on pixel
  // centers: e.g. a two-pixel-high image will have pixel centers at 0.25 and
  // 0.75.  The formula is as follows (in fixed-point arithmetic):
  //   y_dst = dst_height * ((y_src + 0.5) / src_height)
  //   dst_pixel = clamp([0, dst_height - 1], floor(y_dst - 0.5))
  // Implement this here as an accumulator + delta, to avoid expensive math
  // in the loop.
  int source_y_subpixel_accum =
    ((kFractionMax / 2) * source_height) / height - (kFractionMax / 2);
  int source_y_subpixel_delta = ((1 << kFractionBits) * source_height) / height;

  // TODO(fbarchard): Split this into separate function for better efficiency.
  for (int y = 0; y < height; ++y) {
    uint8* dest_pixel = rgb_buf + y * rgb_pitch;
    int source_y_subpixel = source_y_subpixel_accum;
    source_y_subpixel_accum += source_y_subpixel_delta;
    if (source_y_subpixel < 0)
      source_y_subpixel = 0;
    else if (source_y_subpixel > ((source_height - 1) << kFractionBits))
      source_y_subpixel = (source_height - 1) << kFractionBits;

    const uint8* y_ptr = NULL;
    const uint8* u_ptr = NULL;
    const uint8* v_ptr = NULL;
    // Apply vertical filtering if necessary.
    // TODO(fbarchard): Remove memcpy when not necessary.
    if (filter & media::FILTER_BILINEAR_V) {
      int source_y = source_y_subpixel >> kFractionBits;
      y_ptr = y_buf + source_y * y_pitch;
      u_ptr = u_buf + (source_y >> y_shift) * uv_pitch;
      v_ptr = v_buf + (source_y >> y_shift) * uv_pitch;

      // Vertical scaler uses 16.8 fixed point.
      int source_y_fraction =
          (source_y_subpixel & kFractionMask) >> 8;
      if (source_y_fraction != 0) {
        filter_proc(ybuf, y_ptr, y_ptr + y_pitch, source_width,
                    source_y_fraction);
      } else {
        memcpy(ybuf, y_ptr, source_width);
      }
      y_ptr = ybuf;
      ybuf[source_width] = ybuf[source_width-1];

      int uv_source_width = (source_width + 1) / 2;
      int source_uv_fraction;

      // For formats with half-height UV planes, each even-numbered pixel row
      // should not interpolate, since the next row to interpolate from should
      // be a duplicate of the current row.
      if (y_shift && (source_y & 0x1) == 0)
        source_uv_fraction = 0;
      else
        source_uv_fraction = source_y_fraction;

      if (source_uv_fraction != 0) {
        filter_proc(ubuf, u_ptr, u_ptr + uv_pitch, uv_source_width,
            source_uv_fraction);
        filter_proc(vbuf, v_ptr, v_ptr + uv_pitch, uv_source_width,
            source_uv_fraction);
      } else {
        memcpy(ubuf, u_ptr, uv_source_width);
        memcpy(vbuf, v_ptr, uv_source_width);
      }
      u_ptr = ubuf;
      v_ptr = vbuf;
      ubuf[uv_source_width] = ubuf[uv_source_width - 1];
      vbuf[uv_source_width] = vbuf[uv_source_width - 1];
    } else {
      // Offset by 1/2 pixel for center sampling.
      int source_y = (source_y_subpixel + (kFractionMax / 2)) >> kFractionBits;
      y_ptr = y_buf + source_y * y_pitch;
      u_ptr = u_buf + (source_y >> y_shift) * uv_pitch;
      v_ptr = v_buf + (source_y >> y_shift) * uv_pitch;
    }
    if (source_dx == kFractionMax) {  // Not scaled
      convert_proc(y_ptr, u_ptr, v_ptr, dest_pixel, width);
    } else {
      if (filter & FILTER_BILINEAR_H) {
        linear_scale_proc(y_ptr, u_ptr, v_ptr, dest_pixel, width, source_dx);
      } else {
        scale_proc(y_ptr, u_ptr, v_ptr, dest_pixel, width, source_dx);
      }
    }
  }

  EmptyRegisterState();
}

// Scale a frame of YV12 to 32 bit ARGB for a specific rectangle.
void ScaleYUVToRGB32WithRect(const uint8* y_buf,
                             const uint8* u_buf,
                             const uint8* v_buf,
                             uint8* rgb_buf,
                             int source_width,
                             int source_height,
                             int dest_width,
                             int dest_height,
                             int dest_rect_left,
                             int dest_rect_top,
                             int dest_rect_right,
                             int dest_rect_bottom,
                             int y_pitch,
                             int uv_pitch,
                             int rgb_pitch) {
  static FilterYUVRowsProc filter_proc = NULL;
  if (!filter_proc)
    filter_proc = ChooseFilterYUVRowsProc();

  // This routine doesn't currently support up-scaling.
  CHECK_LE(dest_width, source_width);
  CHECK_LE(dest_height, source_height);

  // Sanity-check the destination rectangle.
  DCHECK(dest_rect_left >= 0 && dest_rect_right <= dest_width);
  DCHECK(dest_rect_top >= 0 && dest_rect_bottom <= dest_height);
  DCHECK(dest_rect_right > dest_rect_left);
  DCHECK(dest_rect_bottom > dest_rect_top);

  // Fixed-point value of vertical and horizontal scale down factor.
  // Values are in the format 16.16.
  int y_step = kFractionMax * source_height / dest_height;
  int x_step = kFractionMax * source_width / dest_width;

  // Determine the coordinates of the rectangle in 16.16 coords.
  // NB: Our origin is the *center* of the top/left pixel, NOT its top/left.
  // If we're down-scaling by more than a factor of two, we start with a 50%
  // fraction to avoid degenerating to point-sampling - we should really just
  // fix the fraction at 50% for all pixels in that case.
  int source_left = dest_rect_left * x_step;
  int source_right = (dest_rect_right - 1) * x_step;
  if (x_step < kFractionMax * 2) {
    source_left += ((x_step - kFractionMax) / 2);
    source_right += ((x_step - kFractionMax) / 2);
  } else {
    source_left += kFractionMax / 2;
    source_right += kFractionMax / 2;
  }
  int source_top = dest_rect_top * y_step;
  if (y_step < kFractionMax * 2) {
    source_top += ((y_step - kFractionMax) / 2);
  } else {
    source_top += kFractionMax / 2;
  }

  // Determine the parts of the Y, U and V buffers to interpolate.
  int source_y_left = source_left >> kFractionBits;
  int source_y_right = std::min(
      (source_right >> kFractionBits) + 2,
      source_width + 1);

  int source_uv_left = source_y_left / 2;
  int source_uv_right = std::min(
      (source_right >> (kFractionBits + 1)) + 2,
      (source_width + 1) / 2);

  int source_y_width = source_y_right - source_y_left;
  int source_uv_width = source_uv_right - source_uv_left;

  // Determine number of pixels in each output row.
  int dest_rect_width = dest_rect_right - dest_rect_left;

  // Intermediate buffer for vertical interpolation.
  // 4096 bytes allows 3 buffers to fit in 12k, which fits in a 16K L1 cache,
  // and is bigger than most users will generally need.
  // The buffer is 16-byte aligned and padded with 16 extra bytes; some of the
  // FilterYUVRowProcs have alignment requirements, and the SSE version can
  // write up to 16 bytes past the end of the buffer.
  const int kFilterBufferSize = 4096;
  if (source_width > kFilterBufferSize)
    filter_proc = NULL;
  uint8 yuv_temp[16 + kFilterBufferSize * 3 + 16];
  uint8* y_temp =
      reinterpret_cast<uint8*>(
          reinterpret_cast<uintptr_t>(yuv_temp + 15) & ~15);
  uint8* u_temp = y_temp + kFilterBufferSize;
  uint8* v_temp = u_temp + kFilterBufferSize;

  // Move to the top-left pixel of output.
  rgb_buf += dest_rect_top * rgb_pitch;
  rgb_buf += dest_rect_left * 4;

  // For each destination row perform interpolation and color space
  // conversion to produce the output.
  for (int row = dest_rect_top; row < dest_rect_bottom; ++row) {
    // Round the fixed-point y position to get the current row.
    int source_row = source_top >> kFractionBits;
    int source_uv_row = source_row / 2;
    DCHECK(source_row < source_height);

    // Locate the first row for each plane for interpolation.
    const uint8* y0_ptr = y_buf + y_pitch * source_row + source_y_left;
    const uint8* u0_ptr = u_buf + uv_pitch * source_uv_row + source_uv_left;
    const uint8* v0_ptr = v_buf + uv_pitch * source_uv_row + source_uv_left;
    const uint8* y1_ptr = NULL;
    const uint8* u1_ptr = NULL;
    const uint8* v1_ptr = NULL;

    // Locate the second row for interpolation, being careful not to overrun.
    if (source_row + 1 >= source_height) {
      y1_ptr = y0_ptr;
    } else {
      y1_ptr = y0_ptr + y_pitch;
    }
    if (source_uv_row + 1 >= (source_height + 1) / 2) {
      u1_ptr = u0_ptr;
      v1_ptr = v0_ptr;
    } else {
      u1_ptr = u0_ptr + uv_pitch;
      v1_ptr = v0_ptr + uv_pitch;
    }

    if (filter_proc) {
      // Vertical scaler uses 16.8 fixed point.
      int fraction = (source_top & kFractionMask) >> 8;
      filter_proc(y_temp + source_y_left, y0_ptr, y1_ptr,
                  source_y_width, fraction);
      filter_proc(u_temp + source_uv_left, u0_ptr, u1_ptr,
                  source_uv_width, fraction);
      filter_proc(v_temp + source_uv_left, v0_ptr, v1_ptr,
                  source_uv_width, fraction);

      // Perform horizontal interpolation and color space conversion.
      // TODO(hclam): Use the MMX version after more testing.
      LinearScaleYUVToRGB32RowWithRange_C(
          y_temp, u_temp, v_temp, rgb_buf,
          dest_rect_width, source_left, x_step);
    } else {
      // If the frame is too large then we linear scale a single row.
      LinearScaleYUVToRGB32RowWithRange_C(
          y0_ptr, u0_ptr, v0_ptr, rgb_buf,
          dest_rect_width, source_left, x_step);
    }

    // Advance vertically in the source and destination image.
    source_top += y_step;
    rgb_buf += rgb_pitch;
  }

  EmptyRegisterState();
}

void ConvertRGB32ToYUV(const uint8* rgbframe,
                       uint8* yplane,
                       uint8* uplane,
                       uint8* vplane,
                       int width,
                       int height,
                       int rgbstride,
                       int ystride,
                       int uvstride) {
  static void (*convert_proc)(const uint8*, uint8*, uint8*, uint8*,
                              int, int, int, int, int) = NULL;
  if (!convert_proc) {
#if defined(ARCH_CPU_ARM_FAMILY) || defined(ARCH_CPU_MIPS_FAMILY)
    // For ARM and MIPS processors, always use C version.
    // TODO(hclam): Implement a NEON version.
    convert_proc = &ConvertRGB32ToYUV_C;
#elif defined(__LB_PS3__)
    // For these, always use C version.
    convert_proc = &ConvertRGB32ToYUV_C;
#else
    // TODO(hclam): Switch to SSSE3 version when the cyan problem is solved.
    // See: crbug.com/100462
    base::CPU cpu;
    if (cpu.has_sse2())
      convert_proc = &ConvertRGB32ToYUV_SSE2;
    else
      convert_proc = &ConvertRGB32ToYUV_C;
#endif
  }

  convert_proc(rgbframe, yplane, uplane, vplane, width, height,
               rgbstride, ystride, uvstride);
}

void ConvertRGB24ToYUV(const uint8* rgbframe,
                       uint8* yplane,
                       uint8* uplane,
                       uint8* vplane,
                       int width,
                       int height,
                       int rgbstride,
                       int ystride,
                       int uvstride) {
#if defined(ARCH_CPU_ARM_FAMILY) || defined(ARCH_CPU_MIPS_FAMILY)
  ConvertRGB24ToYUV_C(rgbframe, yplane, uplane, vplane, width, height,
                      rgbstride, ystride, uvstride);
#else
  static void (*convert_proc)(const uint8*, uint8*, uint8*, uint8*,
                              int, int, int, int, int) = NULL;
  if (!convert_proc) {
    base::CPU cpu;
    if (cpu.has_ssse3())
      convert_proc = &ConvertRGB24ToYUV_SSSE3;
    else
      convert_proc = &ConvertRGB24ToYUV_C;
  }
  convert_proc(rgbframe, yplane, uplane, vplane, width, height,
               rgbstride, ystride, uvstride);
#endif
}

void ConvertYUY2ToYUV(const uint8* src,
                      uint8* yplane,
                      uint8* uplane,
                      uint8* vplane,
                      int width,
                      int height) {
  for (int i = 0; i < height / 2; ++i) {
    for (int j = 0; j < (width / 2); ++j) {
      yplane[0] = src[0];
      *uplane = src[1];
      yplane[1] = src[2];
      *vplane = src[3];
      src += 4;
      yplane += 2;
      uplane++;
      vplane++;
    }
    for (int j = 0; j < (width / 2); ++j) {
      yplane[0] = src[0];
      yplane[1] = src[2];
      src += 4;
      yplane += 2;
    }
  }
}

void ConvertNV21ToYUV(const uint8* src,
                      uint8* yplane,
                      uint8* uplane,
                      uint8* vplane,
                      int width,
                      int height) {
  int y_plane_size = width * height;
  memcpy(yplane, src, y_plane_size);

  src += y_plane_size;
  int u_plane_size = y_plane_size >> 2;
  for (int i = 0; i < u_plane_size; ++i) {
    *vplane++ = *src++;
    *uplane++ = *src++;
  }
}

void ConvertYUVToRGB32(const uint8* yplane,
                       const uint8* uplane,
                       const uint8* vplane,
                       uint8* rgbframe,
                       int width,
                       int height,
                       int ystride,
                       int uvstride,
                       int rgbstride,
                       YUVType yuv_type) {
#if defined(ARCH_CPU_ARM_FAMILY) || defined(ARCH_CPU_MIPS_FAMILY)
  ConvertYUVToRGB32_C(yplane, uplane, vplane, rgbframe,
                      width, height, ystride, uvstride, rgbstride, yuv_type);
#else
  static ConvertYUVToRGB32Proc convert_proc = NULL;
  if (!convert_proc) {
    base::CPU cpu;
    if (cpu.has_sse())
      convert_proc = &ConvertYUVToRGB32_SSE;
    else if (cpu.has_mmx())
      convert_proc = &ConvertYUVToRGB32_MMX;
    else
      convert_proc = &ConvertYUVToRGB32_C;
  }

  convert_proc(yplane, uplane, vplane, rgbframe,
               width, height, ystride, uvstride, rgbstride, yuv_type);
#endif
}

}  // namespace media