/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-*/
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "ImageConversion.h"

#include "ImageContainer.h"
#include "YCbCrUtils.h"
#include "libyuv/convert.h"
#include "libyuv/convert_from_argb.h"
#include "libyuv/scale_argb.h"
#include "mozilla/PodOperations.h"
#include "mozilla/RefPtr.h"
#include "mozilla/dom/ImageBitmapBinding.h"
#include "mozilla/dom/ImageUtils.h"
#include "mozilla/gfx/Point.h"
#include "mozilla/gfx/Swizzle.h"
#include "nsThreadUtils.h"
#include "skia/include/core/SkBitmap.h"
#include "skia/include/core/SkColorSpace.h"
#include "skia/include/core/SkImage.h"
#include "skia/include/core/SkImageInfo.h"

using mozilla::ImageFormat;
using mozilla::dom::ImageBitmapFormat;
using mozilla::dom::ImageUtils;
using mozilla::gfx::DataSourceSurface;
using mozilla::gfx::IntSize;
using mozilla::gfx::SourceSurface;
using mozilla::gfx::SurfaceFormat;
using mozilla::layers::Image;
using mozilla::layers::PlanarYCbCrData;
using mozilla::layers::PlanarYCbCrImage;

static const PlanarYCbCrData* GetPlanarYCbCrData(Image* aImage) {
  switch (aImage->GetFormat()) {
    case ImageFormat::PLANAR_YCBCR:
      return aImage->AsPlanarYCbCrImage()->GetData();
    case ImageFormat::NV_IMAGE:
      return aImage->AsNVImage()->GetData();
    default:
      return nullptr;
  }
}

static nsresult MapRv(int aRv) {
  // Docs for libyuv::ConvertToI420 say:
  // Returns 0 for successful; -1 for invalid parameter. Non-zero for failure.
  switch (aRv) {
    case 0:
      return NS_OK;
    case -1:
      return NS_ERROR_INVALID_ARG;
    default:
      return NS_ERROR_FAILURE;
  }
}

namespace mozilla {

already_AddRefed<SourceSurface> GetSourceSurface(Image* aImage) {
  if (!aImage->AsGLImage() || NS_IsMainThread()) {
    return aImage->GetAsSourceSurface();
  }

  // GLImage::GetAsSourceSurface() only supports main thread
  RefPtr<SourceSurface> surf;
  NS_DispatchAndSpinEventLoopUntilComplete(
      "ImageToI420::GLImage::GetSourceSurface"_ns,
      mozilla::GetMainThreadSerialEventTarget(),
      NS_NewRunnableFunction(
          "ImageToI420::GLImage::GetSourceSurface",
          [&aImage, &surf]() { surf = aImage->GetAsSourceSurface(); }));

  return surf.forget();
}

nsresult ConvertToI420(Image* aImage, uint8_t* aDestY, int aDestStrideY,
                       uint8_t* aDestU, int aDestStrideU, uint8_t* aDestV,
                       int aDestStrideV, const IntSize& aDestSize) {
  if (!aImage->IsValid()) {
    return NS_ERROR_INVALID_ARG;
  }

  const IntSize imageSize = aImage->GetSize();
  auto srcPixelCount = CheckedInt<int32_t>(imageSize.width) * imageSize.height;
  auto dstPixelCount = CheckedInt<int32_t>(aDestSize.width) * aDestSize.height;
  if (!srcPixelCount.isValid() || !dstPixelCount.isValid()) {
    MOZ_ASSERT_UNREACHABLE("Bad input or output sizes");
    return NS_ERROR_INVALID_ARG;
  }

  // If we are downscaling, we prefer an early scale. If we are upscaling, we
  // prefer a late scale. This minimizes the number of pixel manipulations.
  // Depending on the input format, we may be forced to do a late scale after
  // conversion to I420, because we don't support scaling the input format.
  const bool needsScale = imageSize != aDestSize;
  bool earlyScale = srcPixelCount.value() > dstPixelCount.value();

  Maybe<DataSourceSurface::ScopedMap> surfaceMap;
  SurfaceFormat surfaceFormat = SurfaceFormat::UNKNOWN;

  const PlanarYCbCrData* data = GetPlanarYCbCrData(aImage);
  Maybe<dom::ImageBitmapFormat> format;
  if (data) {
    const ImageUtils imageUtils(aImage);
    format = imageUtils.GetFormat();
    if (format.isNothing()) {
      MOZ_ASSERT_UNREACHABLE("YUV format conversion not implemented");
      return NS_ERROR_NOT_IMPLEMENTED;
    }

    switch (format.value()) {
      case ImageBitmapFormat::YUV420P:
        // Since the input and output formats match, we can copy or scale
        // directly to the output buffer.
        if (needsScale) {
          return MapRv(libyuv::I420Scale(
              data->mYChannel, data->mYStride, data->mCbChannel,
              data->mCbCrStride, data->mCrChannel, data->mCbCrStride,
              imageSize.width, imageSize.height, aDestY, aDestStrideY, aDestU,
              aDestStrideU, aDestV, aDestStrideV, aDestSize.width,
              aDestSize.height, libyuv::FilterMode::kFilterBox));
        }
        return MapRv(libyuv::I420ToI420(
            data->mYChannel, data->mYStride, data->mCbChannel,
            data->mCbCrStride, data->mCrChannel, data->mCbCrStride, aDestY,
            aDestStrideY, aDestU, aDestStrideU, aDestV, aDestStrideV,
            aDestSize.width, aDestSize.height));
      case ImageBitmapFormat::YUV422P:
        if (!needsScale) {
          return MapRv(libyuv::I422ToI420(
              data->mYChannel, data->mYStride, data->mCbChannel,
              data->mCbCrStride, data->mCrChannel, data->mCbCrStride, aDestY,
              aDestStrideY, aDestU, aDestStrideU, aDestV, aDestStrideV,
              aDestSize.width, aDestSize.height));
        }
        break;
      case ImageBitmapFormat::YUV444P:
        if (!needsScale) {
          return MapRv(libyuv::I444ToI420(
              data->mYChannel, data->mYStride, data->mCbChannel,
              data->mCbCrStride, data->mCrChannel, data->mCbCrStride, aDestY,
              aDestStrideY, aDestU, aDestStrideU, aDestV, aDestStrideV,
              aDestSize.width, aDestSize.height));
        }
        break;
      case ImageBitmapFormat::YUV420SP_NV12:
        if (!needsScale) {
          return MapRv(libyuv::NV12ToI420(
              data->mYChannel, data->mYStride, data->mCbChannel,
              data->mCbCrStride, aDestY, aDestStrideY, aDestU, aDestStrideU,
              aDestV, aDestStrideV, aDestSize.width, aDestSize.height));
        }
        break;
      case ImageBitmapFormat::YUV420SP_NV21:
        if (!needsScale) {
          return MapRv(libyuv::NV21ToI420(
              data->mYChannel, data->mYStride, data->mCrChannel,
              data->mCbCrStride, aDestY, aDestStrideY, aDestU, aDestStrideU,
              aDestV, aDestStrideV, aDestSize.width, aDestSize.height));
        }
        earlyScale = false;
        break;
      default:
        MOZ_ASSERT_UNREACHABLE("YUV format conversion not implemented");
        return NS_ERROR_NOT_IMPLEMENTED;
    }
  } else {
    RefPtr<SourceSurface> surface = GetSourceSurface(aImage);
    if (!surface) {
      return NS_ERROR_FAILURE;
    }

    RefPtr<DataSourceSurface> dataSurface = surface->GetDataSurface();
    if (!dataSurface) {
      return NS_ERROR_FAILURE;
    }

    surfaceMap.emplace(dataSurface, DataSourceSurface::READ);
    if (!surfaceMap->IsMapped()) {
      return NS_ERROR_FAILURE;
    }

    surfaceFormat = dataSurface->GetFormat();
    switch (surfaceFormat) {
      case SurfaceFormat::B8G8R8A8:
      case SurfaceFormat::B8G8R8X8:
        if (!needsScale) {
          return MapRv(
              libyuv::ARGBToI420(static_cast<uint8_t*>(surfaceMap->GetData()),
                                 surfaceMap->GetStride(), aDestY, aDestStrideY,
                                 aDestU, aDestStrideU, aDestV, aDestStrideV,
                                 aDestSize.width, aDestSize.height));
        }
        break;
      case SurfaceFormat::R8G8B8A8:
      case SurfaceFormat::R8G8B8X8:
        if (!needsScale) {
          return MapRv(
              libyuv::ABGRToI420(static_cast<uint8_t*>(surfaceMap->GetData()),
                                 surfaceMap->GetStride(), aDestY, aDestStrideY,
                                 aDestU, aDestStrideU, aDestV, aDestStrideV,
                                 aDestSize.width, aDestSize.height));
        }
        break;
      case SurfaceFormat::R5G6B5_UINT16:
        if (!needsScale) {
          return MapRv(libyuv::RGB565ToI420(
              static_cast<uint8_t*>(surfaceMap->GetData()),
              surfaceMap->GetStride(), aDestY, aDestStrideY, aDestU,
              aDestStrideU, aDestV, aDestStrideV, aDestSize.width,
              aDestSize.height));
        }
        earlyScale = false;
        break;
      default:
        MOZ_ASSERT_UNREACHABLE("Surface format conversion not implemented");
        return NS_ERROR_NOT_IMPLEMENTED;
    }
  }

  MOZ_DIAGNOSTIC_ASSERT(needsScale);

  // We have to scale, and we are unable to scale directly, so we need a
  // temporary buffer to hold the scaled result in the input format, or the
  // unscaled result in the output format.
  IntSize tempBufSize;
  IntSize tempBufCbCrSize;
  if (earlyScale) {
    // Early scaling means we are scaling from the input buffer to a temporary
    // buffer of the same format.
    tempBufSize = aDestSize;
    if (data) {
      tempBufCbCrSize = gfx::ChromaSize(tempBufSize, data->mChromaSubsampling);
    }
  } else {
    // Late scaling means we are scaling from a temporary I420 buffer to the
    // destination I420 buffer.
    tempBufSize = imageSize;
    tempBufCbCrSize = gfx::ChromaSize(
        tempBufSize, gfx::ChromaSubsampling::HALF_WIDTH_AND_HEIGHT);
  }

  MOZ_ASSERT(!tempBufSize.IsEmpty());

  // Make sure we can allocate the temporary buffer.
  gfx::AlignedArray<uint8_t> tempBuf;
  uint8_t* tempBufY = nullptr;
  uint8_t* tempBufU = nullptr;
  uint8_t* tempBufV = nullptr;
  int32_t tempRgbStride = 0;
  if (!tempBufCbCrSize.IsEmpty()) {
    // Our temporary buffer is represented as a YUV format.
    auto tempBufYLen =
        CheckedInt<size_t>(tempBufSize.width) * tempBufSize.height;
    auto tempBufCbCrLen =
        CheckedInt<size_t>(tempBufCbCrSize.width) * tempBufCbCrSize.height;
    auto tempBufLen = tempBufYLen + 2 * tempBufCbCrLen;
    if (!tempBufLen.isValid()) {
      MOZ_ASSERT_UNREACHABLE("Bad buffer size!");
      return NS_ERROR_FAILURE;
    }

    tempBuf.Realloc(tempBufLen.value());
    if (!tempBuf) {
      return NS_ERROR_OUT_OF_MEMORY;
    }

    tempBufY = tempBuf;
    tempBufU = tempBufY + tempBufYLen.value();
    tempBufV = tempBufU + tempBufCbCrLen.value();
  } else {
    // The temporary buffer is represented as a RGBA/BGRA format.
    auto tempStride = CheckedInt<int32_t>(tempBufSize.width) * 4;
    auto tempBufLen = tempStride * tempBufSize.height;
    if (!tempStride.isValid() || !tempBufLen.isValid()) {
      MOZ_ASSERT_UNREACHABLE("Bad buffer size!");
      return NS_ERROR_FAILURE;
    }

    tempBuf.Realloc(tempBufLen.value());
    if (!tempBuf) {
      return NS_ERROR_OUT_OF_MEMORY;
    }

    tempRgbStride = tempStride.value();
  }

  nsresult rv;
  if (!earlyScale) {
    // First convert whatever the input format is to I420 into the temp buffer.
    if (data) {
      switch (format.value()) {
        case ImageBitmapFormat::YUV422P:
          rv = MapRv(libyuv::I422ToI420(
              data->mYChannel, data->mYStride, data->mCbChannel,
              data->mCbCrStride, data->mCrChannel, data->mCbCrStride, tempBufY,
              tempBufSize.width, tempBufU, tempBufCbCrSize.width, tempBufV,
              tempBufCbCrSize.width, tempBufSize.width, tempBufSize.height));
          break;
        case ImageBitmapFormat::YUV444P:
          rv = MapRv(libyuv::I444ToI420(
              data->mYChannel, data->mYStride, data->mCbChannel,
              data->mCbCrStride, data->mCrChannel, data->mCbCrStride, tempBufY,
              tempBufSize.width, tempBufU, tempBufCbCrSize.width, tempBufV,
              tempBufCbCrSize.width, tempBufSize.width, tempBufSize.height));
          break;
        case ImageBitmapFormat::YUV420SP_NV12:
          rv = MapRv(libyuv::NV12ToI420(
              data->mYChannel, data->mYStride, data->mCbChannel,
              data->mCbCrStride, tempBufY, tempBufSize.width, tempBufU,
              tempBufCbCrSize.width, tempBufV, tempBufCbCrSize.width,
              tempBufSize.width, tempBufSize.height));
          break;
        case ImageBitmapFormat::YUV420SP_NV21:
          rv = MapRv(libyuv::NV21ToI420(
              data->mYChannel, data->mYStride, data->mCrChannel,
              data->mCbCrStride, tempBufY, tempBufSize.width, tempBufU,
              tempBufCbCrSize.width, tempBufV, tempBufCbCrSize.width,
              tempBufSize.width, tempBufSize.height));
          break;
        default:
          MOZ_ASSERT_UNREACHABLE("YUV format conversion not implemented");
          return NS_ERROR_UNEXPECTED;
      }
    } else {
      switch (surfaceFormat) {
        case SurfaceFormat::B8G8R8A8:
        case SurfaceFormat::B8G8R8X8:
          rv = MapRv(libyuv::ARGBToI420(
              static_cast<uint8_t*>(surfaceMap->GetData()),
              surfaceMap->GetStride(), tempBufY, tempBufSize.width, tempBufU,
              tempBufCbCrSize.width, tempBufV, tempBufCbCrSize.width,
              tempBufSize.width, tempBufSize.height));
          break;
        case SurfaceFormat::R8G8B8A8:
        case SurfaceFormat::R8G8B8X8:
          rv = MapRv(libyuv::ABGRToI420(
              static_cast<uint8_t*>(surfaceMap->GetData()),
              surfaceMap->GetStride(), tempBufY, tempBufSize.width, tempBufU,
              tempBufCbCrSize.width, tempBufV, tempBufCbCrSize.width,
              tempBufSize.width, tempBufSize.height));
          break;
        case SurfaceFormat::R5G6B5_UINT16:
          rv = MapRv(libyuv::RGB565ToI420(
              static_cast<uint8_t*>(surfaceMap->GetData()),
              surfaceMap->GetStride(), tempBufY, tempBufSize.width, tempBufU,
              tempBufCbCrSize.width, tempBufV, tempBufCbCrSize.width,
              tempBufSize.width, tempBufSize.height));
          break;
        default:
          MOZ_ASSERT_UNREACHABLE("Surface format conversion not implemented");
          return NS_ERROR_NOT_IMPLEMENTED;
      }
    }

    if (NS_FAILED(rv)) {
      return rv;
    }

    // Now do the scale in I420 to the output buffer.
    return MapRv(libyuv::I420Scale(
        tempBufY, tempBufSize.width, tempBufU, tempBufCbCrSize.width, tempBufV,
        tempBufCbCrSize.width, tempBufSize.width, tempBufSize.height, aDestY,
        aDestStrideY, aDestU, aDestStrideU, aDestV, aDestStrideV,
        aDestSize.width, aDestSize.height, libyuv::FilterMode::kFilterBox));
  }

  if (data) {
    // First scale in the input format to the desired size into temp buffer, and
    // then convert that into the final I420 result.
    switch (format.value()) {
      case ImageBitmapFormat::YUV422P:
        rv = MapRv(libyuv::I422Scale(
            data->mYChannel, data->mYStride, data->mCbChannel,
            data->mCbCrStride, data->mCrChannel, data->mCbCrStride,
            imageSize.width, imageSize.height, tempBufY, tempBufSize.width,
            tempBufU, tempBufCbCrSize.width, tempBufV, tempBufCbCrSize.width,
            tempBufSize.width, tempBufSize.height,
            libyuv::FilterMode::kFilterBox));
        if (NS_FAILED(rv)) {
          return rv;
        }
        return MapRv(libyuv::I422ToI420(
            tempBufY, tempBufSize.width, tempBufU, tempBufCbCrSize.width,
            tempBufV, tempBufCbCrSize.width, aDestY, aDestStrideY, aDestU,
            aDestStrideU, aDestV, aDestStrideV, aDestSize.width,
            aDestSize.height));
      case ImageBitmapFormat::YUV444P:
        rv = MapRv(libyuv::I444Scale(
            data->mYChannel, data->mYStride, data->mCbChannel,
            data->mCbCrStride, data->mCrChannel, data->mCbCrStride,
            imageSize.width, imageSize.height, tempBufY, tempBufSize.width,
            tempBufU, tempBufCbCrSize.width, tempBufV, tempBufCbCrSize.width,
            tempBufSize.width, tempBufSize.height,
            libyuv::FilterMode::kFilterBox));
        if (NS_FAILED(rv)) {
          return rv;
        }
        return MapRv(libyuv::I444ToI420(
            tempBufY, tempBufSize.width, tempBufU, tempBufCbCrSize.width,
            tempBufV, tempBufCbCrSize.width, aDestY, aDestStrideY, aDestU,
            aDestStrideU, aDestV, aDestStrideV, aDestSize.width,
            aDestSize.height));
      case ImageBitmapFormat::YUV420SP_NV12:
        rv = MapRv(libyuv::NV12Scale(
            data->mYChannel, data->mYStride, data->mCbChannel,
            data->mCbCrStride, imageSize.width, imageSize.height, tempBufY,
            tempBufSize.width, tempBufU, tempBufCbCrSize.width,
            tempBufSize.width, tempBufSize.height,
            libyuv::FilterMode::kFilterBox));
        if (NS_FAILED(rv)) {
          return rv;
        }
        return MapRv(libyuv::NV12ToI420(
            tempBufY, tempBufSize.width, tempBufU, tempBufCbCrSize.width,
            aDestY, aDestStrideY, aDestU, aDestStrideU, aDestV, aDestStrideV,
            aDestSize.width, aDestSize.height));
      default:
        MOZ_ASSERT_UNREACHABLE("YUV format conversion not implemented");
        return NS_ERROR_NOT_IMPLEMENTED;
    }
  }

  MOZ_DIAGNOSTIC_ASSERT(surfaceFormat == SurfaceFormat::B8G8R8X8 ||
                        surfaceFormat == SurfaceFormat::B8G8R8A8 ||
                        surfaceFormat == SurfaceFormat::R8G8B8X8 ||
                        surfaceFormat == SurfaceFormat::R8G8B8A8);

  // We can use the same scaling method for either BGRA or RGBA since the
  // channel orders don't matter to the scaling algorithm.
  rv = MapRv(libyuv::ARGBScale(
      surfaceMap->GetData(), surfaceMap->GetStride(), imageSize.width,
      imageSize.height, tempBuf, tempRgbStride, tempBufSize.width,
      tempBufSize.height, libyuv::FilterMode::kFilterBox));
  if (NS_FAILED(rv)) {
    return rv;
  }

  // Now convert the scale result to I420.
  if (surfaceFormat == SurfaceFormat::B8G8R8A8 ||
      surfaceFormat == SurfaceFormat::B8G8R8X8) {
    return MapRv(libyuv::ARGBToI420(
        tempBuf, tempRgbStride, aDestY, aDestStrideY, aDestU, aDestStrideU,
        aDestV, aDestStrideV, aDestSize.width, aDestSize.height));
  }

  return MapRv(libyuv::ABGRToI420(tempBuf, tempRgbStride, aDestY, aDestStrideY,
                                  aDestU, aDestStrideU, aDestV, aDestStrideV,
                                  aDestSize.width, aDestSize.height));
}

static int32_t CeilingOfHalf(int32_t aValue) {
  MOZ_ASSERT(aValue >= 0);
  return aValue / 2 + (aValue % 2);
}

nsresult ConvertToNV12(layers::Image* aImage, uint8_t* aDestY, int aDestStrideY,
                       uint8_t* aDestUV, int aDestStrideUV,
                       gfx::IntSize aDestSize) {
  if (!aImage->IsValid()) {
    return NS_ERROR_INVALID_ARG;
  }

  if (const PlanarYCbCrData* data = GetPlanarYCbCrData(aImage)) {
    const ImageUtils imageUtils(aImage);
    Maybe<dom::ImageBitmapFormat> format = imageUtils.GetFormat();
    if (format.isNothing()) {
      MOZ_ASSERT_UNREACHABLE("YUV format conversion not implemented");
      return NS_ERROR_NOT_IMPLEMENTED;
    }

    if (format.value() != ImageBitmapFormat::YUV420P) {
      NS_WARNING("ConvertToNV12: Convert YUV data in I420 only");
      return NS_ERROR_NOT_IMPLEMENTED;
    }

    PlanarYCbCrData i420Source = *data;
    gfx::AlignedArray<uint8_t> scaledI420Buffer;

    if (aDestSize != aImage->GetSize()) {
      const int32_t halfWidth = CeilingOfHalf(aDestSize.width);
      const uint32_t halfHeight = CeilingOfHalf(aDestSize.height);

      CheckedInt<size_t> ySize(aDestSize.width);
      ySize *= aDestSize.height;

      CheckedInt<size_t> uSize(halfWidth);
      uSize *= halfHeight;

      CheckedInt<size_t> vSize(uSize);

      CheckedInt<size_t> i420Size = ySize + uSize + vSize;
      if (!i420Size.isValid()) {
        NS_WARNING("ConvertToNV12: Destination size is too large");
        return NS_ERROR_INVALID_ARG;
      }

      scaledI420Buffer.Realloc(i420Size.value());
      if (!scaledI420Buffer) {
        NS_WARNING(
            "ConvertToNV12: Failed to allocate buffer for rescaled I420 image");
        return NS_ERROR_OUT_OF_MEMORY;
      }

      // Y plane
      i420Source.mYChannel = scaledI420Buffer;
      i420Source.mYStride = aDestSize.width;
      i420Source.mYSkip = 0;

      // Cb plane (aka U)
      i420Source.mCbChannel = i420Source.mYChannel + ySize.value();
      i420Source.mCbSkip = 0;

      // Cr plane (aka V)
      i420Source.mCrChannel = i420Source.mCbChannel + uSize.value();
      i420Source.mCrSkip = 0;

      i420Source.mCbCrStride = halfWidth;
      i420Source.mChromaSubsampling =
          gfx::ChromaSubsampling::HALF_WIDTH_AND_HEIGHT;
      i420Source.mPictureRect = {0, 0, aDestSize.width, aDestSize.height};

      nsresult rv = MapRv(libyuv::I420Scale(
          data->mYChannel, data->mYStride, data->mCbChannel, data->mCbCrStride,
          data->mCrChannel, data->mCbCrStride, aImage->GetSize().width,
          aImage->GetSize().height, i420Source.mYChannel, i420Source.mYStride,
          i420Source.mCbChannel, i420Source.mCbCrStride, i420Source.mCrChannel,
          i420Source.mCbCrStride, i420Source.mPictureRect.width,
          i420Source.mPictureRect.height, libyuv::FilterMode::kFilterBox));
      if (NS_FAILED(rv)) {
        NS_WARNING("ConvertToNV12: I420Scale failed");
        return rv;
      }
    }

    return MapRv(libyuv::I420ToNV12(
        i420Source.mYChannel, i420Source.mYStride, i420Source.mCbChannel,
        i420Source.mCbCrStride, i420Source.mCrChannel, i420Source.mCbCrStride,
        aDestY, aDestStrideY, aDestUV, aDestStrideUV, aDestSize.width,
        aDestSize.height));
  }

  RefPtr<SourceSurface> surf = GetSourceSurface(aImage);
  if (!surf) {
    return NS_ERROR_FAILURE;
  }

  RefPtr<DataSourceSurface> data = surf->GetDataSurface();
  if (!data) {
    return NS_ERROR_FAILURE;
  }

  DataSourceSurface::ScopedMap map(data, DataSourceSurface::READ);
  if (!map.IsMapped()) {
    return NS_ERROR_FAILURE;
  }

  if (surf->GetFormat() != SurfaceFormat::B8G8R8A8 &&
      surf->GetFormat() != SurfaceFormat::B8G8R8X8) {
    NS_WARNING("ConvertToNV12: Convert SurfaceFormat in BGR* only");
    return NS_ERROR_NOT_IMPLEMENTED;
  }

  struct RgbSource {
    uint8_t* mBuffer;
    int32_t mStride;
  } rgbSource = {map.GetData(), map.GetStride()};

  gfx::AlignedArray<uint8_t> scaledRGB32Buffer;

  if (aDestSize != aImage->GetSize()) {
    CheckedInt<int> rgbaStride(aDestSize.width);
    rgbaStride *= 4;
    if (!rgbaStride.isValid()) {
      NS_WARNING("ConvertToNV12: Destination width is too large");
      return NS_ERROR_INVALID_ARG;
    }

    CheckedInt<size_t> rgbSize(rgbaStride.value());
    rgbSize *= aDestSize.height;
    if (!rgbSize.isValid()) {
      NS_WARNING("ConvertToNV12: Destination size is too large");
      return NS_ERROR_INVALID_ARG;
    }

    scaledRGB32Buffer.Realloc(rgbSize.value());
    if (!scaledRGB32Buffer) {
      NS_WARNING(
          "ConvertToNV12: Failed to allocate buffer for rescaled RGB32 image");
      return NS_ERROR_OUT_OF_MEMORY;
    }

    nsresult rv = MapRv(libyuv::ARGBScale(
        map.GetData(), map.GetStride(), aImage->GetSize().width,
        aImage->GetSize().height, scaledRGB32Buffer, rgbaStride.value(),
        aDestSize.width, aDestSize.height, libyuv::FilterMode::kFilterBox));
    if (NS_FAILED(rv)) {
      NS_WARNING("ConvertToNV12: ARGBScale failed");
      return rv;
    }

    rgbSource.mBuffer = scaledRGB32Buffer;
    rgbSource.mStride = rgbaStride.value();
  }

  return MapRv(libyuv::ARGBToNV12(rgbSource.mBuffer, rgbSource.mStride, aDestY,
                                  aDestStrideY, aDestUV, aDestStrideUV,
                                  aDestSize.width, aDestSize.height));
}

static bool IsRGBX(const SurfaceFormat& aFormat) {
  return aFormat == SurfaceFormat::B8G8R8A8 ||
         aFormat == SurfaceFormat::B8G8R8X8 ||
         aFormat == SurfaceFormat::R8G8B8A8 ||
         aFormat == SurfaceFormat::R8G8B8X8 ||
         aFormat == SurfaceFormat::X8R8G8B8 ||
         aFormat == SurfaceFormat::A8R8G8B8;
}

static bool HasAlpha(const SurfaceFormat& aFormat) {
  return aFormat == SurfaceFormat::B8G8R8A8 ||
         aFormat == SurfaceFormat::R8G8B8A8 ||
         aFormat == SurfaceFormat::A8R8G8B8;
}

static nsresult SwapRGBA(DataSourceSurface* aSurface,
                         const SurfaceFormat& aDestFormat) {
  if (!aSurface || !IsRGBX(aSurface->GetFormat()) || !IsRGBX(aDestFormat)) {
    return NS_ERROR_INVALID_ARG;
  }

  if (aSurface->GetFormat() == aDestFormat) {
    return NS_OK;
  }

  DataSourceSurface::ScopedMap map(aSurface, DataSourceSurface::READ_WRITE);
  if (!map.IsMapped()) {
    return NS_ERROR_FAILURE;
  }

  gfx::SwizzleData(map.GetData(), map.GetStride(), aSurface->GetFormat(),
                   map.GetData(), map.GetStride(), aDestFormat,
                   aSurface->GetSize());

  return NS_OK;
}

nsresult ConvertToRGBA(Image* aImage, const SurfaceFormat& aDestFormat,
                       uint8_t* aDestBuffer, int aDestStride) {
  if (!aImage || !aImage->IsValid() || aImage->GetSize().IsEmpty() ||
      !aDestBuffer || !IsRGBX(aDestFormat) || aDestStride <= 0) {
    return NS_ERROR_INVALID_ARG;
  }

  // Read YUV image to the given buffer in required RGBA format.
  if (const PlanarYCbCrData* data = GetPlanarYCbCrData(aImage)) {
    SurfaceFormat convertedFormat = aDestFormat;
    gfx::PremultFunc premultOp = nullptr;
    if (data->mAlpha && HasAlpha(aDestFormat)) {
      if (aDestFormat == SurfaceFormat::A8R8G8B8) {
        convertedFormat = SurfaceFormat::B8G8R8A8;
      }
      if (data->mAlpha->mPremultiplied) {
        premultOp = libyuv::ARGBUnattenuate;
      }
    } else {
      if (aDestFormat == SurfaceFormat::X8R8G8B8 ||
          aDestFormat == SurfaceFormat::A8R8G8B8) {
        convertedFormat = SurfaceFormat::B8G8R8X8;
      }
    }

    nsresult result =
        ConvertYCbCrToRGB32(*data, convertedFormat, aDestBuffer,
                            AssertedCast<int32_t>(aDestStride), premultOp);
    if (NS_FAILED(result)) {
      return result;
    }

    if (convertedFormat == aDestFormat) {
      return NS_OK;
    }

    // Since format of the converted data returned from ConvertYCbCrToRGB or
    // ConvertYCbCrAToARGB is BRG* or RBG*, we need swap the RGBA channels to
    // the required format if needed.

    RefPtr<DataSourceSurface> surf =
        gfx::Factory::CreateWrappingDataSourceSurface(
            aDestBuffer, aDestStride, aImage->GetSize(), convertedFormat);

    if (!surf) {
      return NS_ERROR_FAILURE;
    }

    return SwapRGBA(surf.get(), aDestFormat);
  }

  // Read RGBA image to the given buffer in required RGBA format.

  RefPtr<SourceSurface> surf = GetSourceSurface(aImage);
  if (!surf) {
    return NS_ERROR_FAILURE;
  }

  if (!IsRGBX(surf->GetFormat())) {
    return NS_ERROR_NOT_IMPLEMENTED;
  }

  RefPtr<DataSourceSurface> src = surf->GetDataSurface();
  if (!src) {
    return NS_ERROR_FAILURE;
  }

  DataSourceSurface::ScopedMap srcMap(src, DataSourceSurface::READ);
  if (!srcMap.IsMapped()) {
    return NS_ERROR_FAILURE;
  }

  RefPtr<DataSourceSurface> dest =
      gfx::Factory::CreateWrappingDataSourceSurface(
          aDestBuffer, aDestStride, aImage->GetSize(), aDestFormat);

  if (!dest) {
    return NS_ERROR_FAILURE;
  }

  DataSourceSurface::ScopedMap destMap(dest, gfx::DataSourceSurface::WRITE);
  if (!destMap.IsMapped()) {
    return NS_ERROR_FAILURE;
  }

  gfx::SwizzleData(srcMap.GetData(), srcMap.GetStride(), src->GetFormat(),
                   destMap.GetData(), destMap.GetStride(), dest->GetFormat(),
                   dest->GetSize());

  return NS_OK;
}

static SkColorType ToSkColorType(const SurfaceFormat& aFormat) {
  switch (aFormat) {
    case SurfaceFormat::B8G8R8A8:
    case SurfaceFormat::B8G8R8X8:
      return kBGRA_8888_SkColorType;
    case SurfaceFormat::R8G8B8A8:
    case SurfaceFormat::R8G8B8X8:
      return kRGBA_8888_SkColorType;
    default:
      break;
  }
  return kUnknown_SkColorType;
}

nsresult ConvertSRGBBufferToDisplayP3(uint8_t* aSrcBuffer,
                                      const SurfaceFormat& aSrcFormat,
                                      uint8_t* aDestBuffer, int aWidth,
                                      int aHeight) {
  if (!aSrcBuffer || !aDestBuffer || aWidth <= 0 || aHeight <= 0 ||
      !IsRGBX(aSrcFormat)) {
    return NS_ERROR_INVALID_ARG;
  }

  SkColorType srcColorType = ToSkColorType(aSrcFormat);
  if (srcColorType == kUnknown_SkColorType) {
    return NS_ERROR_NOT_IMPLEMENTED;
  }

  // TODO: Provide source's color space info to customize SkColorSpace.
  auto srcColorSpace = SkColorSpace::MakeSRGB();
  SkImageInfo srcInfo = SkImageInfo::Make(aWidth, aHeight, srcColorType,
                                          kUnpremul_SkAlphaType, srcColorSpace);

  constexpr size_t bytesPerPixel = 4;
  CheckedInt<size_t> rowBytes(bytesPerPixel);
  rowBytes *= aWidth;
  if (!rowBytes.isValid()) {
    return NS_ERROR_DOM_MEDIA_OVERFLOW_ERR;
  }

  SkBitmap srcBitmap;
  if (!srcBitmap.installPixels(srcInfo, aSrcBuffer, rowBytes.value())) {
    return NS_ERROR_FAILURE;
  }

  // TODO: Provide destination's color space info to customize SkColorSpace.
  auto destColorSpace =
      SkColorSpace::MakeRGB(SkNamedTransferFn::kSRGB, SkNamedGamut::kDisplayP3);

  SkBitmap destBitmap;
  if (!destBitmap.tryAllocPixels(srcInfo.makeColorSpace(destColorSpace))) {
    return NS_ERROR_FAILURE;
  }

  if (!srcBitmap.readPixels(destBitmap.pixmap())) {
    return NS_ERROR_FAILURE;
  }

  CheckedInt<size_t> size(rowBytes.value());
  size *= aHeight;
  if (!size.isValid()) {
    return NS_ERROR_DOM_MEDIA_OVERFLOW_ERR;
  }

  PodCopy(aDestBuffer, reinterpret_cast<uint8_t*>(destBitmap.getPixels()),
          size.value());
  return NS_OK;
}

}  // namespace mozilla