Kill render_int.hchromium/2973chromium/2972

CPDF_DIBSource was already in its own file, but files needed renaming.

Change-Id: Ib3ac787a0bb33d3f78ecdcdfcdbc938867857a14
Reviewed-on: https://pdfium-review.googlesource.com/2152
Commit-Queue: Nicolás Peña <npm@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>

1 files changed, 1480 insertions, 0 deletions

diff --git a/core/fpdfapi/render/cpdf_dibsource.cpp b/core/fpdfapi/render/cpdf_dibsource.cpp
new file mode 100644
index 0000000000..c84adfe1ec
--- /dev/null
+++ b/core/fpdfapi/render/cpdf_dibsource.cpp
@@ -0,0 +1,1480 @@
+// Copyright 2017 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#include "core/fpdfapi/render/cpdf_dibsource.h"
+
+#include <algorithm>
+#include <memory>
+#include <vector>
+
+#include "core/fpdfapi/cpdf_modulemgr.h"
+#include "core/fpdfapi/page/cpdf_docpagedata.h"
+#include "core/fpdfapi/page/cpdf_image.h"
+#include "core/fpdfapi/page/cpdf_imageobject.h"
+#include "core/fpdfapi/parser/cpdf_array.h"
+#include "core/fpdfapi/parser/cpdf_dictionary.h"
+#include "core/fpdfapi/parser/cpdf_document.h"
+#include "core/fpdfapi/parser/fpdf_parser_decode.h"
+#include "core/fpdfapi/render/cpdf_pagerendercache.h"
+#include "core/fpdfapi/render/cpdf_renderstatus.h"
+#include "core/fxcodec/fx_codec.h"
+#include "core/fxcrt/fx_safe_types.h"
+#include "third_party/base/ptr_util.h"
+
+namespace {
+
+unsigned int GetBits8(const uint8_t* pData, uint64_t bitpos, size_t nbits) {
+  ASSERT(nbits == 1 || nbits == 2 || nbits == 4 || nbits == 8 || nbits == 16);
+  ASSERT((bitpos & (nbits - 1)) == 0);
+  unsigned int byte = pData[bitpos / 8];
+  if (nbits == 8)
+    return byte;
+
+  if (nbits == 16)
+    return byte * 256 + pData[bitpos / 8 + 1];
+
+  return (byte >> (8 - nbits - (bitpos % 8))) & ((1 << nbits) - 1);
+}
+
+FX_SAFE_UINT32 CalculatePitch8(uint32_t bpc, uint32_t components, int width) {
+  FX_SAFE_UINT32 pitch = bpc;
+  pitch *= components;
+  pitch *= width;
+  pitch += 7;
+  pitch /= 8;
+  return pitch;
+}
+
+FX_SAFE_UINT32 CalculatePitch32(int bpp, int width) {
+  FX_SAFE_UINT32 pitch = bpp;
+  pitch *= width;
+  pitch += 31;
+  pitch /= 32;  // quantized to number of 32-bit words.
+  pitch *= 4;   // and then back to bytes, (not just /8 in one step).
+  return pitch;
+}
+
+bool IsAllowedBPCValue(int bpc) {
+  return bpc == 1 || bpc == 2 || bpc == 4 || bpc == 8 || bpc == 16;
+}
+
+bool IsAllowedICCComponents(int nComp) {
+  return nComp == 1 || nComp == 3 || nComp == 4;
+}
+
+template <typename T>
+T ClampValue(T value, T max_value) {
+  value = std::min(value, max_value);
+  value = std::max<T>(0, value);
+  return value;
+}
+
+// Wrapper class to use with std::unique_ptr for CJPX_Decoder.
+class JpxBitMapContext {
+ public:
+  explicit JpxBitMapContext(CCodec_JpxModule* jpx_module)
+      : jpx_module_(jpx_module), decoder_(nullptr) {}
+
+  ~JpxBitMapContext() { jpx_module_->DestroyDecoder(decoder_); }
+
+  // Takes ownership of |decoder|.
+  void set_decoder(CJPX_Decoder* decoder) { decoder_ = decoder; }
+
+  CJPX_Decoder* decoder() { return decoder_; }
+
+ private:
+  CCodec_JpxModule* const jpx_module_;  // Weak pointer.
+  CJPX_Decoder* decoder_;               // Decoder, owned.
+
+  // Disallow evil constructors
+  JpxBitMapContext(const JpxBitMapContext&);
+  void operator=(const JpxBitMapContext&);
+};
+
+const int kMaxImageDimension = 0x01FFFF;
+
+}  // namespace
+
+CPDF_DIBSource::CPDF_DIBSource()
+    : m_pDocument(nullptr),
+      m_pStream(nullptr),
+      m_pDict(nullptr),
+      m_pColorSpace(nullptr),
+      m_Family(0),
+      m_bpc(0),
+      m_bpc_orig(0),
+      m_nComponents(0),
+      m_GroupFamily(0),
+      m_MatteColor(0),
+      m_bLoadMask(false),
+      m_bDefaultDecode(true),
+      m_bImageMask(false),
+      m_bDoBpcCheck(true),
+      m_bColorKey(false),
+      m_bHasMask(false),
+      m_bStdCS(false),
+      m_pCompData(nullptr),
+      m_pLineBuf(nullptr),
+      m_pMaskedLine(nullptr),
+      m_pMask(nullptr),
+      m_pMaskStream(nullptr),
+      m_Status(0) {}
+
+CPDF_DIBSource::~CPDF_DIBSource() {
+  FX_Free(m_pMaskedLine);
+  FX_Free(m_pLineBuf);
+  m_pCachedBitmap.reset();
+  FX_Free(m_pCompData);
+  CPDF_ColorSpace* pCS = m_pColorSpace;
+  if (pCS && m_pDocument) {
+    m_pDocument->GetPageData()->ReleaseColorSpace(pCS->GetArray());
+  }
+}
+
+bool CPDF_DIBSource::Load(CPDF_Document* pDoc,
+                          const CPDF_Stream* pStream,
+                          CPDF_DIBSource** ppMask,
+                          uint32_t* pMatteColor,
+                          CPDF_Dictionary* pFormResources,
+                          CPDF_Dictionary* pPageResources,
+                          bool bStdCS,
+                          uint32_t GroupFamily,
+                          bool bLoadMask) {
+  if (!pStream) {
+    return false;
+  }
+  m_pDocument = pDoc;
+  m_pDict = pStream->GetDict();
+  if (!m_pDict) {
+    return false;
+  }
+  m_pStream = pStream;
+  m_Width = m_pDict->GetIntegerFor("Width");
+  m_Height = m_pDict->GetIntegerFor("Height");
+  if (m_Width <= 0 || m_Height <= 0 || m_Width > kMaxImageDimension ||
+      m_Height > kMaxImageDimension) {
+    return false;
+  }
+  m_GroupFamily = GroupFamily;
+  m_bLoadMask = bLoadMask;
+  if (!LoadColorInfo(m_pStream->IsInline() ? pFormResources : nullptr,
+                     pPageResources)) {
+    return false;
+  }
+  if (m_bDoBpcCheck && (m_bpc == 0 || m_nComponents == 0)) {
+    return false;
+  }
+  FX_SAFE_UINT32 src_size =
+      CalculatePitch8(m_bpc, m_nComponents, m_Width) * m_Height;
+  if (!src_size.IsValid()) {
+    return false;
+  }
+  m_pStreamAcc = pdfium::MakeUnique<CPDF_StreamAcc>();
+  m_pStreamAcc->LoadAllData(pStream, false, src_size.ValueOrDie(), true);
+  if (m_pStreamAcc->GetSize() == 0 || !m_pStreamAcc->GetData()) {
+    return false;
+  }
+  if (!CreateDecoder()) {
+    return false;
+  }
+  if (m_bImageMask) {
+    m_bpp = 1;
+    m_bpc = 1;
+    m_nComponents = 1;
+    m_AlphaFlag = 1;
+  } else if (m_bpc * m_nComponents == 1) {
+    m_bpp = 1;
+  } else if (m_bpc * m_nComponents <= 8) {
+    m_bpp = 8;
+  } else {
+    m_bpp = 24;
+  }
+  FX_SAFE_UINT32 pitch = CalculatePitch32(m_bpp, m_Width);
+  if (!pitch.IsValid()) {
+    return false;
+  }
+  m_pLineBuf = FX_Alloc(uint8_t, pitch.ValueOrDie());
+  if (m_pColorSpace && bStdCS) {
+    m_pColorSpace->EnableStdConversion(true);
+  }
+  LoadPalette();
+  if (m_bColorKey) {
+    m_bpp = 32;
+    m_AlphaFlag = 2;
+    pitch = CalculatePitch32(m_bpp, m_Width);
+    if (!pitch.IsValid()) {
+      return false;
+    }
+    m_pMaskedLine = FX_Alloc(uint8_t, pitch.ValueOrDie());
+  }
+  m_Pitch = pitch.ValueOrDie();
+  if (ppMask) {
+    *ppMask = LoadMask(*pMatteColor);
+  }
+  if (m_pColorSpace && bStdCS) {
+    m_pColorSpace->EnableStdConversion(false);
+  }
+  return true;
+}
+
+int CPDF_DIBSource::ContinueToLoadMask() {
+  if (m_bImageMask) {
+    m_bpp = 1;
+    m_bpc = 1;
+    m_nComponents = 1;
+    m_AlphaFlag = 1;
+  } else if (m_bpc * m_nComponents == 1) {
+    m_bpp = 1;
+  } else if (m_bpc * m_nComponents <= 8) {
+    m_bpp = 8;
+  } else {
+    m_bpp = 24;
+  }
+  if (!m_bpc || !m_nComponents) {
+    return 0;
+  }
+  FX_SAFE_UINT32 pitch = CalculatePitch32(m_bpp, m_Width);
+  if (!pitch.IsValid()) {
+    return 0;
+  }
+  m_pLineBuf = FX_Alloc(uint8_t, pitch.ValueOrDie());
+  if (m_pColorSpace && m_bStdCS) {
+    m_pColorSpace->EnableStdConversion(true);
+  }
+  LoadPalette();
+  if (m_bColorKey) {
+    m_bpp = 32;
+    m_AlphaFlag = 2;
+    pitch = CalculatePitch32(m_bpp, m_Width);
+    if (!pitch.IsValid()) {
+      return 0;
+    }
+    m_pMaskedLine = FX_Alloc(uint8_t, pitch.ValueOrDie());
+  }
+  m_Pitch = pitch.ValueOrDie();
+  return 1;
+}
+
+int CPDF_DIBSource::StartLoadDIBSource(CPDF_Document* pDoc,
+                                       const CPDF_Stream* pStream,
+                                       bool bHasMask,
+                                       CPDF_Dictionary* pFormResources,
+                                       CPDF_Dictionary* pPageResources,
+                                       bool bStdCS,
+                                       uint32_t GroupFamily,
+                                       bool bLoadMask) {
+  if (!pStream) {
+    return 0;
+  }
+  m_pDocument = pDoc;
+  m_pDict = pStream->GetDict();
+  m_pStream = pStream;
+  m_bStdCS = bStdCS;
+  m_bHasMask = bHasMask;
+  m_Width = m_pDict->GetIntegerFor("Width");
+  m_Height = m_pDict->GetIntegerFor("Height");
+  if (m_Width <= 0 || m_Height <= 0 || m_Width > kMaxImageDimension ||
+      m_Height > kMaxImageDimension) {
+    return 0;
+  }
+  m_GroupFamily = GroupFamily;
+  m_bLoadMask = bLoadMask;
+  if (!LoadColorInfo(m_pStream->IsInline() ? pFormResources : nullptr,
+                     pPageResources)) {
+    return 0;
+  }
+  if (m_bDoBpcCheck && (m_bpc == 0 || m_nComponents == 0)) {
+    return 0;
+  }
+  FX_SAFE_UINT32 src_size =
+      CalculatePitch8(m_bpc, m_nComponents, m_Width) * m_Height;
+  if (!src_size.IsValid()) {
+    return 0;
+  }
+  m_pStreamAcc = pdfium::MakeUnique<CPDF_StreamAcc>();
+  m_pStreamAcc->LoadAllData(pStream, false, src_size.ValueOrDie(), true);
+  if (m_pStreamAcc->GetSize() == 0 || !m_pStreamAcc->GetData()) {
+    return 0;
+  }
+  int ret = CreateDecoder();
+  if (!ret)
+    return ret;
+
+  if (ret != 1) {
+    if (!ContinueToLoadMask()) {
+      return 0;
+    }
+    if (m_bHasMask) {
+      StratLoadMask();
+    }
+    return ret;
+  }
+  if (!ContinueToLoadMask()) {
+    return 0;
+  }
+  if (m_bHasMask) {
+    ret = StratLoadMask();
+  }
+  if (ret == 2) {
+    return ret;
+  }
+  if (m_pColorSpace && m_bStdCS) {
+    m_pColorSpace->EnableStdConversion(false);
+  }
+  return ret;
+}
+
+int CPDF_DIBSource::ContinueLoadDIBSource(IFX_Pause* pPause) {
+  FXCODEC_STATUS ret;
+  if (m_Status == 1) {
+    const CFX_ByteString& decoder = m_pStreamAcc->GetImageDecoder();
+    if (decoder == "JPXDecode") {
+      return 0;
+    }
+    CCodec_Jbig2Module* pJbig2Module = CPDF_ModuleMgr::Get()->GetJbig2Module();
+    if (!m_pJbig2Context) {
+      m_pJbig2Context = pdfium::MakeUnique<CCodec_Jbig2Context>();
+      if (m_pStreamAcc->GetImageParam()) {
+        CPDF_Stream* pGlobals =
+            m_pStreamAcc->GetImageParam()->GetStreamFor("JBIG2Globals");
+        if (pGlobals) {
+          m_pGlobalStream = pdfium::MakeUnique<CPDF_StreamAcc>();
+          m_pGlobalStream->LoadAllData(pGlobals, false);
+        }
+      }
+      ret = pJbig2Module->StartDecode(
+          m_pJbig2Context.get(), m_pDocument->CodecContext(), m_Width, m_Height,
+          m_pStreamAcc.get(), m_pGlobalStream.get(),
+          m_pCachedBitmap->GetBuffer(), m_pCachedBitmap->GetPitch(), pPause);
+      if (ret < 0) {
+        m_pCachedBitmap.reset();
+        m_pGlobalStream.reset();
+        m_pJbig2Context.reset();
+        return 0;
+      }
+      if (ret == FXCODEC_STATUS_DECODE_TOBECONTINUE) {
+        return 2;
+      }
+      int ret1 = 1;
+      if (m_bHasMask) {
+        ret1 = ContinueLoadMaskDIB(pPause);
+        m_Status = 2;
+      }
+      if (ret1 == 2) {
+        return ret1;
+      }
+      if (m_pColorSpace && m_bStdCS) {
+        m_pColorSpace->EnableStdConversion(false);
+      }
+      return ret1;
+    }
+    ret = pJbig2Module->ContinueDecode(m_pJbig2Context.get(), pPause);
+    if (ret < 0) {
+      m_pCachedBitmap.reset();
+      m_pGlobalStream.reset();
+      m_pJbig2Context.reset();
+      return 0;
+    }
+    if (ret == FXCODEC_STATUS_DECODE_TOBECONTINUE) {
+      return 2;
+    }
+    int ret1 = 1;
+    if (m_bHasMask) {
+      ret1 = ContinueLoadMaskDIB(pPause);
+      m_Status = 2;
+    }
+    if (ret1 == 2) {
+      return ret1;
+    }
+    if (m_pColorSpace && m_bStdCS) {
+      m_pColorSpace->EnableStdConversion(false);
+    }
+    return ret1;
+  }
+  if (m_Status == 2) {
+    return ContinueLoadMaskDIB(pPause);
+  }
+  return 0;
+}
+
+bool CPDF_DIBSource::LoadColorInfo(const CPDF_Dictionary* pFormResources,
+                                   const CPDF_Dictionary* pPageResources) {
+  m_bpc_orig = m_pDict->GetIntegerFor("BitsPerComponent");
+  if (m_pDict->GetIntegerFor("ImageMask"))
+    m_bImageMask = true;
+
+  if (m_bImageMask || !m_pDict->KeyExist("ColorSpace")) {
+    if (!m_bImageMask) {
+      CPDF_Object* pFilter = m_pDict->GetDirectObjectFor("Filter");
+      if (pFilter) {
+        CFX_ByteString filter;
+        if (pFilter->IsName()) {
+          filter = pFilter->GetString();
+        } else if (CPDF_Array* pArray = pFilter->AsArray()) {
+          filter = pArray->GetStringAt(pArray->GetCount() - 1);
+        }
+
+        if (filter == "JPXDecode") {
+          m_bDoBpcCheck = false;
+          return true;
+        }
+      }
+    }
+    m_bImageMask = true;
+    m_bpc = m_nComponents = 1;
+    CPDF_Array* pDecode = m_pDict->GetArrayFor("Decode");
+    m_bDefaultDecode = !pDecode || !pDecode->GetIntegerAt(0);
+    return true;
+  }
+
+  CPDF_Object* pCSObj = m_pDict->GetDirectObjectFor("ColorSpace");
+  if (!pCSObj)
+    return false;
+
+  CPDF_DocPageData* pDocPageData = m_pDocument->GetPageData();
+  if (pFormResources)
+    m_pColorSpace = pDocPageData->GetColorSpace(pCSObj, pFormResources);
+  if (!m_pColorSpace)
+    m_pColorSpace = pDocPageData->GetColorSpace(pCSObj, pPageResources);
+  if (!m_pColorSpace)
+    return false;
+
+  m_Family = m_pColorSpace->GetFamily();
+  m_nComponents = m_pColorSpace->CountComponents();
+  if (m_Family == PDFCS_ICCBASED && pCSObj->IsName()) {
+    CFX_ByteString cs = pCSObj->GetString();
+    if (cs == "DeviceGray") {
+      m_nComponents = 1;
+    } else if (cs == "DeviceRGB") {
+      m_nComponents = 3;
+    } else if (cs == "DeviceCMYK") {
+      m_nComponents = 4;
+    }
+  }
+  ValidateDictParam();
+  m_pCompData = GetDecodeAndMaskArray(m_bDefaultDecode, m_bColorKey);
+  return !!m_pCompData;
+}
+
+DIB_COMP_DATA* CPDF_DIBSource::GetDecodeAndMaskArray(bool& bDefaultDecode,
+                                                     bool& bColorKey) {
+  if (!m_pColorSpace) {
+    return nullptr;
+  }
+  DIB_COMP_DATA* pCompData = FX_Alloc(DIB_COMP_DATA, m_nComponents);
+  int max_data = (1 << m_bpc) - 1;
+  CPDF_Array* pDecode = m_pDict->GetArrayFor("Decode");
+  if (pDecode) {
+    for (uint32_t i = 0; i < m_nComponents; i++) {
+      pCompData[i].m_DecodeMin = pDecode->GetNumberAt(i * 2);
+      FX_FLOAT max = pDecode->GetNumberAt(i * 2 + 1);
+      pCompData[i].m_DecodeStep = (max - pCompData[i].m_DecodeMin) / max_data;
+      FX_FLOAT def_value;
+      FX_FLOAT def_min;
+      FX_FLOAT def_max;
+      m_pColorSpace->GetDefaultValue(i, def_value, def_min, def_max);
+      if (m_Family == PDFCS_INDEXED) {
+        def_max = max_data;
+      }
+      if (def_min != pCompData[i].m_DecodeMin || def_max != max) {
+        bDefaultDecode = false;
+      }
+    }
+  } else {
+    for (uint32_t i = 0; i < m_nComponents; i++) {
+      FX_FLOAT def_value;
+      m_pColorSpace->GetDefaultValue(i, def_value, pCompData[i].m_DecodeMin,
+                                     pCompData[i].m_DecodeStep);
+      if (m_Family == PDFCS_INDEXED) {
+        pCompData[i].m_DecodeStep = max_data;
+      }
+      pCompData[i].m_DecodeStep =
+          (pCompData[i].m_DecodeStep - pCompData[i].m_DecodeMin) / max_data;
+    }
+  }
+  if (!m_pDict->KeyExist("SMask")) {
+    CPDF_Object* pMask = m_pDict->GetDirectObjectFor("Mask");
+    if (!pMask) {
+      return pCompData;
+    }
+    if (CPDF_Array* pArray = pMask->AsArray()) {
+      if (pArray->GetCount() >= m_nComponents * 2) {
+        for (uint32_t i = 0; i < m_nComponents; i++) {
+          int min_num = pArray->GetIntegerAt(i * 2);
+          int max_num = pArray->GetIntegerAt(i * 2 + 1);
+          pCompData[i].m_ColorKeyMin = std::max(min_num, 0);
+          pCompData[i].m_ColorKeyMax = std::min(max_num, max_data);
+        }
+      }
+      bColorKey = true;
+    }
+  }
+  return pCompData;
+}
+
+int CPDF_DIBSource::CreateDecoder() {
+  const CFX_ByteString& decoder = m_pStreamAcc->GetImageDecoder();
+  if (decoder.IsEmpty())
+    return 1;
+
+  if (m_bDoBpcCheck && m_bpc == 0)
+    return 0;
+
+  if (decoder == "JPXDecode") {
+    LoadJpxBitmap();
+    return m_pCachedBitmap ? 1 : 0;
+  }
+  if (decoder == "JBIG2Decode") {
+    m_pCachedBitmap = pdfium::MakeUnique<CFX_DIBitmap>();
+    if (!m_pCachedBitmap->Create(
+            m_Width, m_Height, m_bImageMask ? FXDIB_1bppMask : FXDIB_1bppRgb)) {
+      m_pCachedBitmap.reset();
+      return 0;
+    }
+    m_Status = 1;
+    return 2;
+  }
+
+  const uint8_t* src_data = m_pStreamAcc->GetData();
+  uint32_t src_size = m_pStreamAcc->GetSize();
+  const CPDF_Dictionary* pParams = m_pStreamAcc->GetImageParam();
+  if (decoder == "CCITTFaxDecode") {
+    m_pDecoder = FPDFAPI_CreateFaxDecoder(src_data, src_size, m_Width, m_Height,
+                                          pParams);
+  } else if (decoder == "FlateDecode") {
+    m_pDecoder = FPDFAPI_CreateFlateDecoder(
+        src_data, src_size, m_Width, m_Height, m_nComponents, m_bpc, pParams);
+  } else if (decoder == "RunLengthDecode") {
+    m_pDecoder = CPDF_ModuleMgr::Get()
+                     ->GetCodecModule()
+                     ->GetBasicModule()
+                     ->CreateRunLengthDecoder(src_data, src_size, m_Width,
+                                              m_Height, m_nComponents, m_bpc);
+  } else if (decoder == "DCTDecode") {
+    m_pDecoder = CPDF_ModuleMgr::Get()->GetJpegModule()->CreateDecoder(
+        src_data, src_size, m_Width, m_Height, m_nComponents,
+        !pParams || pParams->GetIntegerFor("ColorTransform", 1));
+    if (!m_pDecoder) {
+      bool bTransform = false;
+      int comps;
+      int bpc;
+      CCodec_JpegModule* pJpegModule = CPDF_ModuleMgr::Get()->GetJpegModule();
+      if (pJpegModule->LoadInfo(src_data, src_size, &m_Width, &m_Height, &comps,
+                                &bpc, &bTransform)) {
+        if (m_nComponents != static_cast<uint32_t>(comps)) {
+          FX_Free(m_pCompData);
+          m_pCompData = nullptr;
+          m_nComponents = static_cast<uint32_t>(comps);
+          if (m_pColorSpace) {
+            switch (m_Family) {
+              case PDFCS_DEVICEGRAY:
+              case PDFCS_DEVICERGB:
+              case PDFCS_DEVICECMYK: {
+                uint32_t dwMinComps = ComponentsForFamily(m_Family);
+                if (m_pColorSpace->CountComponents() < dwMinComps ||
+                    m_nComponents < dwMinComps) {
+                  return 0;
+                }
+                break;
+              }
+              case PDFCS_LAB: {
+                if (m_nComponents != 3 || m_pColorSpace->CountComponents() < 3)
+                  return 0;
+                break;
+              }
+              case PDFCS_ICCBASED: {
+                if (!IsAllowedICCComponents(m_nComponents) ||
+                    !IsAllowedICCComponents(m_pColorSpace->CountComponents()) ||
+                    m_pColorSpace->CountComponents() < m_nComponents) {
+                  return 0;
+                }
+                break;
+              }
+              default: {
+                if (m_pColorSpace->CountComponents() != m_nComponents)
+                  return 0;
+                break;
+              }
+            }
+          } else {
+            if (m_Family == PDFCS_LAB && m_nComponents != 3)
+              return 0;
+          }
+          m_pCompData = GetDecodeAndMaskArray(m_bDefaultDecode, m_bColorKey);
+          if (!m_pCompData)
+            return 0;
+        }
+        m_bpc = bpc;
+        m_pDecoder = CPDF_ModuleMgr::Get()->GetJpegModule()->CreateDecoder(
+            src_data, src_size, m_Width, m_Height, m_nComponents, bTransform);
+      }
+    }
+  }
+  if (!m_pDecoder)
+    return 0;
+
+  FX_SAFE_UINT32 requested_pitch =
+      CalculatePitch8(m_bpc, m_nComponents, m_Width);
+  if (!requested_pitch.IsValid())
+    return 0;
+  FX_SAFE_UINT32 provided_pitch = CalculatePitch8(
+      m_pDecoder->GetBPC(), m_pDecoder->CountComps(), m_pDecoder->GetWidth());
+  if (!provided_pitch.IsValid())
+    return 0;
+  if (provided_pitch.ValueOrDie() < requested_pitch.ValueOrDie())
+    return 0;
+  return 1;
+}
+
+void CPDF_DIBSource::LoadJpxBitmap() {
+  CCodec_JpxModule* pJpxModule = CPDF_ModuleMgr::Get()->GetJpxModule();
+  if (!pJpxModule)
+    return;
+
+  std::unique_ptr<JpxBitMapContext> context(new JpxBitMapContext(pJpxModule));
+  context->set_decoder(pJpxModule->CreateDecoder(
+      m_pStreamAcc->GetData(), m_pStreamAcc->GetSize(), m_pColorSpace));
+  if (!context->decoder())
+    return;
+
+  uint32_t width = 0;
+  uint32_t height = 0;
+  uint32_t components = 0;
+  pJpxModule->GetImageInfo(context->decoder(), &width, &height, &components);
+  if (static_cast<int>(width) < m_Width || static_cast<int>(height) < m_Height)
+    return;
+
+  bool bSwapRGB = false;
+  if (m_pColorSpace) {
+    if (components != m_pColorSpace->CountComponents())
+      return;
+
+    if (m_pColorSpace == CPDF_ColorSpace::GetStockCS(PDFCS_DEVICERGB)) {
+      bSwapRGB = true;
+      m_pColorSpace = nullptr;
+    }
+  } else {
+    if (components == 3) {
+      bSwapRGB = true;
+    } else if (components == 4) {
+      m_pColorSpace = CPDF_ColorSpace::GetStockCS(PDFCS_DEVICECMYK);
+    }
+    m_nComponents = components;
+  }
+
+  FXDIB_Format format;
+  if (components == 1) {
+    format = FXDIB_8bppRgb;
+  } else if (components <= 3) {
+    format = FXDIB_Rgb;
+  } else if (components == 4) {
+    format = FXDIB_Rgb32;
+  } else {
+    width = (width * components + 2) / 3;
+    format = FXDIB_Rgb;
+  }
+
+  m_pCachedBitmap = pdfium::MakeUnique<CFX_DIBitmap>();
+  if (!m_pCachedBitmap->Create(width, height, format)) {
+    m_pCachedBitmap.reset();
+    return;
+  }
+  m_pCachedBitmap->Clear(0xFFFFFFFF);
+  std::vector<uint8_t> output_offsets(components);
+  for (uint32_t i = 0; i < components; ++i)
+    output_offsets[i] = i;
+  if (bSwapRGB) {
+    output_offsets[0] = 2;
+    output_offsets[2] = 0;
+  }
+  if (!pJpxModule->Decode(context->decoder(), m_pCachedBitmap->GetBuffer(),
+                          m_pCachedBitmap->GetPitch(), output_offsets)) {
+    m_pCachedBitmap.reset();
+    return;
+  }
+  if (m_pColorSpace && m_pColorSpace->GetFamily() == PDFCS_INDEXED &&
+      m_bpc < 8) {
+    int scale = 8 - m_bpc;
+    for (uint32_t row = 0; row < height; ++row) {
+      uint8_t* scanline =
+          const_cast<uint8_t*>(m_pCachedBitmap->GetScanline(row));
+      for (uint32_t col = 0; col < width; ++col) {
+        *scanline = (*scanline) >> scale;
+        ++scanline;
+      }
+    }
+  }
+  m_bpc = 8;
+}
+
+CPDF_DIBSource* CPDF_DIBSource::LoadMask(uint32_t& MatteColor) {
+  MatteColor = 0xFFFFFFFF;
+  CPDF_Stream* pSoftMask = m_pDict->GetStreamFor("SMask");
+  if (pSoftMask) {
+    CPDF_Array* pMatte = pSoftMask->GetDict()->GetArrayFor("Matte");
+    if (pMatte && m_pColorSpace &&
+        m_pColorSpace->CountComponents() <= m_nComponents) {
+      std::vector<FX_FLOAT> colors(m_nComponents);
+      for (uint32_t i = 0; i < m_nComponents; i++) {
+        colors[i] = pMatte->GetFloatAt(i);
+      }
+      FX_FLOAT R, G, B;
+      m_pColorSpace->GetRGB(colors.data(), R, G, B);
+      MatteColor = FXARGB_MAKE(0, FXSYS_round(R * 255), FXSYS_round(G * 255),
+                               FXSYS_round(B * 255));
+    }
+    return LoadMaskDIB(pSoftMask);
+  }
+
+  if (CPDF_Stream* pStream = ToStream(m_pDict->GetDirectObjectFor("Mask")))
+    return LoadMaskDIB(pStream);
+
+  return nullptr;
+}
+
+int CPDF_DIBSource::StratLoadMask() {
+  m_MatteColor = 0XFFFFFFFF;
+  m_pMaskStream = m_pDict->GetStreamFor("SMask");
+  if (m_pMaskStream) {
+    CPDF_Array* pMatte = m_pMaskStream->GetDict()->GetArrayFor("Matte");
+    if (pMatte && m_pColorSpace &&
+        m_pColorSpace->CountComponents() <= m_nComponents) {
+      FX_FLOAT R, G, B;
+      std::vector<FX_FLOAT> colors(m_nComponents);
+      for (uint32_t i = 0; i < m_nComponents; i++) {
+        colors[i] = pMatte->GetFloatAt(i);
+      }
+      m_pColorSpace->GetRGB(colors.data(), R, G, B);
+      m_MatteColor = FXARGB_MAKE(0, FXSYS_round(R * 255), FXSYS_round(G * 255),
+                                 FXSYS_round(B * 255));
+    }
+    return StartLoadMaskDIB();
+  }
+
+  m_pMaskStream = ToStream(m_pDict->GetDirectObjectFor("Mask"));
+  return m_pMaskStream ? StartLoadMaskDIB() : 1;
+}
+
+int CPDF_DIBSource::ContinueLoadMaskDIB(IFX_Pause* pPause) {
+  if (!m_pMask) {
+    return 1;
+  }
+  int ret = m_pMask->ContinueLoadDIBSource(pPause);
+  if (ret == 2) {
+    return ret;
+  }
+  if (m_pColorSpace && m_bStdCS) {
+    m_pColorSpace->EnableStdConversion(false);
+  }
+  if (!ret) {
+    delete m_pMask;
+    m_pMask = nullptr;
+    return ret;
+  }
+  return 1;
+}
+
+CPDF_DIBSource* CPDF_DIBSource::DetachMask() {
+  CPDF_DIBSource* pDIBSource = m_pMask;
+  m_pMask = nullptr;
+  return pDIBSource;
+}
+
+CPDF_DIBSource* CPDF_DIBSource::LoadMaskDIB(CPDF_Stream* pMask) {
+  CPDF_DIBSource* pMaskSource = new CPDF_DIBSource;
+  if (!pMaskSource->Load(m_pDocument, pMask, nullptr, nullptr, nullptr, nullptr,
+                         true)) {
+    delete pMaskSource;
+    return nullptr;
+  }
+  return pMaskSource;
+}
+
+int CPDF_DIBSource::StartLoadMaskDIB() {
+  m_pMask = new CPDF_DIBSource;
+  int ret = m_pMask->StartLoadDIBSource(m_pDocument, m_pMaskStream, false,
+                                        nullptr, nullptr, true);
+  if (ret == 2) {
+    if (m_Status == 0)
+      m_Status = 2;
+    return 2;
+  }
+  if (!ret) {
+    delete m_pMask;
+    m_pMask = nullptr;
+    return 1;
+  }
+  return 1;
+}
+
+void CPDF_DIBSource::LoadPalette() {
+  if (m_bpc == 0) {
+    return;
+  }
+  if (m_bpc * m_nComponents > 8) {
+    return;
+  }
+  if (!m_pColorSpace) {
+    return;
+  }
+  if (m_bpc * m_nComponents == 1) {
+    if (m_bDefaultDecode &&
+        (m_Family == PDFCS_DEVICEGRAY || m_Family == PDFCS_DEVICERGB)) {
+      return;
+    }
+    if (m_pColorSpace->CountComponents() > 3) {
+      return;
+    }
+    FX_FLOAT color_values[3];
+    color_values[0] = m_pCompData[0].m_DecodeMin;
+    color_values[1] = color_values[2] = color_values[0];
+    FX_FLOAT R = 0.0f, G = 0.0f, B = 0.0f;
+    m_pColorSpace->GetRGB(color_values, R, G, B);
+    FX_ARGB argb0 = ArgbEncode(255, FXSYS_round(R * 255), FXSYS_round(G * 255),
+                               FXSYS_round(B * 255));
+    color_values[0] += m_pCompData[0].m_DecodeStep;
+    color_values[1] += m_pCompData[0].m_DecodeStep;
+    color_values[2] += m_pCompData[0].m_DecodeStep;
+    m_pColorSpace->GetRGB(color_values, R, G, B);
+    FX_ARGB argb1 = ArgbEncode(255, FXSYS_round(R * 255), FXSYS_round(G * 255),
+                               FXSYS_round(B * 255));
+    if (argb0 != 0xFF000000 || argb1 != 0xFFFFFFFF) {
+      SetPaletteArgb(0, argb0);
+      SetPaletteArgb(1, argb1);
+    }
+    return;
+  }
+  if (m_pColorSpace == CPDF_ColorSpace::GetStockCS(PDFCS_DEVICEGRAY) &&
+      m_bpc == 8 && m_bDefaultDecode) {
+  } else {
+    int palette_count = 1 << (m_bpc * m_nComponents);
+    CFX_FixedBufGrow<FX_FLOAT, 16> color_values(m_nComponents);
+    FX_FLOAT* color_value = color_values;
+    for (int i = 0; i < palette_count; i++) {
+      int color_data = i;
+      for (uint32_t j = 0; j < m_nComponents; j++) {
+        int encoded_component = color_data % (1 << m_bpc);
+        color_data /= 1 << m_bpc;
+        color_value[j] = m_pCompData[j].m_DecodeMin +
+                         m_pCompData[j].m_DecodeStep * encoded_component;
+      }
+      FX_FLOAT R = 0, G = 0, B = 0;
+      if (m_nComponents == 1 && m_Family == PDFCS_ICCBASED &&
+          m_pColorSpace->CountComponents() > 1) {
+        int nComponents = m_pColorSpace->CountComponents();
+        std::vector<FX_FLOAT> temp_buf(nComponents);
+        for (int k = 0; k < nComponents; k++) {
+          temp_buf[k] = *color_value;
+        }
+        m_pColorSpace->GetRGB(temp_buf.data(), R, G, B);
+      } else {
+        m_pColorSpace->GetRGB(color_value, R, G, B);
+      }
+      SetPaletteArgb(i, ArgbEncode(255, FXSYS_round(R * 255),
+                                   FXSYS_round(G * 255), FXSYS_round(B * 255)));
+    }
+  }
+}
+
+void CPDF_DIBSource::ValidateDictParam() {
+  m_bpc = m_bpc_orig;
+  CPDF_Object* pFilter = m_pDict->GetDirectObjectFor("Filter");
+  if (pFilter) {
+    if (pFilter->IsName()) {
+      CFX_ByteString filter = pFilter->GetString();
+      if (filter == "CCITTFaxDecode" || filter == "JBIG2Decode") {
+        m_bpc = 1;
+        m_nComponents = 1;
+      } else if (filter == "RunLengthDecode") {
+        if (m_bpc != 1) {
+          m_bpc = 8;
+        }
+      } else if (filter == "DCTDecode") {
+        m_bpc = 8;
+      }
+    } else if (CPDF_Array* pArray = pFilter->AsArray()) {
+      CFX_ByteString filter = pArray->GetStringAt(pArray->GetCount() - 1);
+      if (filter == "CCITTFaxDecode" || filter == "JBIG2Decode") {
+        m_bpc = 1;
+        m_nComponents = 1;
+      } else if (filter == "DCTDecode") {
+        // Previously, filter == "RunLengthDecode" was checked in the "if"
+        // statement as well, but too many documents don't conform to it.
+        m_bpc = 8;
+      }
+    }
+  }
+
+  if (!IsAllowedBPCValue(m_bpc))
+    m_bpc = 0;
+}
+
+void CPDF_DIBSource::TranslateScanline24bpp(uint8_t* dest_scan,
+                                            const uint8_t* src_scan) const {
+  if (m_bpc == 0) {
+    return;
+  }
+  unsigned int max_data = (1 << m_bpc) - 1;
+  if (m_bDefaultDecode) {
+    if (m_Family == PDFCS_DEVICERGB || m_Family == PDFCS_CALRGB) {
+      if (m_nComponents != 3)
+        return;
+
+      const uint8_t* src_pos = src_scan;
+      switch (m_bpc) {
+        case 16:
+          for (int col = 0; col < m_Width; col++) {
+            *dest_scan++ = src_pos[4];
+            *dest_scan++ = src_pos[2];
+            *dest_scan++ = *src_pos;
+            src_pos += 6;
+          }
+          break;
+        case 8:
+          for (int column = 0; column < m_Width; column++) {
+            *dest_scan++ = src_pos[2];
+            *dest_scan++ = src_pos[1];
+            *dest_scan++ = *src_pos;
+            src_pos += 3;
+          }
+          break;
+        default:
+          uint64_t src_bit_pos = 0;
+          size_t dest_byte_pos = 0;
+          for (int column = 0; column < m_Width; column++) {
+            unsigned int R = GetBits8(src_scan, src_bit_pos, m_bpc);
+            src_bit_pos += m_bpc;
+            unsigned int G = GetBits8(src_scan, src_bit_pos, m_bpc);
+            src_bit_pos += m_bpc;
+            unsigned int B = GetBits8(src_scan, src_bit_pos, m_bpc);
+            src_bit_pos += m_bpc;
+            R = std::min(R, max_data);
+            G = std::min(G, max_data);
+            B = std::min(B, max_data);
+            dest_scan[dest_byte_pos] = B * 255 / max_data;
+            dest_scan[dest_byte_pos + 1] = G * 255 / max_data;
+            dest_scan[dest_byte_pos + 2] = R * 255 / max_data;
+            dest_byte_pos += 3;
+          }
+          break;
+      }
+      return;
+    }
+    if (m_bpc == 8) {
+      if (m_nComponents == m_pColorSpace->CountComponents())
+        m_pColorSpace->TranslateImageLine(dest_scan, src_scan, m_Width, m_Width,
+                                          m_Height, TransMask());
+      return;
+    }
+  }
+  CFX_FixedBufGrow<FX_FLOAT, 16> color_values1(m_nComponents);
+  FX_FLOAT* color_values = color_values1;
+  FX_FLOAT R = 0.0f, G = 0.0f, B = 0.0f;
+  if (m_bpc == 8) {
+    uint64_t src_byte_pos = 0;
+    size_t dest_byte_pos = 0;
+    for (int column = 0; column < m_Width; column++) {
+      for (uint32_t color = 0; color < m_nComponents; color++) {
+        uint8_t data = src_scan[src_byte_pos++];
+        color_values[color] = m_pCompData[color].m_DecodeMin +
+                              m_pCompData[color].m_DecodeStep * data;
+      }
+      if (TransMask()) {
+        FX_FLOAT k = 1.0f - color_values[3];
+        R = (1.0f - color_values[0]) * k;
+        G = (1.0f - color_values[1]) * k;
+        B = (1.0f - color_values[2]) * k;
+      } else {
+        m_pColorSpace->GetRGB(color_values, R, G, B);
+      }
+      R = ClampValue(R, 1.0f);
+      G = ClampValue(G, 1.0f);
+      B = ClampValue(B, 1.0f);
+      dest_scan[dest_byte_pos] = static_cast<uint8_t>(B * 255);
+      dest_scan[dest_byte_pos + 1] = static_cast<uint8_t>(G * 255);
+      dest_scan[dest_byte_pos + 2] = static_cast<uint8_t>(R * 255);
+      dest_byte_pos += 3;
+    }
+  } else {
+    uint64_t src_bit_pos = 0;
+    size_t dest_byte_pos = 0;
+    for (int column = 0; column < m_Width; column++) {
+      for (uint32_t color = 0; color < m_nComponents; color++) {
+        unsigned int data = GetBits8(src_scan, src_bit_pos, m_bpc);
+        color_values[color] = m_pCompData[color].m_DecodeMin +
+                              m_pCompData[color].m_DecodeStep * data;
+        src_bit_pos += m_bpc;
+      }
+      if (TransMask()) {
+        FX_FLOAT k = 1.0f - color_values[3];
+        R = (1.0f - color_values[0]) * k;
+        G = (1.0f - color_values[1]) * k;
+        B = (1.0f - color_values[2]) * k;
+      } else {
+        m_pColorSpace->GetRGB(color_values, R, G, B);
+      }
+      R = ClampValue(R, 1.0f);
+      G = ClampValue(G, 1.0f);
+      B = ClampValue(B, 1.0f);
+      dest_scan[dest_byte_pos] = static_cast<uint8_t>(B * 255);
+      dest_scan[dest_byte_pos + 1] = static_cast<uint8_t>(G * 255);
+      dest_scan[dest_byte_pos + 2] = static_cast<uint8_t>(R * 255);
+      dest_byte_pos += 3;
+    }
+  }
+}
+
+uint8_t* CPDF_DIBSource::GetBuffer() const {
+  return m_pCachedBitmap ? m_pCachedBitmap->GetBuffer() : nullptr;
+}
+
+const uint8_t* CPDF_DIBSource::GetScanline(int line) const {
+  if (m_bpc == 0) {
+    return nullptr;
+  }
+  FX_SAFE_UINT32 src_pitch = CalculatePitch8(m_bpc, m_nComponents, m_Width);
+  if (!src_pitch.IsValid())
+    return nullptr;
+  uint32_t src_pitch_value = src_pitch.ValueOrDie();
+  const uint8_t* pSrcLine = nullptr;
+  if (m_pCachedBitmap && src_pitch_value <= m_pCachedBitmap->GetPitch()) {
+    if (line >= m_pCachedBitmap->GetHeight()) {
+      line = m_pCachedBitmap->GetHeight() - 1;
+    }
+    pSrcLine = m_pCachedBitmap->GetScanline(line);
+  } else if (m_pDecoder) {
+    pSrcLine = m_pDecoder->GetScanline(line);
+  } else {
+    if (m_pStreamAcc->GetSize() >= (line + 1) * src_pitch_value) {
+      pSrcLine = m_pStreamAcc->GetData() + line * src_pitch_value;
+    }
+  }
+  if (!pSrcLine) {
+    uint8_t* pLineBuf = m_pMaskedLine ? m_pMaskedLine : m_pLineBuf;
+    FXSYS_memset(pLineBuf, 0xFF, m_Pitch);
+    return pLineBuf;
+  }
+  if (m_bpc * m_nComponents == 1) {
+    if (m_bImageMask && m_bDefaultDecode) {
+      for (uint32_t i = 0; i < src_pitch_value; i++) {
+        m_pLineBuf[i] = ~pSrcLine[i];
+      }
+    } else if (m_bColorKey) {
+      uint32_t reset_argb, set_argb;
+      reset_argb = m_pPalette ? m_pPalette.get()[0] : 0xFF000000;
+      set_argb = m_pPalette ? m_pPalette.get()[1] : 0xFFFFFFFF;
+      if (m_pCompData[0].m_ColorKeyMin == 0) {
+        reset_argb = 0;
+      }
+      if (m_pCompData[0].m_ColorKeyMax == 1) {
+        set_argb = 0;
+      }
+      set_argb = FXARGB_TODIB(set_argb);
+      reset_argb = FXARGB_TODIB(reset_argb);
+      uint32_t* dest_scan = reinterpret_cast<uint32_t*>(m_pMaskedLine);
+      for (int col = 0; col < m_Width; col++) {
+        if (pSrcLine[col / 8] & (1 << (7 - col % 8))) {
+          *dest_scan = set_argb;
+        } else {
+          *dest_scan = reset_argb;
+        }
+        dest_scan++;
+      }
+      return m_pMaskedLine;
+    } else {
+      FXSYS_memcpy(m_pLineBuf, pSrcLine, src_pitch_value);
+    }
+    return m_pLineBuf;
+  }
+  if (m_bpc * m_nComponents <= 8) {
+    if (m_bpc == 8) {
+      FXSYS_memcpy(m_pLineBuf, pSrcLine, src_pitch_value);
+    } else {
+      uint64_t src_bit_pos = 0;
+      for (int col = 0; col < m_Width; col++) {
+        unsigned int color_index = 0;
+        for (uint32_t color = 0; color < m_nComponents; color++) {
+          unsigned int data = GetBits8(pSrcLine, src_bit_pos, m_bpc);
+          color_index |= data << (color * m_bpc);
+          src_bit_pos += m_bpc;
+        }
+        m_pLineBuf[col] = color_index;
+      }
+    }
+    if (m_bColorKey) {
+      uint8_t* pDestPixel = m_pMaskedLine;
+      const uint8_t* pSrcPixel = m_pLineBuf;
+      for (int col = 0; col < m_Width; col++) {
+        uint8_t index = *pSrcPixel++;
+        if (m_pPalette) {
+          *pDestPixel++ = FXARGB_B(m_pPalette.get()[index]);
+          *pDestPixel++ = FXARGB_G(m_pPalette.get()[index]);
+          *pDestPixel++ = FXARGB_R(m_pPalette.get()[index]);
+        } else {
+          *pDestPixel++ = index;
+          *pDestPixel++ = index;
+          *pDestPixel++ = index;
+        }
+        *pDestPixel = (index < m_pCompData[0].m_ColorKeyMin ||
+                       index > m_pCompData[0].m_ColorKeyMax)
+                          ? 0xFF
+                          : 0;
+        pDestPixel++;
+      }
+      return m_pMaskedLine;
+    }
+    return m_pLineBuf;
+  }
+  if (m_bColorKey) {
+    if (m_nComponents == 3 && m_bpc == 8) {
+      uint8_t* alpha_channel = m_pMaskedLine + 3;
+      for (int col = 0; col < m_Width; col++) {
+        const uint8_t* pPixel = pSrcLine + col * 3;
+        alpha_channel[col * 4] = (pPixel[0] < m_pCompData[0].m_ColorKeyMin ||
+                                  pPixel[0] > m_pCompData[0].m_ColorKeyMax ||
+                                  pPixel[1] < m_pCompData[1].m_ColorKeyMin ||
+                                  pPixel[1] > m_pCompData[1].m_ColorKeyMax ||
+                                  pPixel[2] < m_pCompData[2].m_ColorKeyMin ||
+                                  pPixel[2] > m_pCompData[2].m_ColorKeyMax)
+                                     ? 0xFF
+                                     : 0;
+      }
+    } else {
+      FXSYS_memset(m_pMaskedLine, 0xFF, m_Pitch);
+    }
+  }
+  if (m_pColorSpace) {
+    TranslateScanline24bpp(m_pLineBuf, pSrcLine);
+    pSrcLine = m_pLineBuf;
+  }
+  if (m_bColorKey) {
+    const uint8_t* pSrcPixel = pSrcLine;
+    uint8_t* pDestPixel = m_pMaskedLine;
+    for (int col = 0; col < m_Width; col++) {
+      *pDestPixel++ = *pSrcPixel++;
+      *pDestPixel++ = *pSrcPixel++;
+      *pDestPixel++ = *pSrcPixel++;
+      pDestPixel++;
+    }
+    return m_pMaskedLine;
+  }
+  return pSrcLine;
+}
+
+bool CPDF_DIBSource::SkipToScanline(int line, IFX_Pause* pPause) const {
+  return m_pDecoder && m_pDecoder->SkipToScanline(line, pPause);
+}
+
+void CPDF_DIBSource::DownSampleScanline(int line,
+                                        uint8_t* dest_scan,
+                                        int dest_bpp,
+                                        int dest_width,
+                                        bool bFlipX,
+                                        int clip_left,
+                                        int clip_width) const {
+  if (line < 0 || !dest_scan || dest_bpp <= 0 || dest_width <= 0 ||
+      clip_left < 0 || clip_width <= 0) {
+    return;
+  }
+
+  uint32_t src_width = m_Width;
+  FX_SAFE_UINT32 pitch = CalculatePitch8(m_bpc, m_nComponents, m_Width);
+  if (!pitch.IsValid())
+    return;
+
+  const uint8_t* pSrcLine = nullptr;
+  if (m_pCachedBitmap) {
+    pSrcLine = m_pCachedBitmap->GetScanline(line);
+  } else if (m_pDecoder) {
+    pSrcLine = m_pDecoder->GetScanline(line);
+  } else {
+    uint32_t src_pitch = pitch.ValueOrDie();
+    pitch *= (line + 1);
+    if (!pitch.IsValid()) {
+      return;
+    }
+
+    if (m_pStreamAcc->GetSize() >= pitch.ValueOrDie()) {
+      pSrcLine = m_pStreamAcc->GetData() + line * src_pitch;
+    }
+  }
+  int orig_Bpp = m_bpc * m_nComponents / 8;
+  int dest_Bpp = dest_bpp / 8;
+  if (!pSrcLine) {
+    FXSYS_memset(dest_scan, 0xFF, dest_Bpp * clip_width);
+    return;
+  }
+
+  FX_SAFE_INT32 max_src_x = clip_left;
+  max_src_x += clip_width - 1;
+  max_src_x *= src_width;
+  max_src_x /= dest_width;
+  if (!max_src_x.IsValid())
+    return;
+
+  if (m_bpc * m_nComponents == 1) {
+    DownSampleScanline1Bit(orig_Bpp, dest_Bpp, src_width, pSrcLine, dest_scan,
+                           dest_width, bFlipX, clip_left, clip_width);
+  } else if (m_bpc * m_nComponents <= 8) {
+    DownSampleScanline8Bit(orig_Bpp, dest_Bpp, src_width, pSrcLine, dest_scan,
+                           dest_width, bFlipX, clip_left, clip_width);
+  } else {
+    DownSampleScanline32Bit(orig_Bpp, dest_Bpp, src_width, pSrcLine, dest_scan,
+                            dest_width, bFlipX, clip_left, clip_width);
+  }
+}
+
+void CPDF_DIBSource::DownSampleScanline1Bit(int orig_Bpp,
+                                            int dest_Bpp,
+                                            uint32_t src_width,
+                                            const uint8_t* pSrcLine,
+                                            uint8_t* dest_scan,
+                                            int dest_width,
+                                            bool bFlipX,
+                                            int clip_left,
+                                            int clip_width) const {
+  uint32_t set_argb = (uint32_t)-1;
+  uint32_t reset_argb = 0;
+  if (m_bImageMask) {
+    if (m_bDefaultDecode) {
+      set_argb = 0;
+      reset_argb = (uint32_t)-1;
+    }
+  } else if (m_bColorKey) {
+    reset_argb = m_pPalette ? m_pPalette.get()[0] : 0xFF000000;
+    set_argb = m_pPalette ? m_pPalette.get()[1] : 0xFFFFFFFF;
+    if (m_pCompData[0].m_ColorKeyMin == 0) {
+      reset_argb = 0;
+    }
+    if (m_pCompData[0].m_ColorKeyMax == 1) {
+      set_argb = 0;
+    }
+    set_argb = FXARGB_TODIB(set_argb);
+    reset_argb = FXARGB_TODIB(reset_argb);
+    uint32_t* dest_scan_dword = reinterpret_cast<uint32_t*>(dest_scan);
+    for (int i = 0; i < clip_width; i++) {
+      uint32_t src_x = (clip_left + i) * src_width / dest_width;
+      if (bFlipX) {
+        src_x = src_width - src_x - 1;
+      }
+      src_x %= src_width;
+      if (pSrcLine[src_x / 8] & (1 << (7 - src_x % 8))) {
+        dest_scan_dword[i] = set_argb;
+      } else {
+        dest_scan_dword[i] = reset_argb;
+      }
+    }
+    return;
+  } else {
+    if (dest_Bpp == 1) {
+    } else if (m_pPalette) {
+      reset_argb = m_pPalette.get()[0];
+      set_argb = m_pPalette.get()[1];
+    }
+  }
+  for (int i = 0; i < clip_width; i++) {
+    uint32_t src_x = (clip_left + i) * src_width / dest_width;
+    if (bFlipX) {
+      src_x = src_width - src_x - 1;
+    }
+    src_x %= src_width;
+    int dest_pos = i * dest_Bpp;
+    if (pSrcLine[src_x / 8] & (1 << (7 - src_x % 8))) {
+      if (dest_Bpp == 1) {
+        dest_scan[dest_pos] = static_cast<uint8_t>(set_argb);
+      } else if (dest_Bpp == 3) {
+        dest_scan[dest_pos] = FXARGB_B(set_argb);
+        dest_scan[dest_pos + 1] = FXARGB_G(set_argb);
+        dest_scan[dest_pos + 2] = FXARGB_R(set_argb);
+      } else {
+        *reinterpret_cast<uint32_t*>(dest_scan + dest_pos) = set_argb;
+      }
+    } else {
+      if (dest_Bpp == 1) {
+        dest_scan[dest_pos] = static_cast<uint8_t>(reset_argb);
+      } else if (dest_Bpp == 3) {
+        dest_scan[dest_pos] = FXARGB_B(reset_argb);
+        dest_scan[dest_pos + 1] = FXARGB_G(reset_argb);
+        dest_scan[dest_pos + 2] = FXARGB_R(reset_argb);
+      } else {
+        *reinterpret_cast<uint32_t*>(dest_scan + dest_pos) = reset_argb;
+      }
+    }
+  }
+}
+
+void CPDF_DIBSource::DownSampleScanline8Bit(int orig_Bpp,
+                                            int dest_Bpp,
+                                            uint32_t src_width,
+                                            const uint8_t* pSrcLine,
+                                            uint8_t* dest_scan,
+                                            int dest_width,
+                                            bool bFlipX,
+                                            int clip_left,
+                                            int clip_width) const {
+  if (m_bpc < 8) {
+    uint64_t src_bit_pos = 0;
+    for (uint32_t col = 0; col < src_width; col++) {
+      unsigned int color_index = 0;
+      for (uint32_t color = 0; color < m_nComponents; color++) {
+        unsigned int data = GetBits8(pSrcLine, src_bit_pos, m_bpc);
+        color_index |= data << (color * m_bpc);
+        src_bit_pos += m_bpc;
+      }
+      m_pLineBuf[col] = color_index;
+    }
+    pSrcLine = m_pLineBuf;
+  }
+  if (m_bColorKey) {
+    for (int i = 0; i < clip_width; i++) {
+      uint32_t src_x = (clip_left + i) * src_width / dest_width;
+      if (bFlipX) {
+        src_x = src_width - src_x - 1;
+      }
+      src_x %= src_width;
+      uint8_t* pDestPixel = dest_scan + i * 4;
+      uint8_t index = pSrcLine[src_x];
+      if (m_pPalette) {
+        *pDestPixel++ = FXARGB_B(m_pPalette.get()[index]);
+        *pDestPixel++ = FXARGB_G(m_pPalette.get()[index]);
+        *pDestPixel++ = FXARGB_R(m_pPalette.get()[index]);
+      } else {
+        *pDestPixel++ = index;
+        *pDestPixel++ = index;
+        *pDestPixel++ = index;
+      }
+      *pDestPixel = (index < m_pCompData[0].m_ColorKeyMin ||
+                     index > m_pCompData[0].m_ColorKeyMax)
+                        ? 0xFF
+                        : 0;
+    }
+    return;
+  }
+  for (int i = 0; i < clip_width; i++) {
+    uint32_t src_x = (clip_left + i) * src_width / dest_width;
+    if (bFlipX) {
+      src_x = src_width - src_x - 1;
+    }
+    src_x %= src_width;
+    uint8_t index = pSrcLine[src_x];
+    if (dest_Bpp == 1) {
+      dest_scan[i] = index;
+    } else {
+      int dest_pos = i * dest_Bpp;
+      FX_ARGB argb = m_pPalette.get()[index];
+      dest_scan[dest_pos] = FXARGB_B(argb);
+      dest_scan[dest_pos + 1] = FXARGB_G(argb);
+      dest_scan[dest_pos + 2] = FXARGB_R(argb);
+    }
+  }
+}
+
+void CPDF_DIBSource::DownSampleScanline32Bit(int orig_Bpp,
+                                             int dest_Bpp,
+                                             uint32_t src_width,
+                                             const uint8_t* pSrcLine,
+                                             uint8_t* dest_scan,
+                                             int dest_width,
+                                             bool bFlipX,
+                                             int clip_left,
+                                             int clip_width) const {
+  // last_src_x used to store the last seen src_x position which should be
+  // in [0, src_width). Set the initial value to be an invalid src_x value.
+  uint32_t last_src_x = src_width;
+  FX_ARGB last_argb = FXARGB_MAKE(0xFF, 0xFF, 0xFF, 0xFF);
+  FX_FLOAT unit_To8Bpc = 255.0f / ((1 << m_bpc) - 1);
+  for (int i = 0; i < clip_width; i++) {
+    int dest_x = clip_left + i;
+    uint32_t src_x = (bFlipX ? (dest_width - dest_x - 1) : dest_x) *
+                     (int64_t)src_width / dest_width;
+    src_x %= src_width;
+
+    uint8_t* pDestPixel = dest_scan + i * dest_Bpp;
+    FX_ARGB argb;
+    if (src_x == last_src_x) {
+      argb = last_argb;
+    } else {
+      CFX_FixedBufGrow<uint8_t, 128> extracted_components(m_nComponents);
+      const uint8_t* pSrcPixel = nullptr;
+      if (m_bpc % 8 != 0) {
+        // No need to check for 32-bit overflow, as |src_x| is bounded by
+        // |src_width| and DownSampleScanline() already checked for overflow
+        // with the pitch calculation.
+        size_t num_bits = src_x * m_bpc * m_nComponents;
+        uint64_t src_bit_pos = num_bits % 8;
+        pSrcPixel = pSrcLine + num_bits / 8;
+        for (uint32_t j = 0; j < m_nComponents; ++j) {
+          extracted_components[j] = static_cast<uint8_t>(
+              GetBits8(pSrcPixel, src_bit_pos, m_bpc) * unit_To8Bpc);
+          src_bit_pos += m_bpc;
+        }
+        pSrcPixel = extracted_components;
+      } else {
+        pSrcPixel = pSrcLine + src_x * orig_Bpp;
+        if (m_bpc == 16) {
+          for (uint32_t j = 0; j < m_nComponents; ++j)
+            extracted_components[j] = pSrcPixel[j * 2];
+          pSrcPixel = extracted_components;
+        }
+      }
+
+      if (m_pColorSpace) {
+        uint8_t color[4];
+        const bool bTransMask = TransMask();
+        if (m_bDefaultDecode) {
+          m_pColorSpace->TranslateImageLine(color, pSrcPixel, 1, 0, 0,
+                                            bTransMask);
+        } else {
+          for (uint32_t j = 0; j < m_nComponents; ++j) {
+            FX_FLOAT component_value =
+                static_cast<FX_FLOAT>(extracted_components[j]);
+            int color_value = static_cast<int>(
+                (m_pCompData[j].m_DecodeMin +
+                 m_pCompData[j].m_DecodeStep * component_value) *
+                    255.0f +
+                0.5f);
+            extracted_components[j] =
+                color_value > 255 ? 255 : (color_value < 0 ? 0 : color_value);
+          }
+          m_pColorSpace->TranslateImageLine(color, extracted_components, 1, 0,
+                                            0, bTransMask);
+        }
+        argb = FXARGB_MAKE(0xFF, color[2], color[1], color[0]);
+      } else {
+        argb = FXARGB_MAKE(0xFF, pSrcPixel[2], pSrcPixel[1], pSrcPixel[0]);
+      }
+      if (m_bColorKey) {
+        int alpha = 0xFF;
+        if (m_nComponents == 3 && m_bpc == 8) {
+          alpha = (pSrcPixel[0] < m_pCompData[0].m_ColorKeyMin ||
+                   pSrcPixel[0] > m_pCompData[0].m_ColorKeyMax ||
+                   pSrcPixel[1] < m_pCompData[1].m_ColorKeyMin ||
+                   pSrcPixel[1] > m_pCompData[1].m_ColorKeyMax ||
+                   pSrcPixel[2] < m_pCompData[2].m_ColorKeyMin ||
+                   pSrcPixel[2] > m_pCompData[2].m_ColorKeyMax)
+                      ? 0xFF
+                      : 0;
+        }
+        argb &= 0xFFFFFF;
+        argb |= alpha << 24;
+      }
+      last_src_x = src_x;
+      last_argb = argb;
+    }
+    if (dest_Bpp == 4) {
+      *reinterpret_cast<uint32_t*>(pDestPixel) = FXARGB_TODIB(argb);
+    } else {
+      *pDestPixel++ = FXARGB_B(argb);
+      *pDestPixel++ = FXARGB_G(argb);
+      *pDestPixel = FXARGB_R(argb);
+    }
+  }
+}
+
+bool CPDF_DIBSource::TransMask() const {
+  return m_bLoadMask && m_GroupFamily == PDFCS_DEVICECMYK &&
+         m_Family == PDFCS_DEVICECMYK;
+}