Encapsulate more JPEG2000 decoding logic
Even though previous CLs moved some code out to helper functions,
CPDF_DIB::LoadJpxBitmap() is still over 150 lines long. Do another round
of refactoring to move JPEG2000 decoding logic into a separate
JpxDecodeConversion class.
Change-Id: I64d72dcd618210f022f545efee844a46f3f08589
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/134212
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
diff --git a/core/fpdfapi/page/cpdf_dib.cpp b/core/fpdfapi/page/cpdf_dib.cpp
index ed153fe..ede4844 100644
--- a/core/fpdfapi/page/cpdf_dib.cpp
+++ b/core/fpdfapi/page/cpdf_dib.cpp
@@ -201,17 +201,6 @@
NOTREACHED();
}
-std::optional<JpxDecodeAction> GetJpxDecodeAction(
- const CJPX_Decoder::JpxImageInfo& jpx_info,
- const CPDF_ColorSpace* pdf_colorspace) {
- if (pdf_colorspace) {
- return GetJpxDecodeActionFromColorSpaces(jpx_info, pdf_colorspace);
- }
-
- // When PDF does not provide a color space, check the image color space.
- return GetJpxDecodeActionFromImageColorSpace(jpx_info);
-}
-
int GetComponentCountFromOpjColorSpace(OPJ_COLOR_SPACE colorspace) {
switch (colorspace) {
case OPJ_CLRSPC_UNKNOWN:
@@ -232,6 +221,89 @@
NOTREACHED();
}
+class JpxDecodeConversion {
+ public:
+ static std::optional<JpxDecodeConversion> Create(
+ const CJPX_Decoder::JpxImageInfo& jpx_info,
+ const CPDF_ColorSpace* pdf_colorspace) {
+ // When the PDF does not provide a color space, check the image color space.
+ std::optional<JpxDecodeAction> maybe_action =
+ pdf_colorspace
+ ? GetJpxDecodeActionFromColorSpaces(jpx_info, pdf_colorspace)
+ : GetJpxDecodeActionFromImageColorSpace(jpx_info);
+ if (!maybe_action.has_value()) {
+ return std::nullopt;
+ }
+
+ JpxDecodeConversion conversion;
+ conversion.action_ = maybe_action.value();
+ switch (conversion.action_) {
+ case JpxDecodeAction::kDoNothing:
+ break;
+
+ case JpxDecodeAction::kUseGray:
+ conversion.override_colorspace_ =
+ CPDF_ColorSpace::GetStockCS(CPDF_ColorSpace::Family::kDeviceGray);
+ break;
+
+ case JpxDecodeAction::kUseIndexed:
+ break;
+
+ case JpxDecodeAction::kUseRgb:
+ DCHECK_GE(jpx_info.channels, 3);
+ conversion.override_colorspace_ = nullptr;
+ break;
+
+ case JpxDecodeAction::kUseCmyk:
+ conversion.override_colorspace_ =
+ CPDF_ColorSpace::GetStockCS(CPDF_ColorSpace::Family::kDeviceCMYK);
+ break;
+
+ case JpxDecodeAction::kConvertArgbToRgb:
+ conversion.override_colorspace_ = nullptr;
+ break;
+ }
+
+ // If there exists a PDF colorspace, then CPDF_DIB already has the
+ // components count.
+ if (!pdf_colorspace) {
+ conversion.jpx_components_count_ =
+ GetComponentCountFromOpjColorSpace(jpx_info.colorspace);
+ }
+ return conversion;
+ }
+
+ JpxDecodeAction action() const { return action_; }
+
+ const std::optional<RetainPtr<CPDF_ColorSpace>>& override_colorspace() const {
+ return override_colorspace_;
+ }
+
+ const std::optional<int>& jpx_components_count() const {
+ return jpx_components_count_;
+ }
+
+ bool swap_rgb() const {
+ return action_ == JpxDecodeAction::kUseRgb ||
+ action_ == JpxDecodeAction::kConvertArgbToRgb;
+ }
+
+ private:
+ JpxDecodeAction action_;
+
+ // The colorspace to override the existing colorspace.
+ //
+ // std::nullopt means no override colorspace.
+ // nullptr means reset the colorspace.
+ std::optional<RetainPtr<CPDF_ColorSpace>> override_colorspace_;
+
+ // The components count from the JPEG2000 image.
+ //
+ // std::nullopt means no new components count.
+ // Value <= 0 means failure.
+ std::optional<int> jpx_components_count_;
+};
+
} // namespace
CPDF_DIB::CPDF_DIB(CPDF_Document* pDoc, RetainPtr<const CPDF_Stream> pStream)
@@ -729,66 +801,39 @@
return nullptr;
}
- RetainPtr<CPDF_ColorSpace> original_colorspace = color_space_;
- bool swap_rgb = false;
- bool convert_argb_to_rgb = false;
- auto maybe_action = GetJpxDecodeAction(image_info, color_space_.Get());
- if (!maybe_action.has_value()) {
+ auto maybe_conversion =
+ JpxDecodeConversion::Create(image_info, color_space_.Get());
+ if (!maybe_conversion.has_value()) {
return nullptr;
}
- const auto& action = maybe_action.value();
- switch (action) {
- case JpxDecodeAction::kDoNothing:
- break;
-
- case JpxDecodeAction::kUseGray:
- color_space_ =
- CPDF_ColorSpace::GetStockCS(CPDF_ColorSpace::Family::kDeviceGray);
- break;
-
- case JpxDecodeAction::kUseIndexed:
- break;
-
- case JpxDecodeAction::kUseRgb:
- DCHECK(image_info.channels >= 3);
- swap_rgb = true;
- color_space_ = nullptr;
- break;
-
- case JpxDecodeAction::kUseCmyk:
- color_space_ =
- CPDF_ColorSpace::GetStockCS(CPDF_ColorSpace::Family::kDeviceCMYK);
- break;
-
- case JpxDecodeAction::kConvertArgbToRgb:
- swap_rgb = true;
- convert_argb_to_rgb = true;
- color_space_.Reset();
- break;
+ const auto& conversion = maybe_conversion.value();
+ if (conversion.override_colorspace().has_value()) {
+ color_space_ = conversion.override_colorspace().value();
}
- // If |original_colorspace| exists, then LoadColorInfo() already set
- // |components_|.
- if (original_colorspace) {
- DCHECK_NE(0u, components_);
- } else {
+ if (conversion.jpx_components_count().has_value()) {
DCHECK_EQ(0u, components_);
- components_ = GetComponentCountFromOpjColorSpace(image_info.colorspace);
- if (components_ == 0) {
+ components_ = conversion.jpx_components_count().value();
+ if (components_ <= 0) {
return nullptr;
}
+ } else {
+ // LoadColorInfo() already set `components_`.
+ DCHECK_NE(0u, components_);
}
FXDIB_Format format;
- if (action == JpxDecodeAction::kUseGray ||
- action == JpxDecodeAction::kUseIndexed) {
+ if (conversion.action() == JpxDecodeAction::kUseGray ||
+ conversion.action() == JpxDecodeAction::kUseIndexed) {
format = FXDIB_Format::k8bppRgb;
- } else if (action == JpxDecodeAction::kUseRgb && image_info.channels == 3) {
+ } else if (conversion.action() == JpxDecodeAction::kUseRgb &&
+ image_info.channels == 3) {
format = FXDIB_Format::kBgr;
- } else if (action == JpxDecodeAction::kUseRgb && image_info.channels == 4) {
+ } else if (conversion.action() == JpxDecodeAction::kUseRgb &&
+ image_info.channels == 4) {
format = FXDIB_Format::kBgrx;
- } else if (action == JpxDecodeAction::kConvertArgbToRgb) {
+ } else if (conversion.action() == JpxDecodeAction::kConvertArgbToRgb) {
CHECK_GE(image_info.channels, 4);
format = FXDIB_Format::kBgrx;
} else {
@@ -803,11 +848,12 @@
result_bitmap->Clear(0xFFFFFFFF);
if (!decoder->Decode(result_bitmap->GetWritableBuffer(),
- result_bitmap->GetPitch(), swap_rgb, components_)) {
+ result_bitmap->GetPitch(), conversion.swap_rgb(),
+ components_)) {
return nullptr;
}
- if (convert_argb_to_rgb) {
+ if (conversion.action() == JpxDecodeAction::kConvertArgbToRgb) {
DCHECK_EQ(3u, components_);
auto rgb_bitmap = pdfium::MakeRetain<CFX_DIBitmap>();
if (!rgb_bitmap->Create(image_info.width, image_info.height,
