APIs and tests for retrieving raw/decoded data from image objects

Added FPDFImageObj_GetImageDataDecoded() for retrieving the uncompressed
data of an image, and FPDFImageObj_GetImageDataRaw() for retrieving the
raw data of an image.
    * Refactored out DecodeStreamMaybeCopyAndReturnLength(), which is
      used to decode both attachment data and image data.
    * Within DecodeStreamMaybeCopyAndReturnLength(), used a different
      decoder function which takes care of multiple filters if exist. As
      a result, CPDF_StreamParser::DecodeInlineStream() which was made
      static previously is now moved back into namespace.

Bug=pdfium:677

Change-Id: I22a22c99acaca98ef8c15f88911f2646a2c854d5
Reviewed-on: https://pdfium-review.googlesource.com/9811
Commit-Queue: Jane Liu <janeliulwq@google.com>
Reviewed-by: Lei Zhang <thestig@chromium.org>

1 files changed, 29 insertions, 0 deletions

diff --git a/public/fpdf_edit.h b/public/fpdf_edit.h
index e5607d1716..dc710b5f52 100644
--- a/public/fpdf_edit.h
+++ b/public/fpdf_edit.h
@@ -298,6 +298,35 @@ DLLEXPORT FPDF_BOOL STDCALL FPDFImageObj_SetBitmap(FPDF_PAGE* pages,
 DLLEXPORT FPDF_BITMAP STDCALL
 FPDFImageObj_GetBitmap(FPDF_PAGEOBJECT image_object);
 
+// Get the decoded image data of |image_object|. The decoded data is the
+// uncompressed image data, i.e. the raw image data after having all filters
+// applied. |buffer| is only modified if |buflen| is longer than the length of
+// the decoded image data.
+//
+//   image_object - handle to an image object.
+//   buffer       - buffer for holding the decoded image data in raw bytes.
+//   buflen       - length of the buffer.
+//
+// Returns the length of the decoded image data.
+DLLEXPORT unsigned long STDCALL
+FPDFImageObj_GetImageDataDecoded(FPDF_PAGEOBJECT image_object,
+                                 void* buffer,
+                                 unsigned long buflen);
+
+// Get the raw image data of |image_object|. The raw data is the image data as
+// stored in the PDF without applying any filters. |buffer| is only modified if
+// |buflen| is longer than the length of the raw image data.
+//
+//   image_object - handle to an image object.
+//   buffer       - buffer for holding the raw image data in raw bytes.
+//   buflen       - length of the buffer.
+//
+// Returns the length of the raw image data.
+DLLEXPORT unsigned long STDCALL
+FPDFImageObj_GetImageDataRaw(FPDF_PAGEOBJECT image_object,
+                             void* buffer,
+                             unsigned long buflen);
+
 // Create a new path object at an initial position.
 //
 //   x - initial horizontal position.