core/ difference with XFA (for information only).

core/src/fxcodec/codec/fx_codec_jpeg.cpp

 // Copyright 2014 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 <setjmp.h>
 
 #include "../../../include/fxcodec/fx_codec.h"
 #include "../../../include/fxcrt/fx_safe_types.h"
@@ skipping 206 matching lines @@
       dest.next_output_byte = dest_buf + dest_buf_length - dest.free_in_buffer;
       dest_buf_length += JPEG_BLOCK_SIZE;
       dest.free_in_buffer += JPEG_BLOCK_SIZE;
     }
   }
   jpeg_finish_compress(&cinfo);
   jpeg_destroy_compress(&cinfo);
   FX_Free(line_buf);
   dest_size = dest_buf_length - (FX_STRSIZE)dest.free_in_buffer;
 }
+#ifdef PDF_ENABLE_XFA
+static void _JpegLoadAttribute(struct jpeg_decompress_struct* pInfo,
+                               CFX_DIBAttribute* pAttribute) {
+  if (pInfo == NULL || pAttribute == NULL) {
+    return;
+  }
+  if (pAttribute) {
+    pAttribute->m_nXDPI = pInfo->X_density;
+    pAttribute->m_nYDPI = pInfo->Y_density;
+    pAttribute->m_wDPIUnit = pInfo->density_unit;
+  }
+}
+#endif
 static FX_BOOL _JpegLoadInfo(const uint8_t* src_buf,
                              FX_DWORD src_size,
                              int& width,
                              int& height,
                              int& num_components,
                              int& bits_per_components,
                              FX_BOOL& color_transform,
                              uint8_t** icc_buf_ptr,
                              FX_DWORD* icc_length) {
   _JpegScanSOI(src_buf, src_size);
@@ skipping 413 matching lines @@
     src_size -= p->m_SkipSize;
     src_buf += p->m_SkipSize;
     p->m_SkipSize = 0;
   }
   p->m_SrcMgr.next_input_byte = src_buf;
   p->m_SrcMgr.bytes_in_buffer = src_size;
 }
 int CCodec_JpegModule::ReadHeader(void* pContext,
                                   int* width,
                                   int* height,
+#ifndef PDF_ENABLE_XFA
                                   int* nComps) {
+#else
+                                  int* nComps,
+                                  CFX_DIBAttribute* pAttribute) {
+#endif
   if (m_pExtProvider) {
+#ifndef PDF_ENABLE_XFA
     return m_pExtProvider->ReadHeader(pContext, width, height, nComps);
+#else
+    return m_pExtProvider->ReadHeader(pContext, width, height, nComps,
+                                      pAttribute);
+#endif
   }
   FXJPEG_Context* p = (FXJPEG_Context*)pContext;
   if (setjmp(p->m_JumpMark) == -1) {
     return 1;
   }
   int ret = jpeg_read_header(&p->m_Info, true);
   if (ret == JPEG_SUSPENDED) {
     return 2;
   }
   if (ret != JPEG_HEADER_OK) {
     return 1;
   }
   *width = p->m_Info.image_width;
   *height = p->m_Info.image_height;
   *nComps = p->m_Info.num_components;
+#ifdef PDF_ENABLE_XFA
+  _JpegLoadAttribute(&p->m_Info, pAttribute);
+#endif
   return 0;
 }
 int CCodec_JpegModule::StartScanline(void* pContext, int down_scale) {
   if (m_pExtProvider) {
     return m_pExtProvider->StartScanline(pContext, down_scale);
   }
   FXJPEG_Context* p = (FXJPEG_Context*)pContext;
   if (setjmp(p->m_JumpMark) == -1) {
     return 0;
   }
@@ skipping 19 matching lines @@
   }
   if (avail_buf_ptr != NULL) {
     *avail_buf_ptr = NULL;
     if (((FXJPEG_Context*)pContext)->m_SrcMgr.bytes_in_buffer > 0) {
       *avail_buf_ptr =
           (uint8_t*)((FXJPEG_Context*)pContext)->m_SrcMgr.next_input_byte;
     }
   }
   return (FX_DWORD)((FXJPEG_Context*)pContext)->m_SrcMgr.bytes_in_buffer;
 }