diff --git a/core/fxcodec/bmp/cfx_bmpdecompressor.cpp b/core/fxcodec/bmp/cfx_bmpdecompressor.cpp
index 34c03da..0713429 100644
--- a/core/fxcodec/bmp/cfx_bmpdecompressor.cpp
+++ b/core/fxcodec/bmp/cfx_bmpdecompressor.cpp
@@ -104,10 +104,13 @@
     NOTREACHED();
   }
 
+  size_t pos = input_buffer_->GetPosition();
   if (!ReadData(reinterpret_cast<uint8_t*>(&img_ifh_size_),
                 sizeof(img_ifh_size_))) {
     return false;
   }
+  if (!input_buffer_->Seek(pos))
+    return false;
 
   img_ifh_size_ =
       FXDWORD_GET_LSBFIRST(reinterpret_cast<uint8_t*>(&img_ifh_size_));
diff --git a/core/fxcodec/progressivedecoder.cpp b/core/fxcodec/progressivedecoder.cpp
index 4e755ed..87223d6 100644
--- a/core/fxcodec/progressivedecoder.cpp
+++ b/core/fxcodec/progressivedecoder.cpp
@@ -747,9 +747,8 @@
     return false;
   }
 
-  uint32_t availableData = m_pCodecMemory->GetSize() > m_offSet
-                               ? m_pCodecMemory->GetSize() - m_offSet
-                               : 0;
+  uint32_t availableData = m_pFile->GetSize() - m_offSet +
+                           pBmpModule->GetAvailInput(pBmpContext.get());
   if (neededData > availableData) {
     m_status = FXCODEC_STATUS_ERR_FORMAT;
     return false;