2 files changed, 9 insertions, 0 deletions
diff --git a/indra/llimage/llimagej2c.cpp b/indra/llimage/llimagej2c.cpp
index 80fec7f8a0..6b49f3de88 100644
--- a/indra/llimage/llimagej2c.cpp
+++ b/indra/llimage/llimagej2c.cpp
@@ -139,6 +139,10 @@ BOOL LLImageJ2C::updateData()
 	return res;
 }
 
+BOOL LLImageJ2C::initDecode(LLImageRaw &raw_image, int discard_level, int* region)
+{
+	return mImpl->initDecode(*this,raw_image,discard_level,region);
+}
 
 BOOL LLImageJ2C::decode(LLImageRaw *raw_imagep, F32 decode_time)
 {
@@ -251,6 +255,9 @@ S32 LLImageJ2C::calcHeaderSizeJ2C()
 //static
 S32 LLImageJ2C::calcDataSizeJ2C(S32 w, S32 h, S32 comp, S32 discard_level, F32 rate)
 {
+	// Note: this only provides an *estimate* of the size in bytes of an image level
+	// *TODO: find a way to read the true size (when available) and convey the fact
+	// that the result is an estimate in the other cases
 	if (rate <= 0.f) rate = .125f;
 	while (discard_level > 0)
 	{
diff --git a/indra/llimage/llimagej2c.h b/indra/llimage/llimagej2c.h
index dd5bec8b2e..7af1c13921 100644
--- a/indra/llimage/llimagej2c.h
+++ b/indra/llimage/llimagej2c.h
@@ -56,6 +56,7 @@ public:
 	/*virtual*/ void resetLastError();
 	/*virtual*/ void setLastError(const std::string& message, const std::string& filename = std::string());
 	
+	BOOL initDecode(LLImageRaw &raw_image, int discard_level, int* region);
 	
 	// Encode with comment text 
 	BOOL encode(const LLImageRaw *raw_imagep, const char* comment_text, F32 encode_time=0.0);
@@ -117,6 +118,7 @@ protected:
 	virtual BOOL decodeImpl(LLImageJ2C &base, LLImageRaw &raw_image, F32 decode_time, S32 first_channel, S32 max_channel_count) = 0;
 	virtual BOOL encodeImpl(LLImageJ2C &base, const LLImageRaw &raw_image, const char* comment_text, F32 encode_time=0.0,
 							BOOL reversible=FALSE) = 0;
+	virtual BOOL initDecode(LLImageJ2C &base, LLImageRaw &raw_image, int discard_level = -1, int* region = NULL) = 0;
 
 	friend class LLImageJ2C;
 };