tiff_filewriter.cpp

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	return true;
	
}	// FlipDSDTable

// =================================================================================================
// FlipOECFSFRTable
// ================
//
// The OECF and SFR tables have the same layout:
//    2 short counts, columns and rows
//    c ASCII strings, null terminated, column names
//    c*r rationals

static bool FlipOECFSFRTable ( void* voidPtr, XMP_Uns32 tagLen, GetUns16_Proc GetUns16 )
{
	XMP_Uns16* u16Ptr = (XMP_Uns16*)voidPtr;

	Flip2 ( &u16Ptr[0] );	// Flip the data to match the master TIFF.
	Flip2 ( &u16Ptr[1] );
	
	XMP_Uns16 columns = GetUns16 ( &u16Ptr[0] );	// Fetch using the master TIFF's routine.
	XMP_Uns16 rows    = GetUns16 ( &u16Ptr[1] );
	
	XMP_Uns32 minLen = 4 + columns + (8 * columns * rows);	// Minimum legit tag size.
	if ( tagLen < minLen ) return false;
	
	// Compute the start of the rationals from the end of value. No need to walk through the names.
	XMP_Uns32* u32Ptr = (XMP_Uns32*) ((XMP_Uns8*)voidPtr + tagLen - (8 * columns * rows));

	for ( size_t i = 2*columns*rows; i > 0; --i, ++u32Ptr ) Flip4 ( u32Ptr );
	
	return true;
	
}	// FlipOECFSFRTable

// =================================================================================================
// TIFF_FileWriter::ProcessPShop6IFD
// =================================
//
// Photoshop 6 wrote wacky TIFF files that have much of the Exif metadata buried inside of image
// resource 1058, which is itself within tag 34377 in the 0th IFD. This routine moves the buried
// tags up to the parent file. Existing tags are not replaced.
//
// While it is tempting to try to directly use the TIFF_MemoryReader's tweaked IFD info, making that
// visible would compromise implementation separation. Better to pay the modest runtime cost of 
// using the official GetIFD method, letting it build the map.
//
// The tags that get moved are marked as being changed, as is the IFD they are moved into, but the
// overall TIFF_FileWriter object is not. We don't want this integration on its own to force a file
// update, but a file update should include these changes.

// ! Be careful to not move tags that are the nasty Exif explicit offsets, e.g. the Exif or GPS IFD
// ! "pointers". These are tags with a LONG type and count of 1, whose value is an offset into the
// ! buried TIFF stream. We can't reliably plant that offset into the outer IFD structure.

// ! To make things even more fun, the buried Exif might not have the same endianness as the outer!

void TIFF_FileWriter::ProcessPShop6IFD ( const TIFF_MemoryReader& buriedExif, XMP_Uns8 ifd )
{
	bool ok, found;
	TagInfoMap ps6IFD;
	
	found = buriedExif.GetIFD ( ifd, &ps6IFD );
	if ( ! found ) return;
	
	bool needsFlipping = (this->bigEndian != buriedExif.IsBigEndian());
	
	InternalIFDInfo* masterIFD = &this->containedIFDs[ifd];
	
	TagInfoMap::const_iterator ps6Pos = ps6IFD.begin();
	TagInfoMap::const_iterator ps6End = ps6IFD.end();
		
	for ( ; ps6Pos != ps6End; ++ps6Pos ) {
	
		// Copy buried tags to the master IFD if they don't already exist there.
		
		const TagInfo& ps6Tag = ps6Pos->second;
	
		if ( this->FindTagInIFD ( ifd, ps6Tag.id ) != 0 ) continue;	// Keep existing master tags.
		if ( needsFlipping && (ps6Tag.id == 37500) ) continue;	// Don't copy an unflipped MakerNote.
		if ( (ps6Tag.id == kTIFF_ExifIFDPointer) ||	// Skip the tags that are explicit offsets.
			 (ps6Tag.id == kTIFF_GPSInfoIFDPointer) ||
			 (ps6Tag.id == kTIFF_JPEGInterchangeFormat) ||
			 (ps6Tag.id == kTIFF_InteroperabilityIFDPointer) ) continue;
		
		void* voidPtr = CopyTagToMasterIFD ( ps6Tag, masterIFD );
		
		if ( needsFlipping ) {
			switch ( ps6Tag.type ) {
	
				case kTIFF_ByteType:
				case kTIFF_SByteType:
				case kTIFF_ASCIIType:
					// Nothing more to do.
					break;
	
				case kTIFF_ShortType:
				case kTIFF_SShortType:
					{
						XMP_Uns16* u16Ptr = (XMP_Uns16*)voidPtr;
						for ( size_t i = ps6Tag.count; i > 0; --i, ++u16Ptr ) Flip2 ( u16Ptr );
					}
					break;
	
				case kTIFF_LongType:
				case kTIFF_SLongType:
				case kTIFF_FloatType:
					{
						XMP_Uns32* u32Ptr = (XMP_Uns32*)voidPtr;
						for ( size_t i = ps6Tag.count; i > 0; --i, ++u32Ptr ) Flip4 ( u32Ptr );
					}
					break;
	
				case kTIFF_RationalType:
				case kTIFF_SRationalType:
					{
						XMP_Uns32* ratPtr = (XMP_Uns32*)voidPtr;
						for ( size_t i = (2 * ps6Tag.count); i > 0; --i, ++ratPtr ) Flip4 ( ratPtr );
					}
					break;
	
				case kTIFF_DoubleType:
					{
						XMP_Uns64* u64Ptr = (XMP_Uns64*)voidPtr;
						for ( size_t i = ps6Tag.count; i > 0; --i, ++u64Ptr ) Flip8 ( u64Ptr );
					}
					break;
	
				case kTIFF_UndefinedType:
					// Fix up the few kinds of special tables that Exif 2.2 defines.
					ok = true;	// Keep everything that isn't a special table.
					if ( ps6Tag.id == kTIFF_CFAPattern ) {
						ok = FlipCFATable ( voidPtr, ps6Tag.dataLen, this->GetUns16 );
					} else if ( ps6Tag.id == kTIFF_DeviceSettingDescription ) {
						ok = FlipDSDTable ( voidPtr, ps6Tag.dataLen, this->GetUns16 );
					} else if ( (ps6Tag.id == kTIFF_OECF) || (ps6Tag.id == kTIFF_SpatialFrequencyResponse) ) {
						ok = FlipOECFSFRTable ( voidPtr, ps6Tag.dataLen, this->GetUns16 );
					}
					if ( ! ok ) this->DeleteTag ( ifd, ps6Tag.id );
					break;
				
				default:
					// ? XMP_Throw ( "Unexpected tag type", kXMPErr_InternalFailure );
					this->DeleteTag ( ifd, ps6Tag.id );
					break;
	
			}
		}
		
	}
	
}	// TIFF_FileWriter::ProcessPShop6IFD

// =================================================================================================
// TIFF_FileWriter::DetermineAppendInfo
// ====================================

#ifndef Trace_DetermineAppendInfo
	#define Trace_DetermineAppendInfo 0
#endif

XMP_Uns32 TIFF_FileWriter::DetermineAppendInfo ( XMP_Uns32 appendedOrigin,
												 bool      appendedIFDs[kTIFF_KnownIFDCount],
												 XMP_Uns32 newIFDOffsets[kTIFF_KnownIFDCount],
												 bool      appendAll /* = false */ )
{
	XMP_Uns32 appendedLength = 0;
	XMP_Assert ( (appendedOrigin & 1) == 0 );	// Make sure it is even.
	
	#if Trace_DetermineAppendInfo
	{
		printf ( "\nEntering TIFF_FileWriter::DetermineAppendInfo%s\n", (appendAll ? ", append all" : "") );
		for ( int ifd = 0; ifd < kTIFF_KnownIFDCount; ++ifd ) {
			InternalIFDInfo & thisIFD = this->containedIFDs[ifd];
			printf ( "\n   IFD %d, origCount %d, map.size %d, origOffset %d (0x%X), origNextIFD %d (0x%X)",
					 ifd, thisIFD.origCount, thisIFD.tagMap.size(),
					 thisIFD.origOffset, thisIFD.origOffset, thisIFD.origNextIFD, thisIFD.origNextIFD );
			if ( thisIFD.changed ) printf ( ", changed" );
			if ( thisIFD.origCount < thisIFD.tagMap.size() ) printf ( ", should get appended" );
			printf ( "\n" );
			InternalTagMap::iterator tagPos;
			InternalTagMap::iterator tagEnd = thisIFD.tagMap.end();
			for ( tagPos = thisIFD.tagMap.begin(); tagPos != tagEnd; ++tagPos ) {
				InternalTagInfo & thisTag = tagPos->second;
				printf ( "      Tag %d, dataOrOffset 0x%X, origLen %d, origOffset %d (0x%X)",
						 thisTag.id, thisTag.dataOrOffset, thisTag.origLen, thisTag.origOffset, thisTag.origOffset );
				if ( thisTag.changed ) printf ( ", changed" );
				if ( (thisTag.dataLen > thisTag.origLen) && (thisTag.dataLen > 4) ) printf ( ", should get appended" );
				printf ( "\n" );
			}
		}
		printf ( "\n" );
	}
	#endif
	
	// Determine which of the IFDs will be appended. If the Exif, GPS, or Interoperability IFDs are
	// appended, set dummy values for their offsets in the "owning" IFD. This must be done first
	// since this might cause the owning IFD to grow.
	
	if ( ! appendAll ) {
		for ( int i = 0; i < kTIFF_KnownIFDCount ;++i ) appendedIFDs[i] = false;
	} else {
		for ( int i = 0; i < kTIFF_KnownIFDCount ;++i ) appendedIFDs[i] = (this->containedIFDs[i].tagMap.size() > 0);
	}
	
	appendedIFDs[kTIFF_InteropIFD] |= (this->containedIFDs[kTIFF_InteropIFD].origCount <
									   this->containedIFDs[kTIFF_InteropIFD].tagMap.size());
	if ( appendedIFDs[kTIFF_InteropIFD] ) {
		this->SetTag_Long ( kTIFF_ExifIFD, kTIFF_InteroperabilityIFDPointer, 0xABADABAD );
	}
	
	appendedIFDs[kTIFF_GPSInfoIFD] |= (this->containedIFDs[kTIFF_GPSInfoIFD].origCount <
									   this->containedIFDs[kTIFF_GPSInfoIFD].tagMap.size());
	if ( appendedIFDs[kTIFF_GPSInfoIFD] ) {
		this->SetTag_Long ( kTIFF_PrimaryIFD, kTIFF_GPSInfoIFDPointer, 0xABADABAD );
	}
	
	appendedIFDs[kTIFF_ExifIFD] |= (this->containedIFDs[kTIFF_ExifIFD].origCount <
								    this->containedIFDs[kTIFF_ExifIFD].tagMap.size());
	if ( appendedIFDs[kTIFF_ExifIFD] ) {
		this->SetTag_Long ( kTIFF_PrimaryIFD, kTIFF_ExifIFDPointer, 0xABADABAD );
	}
	
	appendedIFDs[kTIFF_TNailIFD] |= (this->containedIFDs[kTIFF_TNailIFD].origCount <
									 this->containedIFDs[kTIFF_TNailIFD].tagMap.size());
	
	appendedIFDs[kTIFF_PrimaryIFD] |= (this->containedIFDs[kTIFF_PrimaryIFD].origCount <
									   this->containedIFDs[kTIFF_PrimaryIFD].tagMap.size());

	// The appended data (if any) will be a sequence of an IFD followed by its large values.
	// Determine the new offsets for the appended IFDs and tag values, and the total amount of
	// appended stuff. 
		
	for ( int ifd = 0; ifd < kTIFF_KnownIFDCount ;++ifd ) {
	
		InternalIFDInfo& ifdInfo ( this->containedIFDs[ifd] );
		size_t tagCount = ifdInfo.tagMap.size();

		if ( ! (appendAll | ifdInfo.changed) ) continue;
		if ( tagCount == 0 ) continue;
		
		newIFDOffsets[ifd] = ifdInfo.origOffset;
		if ( appendedIFDs[ifd] ) {
			newIFDOffsets[ifd] = appendedOrigin + appendedLength;
			appendedLength += 6 + (12 * tagCount);
		}
		
		InternalTagMap::iterator tagPos = ifdInfo.tagMap.begin();
		InternalTagMap::iterator tagEnd = ifdInfo.tagMap.end();

		for ( ; tagPos != tagEnd; ++tagPos ) {

			InternalTagInfo & currTag ( tagPos->second );
			if ( (! (appendAll | currTag.changed)) || (currTag.dataLen <= 4) ) continue;

			if ( (currTag.dataLen <= currTag.origLen) && (! appendAll) ) {
				this->PutUns32 ( currTag.origOffset, &currTag.dataOrOffset );	// Reuse the old space.
			} else {
				this->PutUns32 ( (appendedOrigin + appendedLength), &currTag.dataOrOffset );	// Set the appended offset.
				appendedLength += ((currTag.dataLen + 1) & 0xFFFFFFFEUL);	// Round to an even size.
			}

		}
	
	}
	
	// If the Exif, GPS, or Interoperability IFDs get appended, update the tag values for their new offsets.
	
	if ( appendedIFDs[kTIFF_ExifIFD] ) {
		this->SetTag_Long ( kTIFF_PrimaryIFD, kTIFF_ExifIFDPointer, newIFDOffsets[kTIFF_ExifIFD] );
	}
	if ( appendedIFDs[kTIFF_GPSInfoIFD] ) {
		this->SetTag_Long ( kTIFF_PrimaryIFD, kTIFF_GPSInfoIFDPointer, newIFDOffsets[kTIFF_GPSInfoIFD] );
	}
	if ( appendedIFDs[kTIFF_InteropIFD] ) {
		this->SetTag_Long ( kTIFF_ExifIFD, kTIFF_InteroperabilityIFDPointer, newIFDOffsets[kTIFF_InteropIFD] );
	}
	
	#if Trace_DetermineAppendInfo
	{
		printf ( "Exiting TIFF_FileWriter::DetermineAppendInfo\n" );
		for ( int ifd = 0; ifd < kTIFF_KnownIFDCount; ++ifd ) {
			InternalIFDInfo & thisIFD = this->containedIFDs[ifd];
			printf ( "\n   IFD %d, origCount %d, map.size %d, origOffset %d (0x%X), origNextIFD %d (0x%X)",
					 ifd, thisIFD.origCount, thisIFD.tagMap.size(),
					 thisIFD.origOffset, thisIFD.origOffset, thisIFD.origNextIFD, thisIFD.origNextIFD );
			if ( thisIFD.changed ) printf ( ", changed" );
			if ( appendedIFDs[ifd] ) printf ( ", will be appended at %d (0x%X)", newIFDOffsets[ifd], newIFDOffsets[ifd] );
			printf ( "\n" );
			InternalTagMap::iterator tagPos;
			InternalTagMap::iterator tagEnd = thisIFD.tagMap.end();
			for ( tagPos = thisIFD.tagMap.begin(); tagPos != tagEnd; ++tagPos ) {
				InternalTagInfo & thisTag = tagPos->second;
				printf ( "      Tag %d, dataOrOffset 0x%X, origLen %d, origOffset %d (0x%X)",
						 thisTag.id, thisTag.dataOrOffset, thisTag.origLen, thisTag.origOffset, thisTag.origOffset );
				if ( thisTag.changed ) printf ( ", changed" );
				if ( (thisTag.dataLen > thisTag.origLen) && (thisTag.dataLen > 4) ) {
					XMP_Uns32 newOffset = this->GetUns32 ( &thisTag.dataOrOffset );
					printf ( ", will be appended at %d (0x%X)", newOffset, newOffset );
				}
				printf ( "\n" );
			}
		}
		printf ( "\n" );
	}
	#endif
	
	return appendedLength;
	
}	// TIFF_FileWriter::DetermineAppendInfo

// =================================================================================================
// TIFF_FileWriter::UpdateMemByAppend
// ==================================
//
// Normally we update TIFF in a conservative "by-append" manner. Changes are written in-place where
// they fit, anything requiring growth is appended to the end and the old space is abandoned. The
// end for memory-based TIFF is the end of the data block, the end for file-based TIFF is the end of
// the file. This update-by-append model has the advantage of not perturbing any hidden offsets, a
// common feature of proprietary MakerNotes.
//
// When doing the update-by-append we're only going to be modifying things that have changed. This
// means IFDs with changed, added, or deleted tags, and large values for changed or added tags. The
// IFDs and tag values are updated in-place if they fit, leaving holes in the stream if the new
// value is smaller than the old.

// ** Someday we might want to use the FreeOffsets and FreeByteCounts tags to track free space.
// ** Probably not a huge win in practice though, and the TIFF spec says they are not recommended
// ** for general interchange use.

void TIFF_FileWriter::UpdateMemByAppend ( XMP_Uns8** newStream_out, XMP_Uns32* newLength_out,
										  bool appendAll /* = false */, XMP_Uns32 extraSpace /* = 0 */ )
{
	bool appendedIFDs[kTIFF_KnownIFDCount];
	XMP_Uns32 newIFDOffsets[kTIFF_KnownIFDCount];
	XMP_Uns32 appendedOrigin = ((this->tiffLength + 1) & 0xFFFFFFFEUL);	// Start at an even offset.
	XMP_Uns32 appendedLength = DetermineAppendInfo ( appendedOrigin, appendedIFDs, newIFDOffsets, appendAll );