ximaexif.cpp

It s a tool designed to extract as much information as possible from Bluetooth devices without the r

            *LastExifRefdP = ValuePtr+ByteCount;
        }

        /* Extract useful components of tag */
        switch(Tag){

            case TAG_MAKE:
                strncpy(m_exifinfo->CameraMake, (char*)ValuePtr, 31);
                break;

            case TAG_MODEL:
                strncpy(m_exifinfo->CameraModel, (char*)ValuePtr, 39);
                break;

			case TAG_EXIF_VERSION:
				strncpy(m_exifinfo->Version,(char*)ValuePtr, 4);
				break;

            case TAG_DATETIME_ORIGINAL:
                strncpy(m_exifinfo->DateTime, (char*)ValuePtr, 19);
                break;

            case TAG_USERCOMMENT:
                // Olympus has this padded with trailing spaces. Remove these first. 
                for (a=ByteCount;;){
                    a--;
                    if (((char*)ValuePtr)[a] == ' '){
                        ((char*)ValuePtr)[a] = '\0';
                    }else{
                        break;
                    }
                    if (a == 0) break;
                }

                /* Copy the comment */
                if (memcmp(ValuePtr, "ASCII",5) == 0){
                    for (a=5;a<10;a++){
                        char c;
                        c = ((char*)ValuePtr)[a];
                        if (c != '\0' && c != ' '){
                            strncpy(m_exifinfo->Comments, (char*)ValuePtr+a, 199);
                            break;
                        }
                    }
                    
                }else{
                    strncpy(m_exifinfo->Comments, (char*)ValuePtr, 199);
                }
                break;

            case TAG_FNUMBER:
                /* Simplest way of expressing aperture, so I trust it the most.
                   (overwrite previously computd value if there is one)
                   */
                m_exifinfo->ApertureFNumber = (float)ConvertAnyFormat(ValuePtr, Format);
                break;

            case TAG_APERTURE:
            case TAG_MAXAPERTURE:
                /* More relevant info always comes earlier, so only
                 use this field if we don't have appropriate aperture
                 information yet. 
                */
                if (m_exifinfo->ApertureFNumber == 0){
                    m_exifinfo->ApertureFNumber = (float)exp(ConvertAnyFormat(ValuePtr, Format)*log(2.0f)*0.5);
                }
                break;

			case TAG_BRIGHTNESS:
				m_exifinfo->Brightness = (float)ConvertAnyFormat(ValuePtr, Format);
				break;

            case TAG_FOCALLENGTH:
                /* Nice digital cameras actually save the focal length
                   as a function of how farthey are zoomed in. 
                */

                m_exifinfo->FocalLength = (float)ConvertAnyFormat(ValuePtr, Format);
                break;

            case TAG_SUBJECT_DISTANCE:
                /* Inidcates the distacne the autofocus camera is focused to.
                   Tends to be less accurate as distance increases.
                */
                m_exifinfo->Distance = (float)ConvertAnyFormat(ValuePtr, Format);
                break;

            case TAG_EXPOSURETIME:
                /* Simplest way of expressing exposure time, so I
                   trust it most.  (overwrite previously computd value
                   if there is one) 
                */
                m_exifinfo->ExposureTime = 
                    (float)ConvertAnyFormat(ValuePtr, Format);
                break;

            case TAG_SHUTTERSPEED:
                /* More complicated way of expressing exposure time,
                   so only use this value if we don't already have it
                   from somewhere else.  
                */
                if (m_exifinfo->ExposureTime == 0){
                    m_exifinfo->ExposureTime = (float)
                        (1/exp(ConvertAnyFormat(ValuePtr, Format)*log(2.0f)));
                }
                break;

            case TAG_FLASH:
                if ((int)ConvertAnyFormat(ValuePtr, Format) & 7){
                    m_exifinfo->FlashUsed = 1;
                }else{
                    m_exifinfo->FlashUsed = 0;
                }
                break;

            case TAG_ORIENTATION:
                m_exifinfo->Orientation = (int)ConvertAnyFormat(ValuePtr, Format);
                if (m_exifinfo->Orientation < 1 || m_exifinfo->Orientation > 8){
                    strcpy(m_szLastError,"Undefined rotation value");
                    m_exifinfo->Orientation = 0;
                }
                break;

            case TAG_EXIF_IMAGELENGTH:
            case TAG_EXIF_IMAGEWIDTH:
                /* Use largest of height and width to deal with images
                   that have been rotated to portrait format.  
                */
                a = (int)ConvertAnyFormat(ValuePtr, Format);
                if (ExifImageWidth < a) ExifImageWidth = a;
                break;

            case TAG_FOCALPLANEXRES:
                m_exifinfo->FocalplaneXRes = (float)ConvertAnyFormat(ValuePtr, Format);
                break;

            case TAG_FOCALPLANEYRES:
                m_exifinfo->FocalplaneYRes = (float)ConvertAnyFormat(ValuePtr, Format);
                break;

			case TAG_RESOLUTIONUNIT:
                switch((int)ConvertAnyFormat(ValuePtr, Format)){
                    case 1: m_exifinfo->ResolutionUnit = 1.0f; break; /* 1 inch */
                    case 2:	m_exifinfo->ResolutionUnit = 1.0f; break;
                    case 3: m_exifinfo->ResolutionUnit = 0.3937007874f;    break;  /* 1 centimeter*/
                    case 4: m_exifinfo->ResolutionUnit = 0.03937007874f;   break;  /* 1 millimeter*/
                    case 5: m_exifinfo->ResolutionUnit = 0.00003937007874f;  /* 1 micrometer*/
                }
                break;

            case TAG_FOCALPLANEUNITS:
                switch((int)ConvertAnyFormat(ValuePtr, Format)){
                    case 1: m_exifinfo->FocalplaneUnits = 1.0f; break; /* 1 inch */
                    case 2:	m_exifinfo->FocalplaneUnits = 1.0f; break;
                    case 3: m_exifinfo->FocalplaneUnits = 0.3937007874f;    break;  /* 1 centimeter*/
                    case 4: m_exifinfo->FocalplaneUnits = 0.03937007874f;   break;  /* 1 millimeter*/
                    case 5: m_exifinfo->FocalplaneUnits = 0.00003937007874f;  /* 1 micrometer*/
                }
                break;

                // Remaining cases contributed by: Volker C. Schoech <schoech(at)gmx(dot)de>

            case TAG_EXPOSURE_BIAS:
                m_exifinfo->ExposureBias = (float) ConvertAnyFormat(ValuePtr, Format);
                break;

            case TAG_WHITEBALANCE:
                m_exifinfo->Whitebalance = (int)ConvertAnyFormat(ValuePtr, Format);
                break;

            case TAG_METERING_MODE:
                m_exifinfo->MeteringMode = (int)ConvertAnyFormat(ValuePtr, Format);
                break;

            case TAG_EXPOSURE_PROGRAM:
                m_exifinfo->ExposureProgram = (int)ConvertAnyFormat(ValuePtr, Format);
                break;

            case TAG_ISO_EQUIVALENT:
                m_exifinfo->ISOequivalent = (int)ConvertAnyFormat(ValuePtr, Format);
                if ( m_exifinfo->ISOequivalent < 50 ) m_exifinfo->ISOequivalent *= 200;
                break;

            case TAG_COMPRESSION_LEVEL:
                m_exifinfo->CompressionLevel = (int)ConvertAnyFormat(ValuePtr, Format);
                break;

            case TAG_XRESOLUTION:
                m_exifinfo->Xresolution = (float)ConvertAnyFormat(ValuePtr, Format);
                break;
            case TAG_YRESOLUTION:
                m_exifinfo->Yresolution = (float)ConvertAnyFormat(ValuePtr, Format);
                break;

            case TAG_THUMBNAIL_OFFSET:
                ThumbnailOffset = (unsigned)ConvertAnyFormat(ValuePtr, Format);
                break;

            case TAG_THUMBNAIL_LENGTH:
                ThumbnailSize = (unsigned)ConvertAnyFormat(ValuePtr, Format);
                break;

        }

        if (Tag == TAG_EXIF_OFFSET || Tag == TAG_INTEROP_OFFSET){
            unsigned char * SubdirStart;
			unsigned Offset = Get32u(ValuePtr);
			if (Offset>8){
				SubdirStart = OffsetBase + Offset;
				if (SubdirStart < OffsetBase || 
					SubdirStart > OffsetBase+ExifLength){
					strcpy(m_szLastError,"Illegal subdirectory link");
					return false;
				}
				ProcessExifDir(SubdirStart, OffsetBase, ExifLength, m_exifinfo, LastExifRefdP);
			}
            continue;
        }
    }


    {
        /* In addition to linking to subdirectories via exif tags,
           there's also a potential link to another directory at the end
           of each directory.  This has got to be the result of a
           committee!  
        */
        unsigned char * SubdirStart;
        unsigned Offset;
        Offset = Get16u(DirStart+2+12*NumDirEntries);
        if (Offset){
            SubdirStart = OffsetBase + Offset;
            if (SubdirStart < OffsetBase 
                || SubdirStart > OffsetBase+ExifLength){
                strcpy(m_szLastError,"Illegal subdirectory link");
				return false;
            }
            ProcessExifDir(SubdirStart, OffsetBase, ExifLength, m_exifinfo, LastExifRefdP);
        }
    }


    if (ThumbnailSize && ThumbnailOffset){
        if (ThumbnailSize + ThumbnailOffset <= ExifLength){
            /* The thumbnail pointer appears to be valid.  Store it. */
            m_exifinfo->ThumbnailPointer = OffsetBase + ThumbnailOffset;
            m_exifinfo->ThumbnailSize = ThumbnailSize;
        }
    }

	return true;
}
////////////////////////////////////////////////////////////////////////////////
/*--------------------------------------------------------------------------
   Evaluate number, be it int, rational, or float from directory.
--------------------------------------------------------------------------*/
double CxImageJPG::CxExifInfo::ConvertAnyFormat(void * ValuePtr, int Format)
{
    double Value;
    Value = 0;

    switch(Format){
        case FMT_SBYTE:     Value = *(signed char *)ValuePtr;  break;
        case FMT_BYTE:      Value = *(unsigned char *)ValuePtr;        break;

        case FMT_USHORT:    Value = Get16u(ValuePtr);          break;
        case FMT_ULONG:     Value = Get32u(ValuePtr);          break;

        case FMT_URATIONAL:
        case FMT_SRATIONAL: 
            {
                int Num,Den;
                Num = Get32s(ValuePtr);
                Den = Get32s(4+(char *)ValuePtr);
                if (Den == 0){
                    Value = 0;
                }else{
                    Value = (double)Num/Den;
                }
                break;
            }

        case FMT_SSHORT:    Value = (signed short)Get16u(ValuePtr);  break;
        case FMT_SLONG:     Value = Get32s(ValuePtr);                break;

        /* Not sure if this is correct (never seen float used in Exif format)
         */
        case FMT_SINGLE:    Value = (double)*(float *)ValuePtr;      break;
        case FMT_DOUBLE:    Value = *(double *)ValuePtr;             break;
    }
    return Value;
}
////////////////////////////////////////////////////////////////////////////////
void CxImageJPG::CxExifInfo::process_COM (const BYTE * Data, int length)
{
    int ch;
    char Comment[MAX_COMMENT+1];
    int nch;
    int a;

    nch = 0;

    if (length > MAX_COMMENT) length = MAX_COMMENT; // Truncate if it won't fit in our structure.

    for (a=2;a<length;a++){
        ch = Data[a];

        if (ch == '\r' && Data[a+1] == '\n') continue; // Remove cr followed by lf.

        if (isprint(ch) || ch == '\n' || ch == '\t'){
            Comment[nch++] = (char)ch;
        }else{
            Comment[nch++] = '?';
        }
    }

    Comment[nch] = '\0'; // Null terminate

    //if (ShowTags) printf("COM marker comment: %s\n",Comment);

    strcpy(m_exifinfo->Comments,Comment);
}
////////////////////////////////////////////////////////////////////////////////
void CxImageJPG::CxExifInfo::process_SOFn (const BYTE * Data, int marker)
{
    int data_precision, num_components;

    data_precision = Data[2];
    m_exifinfo->Height = Get16m((void*)(Data+3));
    m_exifinfo->Width = Get16m((void*)(Data+5));
    num_components = Data[7];

    if (num_components == 3){
        m_exifinfo->IsColor = 1;
    }else{
        m_exifinfo->IsColor = 0;
    }

    m_exifinfo->Process = marker;

    //if (ShowTags) printf("JPEG image is %uw * %uh, %d color components, %d bits per sample\n",
    //               ImageInfo.Width, ImageInfo.Height, num_components, data_precision);
}
////////////////////////////////////////////////////////////////////////////////
/**
 * this will work only on a CxImageJPG object, if the image originally has valid EXIF data
 \verbatim
	CxImageJPG jpg;
	CxIOFile in,out;
	in.Open("D:\\exif_in.jpg","rb");
	out.Open("D:\\exif_out.jpg","w+b");
	jpg.Decode(&in);
	if (jpg.IsValid()){
		jpg.RotateLeft();
		jpg.Encode(&out);
	}
 \endverbatim
*/
bool CxImageJPG::CxExifInfo::EncodeExif(CxFile * hFile)
{
    int a;

    if (FindSection(M_SOS)==NULL){
		strcpy(m_szLastError,"Can't write exif : didn't read all");
		return false;
    }

    // Initial static jpeg marker.
	hFile->PutC(0xff);
	hFile->PutC(0xd8);
    
    if (Sections[0].Type != M_EXIF && Sections[0].Type != M_JFIF){
        // The image must start with an exif or jfif marker.  If we threw those away, create one.
        static BYTE JfifHead[18] = {
            0xff, M_JFIF,
            0x00, 0x10, 'J' , 'F' , 'I' , 'F' , 0x00, 0x01, 
            0x01, 0x01, 0x01, 0x2C, 0x01, 0x2C, 0x00, 0x00 
        };
        hFile->Write(JfifHead, 18, 1);
    }

    // Write all the misc sections
    for (a=0;a<SectionsRead-1;a++){
        hFile->PutC(0xff);
        hFile->PutC(Sections[a].Type);
        hFile->Write(Sections[a].Data, Sections[a].Size, 1);
    }

    // Write the remaining image data.
    hFile->Write(Sections[a].Data, Sections[a].Size, 1);

	return true;
}
////////////////////////////////////////////////////////////////////////////////
void CxImageJPG::CxExifInfo::DiscardAllButExif()
{
    Section_t ExifKeeper;
    Section_t CommentKeeper;
    int a;

    memset(&ExifKeeper, 0, sizeof(ExifKeeper));
    memset(&CommentKeeper, 0, sizeof(ExifKeeper));

    for (a=0;a<SectionsRead;a++){
        if (Sections[a].Type == M_EXIF && ExifKeeper.Type == 0){
            ExifKeeper = Sections[a];
        }else if (Sections[a].Type == M_COM && CommentKeeper.Type == 0){
            CommentKeeper = Sections[a];
        }else{
            free(Sections[a].Data);
			Sections[a].Data = 0;
        }
    }
    SectionsRead = 0;
    if (ExifKeeper.Type){
        Sections[SectionsRead++] = ExifKeeper;
    }
    if (CommentKeeper.Type){
        Sections[SectionsRead++] = CommentKeeper;
    }
}
////////////////////////////////////////////////////////////////////////////////
void* CxImageJPG::CxExifInfo::FindSection(int SectionType)
{
    int a;
    for (a=0;a<SectionsRead-1;a++){
        if (Sections[a].Type == SectionType){
            return &Sections[a];
        }
    }
    // Could not be found.
    return NULL;
}
////////////////////////////////////////////////////////////////////////////////
#endif 	// CXIMAGEJPG_SUPPORT_EXIF