+void JPXStream::getImageParams(int *bitsPerComponent,
+ StreamColorSpaceMode *csMode) {
+ Guint boxType, boxLen, dataLen, csEnum;
+ Guint bpc1, dummy, i;
+ int csMeth, csPrec, csPrec1, dummy2;
+ StreamColorSpaceMode csMode1;
+ GBool haveBPC, haveCSMode;
+
+ csPrec = 0; // make gcc happy
+ haveBPC = haveCSMode = gFalse;
+ str->reset();
+ if (str->lookChar() == 0xff) {
+ getImageParams2(bitsPerComponent, csMode);
+ } else {
+ while (readBoxHdr(&boxType, &boxLen, &dataLen)) {
+ if (boxType == 0x6a703268) { // JP2 header
+ // skip the superbox
+ } else if (boxType == 0x69686472) { // image header
+ if (readULong(&dummy) &&
+ readULong(&dummy) &&
+ readUWord(&dummy) &&
+ readUByte(&bpc1) &&
+ readUByte(&dummy) &&
+ readUByte(&dummy) &&
+ readUByte(&dummy)) {
+ *bitsPerComponent = bpc1 + 1;
+ haveBPC = gTrue;
+ }
+ } else if (boxType == 0x636F6C72) { // color specification
+ if (readByte(&csMeth) &&
+ readByte(&csPrec1) &&
+ readByte(&dummy2)) {
+ if (csMeth == 1) {
+ if (readULong(&csEnum)) {
+ csMode1 = streamCSNone;
+ if (csEnum == jpxCSBiLevel ||
+ csEnum == jpxCSGrayscale) {
+ csMode1 = streamCSDeviceGray;
+ } else if (csEnum == jpxCSCMYK) {
+ csMode1 = streamCSDeviceCMYK;
+ } else if (csEnum == jpxCSsRGB ||
+ csEnum == jpxCSCISesRGB ||
+ csEnum == jpxCSROMMRGB) {
+ csMode1 = streamCSDeviceRGB;
+ }
+ if (csMode1 != streamCSNone &&
+ (!haveCSMode || csPrec1 > csPrec)) {
+ *csMode = csMode1;
+ csPrec = csPrec1;
+ haveCSMode = gTrue;
+ }
+ for (i = 0; i < dataLen - 7; ++i) {
+ str->getChar();
+ }
+ }
+ } else {
+ for (i = 0; i < dataLen - 3; ++i) {
+ str->getChar();
+ }
+ }
+ }
+ } else if (boxType == 0x6A703263) { // codestream
+ if (!(haveBPC && haveCSMode)) {
+ getImageParams2(bitsPerComponent, csMode);
+ }
+ break;
+ } else {
+ for (i = 0; i < dataLen; ++i) {
+ str->getChar();
+ }
+ }
+ }
+ }
+ str->close();
+}
+
+// Get image parameters from the codestream.
+void JPXStream::getImageParams2(int *bitsPerComponent,
+ StreamColorSpaceMode *csMode) {
+ int segType;
+ Guint segLen, nComps1, bpc1, dummy, i;
+
+ while (readMarkerHdr(&segType, &segLen)) {
+ if (segType == 0x51) { // SIZ - image and tile size
+ if (readUWord(&dummy) &&
+ readULong(&dummy) &&
+ readULong(&dummy) &&
+ readULong(&dummy) &&
+ readULong(&dummy) &&
+ readULong(&dummy) &&
+ readULong(&dummy) &&
+ readULong(&dummy) &&
+ readULong(&dummy) &&
+ readUWord(&nComps1) &&
+ readUByte(&bpc1)) {
+ *bitsPerComponent = (bpc1 & 0x7f) + 1;
+ // if there's no color space info, take a guess
+ if (nComps1 == 1) {
+ *csMode = streamCSDeviceGray;
+ } else if (nComps1 == 3) {
+ *csMode = streamCSDeviceRGB;
+ } else if (nComps1 == 4) {
+ *csMode = streamCSDeviceCMYK;
+ }
+ }
+ break;
+ } else {
+ if (segLen > 2) {
+ for (i = 0; i < segLen - 2; ++i) {
+ str->getChar();
+ }
+ }
+ }
+ }
+}
+