mode = Mode.forBits(bits.readBits(4)); // mode is encoded by 4 bits
}
if (!mode.equals(Mode.TERMINATOR)) {
- // How many characters will follow, encoded in this mode?
- int count = bits.readBits(mode.getCharacterCountBits(version));
- if (mode.equals(Mode.NUMERIC)) {
- decodeNumericSegment(bits, result, count);
- } else if (mode.equals(Mode.ALPHANUMERIC)) {
- decodeAlphanumericSegment(bits, result, count);
- } else if (mode.equals(Mode.BYTE)) {
- decodeByteSegment(bits, result, count);
- } else if (mode.equals(Mode.KANJI)) {
- decodeKanjiSegment(bits, result, count);
+ if (mode.equals(Mode.ECI)) {
+ // Count doesn't apply to ECI
+ parseECI(bits);
+ // We don't currently do anything with ECI, since there seems to be no reference
+ // defining what each value means. AIM's "Extended Channel Interpretations" does
+ // not define it. I have never observed a QR Code using it. So for now, we at least
+ // parse it but don't know how to take action on it.
} else {
- throw new ReaderException("Unsupported mode indicator");
+ // How many characters will follow, encoded in this mode?
+ int count = bits.readBits(mode.getCharacterCountBits(version));
+ if (mode.equals(Mode.NUMERIC)) {
+ decodeNumericSegment(bits, result, count);
+ } else if (mode.equals(Mode.ALPHANUMERIC)) {
+ decodeAlphanumericSegment(bits, result, count);
+ } else if (mode.equals(Mode.BYTE)) {
+ decodeByteSegment(bits, result, count);
+ } else if (mode.equals(Mode.KANJI)) {
+ decodeKanjiSegment(bits, result, count);
+ } else {
+ throw new ReaderException("Unsupported mode indicator");
+ }
}
}
} while (!mode.equals(Mode.TERMINATOR));
return result.toString();
}
+ private static int parseECI(BitSource bits) {
+ int firstByte = bits.readBits(8);
+ if (firstByte & 0x80 == 0) {
+ // just one byte
+ return firstByte & 0x7F;
+ } else if (firstByte & 0xC0 == 0x80) {
+ // two bytes
+ int secondByte = bits.readBits(8);
+ return ((firstByte & 0x3F) << 8) | secondByte;
+ } else if (firstByte & 0xE0 == 0xC0) {
+ // three bytes
+ int secondByte = bits.readBits(8);
+ int thirdByte = bits.readBits(8);
+ return ((firstByte & 0x1F) << 16) | (secondByte << 8) | thirdByte;
+ }
+ }
+
private static void decodeKanjiSegment(BitSource bits,
StringBuffer result,
int count) throws ReaderException {
static final Mode NUMERIC = new Mode(new int[]{10, 12, 14});
static final Mode ALPHANUMERIC = new Mode(new int[]{9, 11, 13});
static final Mode BYTE = new Mode(new int[]{8, 16, 16});
+ static final Mode ECI = new Mode(null); // character counts don't apply
static final Mode KANJI = new Mode(new int[]{8, 10, 12});
private final int[] characterCountBitsForVersions;
return ALPHANUMERIC;
case 0x4:
return BYTE;
+ case 0x7:
+ return ECI;
case 0x8:
return KANJI;
default:
* count of characters that will follow encoded in this {@link Mode}
*/
int getCharacterCountBits(Version version) {
+ if (this == ECI) {
+ throw new UnsupportedOperationException("Character count doesn't apply to ECI mode");
+ }
int number = version.getVersionNumber();
int offset;
if (number <= 9) {