import android.util.Log;
+import com.android.gallery3d.exif.ExifInvalidFormatException;
+import com.android.gallery3d.exif.ExifParser;
+import com.android.gallery3d.exif.ExifTag;
+
import java.io.IOException;
import java.io.InputStream;
public class Exif {
- private static final String TAG = "CameraExif";
+ private static final String TAG = "GalleryExif";
public static int getOrientation(InputStream is) {
if (is == null) {
return 0;
}
- byte[] buf = new byte[8];
- int length = 0;
-
- // ISO/IEC 10918-1:1993(E)
- while (read(is, buf, 2) && (buf[0] & 0xFF) == 0xFF) {
- int marker = buf[1] & 0xFF;
-
- // Check if the marker is a padding.
- if (marker == 0xFF) {
- continue;
- }
-
- // Check if the marker is SOI or TEM.
- if (marker == 0xD8 || marker == 0x01) {
- continue;
- }
- // Check if the marker is EOI or SOS.
- if (marker == 0xD9 || marker == 0xDA) {
- return 0;
- }
-
- // Get the length and check if it is reasonable.
- if (!read(is, buf, 2)) {
- return 0;
- }
- length = pack(buf, 0, 2, false);
- if (length < 2) {
- Log.e(TAG, "Invalid length");
- return 0;
- }
- length -= 2;
-
- // Break if the marker is EXIF in APP1.
- if (marker == 0xE1 && length >= 6) {
- if (!read(is, buf, 6)) return 0;
- length -= 6;
- if (pack(buf, 0, 4, false) == 0x45786966 &&
- pack(buf, 4, 2, false) == 0) {
- break;
- }
- }
-
- // Skip other markers.
- try {
- is.skip(length);
- } catch (IOException ex) {
- return 0;
- }
- length = 0;
- }
-
- // JEITA CP-3451 Exif Version 2.2
- if (length > 8) {
- int offset = 0;
- byte[] jpeg = new byte[length];
- if (!read(is, jpeg, length)) {
- return 0;
- }
-
- // Identify the byte order.
- int tag = pack(jpeg, offset, 4, false);
- if (tag != 0x49492A00 && tag != 0x4D4D002A) {
- Log.e(TAG, "Invalid byte order");
- return 0;
- }
- boolean littleEndian = (tag == 0x49492A00);
-
- // Get the offset and check if it is reasonable.
- int count = pack(jpeg, offset + 4, 4, littleEndian) + 2;
- if (count < 10 || count > length) {
- Log.e(TAG, "Invalid offset");
- return 0;
- }
- offset += count;
- length -= count;
-
- // Get the count and go through all the elements.
- count = pack(jpeg, offset - 2, 2, littleEndian);
- while (count-- > 0 && length >= 12) {
- // Get the tag and check if it is orientation.
- tag = pack(jpeg, offset, 2, littleEndian);
- if (tag == 0x0112) {
- // We do not really care about type and count, do we?
- int orientation = pack(jpeg, offset + 8, 2, littleEndian);
- switch (orientation) {
- case 1:
- return 0;
- case 3:
- return 180;
- case 6:
- return 90;
- case 8:
- return 270;
+ try {
+ ExifParser parser = ExifParser.parse(is, ExifParser.OPTION_IFD_0);
+ int event = parser.next();
+ while (event != ExifParser.EVENT_END) {
+ if (event == ExifParser.EVENT_NEW_TAG) {
+ ExifTag tag = parser.getTag();
+ if (tag.getTagId() == ExifTag.TAG_ORIENTATION &&
+ tag.hasValue()) {
+ int orient = tag.getUnsignedShort(0);
+ switch (orient) {
+ case ExifTag.Orientation.TOP_LEFT:
+ return 0;
+ case ExifTag.Orientation.BOTTOM_LEFT:
+ return 180;
+ case ExifTag.Orientation.RIGHT_TOP:
+ return 90;
+ case ExifTag.Orientation.RIGHT_BOTTOM:
+ return 270;
+ default:
+ Log.i(TAG, "Unsupported orientation");
+ return 0;
+ }
}
- Log.i(TAG, "Unsupported orientation");
- return 0;
}
- offset += 12;
- length -= 12;
+ event = parser.next();
}
- }
-
- Log.i(TAG, "Orientation not found");
- return 0;
- }
-
- private static int pack(byte[] bytes, int offset, int length,
- boolean littleEndian) {
- int step = 1;
- if (littleEndian) {
- offset += length - 1;
- step = -1;
- }
-
- int value = 0;
- while (length-- > 0) {
- value = (value << 8) | (bytes[offset] & 0xFF);
- offset += step;
- }
- return value;
- }
-
- private static boolean read(InputStream is, byte[] buf, int length) {
- try {
- return is.read(buf, 0, length) == length;
- } catch (IOException ex) {
- return false;
+ Log.i(TAG, "Orientation not found");
+ return 0;
+ } catch (IOException e) {
+ Log.w(TAG, "Failed to read EXIF orientation", e);
+ return 0;
+ } catch (ExifInvalidFormatException e) {
+ Log.w(TAG, "Failed to read EXIF orientation", e);
+ return 0;
}
}
}