Add support for parsing Exif chunk in PNG (740558e4) · Commits · e / os / android_frameworks_base

media/java/android/media/ExifInterface.java

+140 −19

Original line number	Diff line number	Diff line
		@@ -493,6 +493,19 @@ public class ExifInterface {
		// See http://www.exiv2.org/makernote.html#R11
		private static final int PEF_MAKER_NOTE_SKIP_SIZE = 6;

		// See PNG (Portable Network Graphics) Specification, Version 1.2,
		// 3.1. PNG file signature
		private static final byte[] PNG_SIGNATURE = new byte[] {(byte) 0x89, (byte) 0x50, (byte) 0x4e,
		(byte) 0x47, (byte) 0x0d, (byte) 0x0a, (byte) 0x1a, (byte) 0x0a};
		// See PNG (Portable Network Graphics) Specification, Version 1.2,
		// 3.7. eXIf Exchangeable Image File (Exif) Profile
		private static final byte[] PNG_CHUNK_TYPE_EXIF = new byte[]{(byte) 0x65, (byte) 0x58,
		(byte) 0x49, (byte) 0x66};
		private static final byte[] PNG_CHUNK_TYPE_IEND = new byte[]{(byte) 0x49, (byte) 0x45,
		(byte) 0x4e, (byte) 0x44};
		private static final int PNG_CHUNK_LENGTH_BYTE_LENGTH = 4;
		private static final int PNG_CHUNK_CRC_BYTE_LENGTH = 4;

		@UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 115609023)
		private static SimpleDateFormat sFormatter;
		private static SimpleDateFormat sFormatterTz;
		@@ -1310,6 +1323,7 @@ public class ExifInterface {
		private static final int IMAGE_TYPE_RW2 = 10;
		private static final int IMAGE_TYPE_SRW = 11;
		private static final int IMAGE_TYPE_HEIF = 12;
		private static final int IMAGE_TYPE_PNG = 13;

		static {
		sFormatter = new SimpleDateFormat("yyyy:MM:dd HH:mm:ss");
		@@ -1779,6 +1793,10 @@ public class ExifInterface {
		getRw2Attributes(inputStream);
		break;
		}
		case IMAGE_TYPE_PNG: {
		getPngAttributes(inputStream);
		break;
		}
		case IMAGE_TYPE_ARW:
		case IMAGE_TYPE_CR2:
		case IMAGE_TYPE_DNG:
		@@ -1992,6 +2010,7 @@ public class ExifInterface {
		if (in.skip(mThumbnailOffset) != mThumbnailOffset) {
		throw new IOException("Corrupted image");
		}
		// TODO: Need to handle potential OutOfMemoryError
		byte[] buffer = new byte[mThumbnailLength];
		if (in.read(buffer) != mThumbnailLength) {
		throw new IOException("Corrupted image");
		@@ -2331,6 +2350,8 @@ public class ExifInterface {
		return IMAGE_TYPE_ORF;
		} else if (isRw2Format(signatureCheckBytes)) {
		return IMAGE_TYPE_RW2;
		} else if (isPngFormat(signatureCheckBytes)) {
		return IMAGE_TYPE_PNG;
		}
		// Certain file formats (PEF) are identified in readImageFileDirectory()
		return IMAGE_TYPE_UNKNOWN;
		@@ -2446,16 +2467,24 @@ public class ExifInterface {
		* http://fileformats.archiveteam.org/wiki/Olympus_ORF
		*/
		private boolean isOrfFormat(byte[] signatureCheckBytes) throws IOException {
		ByteOrderedDataInputStream signatureInputStream =
		new ByteOrderedDataInputStream(signatureCheckBytes);
		ByteOrderedDataInputStream signatureInputStream = null;

		try {
		signatureInputStream = new ByteOrderedDataInputStream(signatureCheckBytes);

		// Read byte order
		mExifByteOrder = readByteOrder(signatureInputStream);
		// Set byte order
		signatureInputStream.setByteOrder(mExifByteOrder);

		short orfSignature = signatureInputStream.readShort();
		if (orfSignature == ORF_SIGNATURE_1 \|\| orfSignature == ORF_SIGNATURE_2) {
		return true;
		return orfSignature == ORF_SIGNATURE_1 \|\| orfSignature == ORF_SIGNATURE_2;
		} catch (Exception e) {
		// Do nothing
		} finally {
		if (signatureInputStream != null) {
		signatureInputStream.close();
		}
		}
		return false;
		}
		@@ -2465,20 +2494,42 @@ public class ExifInterface {
		* See http://lclevy.free.fr/raw/
		*/
		private boolean isRw2Format(byte[] signatureCheckBytes) throws IOException {
		ByteOrderedDataInputStream signatureInputStream =
		new ByteOrderedDataInputStream(signatureCheckBytes);
		ByteOrderedDataInputStream signatureInputStream = null;

		try {
		signatureInputStream = new ByteOrderedDataInputStream(signatureCheckBytes);

		// Read byte order
		mExifByteOrder = readByteOrder(signatureInputStream);
		// Set byte order
		signatureInputStream.setByteOrder(mExifByteOrder);

		short signatureByte = signatureInputStream.readShort();
		if (signatureByte == RW2_SIGNATURE) {
		return true;
		signatureInputStream.close();
		return signatureByte == RW2_SIGNATURE;
		} catch (Exception e) {
		// Do nothing
		} finally {
		if (signatureInputStream != null) {
		signatureInputStream.close();
		}
		}
		return false;
		}

		/**
		* PNG's file signature is first 8 bytes.
		* See PNG (Portable Network Graphics) Specification, Version 1.2, 3.1. PNG file signature
		*/
		private boolean isPngFormat(byte[] signatureCheckBytes) throws IOException {
		for (int i = 0; i < PNG_SIGNATURE.length; i++) {
		if (signatureCheckBytes[i] != PNG_SIGNATURE[i]) {
		return false;
		}
		}
		return true;
		}

		/**
		* Loads EXIF attributes from a JPEG input stream.
		*
		@@ -2553,7 +2604,7 @@ public class ExifInterface {

		readExifSegment(value, imageType);

		// Save offset values for createJpegThumbnailBitmap() function
		// Save offset values for handleThumbnailFromJfif() function
		mExifOffset = (int) offset;
		} else if (ArrayUtils.startsWith(bytes, IDENTIFIER_XMP_APP1)) {
		// See XMP Specification Part 3: Storage in Files, 1.1.3 JPEG, Table 6
		@@ -2854,6 +2905,7 @@ public class ExifInterface {
		throw new IOException("Invalid identifier");
		}

		// TODO: Need to handle potential OutOfMemoryError
		byte[] bytes = new byte[length];
		if (in.read(bytes) != length) {
		throw new IOException("Can't read exif");
		@@ -2980,6 +3032,64 @@ public class ExifInterface {
		}
		}

		// PNG contains the EXIF data as a Special-Purpose Chunk
		private void getPngAttributes(ByteOrderedDataInputStream in) throws IOException {
		if (DEBUG) {
		Log.d(TAG, "getPngAttributes starting with: " + in);
		}

		// PNG uses Big Endian by default.
		// See PNG (Portable Network Graphics) Specification, Version 1.2,
		// 2.1. Integers and byte order
		in.setByteOrder(ByteOrder.BIG_ENDIAN);

		// Skip the signature bytes
		in.seek(PNG_SIGNATURE.length);

		try {
		while (true) {
		// Each chunk is made up of four parts:
		// 1) Length: 4-byte unsigned integer indicating the number of bytes in the
		// Chunk Data field. Excludes Chunk Type and CRC bytes.
		// 2) Chunk Type: 4-byte chunk type code.
		// 3) Chunk Data: The data bytes. Can be zero-length.
		// 4) CRC: 4-byte data calculated on the preceding bytes in the chunk. Always
		// present.
		// --> 4 (length bytes) + 4 (type bytes) + X (data bytes) + 4 (CRC bytes)
		// See PNG (Portable Network Graphics) Specification, Version 1.2,
		// 3.2. Chunk layout
		int length = in.readInt();

		byte[] type = new byte[PNG_CHUNK_LENGTH_BYTE_LENGTH];
		if (in.read(type) != type.length) {
		throw new IOException("Encountered invalid length while parsing PNG chunk"
		+ "type");
		}

		if (Arrays.equals(type, PNG_CHUNK_TYPE_IEND)) {
		// IEND marks the end of the image.
		break;
		} else if (Arrays.equals(type, PNG_CHUNK_TYPE_EXIF)) {
		// TODO: Need to handle potential OutOfMemoryError
		byte[] data = new byte[length];
		if (in.read(data) != length) {
		throw new IOException("Failed to read given length for given PNG chunk "
		+ "type: " + byteArrayToHexString(type));
		}
		readExifSegment(data, IFD_TYPE_PRIMARY);
		break;
		} else {
		// Skip to next chunk
		in.skipBytes(length + PNG_CHUNK_CRC_BYTE_LENGTH);
		}
		}
		} catch (EOFException e) {
		// Should not reach here. Will only reach here if the file is corrupted or
		// does not follow the PNG specifications
		throw new IOException("Encountered corrupt PNG file.");
		}
		}

		// Stores a new JPEG image with EXIF attributes into a given output stream.
		private void saveJpegAttributes(InputStream inputStream, OutputStream outputStream)
		throws IOException {
		@@ -3485,6 +3595,7 @@ public class ExifInterface {

		if (mFilename == null && mAssetInputStream == null
		&& mSeekableFileDescriptor == null) {
		// TODO: Need to handle potential OutOfMemoryError
		// Save the thumbnail in memory if the input doesn't support reading again.
		byte[] thumbnailBytes = new byte[thumbnailLength];
		in.seek(thumbnailOffset);
		@@ -3518,6 +3629,7 @@ public class ExifInterface {
		return;
		}

		// TODO: Need to handle potential OutOfMemoryError
		// Set thumbnail byte array data for non-consecutive strip bytes
		byte[] totalStripBytes =
		new byte[(int) Arrays.stream(stripByteCounts).sum()];
		@@ -3536,6 +3648,7 @@ public class ExifInterface {
		in.seek(skipBytes);
		bytesRead += skipBytes;

		// TODO: Need to handle potential OutOfMemoryError
		// Read strip bytes
		byte[] stripBytes = new byte[stripByteCount];
		in.read(stripBytes);
		@@ -4335,4 +4448,12 @@ public class ExifInterface {
		}
		return null;
		}

		private static String byteArrayToHexString(byte[] bytes) {
		StringBuilder sb = new StringBuilder(bytes.length * 2);
		for (int i = 0; i < bytes.length; i++) {
		sb.append(String.format("%02x", bytes[i]));
		}
		return sb.toString();
		}
		}