Add support for parsing WebP files (3949c682) · Commits · e / os / android_frameworks_base

media/java/android/media/ExifInterface.java

+118 −7

Original line number	Diff line number	Diff line
		@@ -507,6 +507,15 @@ public class ExifInterface {
		private static final int PNG_CHUNK_LENGTH_BYTE_LENGTH = 4;
		private static final int PNG_CHUNK_CRC_BYTE_LENGTH = 4;

		// See https://developers.google.com/speed/webp/docs/riff_container, Section "WebP File Header"
		private static final byte[] WEBP_SIGNATURE_1 = new byte[] {'R', 'I', 'F', 'F'};
		private static final byte[] WEBP_SIGNATURE_2 = new byte[] {'W', 'E', 'B', 'P'};
		private static final int WEBP_FILE_SIZE_BYTE_LENGTH = 4;
		private static final byte[] WEBP_CHUNK_TYPE_EXIF = new byte[]{(byte) 0x45, (byte) 0x58,
		(byte) 0x49, (byte) 0x46};
		private static final int WEBP_CHUNK_TYPE_BYTE_LENGTH = 4;
		private static final int WEBP_CHUNK_SIZE_BYTE_LENGTH = 4;

		@UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 115609023)
		private static SimpleDateFormat sFormatter;
		private static SimpleDateFormat sFormatterTz;
		@@ -1325,6 +1334,7 @@ public class ExifInterface {
		private static final int IMAGE_TYPE_SRW = 11;
		private static final int IMAGE_TYPE_HEIF = 12;
		private static final int IMAGE_TYPE_PNG = 13;
		private static final int IMAGE_TYPE_WEBP = 14;

		static {
		sFormatter = new SimpleDateFormat("yyyy:MM:dd HH:mm:ss");
		@@ -1869,6 +1879,10 @@ public class ExifInterface {
		getPngAttributes(inputStream);
		break;
		}
		case IMAGE_TYPE_WEBP: {
		getWebpAttributes(inputStream);
		break;
		}
		case IMAGE_TYPE_ARW:
		case IMAGE_TYPE_CR2:
		case IMAGE_TYPE_DNG:
		@@ -2431,6 +2445,8 @@ public class ExifInterface {
		return IMAGE_TYPE_RW2;
		} else if (isPngFormat(signatureCheckBytes)) {
		return IMAGE_TYPE_PNG;
		} else if (isWebpFormat(signatureCheckBytes)) {
		return IMAGE_TYPE_WEBP;
		}
		// Certain file formats (PEF) are identified in readImageFileDirectory()
		return IMAGE_TYPE_UNKNOWN;
		@@ -2609,6 +2625,26 @@ public class ExifInterface {
		return true;
		}

		/**
		* WebP's file signature is composed of 12 bytes:
		* 'RIFF' (4 bytes) + file length value (4 bytes) + 'WEBP' (4 bytes)
		* See https://developers.google.com/speed/webp/docs/riff_container, Section "WebP File Header"
		*/
		private boolean isWebpFormat(byte[] signatureCheckBytes) throws IOException {
		for (int i = 0; i < WEBP_SIGNATURE_1.length; i++) {
		if (signatureCheckBytes[i] != WEBP_SIGNATURE_1[i]) {
		return false;
		}
		}
		for (int i = 0; i < WEBP_SIGNATURE_2.length; i++) {
		if (signatureCheckBytes[i + WEBP_SIGNATURE_1.length + WEBP_FILE_SIZE_BYTE_LENGTH]
		!= WEBP_SIGNATURE_2[i]) {
		return false;
		}
		}
		return true;
		}

		private static boolean isStandalone(InputStream inputStream) throws IOException {
		byte[] signatureCheckBytes = new byte[IDENTIFIER_EXIF_APP1.length];
		inputStream.read(signatureCheckBytes);
		@@ -3146,7 +3182,7 @@ public class ExifInterface {
		int bytesRead = 0;

		// Skip the signature bytes
		in.seek(PNG_SIGNATURE.length);
		in.skipBytes(PNG_SIGNATURE.length);
		bytesRead += PNG_SIGNATURE.length;

		try {
		@@ -3200,6 +3236,75 @@ public class ExifInterface {
		}
		}

		// WebP contains EXIF data as a RIFF File Format Chunk
		// All references below can be found in the following link.
		// https://developers.google.com/speed/webp/docs/riff_container
		private void getWebpAttributes(ByteOrderedDataInputStream in) throws IOException {
		if (DEBUG) {
		Log.d(TAG, "getWebpAttributes starting with: " + in);
		}
		// WebP uses little-endian by default.
		// See Section "Terminology & Basics"
		in.setByteOrder(ByteOrder.LITTLE_ENDIAN);
		in.skipBytes(WEBP_SIGNATURE_1.length);
		// File size corresponds to the size of the entire file from offset 8.
		// See Section "WebP File Header"
		int fileSize = in.readInt() + 8;
		int bytesRead = 8;
		bytesRead += in.skipBytes(WEBP_SIGNATURE_2.length);
		try {
		while (true) {
		// Each chunk is made up of three parts:
		// 1) Chunk FourCC: 4-byte concatenating four ASCII characters.
		// 2) Chunk Size: 4-byte unsigned integer indicating the size of the chunk.
		// Excludes Chunk FourCC and Chunk Size bytes.
		// 3) Chunk Payload: data payload. A single padding byte ('0') is added if
		// Chunk Size is odd.
		// See Section "RIFF File Format"
		byte[] code = new byte[WEBP_CHUNK_TYPE_BYTE_LENGTH];
		if (in.read(code) != code.length) {
		throw new IOException("Encountered invalid length while parsing WebP chunk"
		+ "type");
		}
		bytesRead += 4;
		int chunkSize = in.readInt();
		bytesRead += 4;
		if (Arrays.equals(WEBP_CHUNK_TYPE_EXIF, code)) {
		// TODO: Need to handle potential OutOfMemoryError
		byte[] payload = new byte[chunkSize];
		if (in.read(payload) != chunkSize) {
		throw new IOException("Failed to read given length for given PNG chunk "
		+ "type: " + byteArrayToHexString(code));
		}
		readExifSegment(payload, IFD_TYPE_PRIMARY);
		break;
		} else {
		// Add a single padding byte at end if chunk size is odd
		chunkSize = (chunkSize % 2 == 1) ? chunkSize + 1 : chunkSize;
		// Check if skipping to next chunk is necessary
		if (bytesRead + chunkSize == fileSize) {
		// Reached end of file
		break;
		} else if (bytesRead + chunkSize > fileSize) {
		throw new IOException("Encountered WebP file with invalid chunk size");
		}
		// Skip to next chunk
		int skipped = in.skipBytes(chunkSize);
		if (skipped != chunkSize) {
		throw new IOException("Encountered WebP file with invalid chunk size");
		}
		bytesRead += skipped;
		}
		}
		// Save offset values for handleThumbnailFromJfif() function
		mExifOffset = bytesRead;
		} catch (EOFException e) {
		// Should not reach here. Will only reach here if the file is corrupted or
		// does not follow the WebP specifications
		throw new IOException("Encountered corrupt WebP file.");
		}
		}

		// Stores a new JPEG image with EXIF attributes into a given output stream.
		private void saveJpegAttributes(InputStream inputStream, OutputStream outputStream)
		throws IOException {
		@@ -3684,12 +3789,18 @@ public class ExifInterface {
		int thumbnailOffset = jpegInterchangeFormatAttribute.getIntValue(mExifByteOrder);
		int thumbnailLength = jpegInterchangeFormatLengthAttribute.getIntValue(mExifByteOrder);

		if (mMimeType == IMAGE_TYPE_JPEG \|\| mMimeType == IMAGE_TYPE_RAF
		\|\| mMimeType == IMAGE_TYPE_RW2 \|\| mMimeType == IMAGE_TYPE_PNG) {
		switch (mMimeType) {
		case IMAGE_TYPE_JPEG:
		case IMAGE_TYPE_RAF:
		case IMAGE_TYPE_RW2:
		case IMAGE_TYPE_PNG:
		case IMAGE_TYPE_WEBP:
		thumbnailOffset += mExifOffset;
		} else if (mMimeType == IMAGE_TYPE_ORF) {
		break;
		case IMAGE_TYPE_ORF:
		// Update offset value since RAF files have IFD data preceding MakerNote data.
		thumbnailOffset += mOrfMakerNoteOffset;
		break;
		}
		// The following code limits the size of thumbnail size not to overflow EXIF data area.
		thumbnailLength = Math.min(thumbnailLength, in.getLength() - thumbnailOffset);