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Commit 252c1a2f authored by Jin Seok Park's avatar Jin Seok Park
Browse files

Fix minor bugs 

Save offset values to the Exif chunk in PNG so that the correct
offset values for thumbnail data can be retrieved.

Bug: 138376314
Test: Run cts ExifInterfaceTest
Change-Id: I0fd8b0eb7d5fdb1a60f292c8fe41e9b7cb830fe6
parent 012117e8

media/java/android/media/ExifInterface.java

+14 −3
Original line number Diff line number Diff line
@@ -2776,7 +2776,7 @@ public class ExifInterface { 
        updateImageSizeValues(in, IFD_TYPE_THUMBNAIL);



        // Check if each image data is in valid position.

        validateImages(in);

        validateImages();



        if (mMimeType == IMAGE_TYPE_PEF) {

            // PEF files contain a MakerNote data, which contains the data for ColorSpace tag.
@@ -3143,8 +3143,11 @@ public class ExifInterface { 
        // 2.1. Integers and byte order

        in.setByteOrder(ByteOrder.BIG_ENDIAN);



        int bytesRead = 0;



        // Skip the signature bytes

        in.seek(PNG_SIGNATURE.length);

        bytesRead += PNG_SIGNATURE.length;



        try {

            while (true) {
@@ -3159,12 +3162,14 @@ public class ExifInterface { 
                // See PNG (Portable Network Graphics) Specification, Version 1.2,

                // 3.2. Chunk layout

                int length = in.readInt();

                bytesRead += 4;



                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");

                }

                bytesRead += PNG_CHUNK_LENGTH_BYTE_LENGTH;



                if (Arrays.equals(type, PNG_CHUNK_TYPE_IEND)) {

                    // IEND marks the end of the image.
@@ -3177,12 +3182,17 @@ public class ExifInterface { 
                                + "type: " + byteArrayToHexString(type));

                    }

                    readExifSegment(data, IFD_TYPE_PRIMARY);



                    validateImages();

                    break;

                } else {

                    // Skip to next chunk

                    in.skipBytes(length + PNG_CHUNK_CRC_BYTE_LENGTH);

                    bytesRead += length + PNG_CHUNK_CRC_BYTE_LENGTH;

                }

            }

            // 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 PNG specifications
@@ -3675,7 +3685,7 @@ public class ExifInterface { 
            int thumbnailLength = jpegInterchangeFormatLengthAttribute.getIntValue(mExifByteOrder);



            if (mMimeType == IMAGE_TYPE_JPEG || mMimeType == IMAGE_TYPE_RAF

                    || mMimeType == IMAGE_TYPE_RW2) {

                    || mMimeType == IMAGE_TYPE_RW2 || mMimeType == IMAGE_TYPE_PNG) {

                thumbnailOffset += mExifOffset;

            } else if (mMimeType == IMAGE_TYPE_ORF) {

                // Update offset value since RAF files have IFD data preceding MakerNote data.
@@ -3819,12 +3829,13 @@ public class ExifInterface { 
    }



    // Validate primary, preview, thumbnail image data by comparing image size

    private void validateImages(InputStream in) throws IOException {

    private void validateImages() throws IOException {

        // Swap images based on size (primary > preview > thumbnail)

        swapBasedOnImageSize(IFD_TYPE_PRIMARY, IFD_TYPE_PREVIEW);

        swapBasedOnImageSize(IFD_TYPE_PRIMARY, IFD_TYPE_THUMBNAIL);

        swapBasedOnImageSize(IFD_TYPE_PREVIEW, IFD_TYPE_THUMBNAIL);



        // TODO (b/142296453): Revise image width/height setting logic

        // Check if image has PixelXDimension/PixelYDimension tags, which contain valid image

        // sizes, excluding padding at the right end or bottom end of the image to make sure that

        // the values are multiples of 64. See JEITA CP-3451C Table 5 and Section 4.8.1. B.