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/*
* Copyright 2002-2017 Drew Noakes
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* More information about this project is available at:
*
* https://drewnoakes.com/code/exif/
* https://github.com/drewnoakes/metadata-extractor
*/
package com.drew.metadata.webp;
import com.drew.imaging.riff.RiffHandler;
import com.drew.lang.ByteArrayReader;
import com.drew.lang.RandomAccessReader;
import com.drew.lang.annotations.NotNull;
import com.drew.metadata.Metadata;
import com.drew.metadata.exif.ExifReader;
import com.drew.metadata.icc.IccReader;
import com.drew.metadata.xmp.XmpReader;
import java.io.IOException;
/**
* Implementation of {@link RiffHandler} specialising in WebP support.
*
* Extracts data from chunk types:
*
* <ul>
* <li><code>"VP8X"</code>: width, height, is animation, has alpha</li>
* <li><code>"EXIF"</code>: full Exif data</li>
* <li><code>"ICCP"</code>: full ICC profile</li>
* <li><code>"XMP "</code>: full XMP data</li>
* </ul>
*/
public class WebpRiffHandler implements RiffHandler
{
@NotNull
private final Metadata _metadata;
public WebpRiffHandler(@NotNull Metadata metadata)
{
_metadata = metadata;
}
public boolean shouldAcceptRiffIdentifier(@NotNull String identifier)
{
return identifier.equals(WebpDirectory.FORMAT);
}
public boolean shouldAcceptChunk(@NotNull String fourCC)
{
return fourCC.equals(WebpDirectory.CHUNK_VP8X)
|| fourCC.equals(WebpDirectory.CHUNK_VP8L)
|| fourCC.equals(WebpDirectory.CHUNK_VP8)
|| fourCC.equals(WebpDirectory.CHUNK_EXIF)
|| fourCC.equals(WebpDirectory.CHUNK_ICCP)
|| fourCC.equals(WebpDirectory.CHUNK_XMP);
}
@Override
public boolean shouldAcceptList(@NotNull String fourCC)
{
return false;
}
public void processChunk(@NotNull String fourCC, @NotNull byte[] payload)
{
// System.out.println("Chunk " + fourCC + " " + payload.length + " bytes");
WebpDirectory directory = new WebpDirectory();
if (fourCC.equals(WebpDirectory.CHUNK_EXIF)) {
new ExifReader().extract(new ByteArrayReader(payload), _metadata);
} else if (fourCC.equals(WebpDirectory.CHUNK_ICCP)) {
new IccReader().extract(new ByteArrayReader(payload), _metadata);
} else if (fourCC.equals(WebpDirectory.CHUNK_XMP)) {
new XmpReader().extract(payload, _metadata);
} else if (fourCC.equals(WebpDirectory.CHUNK_VP8X) && payload.length == 10) {
RandomAccessReader reader = new ByteArrayReader(payload);
reader.setMotorolaByteOrder(false);
try {
// Flags
// boolean hasFragments = reader.getBit(0);
boolean isAnimation = reader.getBit(1);
// boolean hasXmp = reader.getBit(2);
// boolean hasExif = reader.getBit(3);
boolean hasAlpha = reader.getBit(4);
// boolean hasIcc = reader.getBit(5);
// Image size
int widthMinusOne = reader.getInt24(4);
int heightMinusOne = reader.getInt24(7);
directory.setInt(WebpDirectory.TAG_IMAGE_WIDTH, widthMinusOne + 1);
directory.setInt(WebpDirectory.TAG_IMAGE_HEIGHT, heightMinusOne + 1);
directory.setBoolean(WebpDirectory.TAG_HAS_ALPHA, hasAlpha);
directory.setBoolean(WebpDirectory.TAG_IS_ANIMATION, isAnimation);
_metadata.addDirectory(directory);
} catch (IOException e) {
e.printStackTrace(System.err);
}
} else if (fourCC.equals(WebpDirectory.CHUNK_VP8L) && payload.length > 4) {
RandomAccessReader reader = new ByteArrayReader(payload);
reader.setMotorolaByteOrder(false);
try {
// https://developers.google.com/speed/webp/docs/webp_lossless_bitstream_specification#2_riff_header
// Expect the signature byte
if (reader.getInt8(0) != 0x2F)
return;
int b1 = reader.getUInt8(1);
int b2 = reader.getUInt8(2);
int b3 = reader.getUInt8(3);
int b4 = reader.getUInt8(4);
// 14 bits for width
int widthMinusOne = (b2 & 0x3F) << 8 | b1;
// 14 bits for height
int heightMinusOne = (b4 & 0x0F) << 10 | b3 << 2 | (b2 & 0xC0) >> 6;
directory.setInt(WebpDirectory.TAG_IMAGE_WIDTH, widthMinusOne + 1);
directory.setInt(WebpDirectory.TAG_IMAGE_HEIGHT, heightMinusOne + 1);
_metadata.addDirectory(directory);
} catch (IOException e) {
e.printStackTrace(System.err);
}
} else if (fourCC.equals(WebpDirectory.CHUNK_VP8) && payload.length > 9) {
RandomAccessReader reader = new ByteArrayReader(payload);
reader.setMotorolaByteOrder(false);
try {
// https://tools.ietf.org/html/rfc6386#section-9.1
// https://github.com/webmproject/libwebp/blob/master/src/enc/syntax.c#L115
// Expect the signature bytes
if (reader.getUInt8(3) != 0x9D ||
reader.getUInt8(4) != 0x01 ||
reader.getUInt8(5) != 0x2A)
return;
int width = reader.getUInt16(6);
int height = reader.getUInt16(8);
directory.setInt(WebpDirectory.TAG_IMAGE_WIDTH, width);
directory.setInt(WebpDirectory.TAG_IMAGE_HEIGHT, height);
_metadata.addDirectory(directory);
} catch (IOException ex) {
directory.addError(ex.getMessage());
}
}
}
}
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