/*
* Copyright 2023 The Android Open Source Project
*
* 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.
*/
package androidx.media3.extractor.heif;
import androidx.media3.common.C;
import androidx.media3.common.MimeTypes;
import androidx.media3.common.util.ParsableByteArray;
import androidx.media3.common.util.UnstableApi;
import androidx.media3.extractor.Extractor;
import androidx.media3.extractor.ExtractorInput;
import androidx.media3.extractor.ExtractorOutput;
import androidx.media3.extractor.PositionHolder;
import androidx.media3.extractor.SingleSampleExtractor;
import java.io.IOException;
/** Extracts data from the HEIF (.heic) container format. */
@UnstableApi
public final class HeifExtractor implements Extractor {
// Specification reference: ISO/IEC 23008-12:2022
private static final int HEIF_FILE_SIGNATURE_PART_1 = 0x66747970;
private static final int HEIF_FILE_SIGNATURE_PART_2 = 0x68656963;
private static final int FILE_SIGNATURE_SEGMENT_LENGTH = 4;
private final ParsableByteArray scratch;
private final SingleSampleExtractor imageExtractor;
/** Creates an instance. */
public HeifExtractor() {
scratch = new ParsableByteArray(FILE_SIGNATURE_SEGMENT_LENGTH);
imageExtractor = new SingleSampleExtractor(C.INDEX_UNSET, C.LENGTH_UNSET, MimeTypes.IMAGE_HEIF);
}
@Override
public boolean sniff(ExtractorInput input) throws IOException {
input.advancePeekPosition(4);
return readAndCompareFourBytes(input, HEIF_FILE_SIGNATURE_PART_1)
&& readAndCompareFourBytes(input, HEIF_FILE_SIGNATURE_PART_2);
}
@Override
public void init(ExtractorOutput output) {
imageExtractor.init(output);
}
@Override
public @ReadResult int read(ExtractorInput input, PositionHolder seekPosition)
throws IOException {
return imageExtractor.read(input, seekPosition);
}
@Override
public void seek(long position, long timeUs) {
imageExtractor.seek(position, timeUs);
}
@Override
public void release() {
// Do nothing.
}
private boolean readAndCompareFourBytes(ExtractorInput input, int bytesToCompare)
throws IOException {
scratch.reset(/* limit= */ FILE_SIGNATURE_SEGMENT_LENGTH);
input.peekFully(scratch.getData(), /* offset= */ 0, FILE_SIGNATURE_SEGMENT_LENGTH);
return scratch.readUnsignedInt() == bytesToCompare;
}
}