diff options
Diffstat (limited to 'mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/extractor/FlacSeekTableSeekMap.java')
-rw-r--r-- | mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/extractor/FlacSeekTableSeekMap.java | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/extractor/FlacSeekTableSeekMap.java b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/extractor/FlacSeekTableSeekMap.java new file mode 100644 index 0000000000..56d54596ac --- /dev/null +++ b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/extractor/FlacSeekTableSeekMap.java @@ -0,0 +1,84 @@ +/* + * Copyright (C) 2019 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 org.mozilla.thirdparty.com.google.android.exoplayer2.extractor; + +import org.mozilla.thirdparty.com.google.android.exoplayer2.C; +import org.mozilla.thirdparty.com.google.android.exoplayer2.util.Assertions; +import org.mozilla.thirdparty.com.google.android.exoplayer2.util.FlacStreamMetadata; +import org.mozilla.thirdparty.com.google.android.exoplayer2.util.Util; + +/** + * A {@link SeekMap} implementation for FLAC streams that contain a <a + * href="https://xiph.org/flac/format.html#metadata_block_seektable">seek table</a>. + */ +public final class FlacSeekTableSeekMap implements SeekMap { + + private final FlacStreamMetadata flacStreamMetadata; + private final long firstFrameOffset; + + /** + * Creates a seek map from the FLAC stream seek table. + * + * @param flacStreamMetadata The stream metadata. + * @param firstFrameOffset The byte offset of the first frame in the stream. + */ + public FlacSeekTableSeekMap(FlacStreamMetadata flacStreamMetadata, long firstFrameOffset) { + this.flacStreamMetadata = flacStreamMetadata; + this.firstFrameOffset = firstFrameOffset; + } + + @Override + public boolean isSeekable() { + return true; + } + + @Override + public long getDurationUs() { + return flacStreamMetadata.getDurationUs(); + } + + @Override + public SeekPoints getSeekPoints(long timeUs) { + Assertions.checkNotNull(flacStreamMetadata.seekTable); + long[] pointSampleNumbers = flacStreamMetadata.seekTable.pointSampleNumbers; + long[] pointOffsets = flacStreamMetadata.seekTable.pointOffsets; + + long targetSampleNumber = flacStreamMetadata.getSampleNumber(timeUs); + int index = + Util.binarySearchFloor( + pointSampleNumbers, + targetSampleNumber, + /* inclusive= */ true, + /* stayInBounds= */ false); + + long seekPointSampleNumber = index == -1 ? 0 : pointSampleNumbers[index]; + long seekPointOffsetFromFirstFrame = index == -1 ? 0 : pointOffsets[index]; + SeekPoint seekPoint = getSeekPoint(seekPointSampleNumber, seekPointOffsetFromFirstFrame); + if (seekPoint.timeUs == timeUs || index == pointSampleNumbers.length - 1) { + return new SeekPoints(seekPoint); + } else { + SeekPoint secondSeekPoint = + getSeekPoint(pointSampleNumbers[index + 1], pointOffsets[index + 1]); + return new SeekPoints(seekPoint, secondSeekPoint); + } + } + + private SeekPoint getSeekPoint(long sampleNumber, long offsetFromFirstFrame) { + long seekTimeUs = sampleNumber * C.MICROS_PER_SECOND / flacStreamMetadata.sampleRate; + long seekPosition = firstFrameOffset + offsetFromFirstFrame; + return new SeekPoint(seekTimeUs, seekPosition); + } +} |