Mp4Util.java
/*
* 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.container;
import androidx.media3.common.util.UnstableApi;
/** Utilities for MP4 container. */
@UnstableApi
public final class Mp4Util {
private static final int UNIX_EPOCH_TO_MP4_TIME_DELTA_SECONDS =
((1970 - 1904) * 365 + 17 /* leap year */) * (24 * 60 * 60);
private Mp4Util() {}
/**
* Returns an MP4 timestamp (in seconds since midnight, January 1, 1904) from a Unix epoch
* timestamp (in milliseconds since midnight, January 1, 1970).
*/
public static long unixTimeToMp4TimeSeconds(long unixTimestampMs) {
return (unixTimestampMs / 1000L + UNIX_EPOCH_TO_MP4_TIME_DELTA_SECONDS);
}
/**
* Returns a Unix epoch timestamp (in milliseconds since midnight, January 1, 1970) from an MP4
* timestamp (in seconds since midnight, January 1, 1904).
*/
public static long mp4TimeToUnixTimeMs(long mp4TimestampSeconds) {
return (mp4TimestampSeconds - UNIX_EPOCH_TO_MP4_TIME_DELTA_SECONDS) * 1000L;
}
}