content: /*
   * Copyright 2022 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 com.google.android.exoplayer2.source.rtsp.reader;
  
  import com.google.android.exoplayer2.C;
  import com.google.android.exoplayer2.util.Util;
  
  /** Utility methods for {@link RtpPayloadReader}s. */
  /* package */ class RtpReaderUtils {
  
    /**
     * Converts RTP timestamp and media frequency to sample presentation time, in microseconds
     *
     * @param startTimeOffsetUs The offset of the RTP timebase, in microseconds.
     * @param rtpTimestamp The RTP timestamp to convert.
     * @param firstReceivedRtpTimestamp The first received RTP timestamp.
     * @param mediaFrequency The media frequency.
     * @return The calculated sample presentation time, in microseconds.
     */
    public static long toSampleTimeUs(
        long startTimeOffsetUs,
        long rtpTimestamp,
        long firstReceivedRtpTimestamp,
        int mediaFrequency) {
      return startTimeOffsetUs
          + Util.scaleLargeTimestamp(
              rtpTimestamp - firstReceivedRtpTimestamp,
              /* multiplier= */ C.MICROS_PER_SECOND,
              /* divisor= */ mediaFrequency);
    }
  
    private RtpReaderUtils() {}
  }
  