content: /*
   * Copyright 2021 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;
  
  import androidx.annotation.Nullable;
  import com.google.android.exoplayer2.C;
  import com.google.android.exoplayer2.source.rtsp.RtspMessageChannel.InterleavedBinaryDataListener;
  import com.google.android.exoplayer2.upstream.DataSource;
  import java.io.IOException;
  
  /** An RTP {@link DataSource}. */
  /* package */ interface RtpDataChannel extends DataSource {
  
    /** Creates {@link RtpDataChannel} for RTSP streams. */
    interface Factory {
  
      /**
       * Creates a new {@link RtpDataChannel} instance for RTP data transfer.
       *
       * @param trackId The track ID.
       * @throws IOException If the data channels failed to open.
       */
      RtpDataChannel createAndOpenDataChannel(int trackId) throws IOException;
  
      /** Returns a fallback {@code Factory}, {@code null} when there is no fallback available. */
      @Nullable
      default Factory createFallbackDataChannelFactory() {
        return null;
      }
    }
  
    /** Returns the RTSP transport header for this {@link RtpDataChannel} */
    String getTransport();
  
    /**
     * Returns the receiving port or channel used by the underlying transport protocol, {@link
     * C#INDEX_UNSET} if the data channel is not opened.
     */
    int getLocalPort();
  
    /**
     * Returns a {@link InterleavedBinaryDataListener} if the implementation supports receiving RTP
     * packets on a side-band protocol, for example RTP-over-RTSP; otherwise {@code null}.
     */
    @Nullable
    InterleavedBinaryDataListener getInterleavedBinaryDataListener();
  }
  