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 static com.google.android.exoplayer2.util.Assertions.checkArgument;
  import static com.google.android.exoplayer2.util.Assertions.checkState;
  
  import android.net.Uri;
  import androidx.annotation.Nullable;
  import com.google.android.exoplayer2.C;
  import com.google.android.exoplayer2.PlaybackException;
  import com.google.android.exoplayer2.upstream.DataSpec;
  import com.google.android.exoplayer2.upstream.TransferListener;
  import com.google.android.exoplayer2.upstream.UdpDataSource;
  import com.google.android.exoplayer2.util.Util;
  import com.google.common.primitives.Ints;
  import java.io.IOException;
  
  /** An {@link RtpDataChannel} for UDP transport. */
  /* package */ final class UdpDataSourceRtpDataChannel implements RtpDataChannel {
  
    private static final String DEFAULT_UDP_TRANSPORT_FORMAT = "RTP/AVP;unicast;client_port=%d-%d";
  
    private final UdpDataSource dataSource;
  
    /** The associated RTCP channel; {@code null} if the current channel is an RTCP channel. */
    @Nullable private UdpDataSourceRtpDataChannel rtcpChannel;
  
    /**
     * Creates a new instance.
     *
     * @param socketTimeoutMs The timeout for {@link #read} in milliseconds.
     */
    public UdpDataSourceRtpDataChannel(long socketTimeoutMs) {
      dataSource =
          new UdpDataSource(UdpDataSource.DEFAULT_MAX_PACKET_SIZE, Ints.checkedCast(socketTimeoutMs));
    }
  
    @Override
    public String getTransport() {
      int dataPortNumber = getLocalPort();
      checkState(dataPortNumber != C.INDEX_UNSET); // Assert open() is called.
      return Util.formatInvariant(DEFAULT_UDP_TRANSPORT_FORMAT, dataPortNumber, dataPortNumber + 1);
    }
  
    @Override
    public int getLocalPort() {
      int port = dataSource.getLocalPort();
      return port == UdpDataSource.UDP_PORT_UNSET ? C.INDEX_UNSET : port;
    }
  
    @Nullable
    @Override
    public RtspMessageChannel.InterleavedBinaryDataListener getInterleavedBinaryDataListener() {
      return null;
    }
  
    @Override
    public void addTransferListener(TransferListener transferListener) {
      dataSource.addTransferListener(transferListener);
    }
  
    @Override
    public long open(DataSpec dataSpec) throws IOException {
      return dataSource.open(dataSpec);
    }
  
    @Nullable
    @Override
    public Uri getUri() {
      return dataSource.getUri();
    }
  
    @Override
    public void close() {
      dataSource.close();
  
      if (rtcpChannel != null) {
        rtcpChannel.close();
      }
    }
  
    @Override
    public int read(byte[] buffer, int offset, int length) throws IOException {
      try {
        return dataSource.read(buffer, offset, length);
      } catch (UdpDataSource.UdpDataSourceException e) {
        if (e.reason == PlaybackException.ERROR_CODE_IO_NETWORK_CONNECTION_TIMEOUT) {
          return C.RESULT_END_OF_INPUT;
        } else {
          throw e;
        }
      }
    }
  
    public void setRtcpChannel(UdpDataSourceRtpDataChannel rtcpChannel) {
      checkArgument(this != rtcpChannel);
      this.rtcpChannel = rtcpChannel;
    }
  }
  