loliball/media3
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Retry RTSP Setup with TCP if response with UDP is UnsupportedTransport

Browse Source 
If RTSP Setup Request with UDP receives HTTP Error Status 461 UnsupportedTransport, then client will retry with TCP.

Issue: google/ExoPlayer#11069
PiperOrigin-RevId: 518807829
This commit is contained in:
michaelkatz 2023-03-23 09:54:54 +00:00 committed by Tianyi Feng
parent df558b59db
commit ecf4d8b891
6 changed files with 346 additions and 66 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
RELEASENOTES.md
View File

@ -42,6 +42,10 @@
* DASH:
* Fix handling of empty segment timelines
([#11014](https://github.com/google/ExoPlayer/issues/11014)).
* RTSP:
* Retry with TCP if RTSP Setup with UDP fails with RTSP Error 461
UnsupportedTransport
([#11069](https://github.com/google/ExoPlayer/issues/11069)).
* IMA DAI extension:
* Fix a bug where a new ad group is inserted in live streams because the
calculated content position in consecutive timelines varies slightly.

21
libraries/exoplayer_rtsp/src/main/java/androidx/media3/exoplayer/rtsp/RtspClient.java
View File

@ -49,6 +49,7 @@ import androidx.media3.common.util.Log;
import androidx.media3.common.util.Util;
import androidx.media3.exoplayer.rtsp.RtspMediaPeriod.RtpLoadInfo;
import androidx.media3.exoplayer.rtsp.RtspMediaSource.RtspPlaybackException;
import androidx.media3.exoplayer.rtsp.RtspMediaSource.RtspUdpUnsupportedTransportException;
import androidx.media3.exoplayer.rtsp.RtspMessageChannel.InterleavedBinaryDataListener;
import androidx.media3.exoplayer.rtsp.RtspMessageUtil.RtspAuthUserInfo;
import androidx.media3.exoplayer.rtsp.RtspMessageUtil.RtspSessionHeader;
@ -577,8 +578,24 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
receivedAuthorizationRequest = true;
return;
}
// fall through: if unauthorized and no userInfo present, or previous authentication
// unsuccessful.
// if unauthorized and no userInfo present, or previous authentication
// unsuccessful, then dispatch RtspPlaybackException
dispatchRtspError(
new RtspPlaybackException(
RtspMessageUtil.toMethodString(requestMethod) + " " + response.status));
return;
case 461:
String exceptionMessage =
RtspMessageUtil.toMethodString(requestMethod) + " " + response.status;
// If request was SETUP with UDP transport protocol, then throw
// RtspUdpUnsupportedTransportException.
String transportHeaderValue =
checkNotNull(matchingRequest.headers.get(RtspHeaders.TRANSPORT));
dispatchRtspError(
requestMethod == METHOD_SETUP && !transportHeaderValue.contains("TCP")
? new RtspUdpUnsupportedTransportException(exceptionMessage)
: new RtspPlaybackException(exceptionMessage));
return;
default:
dispatchRtspError(
new RtspPlaybackException(

12
libraries/exoplayer_rtsp/src/main/java/androidx/media3/exoplayer/rtsp/RtspMediaPeriod.java
View File

@ -518,7 +518,6 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
// using TCP. Retrying will setup new loadables, so will not retry with the current
// loadables.
retryWithRtpTcp();
isUsingRtpTcp = true;
}
return;
}
@ -644,7 +643,13 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
@Override
public void onPlaybackError(RtspPlaybackException error) {
playbackException = error;
if (error instanceof RtspMediaSource.RtspUdpUnsupportedTransportException && !isUsingRtpTcp) {
// Retry playback with TCP if we receive RtspUdpUnsupportedTransportException, and we are
// not already using TCP. Retrying will setup new loadables.
retryWithRtpTcp();
} else {
playbackException = error;
}
}
@Override
@ -668,6 +673,9 @@ import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
}
private void retryWithRtpTcp() {
// Retry should only run once.
isUsingRtpTcp = true;
rtspClient.retryWithRtpTcp();
@Nullable

9
libraries/exoplayer_rtsp/src/main/java/androidx/media3/exoplayer/rtsp/RtspMediaSource.java
View File

@ -192,7 +192,7 @@ public final class RtspMediaSource extends BaseMediaSource {
}
/** Thrown when an exception or error is encountered during loading an RTSP stream. */
public static final class RtspPlaybackException extends IOException {
public static class RtspPlaybackException extends IOException {
public RtspPlaybackException(String message) {
super(message);
}
@ -206,6 +206,13 @@ public final class RtspMediaSource extends BaseMediaSource {
}
}
/** Thrown when an RTSP Unsupported Transport error (461) is encountered during RTSP Setup. */
public static final class RtspUdpUnsupportedTransportException extends RtspPlaybackException {
public RtspUdpUnsupportedTransportException(String message) {
super(message);
}
}
private final MediaItem mediaItem;
private final RtpDataChannel.Factory rtpDataChannelFactory;
private final String userAgent;

73
libraries/exoplayer_rtsp/src/test/java/androidx/media3/exoplayer/rtsp/RtspClientTest.java
View File

@ -453,4 +453,77 @@ public final class RtspClientTest {
RobolectricUtil.runMainLooperUntil(timelineRequestFailed::get);
assertThat(rtspClient.getState()).isEqualTo(RtspClient.RTSP_STATE_UNINITIALIZED);
}
@Test
public void connectServerAndClient_describeResponseRequiresAuthentication_doesNotUpdateTimeline()
throws Exception {
class ResponseProvider implements RtspServer.ResponseProvider {
@Override
public RtspResponse getOptionsResponse() {
return new RtspResponse(
/* status= */ 200,
new RtspHeaders.Builder().add(RtspHeaders.PUBLIC, "OPTIONS, DESCRIBE").build());
}
@Override
public RtspResponse getDescribeResponse(Uri requestedUri, RtspHeaders headers) {
String authorizationHeader = headers.get(RtspHeaders.AUTHORIZATION);
if (authorizationHeader == null) {
return new RtspResponse(
/* status= */ 401,
new RtspHeaders.Builder()
.add(RtspHeaders.CSEQ, headers.get(RtspHeaders.CSEQ))
.add(
RtspHeaders.WWW_AUTHENTICATE,
"Digest realm=\"RTSP server\","
+ " nonce=\"0cdfe9719e7373b7d5bb2913e2115f3f\","
+ " opaque=\"5ccc069c403ebaf9f0171e9517f40e41\"")
.add(RtspHeaders.WWW_AUTHENTICATE, "BASIC realm=\"WallyWorld\"")
.build());
}
if (!authorizationHeader.contains("Digest")) {
return new RtspResponse(
401,
new RtspHeaders.Builder()
.add(RtspHeaders.CSEQ, headers.get(RtspHeaders.CSEQ))
.build());
}
return RtspTestUtils.newDescribeResponseWithSdpMessage(
"v=0\r\n"
+ "o=- 1606776316530225 1 IN IP4 127.0.0.1\r\n"
+ "s=Exoplayer test\r\n"
+ "t=0 0\r\n"
// The session is 50.46s long.
+ "a=range:npt=0-50.46\r\n",
rtpPacketStreamDumps,
requestedUri);
}
}
rtspServer = new RtspServer(new ResponseProvider());
AtomicBoolean timelineRequestFailed = new AtomicBoolean();
rtspClient =
new RtspClient(
new SessionInfoListener() {
@Override
public void onSessionTimelineUpdated(
RtspSessionTiming timing, ImmutableList<RtspMediaTrack> tracks) {}
@Override
public void onSessionTimelineRequestFailed(
String message, @Nullable Throwable cause) {
timelineRequestFailed.set(true);
}
},
EMPTY_PLAYBACK_LISTENER,
/* userAgent= */ "ExoPlayer:RtspClientTest",
RtspTestUtils.getTestUri(rtspServer.startAndGetPortNumber()),
SocketFactory.getDefault(),
/* debugLoggingEnabled= */ false);
rtspClient.start();
RobolectricUtil.runMainLooperUntil(timelineRequestFailed::get);
assertThat(rtspClient.getState()).isEqualTo(RtspClient.RTSP_STATE_UNINITIALIZED);
}
}

293
libraries/exoplayer_rtsp/src/test/java/androidx/media3/exoplayer/rtsp/RtspPlaybackTest.java
View File

@ -15,6 +15,7 @@
*/
package androidx.media3.exoplayer.rtsp;
import static androidx.media3.common.util.Assertions.checkNotNull;
import static androidx.media3.common.util.Assertions.checkStateNotNull;
import static com.google.common.truth.Truth.assertThat;
import static java.lang.Math.min;
@ -42,11 +43,13 @@ import androidx.media3.test.utils.robolectric.TestPlayerRunHelper;
import androidx.test.core.app.ApplicationProvider;
import androidx.test.ext.junit.runners.AndroidJUnit4;
import com.google.common.collect.ImmutableList;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.atomic.AtomicReference;
import javax.net.SocketFactory;
import org.junit.After;
import org.junit.Before;
import org.junit.Rule;
import org.junit.Test;
@ -58,30 +61,20 @@ import org.robolectric.annotation.Config;
@RunWith(AndroidJUnit4.class)
public final class RtspPlaybackTest {
private static final long DEFAULT_TIMEOUT_MS = 8000;
private static final String SESSION_DESCRIPTION =
"v=0\r\n"
+ "o=- 1606776316530225 1 IN IP4 127.0.0.1\r\n"
+ "s=Exoplayer test\r\n"
+ "t=0 0\r\n";
private final Context applicationContext;
private final CapturingRenderersFactory capturingRenderersFactory;
private final Clock clock;
private final FakeUdpDataSourceRtpDataChannel fakeRtpDataChannel;
private final RtpDataChannel.Factory rtpDataChannelFactory;
private Context applicationContext;
private CapturingRenderersFactory capturingRenderersFactory;
private Clock clock;
private RtpPacketStreamDump aacRtpPacketStreamDump;
// ExoPlayer does not support extracting MP4A-LATM RTP payload at the moment.
private RtpPacketStreamDump mpeg2tsRtpPacketStreamDump;
/** Creates a new instance. */
public RtspPlaybackTest() {
applicationContext = ApplicationProvider.getApplicationContext();
capturingRenderersFactory = new CapturingRenderersFactory(applicationContext);
clock = new FakeClock(/* isAutoAdvancing= */ true);
fakeRtpDataChannel = new FakeUdpDataSourceRtpDataChannel();
rtpDataChannelFactory = (trackId) -> fakeRtpDataChannel;
}
private RtspServer rtspServer;
@Rule
public ShadowMediaCodecConfig mediaCodecConfig =
@ -89,61 +82,162 @@ public final class RtspPlaybackTest {
@Before
public void setUp() throws Exception {
applicationContext = ApplicationProvider.getApplicationContext();
capturingRenderersFactory = new CapturingRenderersFactory(applicationContext);
clock = new FakeClock(/* isAutoAdvancing= */ true);
aacRtpPacketStreamDump = RtspTestUtils.readRtpPacketStreamDump("media/rtsp/aac-dump.json");
mpeg2tsRtpPacketStreamDump =
RtspTestUtils.readRtpPacketStreamDump("media/rtsp/mpeg2ts-dump.json");
}
@After
public void tearDown() {
Util.closeQuietly(rtspServer);
}
@Test
public void prepare_withSupportedTrack_playsTrackUntilEnded() throws Exception {
FakeUdpDataSourceRtpDataChannel fakeRtpDataChannel = new FakeUdpDataSourceRtpDataChannel();
RtpDataChannel.Factory rtpDataChannelFactory = (trackId) -> fakeRtpDataChannel;
ResponseProvider responseProvider =
new ResponseProvider(
clock,
ImmutableList.of(aacRtpPacketStreamDump, mpeg2tsRtpPacketStreamDump),
fakeRtpDataChannel);
rtspServer = new RtspServer(responseProvider);
ExoPlayer player = createExoPlayer(rtspServer.startAndGetPortNumber(), rtpDataChannelFactory);
try (RtspServer rtspServer = new RtspServer(responseProvider)) {
ExoPlayer player = createExoPlayer(rtspServer.startAndGetPortNumber(), rtpDataChannelFactory);
PlaybackOutput playbackOutput = PlaybackOutput.register(player, capturingRenderersFactory);
player.prepare();
player.play();
TestPlayerRunHelper.runUntilPlaybackState(player, Player.STATE_ENDED);
player.release();
PlaybackOutput playbackOutput = PlaybackOutput.register(player, capturingRenderersFactory);
player.prepare();
player.play();
TestPlayerRunHelper.runUntilPlaybackState(player, Player.STATE_ENDED);
player.release();
// Only setup the supported track (aac).
assertThat(responseProvider.getDumpsForSetUpTracks()).containsExactly(aacRtpPacketStreamDump);
DumpFileAsserts.assertOutput(
applicationContext, playbackOutput, "playbackdumps/rtsp/aac.dump");
}
// Only setup the supported track (aac).
assertThat(responseProvider.getDumpsForSetUpTracks()).containsExactly(aacRtpPacketStreamDump);
DumpFileAsserts.assertOutput(applicationContext, playbackOutput, "playbackdumps/rtsp/aac.dump");
}
@Test
public void prepare_noSupportedTrack_throwsPreparationError() throws Exception {
try (RtspServer rtspServer =
FakeUdpDataSourceRtpDataChannel fakeRtpDataChannel = new FakeUdpDataSourceRtpDataChannel();
RtpDataChannel.Factory rtpDataChannelFactory = (trackId) -> fakeRtpDataChannel;
rtspServer =
new RtspServer(
new ResponseProvider(
clock, ImmutableList.of(mpeg2tsRtpPacketStreamDump), fakeRtpDataChannel))) {
ExoPlayer player = createExoPlayer(rtspServer.startAndGetPortNumber(), rtpDataChannelFactory);
clock, ImmutableList.of(mpeg2tsRtpPacketStreamDump), fakeRtpDataChannel));
ExoPlayer player = createExoPlayer(rtspServer.startAndGetPortNumber(), rtpDataChannelFactory);
AtomicReference<Throwable> playbackError = new AtomicReference<>();
player.prepare();
player.addListener(
new Listener() {
@Override
public void onPlayerError(PlaybackException error) {
playbackError.set(error);
}
});
RobolectricUtil.runMainLooperUntil(() -> playbackError.get() != null);
player.release();
AtomicReference<Throwable> playbackError = new AtomicReference<>();
player.prepare();
player.addListener(
new Listener() {
@Override
public void onPlayerError(PlaybackException error) {
playbackError.set(error);
}
});
RobolectricUtil.runMainLooperUntil(() -> playbackError.get() != null);
player.release();
assertThat(playbackError.get())
.hasCauseThat()
.hasMessageThat()
.contains("No playable track.");
}
assertThat(playbackError.get()).hasCauseThat().hasMessageThat().contains("No playable track.");
}
@Test
public void prepare_withUdpUnsupportedWithFallback_fallsbackToTcpAndPlaysUntilEnd()
throws Exception {
FakeTcpDataSourceRtpDataChannel fakeTcpRtpDataChannel = new FakeTcpDataSourceRtpDataChannel();
RtpDataChannel.Factory rtpTcpDataChannelFactory = (trackId) -> fakeTcpRtpDataChannel;
ResponseProviderSupportingOnlyTcp responseProviderSupportingOnlyTcp =
new ResponseProviderSupportingOnlyTcp(
clock,
ImmutableList.of(aacRtpPacketStreamDump, mpeg2tsRtpPacketStreamDump),
fakeTcpRtpDataChannel);
ForwardingRtpDataChannelFactory forwardingRtpDataChannelFactory =
new ForwardingRtpDataChannelFactory(
new UdpDataSourceRtpDataChannelFactory(DEFAULT_TIMEOUT_MS), rtpTcpDataChannelFactory);
rtspServer = new RtspServer(responseProviderSupportingOnlyTcp);
ExoPlayer player =
createExoPlayer(rtspServer.startAndGetPortNumber(), forwardingRtpDataChannelFactory);
PlaybackOutput playbackOutput = PlaybackOutput.register(player, capturingRenderersFactory);
player.prepare();
player.play();
TestPlayerRunHelper.runUntilPlaybackState(player, Player.STATE_ENDED);
player.release();
// Only setup the supported track (aac).
assertThat(responseProviderSupportingOnlyTcp.getDumpsForSetUpTracks())
.containsExactly(aacRtpPacketStreamDump);
DumpFileAsserts.assertOutput(applicationContext, playbackOutput, "playbackdumps/rtsp/aac.dump");
}
@Test
public void prepare_withUdpUnsupportedWithoutFallback_throwsRtspPlaybackException()
throws Exception {
FakeUdpDataSourceRtpDataChannel fakeUdpRtpDataChannel = new FakeUdpDataSourceRtpDataChannel();
RtpDataChannel.Factory rtpDataChannelFactory = (trackId) -> fakeUdpRtpDataChannel;
ResponseProviderSupportingOnlyTcp responseProvider =
new ResponseProviderSupportingOnlyTcp(
clock,
ImmutableList.of(aacRtpPacketStreamDump, mpeg2tsRtpPacketStreamDump),
fakeUdpRtpDataChannel);
rtspServer = new RtspServer(responseProvider);
ExoPlayer player = createExoPlayer(rtspServer.startAndGetPortNumber(), rtpDataChannelFactory);
AtomicReference<PlaybackException> playbackError = new AtomicReference<>();
player.prepare();
player.addListener(
new Listener() {
@Override
public void onPlayerError(PlaybackException error) {
playbackError.set(error);
}
});
RobolectricUtil.runMainLooperUntil(() -> playbackError.get() != null);
player.release();
assertThat(playbackError.get())
.hasCauseThat()
.isInstanceOf(RtspMediaSource.RtspPlaybackException.class);
assertThat(playbackError.get())
.hasCauseThat()
.hasMessageThat()
.contains("No fallback data channel factory for TCP retry");
}
@Test
public void prepare_withUdpUnsupportedWithUdpFallback_throwsRtspUdpUnsupportedTransportException()
throws Exception {
FakeUdpDataSourceRtpDataChannel fakeUdpRtpDataChannel = new FakeUdpDataSourceRtpDataChannel();
RtpDataChannel.Factory rtpDataChannelFactory = (trackId) -> fakeUdpRtpDataChannel;
ResponseProviderSupportingOnlyTcp responseProviderSupportingOnlyTcp =
new ResponseProviderSupportingOnlyTcp(
clock,
ImmutableList.of(aacRtpPacketStreamDump, mpeg2tsRtpPacketStreamDump),
fakeUdpRtpDataChannel);
ForwardingRtpDataChannelFactory forwardingRtpDataChannelFactory =
new ForwardingRtpDataChannelFactory(rtpDataChannelFactory, rtpDataChannelFactory);
rtspServer = new RtspServer(responseProviderSupportingOnlyTcp);
ExoPlayer player =
createExoPlayer(rtspServer.startAndGetPortNumber(), forwardingRtpDataChannelFactory);
AtomicReference<PlaybackException> playbackError = new AtomicReference<>();
player.prepare();
player.addListener(
new Listener() {
@Override
public void onPlayerError(PlaybackException error) {
playbackError.set(error);
}
});
RobolectricUtil.runMainLooperUntil(() -> playbackError.get() != null);
player.release();
assertThat(playbackError.get())
.hasCauseThat()
.isInstanceOf(RtspMediaSource.RtspUdpUnsupportedTransportException.class);
assertThat(playbackError.get()).hasCauseThat().hasMessageThat().isEqualTo("SETUP 461");
}
private ExoPlayer createExoPlayer(
@ -163,16 +257,16 @@ public final class RtspPlaybackTest {
return player;
}
private static final class ResponseProvider implements RtspServer.ResponseProvider {
private static class ResponseProvider implements RtspServer.ResponseProvider {
private static final String SESSION_ID = "00000000";
protected static final String SESSION_ID = "00000000";
private final Clock clock;
private final ArrayList<RtpPacketStreamDump> dumpsForSetUpTracks;
private final ImmutableList<RtpPacketStreamDump> rtpPacketStreamDumps;
protected final Clock clock;
protected final ArrayList<RtpPacketStreamDump> dumpsForSetUpTracks;
protected final ImmutableList<RtpPacketStreamDump> rtpPacketStreamDumps;
private final RtspMessageChannel.InterleavedBinaryDataListener binaryDataListener;
private RtpPacketTransmitter packetTransmitter;
protected RtpPacketTransmitter packetTransmitter;
/**
* Creates a new instance.
@ -240,22 +334,54 @@ public final class RtspPlaybackTest {
}
}
private static final class FakeUdpDataSourceRtpDataChannel extends BaseDataSource
implements RtpDataChannel, RtspMessageChannel.InterleavedBinaryDataListener {
private static final class ResponseProviderSupportingOnlyTcp extends ResponseProvider {
private static final int LOCAL_PORT = 40000;
/**
* Creates a new instance.
*
* @param clock The {@link Clock} used in the test.
* @param rtpPacketStreamDumps A list of {@link RtpPacketStreamDump}.
* @param binaryDataListener A {@link RtspMessageChannel.InterleavedBinaryDataListener} to send
* RTP data.
*/
public ResponseProviderSupportingOnlyTcp(
Clock clock,
List<RtpPacketStreamDump> rtpPacketStreamDumps,
RtspMessageChannel.InterleavedBinaryDataListener binaryDataListener) {
super(clock, rtpPacketStreamDumps, binaryDataListener);
}
@Override
public RtspResponse getSetupResponse(Uri requestedUri, RtspHeaders headers) {
String transportHeaderValue = checkNotNull(headers.get(RtspHeaders.TRANSPORT));
if (!transportHeaderValue.contains("TCP")) {
return new RtspResponse(
/* status= */ 461, headers.buildUpon().add(RtspHeaders.SESSION, SESSION_ID).build());
}
for (RtpPacketStreamDump rtpPacketStreamDump : rtpPacketStreamDumps) {
if (requestedUri.toString().contains(rtpPacketStreamDump.trackName)) {
dumpsForSetUpTracks.add(rtpPacketStreamDump);
packetTransmitter = new RtpPacketTransmitter(rtpPacketStreamDump, clock);
}
}
return new RtspResponse(
/* status= */ 200, headers.buildUpon().add(RtspHeaders.SESSION, SESSION_ID).build());
}
}
private abstract static class FakeBaseDataSourceRtpDataChannel extends BaseDataSource
implements RtpDataChannel, RtspMessageChannel.InterleavedBinaryDataListener {
protected static final int LOCAL_PORT = 40000;
private final ConcurrentLinkedQueue<byte[]> packetQueue;
public FakeUdpDataSourceRtpDataChannel() {
public FakeBaseDataSourceRtpDataChannel() {
super(/* isNetwork= */ false);
packetQueue = new ConcurrentLinkedQueue<>();
}
@Override
public String getTransport() {
return Util.formatInvariant("RTP/AVP;unicast;client_port=%d-%d", LOCAL_PORT, LOCAL_PORT + 1);
}
public abstract String getTransport();
@Override
public int getLocalPort() {
@ -307,4 +433,49 @@ public final class RtspPlaybackTest {
return byteToRead;
}
}
private static final class FakeUdpDataSourceRtpDataChannel
extends FakeBaseDataSourceRtpDataChannel {
@Override
public String getTransport() {
return Util.formatInvariant("RTP/AVP;unicast;client_port=%d-%d", LOCAL_PORT, LOCAL_PORT + 1);
}
@Override
public RtspMessageChannel.InterleavedBinaryDataListener getInterleavedBinaryDataListener() {
return null;
}
}
private static final class FakeTcpDataSourceRtpDataChannel
extends FakeBaseDataSourceRtpDataChannel {
@Override
public String getTransport() {
return Util.formatInvariant(
"RTP/AVP/TCP;unicast;interleaved=%d-%d", LOCAL_PORT + 2, LOCAL_PORT + 3);
}
}
private static class ForwardingRtpDataChannelFactory implements RtpDataChannel.Factory {
private final RtpDataChannel.Factory rtpChannelFactory;
private final RtpDataChannel.Factory rtpFallbackChannelFactory;
public ForwardingRtpDataChannelFactory(
RtpDataChannel.Factory rtpChannelFactory,
RtpDataChannel.Factory rtpFallbackChannelFactory) {
this.rtpChannelFactory = rtpChannelFactory;
this.rtpFallbackChannelFactory = rtpFallbackChannelFactory;
}
@Override
public RtpDataChannel createAndOpenDataChannel(int trackId) throws IOException {
return rtpChannelFactory.createAndOpenDataChannel(trackId);
}
@Override
public RtpDataChannel.Factory createFallbackDataChannelFactory() {
return rtpFallbackChannelFactory;
}
}
}