WebRTCWrapper.java

  1package eu.siacs.conversations.xmpp.jingle;
  2
  3import android.content.Context;
  4import android.os.Build;
  5import android.os.Handler;
  6import android.os.Looper;
  7import android.util.Log;
  8
  9import com.google.common.base.Optional;
 10import com.google.common.base.Preconditions;
 11import com.google.common.collect.ImmutableSet;
 12import com.google.common.collect.Iterables;
 13import com.google.common.util.concurrent.Futures;
 14import com.google.common.util.concurrent.ListenableFuture;
 15import com.google.common.util.concurrent.MoreExecutors;
 16import com.google.common.util.concurrent.SettableFuture;
 17
 18import org.webrtc.AudioSource;
 19import org.webrtc.AudioTrack;
 20import org.webrtc.Camera1Enumerator;
 21import org.webrtc.Camera2Enumerator;
 22import org.webrtc.CameraEnumerationAndroid;
 23import org.webrtc.CameraEnumerator;
 24import org.webrtc.CameraVideoCapturer;
 25import org.webrtc.CandidatePairChangeEvent;
 26import org.webrtc.DataChannel;
 27import org.webrtc.DefaultVideoDecoderFactory;
 28import org.webrtc.DefaultVideoEncoderFactory;
 29import org.webrtc.EglBase;
 30import org.webrtc.IceCandidate;
 31import org.webrtc.MediaConstraints;
 32import org.webrtc.MediaStream;
 33import org.webrtc.MediaStreamTrack;
 34import org.webrtc.PeerConnection;
 35import org.webrtc.PeerConnectionFactory;
 36import org.webrtc.RtpReceiver;
 37import org.webrtc.RtpTransceiver;
 38import org.webrtc.SdpObserver;
 39import org.webrtc.SessionDescription;
 40import org.webrtc.SurfaceTextureHelper;
 41import org.webrtc.VideoSource;
 42import org.webrtc.VideoTrack;
 43import org.webrtc.audio.JavaAudioDeviceModule;
 44import org.webrtc.voiceengine.WebRtcAudioEffects;
 45
 46import java.util.ArrayList;
 47import java.util.Collections;
 48import java.util.List;
 49import java.util.Set;
 50
 51import javax.annotation.Nonnull;
 52import javax.annotation.Nullable;
 53
 54import eu.siacs.conversations.Config;
 55import eu.siacs.conversations.services.AppRTCAudioManager;
 56import eu.siacs.conversations.services.XmppConnectionService;
 57
 58public class WebRTCWrapper {
 59
 60    private static final String EXTENDED_LOGGING_TAG = WebRTCWrapper.class.getSimpleName();
 61
 62    //we should probably keep this in sync with: https://github.com/signalapp/Signal-Android/blob/master/app/src/main/java/org/thoughtcrime/securesms/ApplicationContext.java#L296
 63    private static final Set<String> HARDWARE_AEC_BLACKLIST = new ImmutableSet.Builder<String>()
 64            .add("Pixel")
 65            .add("Pixel XL")
 66            .add("Moto G5")
 67            .add("Moto G (5S) Plus")
 68            .add("Moto G4")
 69            .add("TA-1053")
 70            .add("Mi A1")
 71            .add("Mi A2")
 72            .add("E5823") // Sony z5 compact
 73            .add("Redmi Note 5")
 74            .add("FP2") // Fairphone FP2
 75            .add("MI 5")
 76            .build();
 77
 78    private static final int CAPTURING_RESOLUTION = 1920;
 79    private static final int CAPTURING_MAX_FRAME_RATE = 30;
 80
 81    private final EventCallback eventCallback;
 82    private final AppRTCAudioManager.AudioManagerEvents audioManagerEvents = new AppRTCAudioManager.AudioManagerEvents() {
 83        @Override
 84        public void onAudioDeviceChanged(AppRTCAudioManager.AudioDevice selectedAudioDevice, Set<AppRTCAudioManager.AudioDevice> availableAudioDevices) {
 85            eventCallback.onAudioDeviceChanged(selectedAudioDevice, availableAudioDevices);
 86        }
 87    };
 88    private final Handler mainHandler = new Handler(Looper.getMainLooper());
 89    private VideoTrack localVideoTrack = null;
 90    private VideoTrack remoteVideoTrack = null;
 91    private final PeerConnection.Observer peerConnectionObserver = new PeerConnection.Observer() {
 92        @Override
 93        public void onSignalingChange(PeerConnection.SignalingState signalingState) {
 94            Log.d(EXTENDED_LOGGING_TAG, "onSignalingChange(" + signalingState + ")");
 95            //this is called after removeTrack or addTrack
 96            //and should then trigger a content-add or content-remove or something
 97            //https://developer.mozilla.org/en-US/docs/Web/API/RTCPeerConnection/removeTrack
 98        }
 99
100        @Override
101        public void onConnectionChange(PeerConnection.PeerConnectionState newState) {
102            eventCallback.onConnectionChange(newState);
103        }
104
105        @Override
106        public void onIceConnectionChange(PeerConnection.IceConnectionState iceConnectionState) {
107
108        }
109
110        @Override
111        public void onSelectedCandidatePairChanged(CandidatePairChangeEvent event) {
112            Log.d(Config.LOGTAG, "remote candidate selected: " + event.remote);
113            Log.d(Config.LOGTAG, "local candidate selected: " + event.local);
114        }
115
116        @Override
117        public void onIceConnectionReceivingChange(boolean b) {
118
119        }
120
121        @Override
122        public void onIceGatheringChange(PeerConnection.IceGatheringState iceGatheringState) {
123            Log.d(EXTENDED_LOGGING_TAG, "onIceGatheringChange(" + iceGatheringState + ")");
124        }
125
126        @Override
127        public void onIceCandidate(IceCandidate iceCandidate) {
128            eventCallback.onIceCandidate(iceCandidate);
129        }
130
131        @Override
132        public void onIceCandidatesRemoved(IceCandidate[] iceCandidates) {
133
134        }
135
136        @Override
137        public void onAddStream(MediaStream mediaStream) {
138            Log.d(EXTENDED_LOGGING_TAG, "onAddStream(numAudioTracks=" + mediaStream.audioTracks.size() + ",numVideoTracks=" + mediaStream.videoTracks.size() + ")");
139            final List<VideoTrack> videoTracks = mediaStream.videoTracks;
140            if (videoTracks.size() > 0) {
141                remoteVideoTrack = videoTracks.get(0);
142                Log.d(Config.LOGTAG, "remote video track enabled?=" + remoteVideoTrack.enabled());
143            } else {
144                Log.d(Config.LOGTAG, "no remote video tracks found");
145            }
146        }
147
148        @Override
149        public void onRemoveStream(MediaStream mediaStream) {
150
151        }
152
153        @Override
154        public void onDataChannel(DataChannel dataChannel) {
155
156        }
157
158        @Override
159        public void onRenegotiationNeeded() {
160
161        }
162
163        @Override
164        public void onAddTrack(RtpReceiver rtpReceiver, MediaStream[] mediaStreams) {
165            final MediaStreamTrack track = rtpReceiver.track();
166            Log.d(EXTENDED_LOGGING_TAG, "onAddTrack(kind=" + (track == null ? "null" : track.kind()) + ",numMediaStreams=" + mediaStreams.length + ")");
167        }
168
169        @Override
170        public void onTrack(RtpTransceiver transceiver) {
171            Log.d(EXTENDED_LOGGING_TAG, "onTrack(mid=" + transceiver.getMid() + ",media=" + transceiver.getMediaType() + ")");
172        }
173    };
174    @Nullable
175    private PeerConnection peerConnection = null;
176    private AudioTrack localAudioTrack = null;
177    private AppRTCAudioManager appRTCAudioManager = null;
178    private ToneManager toneManager = null;
179    private Context context = null;
180    private EglBase eglBase = null;
181    private CapturerChoice capturerChoice;
182
183    WebRTCWrapper(final EventCallback eventCallback) {
184        this.eventCallback = eventCallback;
185    }
186
187    private static void dispose(final PeerConnection peerConnection) {
188        try {
189            peerConnection.dispose();
190        } catch (final IllegalStateException e) {
191            Log.e(Config.LOGTAG, "unable to dispose of peer connection", e);
192        }
193    }
194
195    @Nullable
196    private static CapturerChoice of(CameraEnumerator enumerator, final String deviceName, Set<String> availableCameras) {
197        final CameraVideoCapturer capturer = enumerator.createCapturer(deviceName, null);
198        if (capturer == null) {
199            return null;
200        }
201        final ArrayList<CameraEnumerationAndroid.CaptureFormat> choices = new ArrayList<>(enumerator.getSupportedFormats(deviceName));
202        Collections.sort(choices, (a, b) -> b.width - a.width);
203        for (final CameraEnumerationAndroid.CaptureFormat captureFormat : choices) {
204            if (captureFormat.width <= CAPTURING_RESOLUTION) {
205                return new CapturerChoice(capturer, captureFormat, availableCameras);
206            }
207        }
208        return null;
209    }
210
211    public void setup(final XmppConnectionService service, final AppRTCAudioManager.SpeakerPhonePreference speakerPhonePreference) throws InitializationException {
212        try {
213            PeerConnectionFactory.initialize(
214                    PeerConnectionFactory.InitializationOptions.builder(service).createInitializationOptions()
215            );
216        } catch (final UnsatisfiedLinkError e) {
217            throw new InitializationException(e);
218        }
219        this.eglBase = EglBase.create();
220        this.context = service;
221        this.toneManager = service.getJingleConnectionManager().toneManager;
222        mainHandler.post(() -> {
223            appRTCAudioManager = AppRTCAudioManager.create(service, speakerPhonePreference);
224            toneManager.setAppRtcAudioManagerHasControl(true);
225            appRTCAudioManager.start(audioManagerEvents);
226            eventCallback.onAudioDeviceChanged(appRTCAudioManager.getSelectedAudioDevice(), appRTCAudioManager.getAudioDevices());
227        });
228    }
229
230    synchronized void initializePeerConnection(final Set<Media> media, final List<PeerConnection.IceServer> iceServers) throws InitializationException {
231        Preconditions.checkState(this.eglBase != null);
232        Preconditions.checkNotNull(media);
233        Preconditions.checkArgument(media.size() > 0, "media can not be empty when initializing peer connection");
234        final boolean setUseHardwareAcousticEchoCanceler = WebRtcAudioEffects.canUseAcousticEchoCanceler() && !HARDWARE_AEC_BLACKLIST.contains(Build.MODEL);
235        Log.d(Config.LOGTAG, String.format("setUseHardwareAcousticEchoCanceler(%s) model=%s", setUseHardwareAcousticEchoCanceler, Build.MODEL));
236        PeerConnectionFactory peerConnectionFactory = PeerConnectionFactory.builder()
237                .setVideoDecoderFactory(new DefaultVideoDecoderFactory(eglBase.getEglBaseContext()))
238                .setVideoEncoderFactory(new DefaultVideoEncoderFactory(eglBase.getEglBaseContext(), true, true))
239                .setAudioDeviceModule(JavaAudioDeviceModule.builder(context)
240                        .setUseHardwareAcousticEchoCanceler(setUseHardwareAcousticEchoCanceler)
241                        .createAudioDeviceModule()
242                )
243                .createPeerConnectionFactory();
244
245
246        final MediaStream stream = peerConnectionFactory.createLocalMediaStream("my-media-stream");
247
248        final Optional<CapturerChoice> optionalCapturerChoice = media.contains(Media.VIDEO) ? getVideoCapturer() : Optional.absent();
249
250        if (optionalCapturerChoice.isPresent()) {
251            this.capturerChoice = optionalCapturerChoice.get();
252            final CameraVideoCapturer capturer = this.capturerChoice.cameraVideoCapturer;
253            final VideoSource videoSource = peerConnectionFactory.createVideoSource(false);
254            SurfaceTextureHelper surfaceTextureHelper = SurfaceTextureHelper.create("webrtc", eglBase.getEglBaseContext());
255            capturer.initialize(surfaceTextureHelper, requireContext(), videoSource.getCapturerObserver());
256            Log.d(Config.LOGTAG, String.format("start capturing at %dx%d@%d", capturerChoice.captureFormat.width, capturerChoice.captureFormat.height, capturerChoice.getFrameRate()));
257            capturer.startCapture(capturerChoice.captureFormat.width, capturerChoice.captureFormat.height, capturerChoice.getFrameRate());
258
259            this.localVideoTrack = peerConnectionFactory.createVideoTrack("my-video-track", videoSource);
260
261            stream.addTrack(this.localVideoTrack);
262        }
263
264
265        if (media.contains(Media.AUDIO)) {
266            //set up audio track
267            final AudioSource audioSource = peerConnectionFactory.createAudioSource(new MediaConstraints());
268            this.localAudioTrack = peerConnectionFactory.createAudioTrack("my-audio-track", audioSource);
269            stream.addTrack(this.localAudioTrack);
270        }
271
272
273        final PeerConnection.RTCConfiguration rtcConfig = new PeerConnection.RTCConfiguration(iceServers);
274        rtcConfig.tcpCandidatePolicy = PeerConnection.TcpCandidatePolicy.DISABLED; //XEP-0176 doesn't support tcp
275        final PeerConnection peerConnection = peerConnectionFactory.createPeerConnection(rtcConfig, peerConnectionObserver);
276        if (peerConnection == null) {
277            throw new InitializationException("Unable to create PeerConnection");
278        }
279        peerConnection.addStream(stream);
280        peerConnection.setAudioPlayout(true);
281        peerConnection.setAudioRecording(true);
282        this.peerConnection = peerConnection;
283    }
284
285    synchronized void close() {
286        final PeerConnection peerConnection = this.peerConnection;
287        final CapturerChoice capturerChoice = this.capturerChoice;
288        final AppRTCAudioManager audioManager = this.appRTCAudioManager;
289        final EglBase eglBase = this.eglBase;
290        if (peerConnection != null) {
291            dispose(peerConnection);
292            this.peerConnection = null;
293        }
294        if (audioManager != null) {
295            toneManager.setAppRtcAudioManagerHasControl(false);
296            mainHandler.post(audioManager::stop);
297        }
298        this.localVideoTrack = null;
299        this.remoteVideoTrack = null;
300        if (capturerChoice != null) {
301            try {
302                capturerChoice.cameraVideoCapturer.stopCapture();
303            } catch (InterruptedException e) {
304                Log.e(Config.LOGTAG, "unable to stop capturing");
305            }
306        }
307        if (eglBase != null) {
308            eglBase.release();
309            this.eglBase = null;
310        }
311    }
312
313    synchronized void verifyClosed() {
314        if (this.peerConnection != null
315                || this.eglBase != null
316                || this.localVideoTrack != null
317                || this.remoteVideoTrack != null) {
318            final IllegalStateException e = new IllegalStateException("WebRTCWrapper hasn't been closed properly");
319            Log.e(Config.LOGTAG, "verifyClosed() failed. Going to throw", e);
320            throw e;
321        }
322    }
323
324    boolean isCameraSwitchable() {
325        final CapturerChoice capturerChoice = this.capturerChoice;
326        return capturerChoice != null && capturerChoice.availableCameras.size() > 1;
327    }
328
329    boolean isFrontCamera() {
330        final CapturerChoice capturerChoice = this.capturerChoice;
331        return capturerChoice == null || capturerChoice.isFrontCamera;
332    }
333
334    ListenableFuture<Boolean> switchCamera() {
335        final CapturerChoice capturerChoice = this.capturerChoice;
336        if (capturerChoice == null) {
337            return Futures.immediateFailedFuture(new IllegalStateException("CameraCapturer has not been initialized"));
338        }
339        final SettableFuture<Boolean> future = SettableFuture.create();
340        capturerChoice.cameraVideoCapturer.switchCamera(new CameraVideoCapturer.CameraSwitchHandler() {
341            @Override
342            public void onCameraSwitchDone(boolean isFrontCamera) {
343                capturerChoice.isFrontCamera = isFrontCamera;
344                future.set(isFrontCamera);
345            }
346
347            @Override
348            public void onCameraSwitchError(final String message) {
349                future.setException(new IllegalStateException(String.format("Unable to switch camera %s", message)));
350            }
351        });
352        return future;
353    }
354
355    boolean isMicrophoneEnabled() {
356        final AudioTrack audioTrack = this.localAudioTrack;
357        if (audioTrack == null) {
358            throw new IllegalStateException("Local audio track does not exist (yet)");
359        }
360        try {
361            return audioTrack.enabled();
362        } catch (final IllegalStateException e) {
363            //sometimes UI might still be rendering the buttons when a background thread has already ended the call
364            return false;
365        }
366    }
367
368    void setMicrophoneEnabled(final boolean enabled) {
369        final AudioTrack audioTrack = this.localAudioTrack;
370        if (audioTrack == null) {
371            throw new IllegalStateException("Local audio track does not exist (yet)");
372        }
373        audioTrack.setEnabled(enabled);
374    }
375
376    boolean isVideoEnabled() {
377        final VideoTrack videoTrack = this.localVideoTrack;
378        if (videoTrack == null) {
379            throw new IllegalStateException("Local video track does not exist");
380        }
381        return videoTrack.enabled();
382    }
383
384    void setVideoEnabled(final boolean enabled) {
385        final VideoTrack videoTrack = this.localVideoTrack;
386        if (videoTrack == null) {
387            throw new IllegalStateException("Local video track does not exist");
388        }
389        videoTrack.setEnabled(enabled);
390    }
391
392    ListenableFuture<SessionDescription> createOffer() {
393        return Futures.transformAsync(getPeerConnectionFuture(), peerConnection -> {
394            final SettableFuture<SessionDescription> future = SettableFuture.create();
395            peerConnection.createOffer(new CreateSdpObserver() {
396                @Override
397                public void onCreateSuccess(SessionDescription sessionDescription) {
398                    future.set(sessionDescription);
399                }
400
401                @Override
402                public void onCreateFailure(String s) {
403                    future.setException(new IllegalStateException("Unable to create offer: " + s));
404                }
405            }, new MediaConstraints());
406            return future;
407        }, MoreExecutors.directExecutor());
408    }
409
410    ListenableFuture<SessionDescription> createAnswer() {
411        return Futures.transformAsync(getPeerConnectionFuture(), peerConnection -> {
412            final SettableFuture<SessionDescription> future = SettableFuture.create();
413            peerConnection.createAnswer(new CreateSdpObserver() {
414                @Override
415                public void onCreateSuccess(SessionDescription sessionDescription) {
416                    future.set(sessionDescription);
417                }
418
419                @Override
420                public void onCreateFailure(String s) {
421                    future.setException(new IllegalStateException("Unable to create answer: " + s));
422                }
423            }, new MediaConstraints());
424            return future;
425        }, MoreExecutors.directExecutor());
426    }
427
428    ListenableFuture<Void> setLocalDescription(final SessionDescription sessionDescription) {
429        Log.d(EXTENDED_LOGGING_TAG, "setting local description:");
430        for (final String line : sessionDescription.description.split(eu.siacs.conversations.xmpp.jingle.SessionDescription.LINE_DIVIDER)) {
431            Log.d(EXTENDED_LOGGING_TAG, line);
432        }
433        return Futures.transformAsync(getPeerConnectionFuture(), peerConnection -> {
434            final SettableFuture<Void> future = SettableFuture.create();
435            peerConnection.setLocalDescription(new SetSdpObserver() {
436                @Override
437                public void onSetSuccess() {
438                    future.set(null);
439                }
440
441                @Override
442                public void onSetFailure(final String s) {
443                    future.setException(new IllegalArgumentException("unable to set local session description: " + s));
444
445                }
446            }, sessionDescription);
447            return future;
448        }, MoreExecutors.directExecutor());
449    }
450
451    ListenableFuture<Void> setRemoteDescription(final SessionDescription sessionDescription) {
452        Log.d(EXTENDED_LOGGING_TAG, "setting remote description:");
453        for (final String line : sessionDescription.description.split(eu.siacs.conversations.xmpp.jingle.SessionDescription.LINE_DIVIDER)) {
454            Log.d(EXTENDED_LOGGING_TAG, line);
455        }
456        return Futures.transformAsync(getPeerConnectionFuture(), peerConnection -> {
457            final SettableFuture<Void> future = SettableFuture.create();
458            peerConnection.setRemoteDescription(new SetSdpObserver() {
459                @Override
460                public void onSetSuccess() {
461                    future.set(null);
462                }
463
464                @Override
465                public void onSetFailure(String s) {
466                    future.setException(new IllegalArgumentException("unable to set remote session description: " + s));
467
468                }
469            }, sessionDescription);
470            return future;
471        }, MoreExecutors.directExecutor());
472    }
473
474    @Nonnull
475    private ListenableFuture<PeerConnection> getPeerConnectionFuture() {
476        final PeerConnection peerConnection = this.peerConnection;
477        if (peerConnection == null) {
478            return Futures.immediateFailedFuture(new IllegalStateException("initialize PeerConnection first"));
479        } else {
480            return Futures.immediateFuture(peerConnection);
481        }
482    }
483
484    void addIceCandidate(IceCandidate iceCandidate) {
485        requirePeerConnection().addIceCandidate(iceCandidate);
486    }
487
488    private CameraEnumerator getCameraEnumerator() {
489        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
490            return new Camera2Enumerator(requireContext());
491        } else {
492            return new Camera1Enumerator();
493        }
494    }
495
496    private Optional<CapturerChoice> getVideoCapturer() {
497        final CameraEnumerator enumerator = getCameraEnumerator();
498        final Set<String> deviceNames = ImmutableSet.copyOf(enumerator.getDeviceNames());
499        for (final String deviceName : deviceNames) {
500            if (enumerator.isFrontFacing(deviceName)) {
501                final CapturerChoice capturerChoice = of(enumerator, deviceName, deviceNames);
502                if (capturerChoice == null) {
503                    return Optional.absent();
504                }
505                capturerChoice.isFrontCamera = true;
506                return Optional.of(capturerChoice);
507            }
508        }
509        if (deviceNames.size() == 0) {
510            return Optional.absent();
511        } else {
512            return Optional.fromNullable(of(enumerator, Iterables.get(deviceNames, 0), deviceNames));
513        }
514    }
515
516    public PeerConnection.PeerConnectionState getState() {
517        return requirePeerConnection().connectionState();
518    }
519
520    EglBase.Context getEglBaseContext() {
521        return this.eglBase.getEglBaseContext();
522    }
523
524    Optional<VideoTrack> getLocalVideoTrack() {
525        return Optional.fromNullable(this.localVideoTrack);
526    }
527
528    Optional<VideoTrack> getRemoteVideoTrack() {
529        return Optional.fromNullable(this.remoteVideoTrack);
530    }
531
532    private PeerConnection requirePeerConnection() {
533        final PeerConnection peerConnection = this.peerConnection;
534        if (peerConnection == null) {
535            throw new IllegalStateException("initialize PeerConnection first");
536        }
537        return peerConnection;
538    }
539
540    private Context requireContext() {
541        final Context context = this.context;
542        if (context == null) {
543            throw new IllegalStateException("call setup first");
544        }
545        return context;
546    }
547
548    AppRTCAudioManager getAudioManager() {
549        return appRTCAudioManager;
550    }
551
552    public interface EventCallback {
553        void onIceCandidate(IceCandidate iceCandidate);
554
555        void onConnectionChange(PeerConnection.PeerConnectionState newState);
556
557        void onAudioDeviceChanged(AppRTCAudioManager.AudioDevice selectedAudioDevice, Set<AppRTCAudioManager.AudioDevice> availableAudioDevices);
558    }
559
560    private static abstract class SetSdpObserver implements SdpObserver {
561
562        @Override
563        public void onCreateSuccess(org.webrtc.SessionDescription sessionDescription) {
564            throw new IllegalStateException("Not able to use SetSdpObserver");
565        }
566
567        @Override
568        public void onCreateFailure(String s) {
569            throw new IllegalStateException("Not able to use SetSdpObserver");
570        }
571
572    }
573
574    private static abstract class CreateSdpObserver implements SdpObserver {
575
576
577        @Override
578        public void onSetSuccess() {
579            throw new IllegalStateException("Not able to use CreateSdpObserver");
580        }
581
582
583        @Override
584        public void onSetFailure(String s) {
585            throw new IllegalStateException("Not able to use CreateSdpObserver");
586        }
587    }
588
589    static class InitializationException extends Exception {
590
591        private InitializationException(final Throwable throwable) {
592            super(throwable);
593        }
594
595        private InitializationException(final String message) {
596            super(message);
597        }
598    }
599
600    private static class CapturerChoice {
601        private final CameraVideoCapturer cameraVideoCapturer;
602        private final CameraEnumerationAndroid.CaptureFormat captureFormat;
603        private final Set<String> availableCameras;
604        private boolean isFrontCamera = false;
605
606        CapturerChoice(CameraVideoCapturer cameraVideoCapturer, CameraEnumerationAndroid.CaptureFormat captureFormat, Set<String> cameras) {
607            this.cameraVideoCapturer = cameraVideoCapturer;
608            this.captureFormat = captureFormat;
609            this.availableCameras = cameras;
610        }
611
612        int getFrameRate() {
613            return Math.max(captureFormat.framerate.min, Math.min(CAPTURING_MAX_FRAME_RATE, captureFormat.framerate.max));
614        }
615    }
616}