javascript - 如何切换相机 webrtc Android

Question

因此，我正在使用 webrtc 构建一个 android 视频通话应用程序，我已经实现了所有东西，并从我的应用程序中测试了视频通话功能，它就像魅力一样。但是现在我想实现用户可以将相机从后部切换到前部的位置，反之亦然。我看到了一个类似的答案，它不是针对 android 的，它说要删除流并协商和新流我没有正确理解如何在这段代码中实现它，所以我希望有人可以帮助我解决这个问题谢谢

JavaScript 文件

localVideo.style.opacity = 0
remoteVideo.style.opacity = 0

localVideo.onplaying = () => { localVideo.style.opacity = 1 }
remoteVideo.onplaying = () => { remoteVideo.style.opacity = 1 }

let peer
function init(userId) {
     peer = new Peer(userId, {
        host: 'messenger-by-margs-video-call.herokuapp.com',
        secure: true
    })

    peer.on('open', () => {
        Android.onPeerConnected()
    })

    listen()
}

let localStream
function listen() {
    peer.on('call', (call) => {

        navigator.getUserMedia({
            audio: true, 
            video: true
        }, (stream) => {
            localVideo.srcObject = stream
            localStream = stream

            call.answer(stream)
            call.on('stream', (remoteStream) => {
                remoteVideo.srcObject = remoteStream

                remoteVideo.className = "primary-video"
                localVideo.className = "secondary-video"

            })

        })
        
    })
}

function startCall(otherUserId) {
    navigator.getUserMedia({
        audio: true,
        video: true
    }, (stream) => {

        localVideo.srcObject = stream
        localStream = stream

        const call = peer.call(otherUserId, stream)
        call.on('stream', (remoteStream) => {
            remoteVideo.srcObject = remoteStream

            remoteVideo.className = "primary-video"
            localVideo.className = "secondary-video"
        })

    })
}

function toggleVideo(b) {
    if (b == "true") {
        localStream.getVideoTracks()[0].enabled = true
    } else {
        localStream.getVideoTracks()[0].enabled = false
    }
} 

function toggleAudio(b) {
    if (b == "true") {
        localStream.getAudioTracks()[0].enabled = true
    } else {
        localStream.getAudioTracks()[0].enabled = false
    }
} 

这是我的 kotlin 活动文件。

class CallActivity : AppCompatActivity() {

    var username = ""
    var friendsUsername = ""

    var isPeerConnected = false

    var firebaseRef = FirebaseDatabase.getInstance().getReference("Users")

    var isAudio = true
    var isVideo = true




    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_video_call)


        username = FirebaseAuth.getInstance().uid.toString();
        friendsUsername = intent.getStringExtra("userid")!!




        call.setOnClickListener {
            sendCallRequest()
        }





        toggleAudioBtn.setOnClickListener {
            isAudio = !isAudio
            callJavascriptFunction("javascript:toggleAudio(\"${isAudio}\")")
            toggleAudioBtn.setImageResource(if (isAudio) R.drawable.ic_baseline_mic_24 else R.drawable.ic_baseline_mic_off_24 )
        }

        toggleVideoBtn.setOnClickListener {
            isVideo = !isVideo
            callJavascriptFunction("javascript:toggleVideo(\"${isVideo}\")")
            toggleVideoBtn.setImageResource(if (isVideo) R.drawable.ic_baseline_videocam_24 else R.drawable.ic_baseline_videocam_off_24 )
        }

        setupWebView()
    }



    private fun sendCallRequest() {
        if (!isPeerConnected) {
            Toast.makeText(this, "You're not connected. Check your internet", Toast.LENGTH_LONG).show()
            return
        }

        firebaseRef.child(friendsUsername).child("videocall").child("incall").setValue(username)
        firebaseRef.child(friendsUsername).child("videocall").child("isAvailable").addValueEventListener(object: ValueEventListener {
            override fun onCancelled(error: DatabaseError) {}

            override fun onDataChange(snapshot: DataSnapshot) {

                if (snapshot.value.toString() == "true") {
                    listenForConnId()
                }

            }

        })

    }

    private fun listenForConnId() {
        firebaseRef.child(friendsUsername).child("videocall").child("connId").addValueEventListener(object: ValueEventListener {
            override fun onCancelled(error: DatabaseError) {}

            override fun onDataChange(snapshot: DataSnapshot) {
                if (snapshot.value == null)
                    return
                switchToControls()
                callJavascriptFunction("javascript:startCall(\"${snapshot.value}\")")
            }

        })
    }

    @SuppressLint("SetJavaScriptEnabled")
    private fun setupWebView() {

        webView.webChromeClient = object: WebChromeClient() {
            override fun onPermissionRequest(request: PermissionRequest?) {
                request?.grant(request.resources)
            }
        }

        webView.settings.javaScriptEnabled = true
        webView.settings.mediaPlaybackRequiresUserGesture = false
        webView.addJavascriptInterface(JavascriptInterface(this), "Android")

        loadVideoCall()
    }

    private fun loadVideoCall() {
        val filePath = "file:android_asset/call.html"
        webView.loadUrl(filePath)

        webView.webViewClient = object: WebViewClient() {
            override fun onPageFinished(view: WebView?, url: String?) {
                initializePeer()
            }
        }
    }

    var uniqueId = ""

    private fun initializePeer() {

        uniqueId = getUniqueID()

        callJavascriptFunction("javascript:init(\"${uniqueId}\")")
        firebaseRef.child(username).child("videocall").child("incall").addValueEventListener(object: ValueEventListener {
            override fun onCancelled(error: DatabaseError) {}

            override fun onDataChange(snapshot: DataSnapshot) {
                onCallRequest(snapshot.value as? String)
            }

        })

    }

    private fun onCallRequest(caller: String?) {
        if (caller == null) return

        callLayout.visibility = View.VISIBLE
        incomingCallTxt.text = "$caller is calling..."

        acceptBtn.setOnClickListener {
            firebaseRef.child(username).child("videocall").child("connId").setValue(uniqueId)
            firebaseRef.child(username).child("videocall").child("isAvailable").setValue(true)

            callLayout.visibility = View.GONE
            switchToControls()
        }

        rejectBtn.setOnClickListener {
            firebaseRef.child(username).child("videocall").child("incall").setValue(null)
            callLayout.visibility = View.GONE
        }

    }

    private fun switchToControls() {
        //inputLayout.visibility = View.GONE
        call.visibility = View.INVISIBLE
        callControlLayout.visibility = View.VISIBLE

    }


    private fun getUniqueID(): String {
        return UUID.randomUUID().toString()
    }

    private fun callJavascriptFunction(functionString: String) {
        webView.post { webView.evaluateJavascript(functionString, null) }
    }


    fun onPeerConnected() {
        isPeerConnected = true
    }

}

我希望这些是我回答的必要信息

标签： javascriptandroidandroid-studiowebrtc