javascript - 如何使用 Microphone.getMicrophone() Actionscript 3 切换音频源

Question

我有一个基于 Wowza 的 webcam.fla 示例的网络摄像头流应用程序。该应用程序将音频和视频从 Flash 传输到 Wowza 服务器，并在其中进行转码等。

我们正在尝试添加一项功能，允许将音频源更改为任何其他系统音频源。到目前为止，我们成功创建了一个包含所有接口(interface)的下拉列表并处理回调，但是，尽管使用 doConnect() 函数启动和停止流，音频源似乎仍然是默认的。

import flash.media.*;
import flash.geom.*;
import flash.net.*;
import flash.media.*;// Should this be duplicated

var parsed:Object = root.loaderInfo.parameters;

var nc:NetConnection = null;
var nsPublish:NetStream = null;
var nsPlay:NetStream = null;
var camera:Camera = null;
var microphone:Microphone = null;

// Testing
var serverName:String = "rtmp://stream-na.example.tv:1935/live";
var movieName:String = "streamName";

var flushVideoBufferTimer:Number = 0;

// Quality settings

var videoBitrate:Number = 200000;
var videoQuality:Number = 80; // Quality %

var videoWidth:Number = 640;
var videoHeight:Number = 360;

var videoFrameRate:Number = 30;


//////////////// UI Functions Bellow

import fl.controls.ComboBox;
import fl.data.DataProvider;

var aCb:ComboBox = new ComboBox();

function createAudioComboBox(sources)
{

    var sourcesArray:Array = new Array();

    aCb.dropdownWidth = 210;
    aCb.width = 200;
    aCb.move(0, 365);
    aCb.prompt = "Change Audio Source";
    aCb.dataProvider = new DataProvider(sourcesArray);
    aCb.addEventListener(Event.CHANGE, changeAudioHandler);

    addChild(aCb);

    for (var index in sources)
    {
        //ExternalInterface.call("logBrowserStreaming", sources[index]);

        aCb.addItem( { label: sources[index], data: index} );

    }

    function changeAudioHandler(event:Event):void
    {

        doConnect();

        //var request:URLRequest = new URLRequest(); 
        //request.url = ComboBox(event.target).selectedItem.data; 
        //navigateToURL(request); 
        //aCb.selectedIndex = -1; 
        var audioSource = ComboBox(event.target).selectedItem.data;

        //microphone:Microphone = null;

        microphone = Microphone.getMicrophone(audioSource);

        microphone.rate = 16;
        microphone.codec = SoundCodec.SPEEX;
        microphone.encodeQuality = 10; // This is shit!! offer better audio in native app?
        microphone.setSilenceLevel(0, -1);
        microphone.setUseEchoSuppression(true);

        //ExternalInterface.call("logBrowserStreaming", audioSource);

        // Trigger restart camera...
        //startCamera(); // Nope

        doConnect();

    }

}

//////////////// Core Streaming Functions Bellow


function startCamera()
{
    // get the default Flash camera and microphone
    camera = Camera.getCamera();
    microphone = Microphone.getMicrophone();

    // here are all the quality and performance settings
    // here are all the quality and performance settings
    if (camera != null)
    {
        //camera.setMode(1280, 720, 30, false);
        camera.setMode(videoWidth, videoHeight, videoFrameRate, false); // false gives framerate priority apparently?? http://www.flash-communications.net/technotes/setMode/index.html
        camera.setQuality(videoBitrate, videoQuality);
        // Max 800kbps;
        camera.setKeyFrameInterval(2);

        // List audio sources names
        // sourceVideoLabel.text += Camera.names;

        // Create audio sources dropdown

        // Hide video sources for now...
        //createVideoComboBox(Camera.names);


    }
    else
    {
        sourceVideoLabel.text = "No Camera Found\n";
    }
    if ( microphone != null)
    {
        microphone.rate = 16;
        microphone.codec = SoundCodec.SPEEX;
        microphone.encodeQuality = 10; // This is shit!! offer better audio in native app?
        microphone.setSilenceLevel(0, -1);
        microphone.setUseEchoSuppression(true);

        // List audio sources names;
        // sourceVideoLabel.text += Microphone.names;

        // Create audio sources dropdown
        createAudioComboBox(Microphone.names);

        // Don't show audio slider for now...
        // createAudioSlider();


        // Don't monitor audio level for now...
        //monitorAudioLevel();

    }
    else
    {
        sourceVideoLabel.text +=  "No Microphone Found\n";
    }

    nameStr.text = movieName;
    AppendCheckbox.selected = false;
    connect.connectStr.text = serverName;
    connect.connectButton.addEventListener(MouseEvent.CLICK, doConnect);

    //enablePlayControls(false);

    doConnect();
}

function ncOnStatus(infoObject:NetStatusEvent)
{
    trace("nc: "+infoObject.info.code+" ("+infoObject.info.description+")");
    if (infoObject.info.code == "NetConnection.Connect.Failed")
    {
        prompt.text = "Connection failed. Try again or email support@chew.tv";
    }
    else if (infoObject.info.code == "NetConnection.Connect.Rejected")
    {
        // Hide connect fail...
        prompt.text = infoObject.info.description;
    }
}

// Ask for permission to use the camera and show the preview to the user
// event:MouseEvent
// doConnect toggles connections on and off.
function doConnect()
{
    // connect to the Wowza Media Server
    if (nc == null)
    {
        // create a connection to the wowza media server
        nc = new NetConnection();
        nc.addEventListener(NetStatusEvent.NET_STATUS, ncOnStatus);
        nc.connect(connect.connectStr.text);

        //connect.connectButton.label = "Disconnect";

        // uncomment this to monitor frame rate and buffer length
        //setInterval("updateStreamValues", 500);

        // Attach camera to preview
        videoCamera.clear();
        videoCamera.attachCamera(camera);

        //enablePlayControls(true);

        // Pass status to 
        // ExternalInterface.call("logBrowserStreaming", "cameraagreed");

    }
    else
    {
        nsPublish = null;
        nsPlay = null;

        videoCamera.attachNetStream(null);
        videoCamera.clear();

        videoRemote.attachNetStream(null);
        videoRemote.clear();

        nc.close();
        nc = null;

        //enablePlayControls(false);

        doSubscribe.label = 'Play';
        doPublish.label = 'Stream';
        AppendCheckbox.selected = false;

        connect.connectButton.label = "Connect";
        prompt.text = "";
    }
}

// function to monitor the frame rate and buffer length
function updateStreamValues()
{
    if (nsPlay != null)
    {
        fpsText.text = (Math.round(nsPlay.currentFPS*1000)/1000)+" fps";
        bufferLenText.text = (Math.round(nsPlay.bufferLength*1000)/1000)+" secs";
    }
    else
    {
        fpsText.text = "";
        bufferLenText.text = "";
    }
}

function nsPlayOnStatus(infoObject:NetStatusEvent)
{
    trace("nsPlay: onStatus: "+infoObject.info.code+" ("+infoObject.info.description+")");
    if (infoObject.info.code == "NetStream.Play.StreamNotFound" || infoObject.info.code == "NetStream.Play.Failed")
    {
        prompt.text = infoObject.info.description;
    }
}

function doCloseRecord()
{
    // after we have hit "Stop" recording and after the buffered video data has been
    // sent to the Wowza Media Server close the publishing stream
    nsPublish.publish("null");
}

// this function gets called every 250 ms to monitor the;
// progress of flushing the video buffer. Once the video
// buffer is empty we close publishing stream
function flushVideoBuffer()
{
    var buffLen:Number = nsPublish.bufferLength;
    if (buffLen == 0)
    {
        clearInterval(flushVideoBufferTimer);
        flushVideoBufferTimer = 0;
        doCloseRecord();
        doPublish.label = 'Stream';
    }
}

function nsPublicOnStatus(infoObject:NetStatusEvent)
{
    trace("nsPublish: "+infoObject.info.code+" ("+infoObject.info.description+")");

    // After calling nsPublish.publish(false); we wait for a status;
    // event of "NetStream.Unpublish.Success" which tells us all the video
    // and audio data has been written to the flv file. It is at this time
    // that we can start playing the video we just recorded.
    if (infoObject.info.code == "NetStream.Unpublish.Success")
    {
        //doPlayStart();
    }

    if (infoObject.info.code == "NetStream.Play.StreamNotFound" || infoObject.info.code == "NetStream.Play.Failed")
    {
        prompt.text = infoObject.info.description;
    }
}

function initH264Recording(nsPublish:NetStream)
{
    var h264Settings:H264VideoStreamSettings = new H264VideoStreamSettings();
    h264Settings.setProfileLevel(H264Profile.BASELINE, H264Level.LEVEL_3);
    nsPublish.videoStreamSettings = h264Settings;
}

// Start recording video to the server
function doStreamStart()
{
    //prompt.text = "Starting stream with mic...";
    //prompt.text = microphone;

    ExternalInterface.call("logBrowserStreaming", "starting stream");

    // stop video playback
    //doPlayStop();

    // create a new NetStream object for publishing
    nsPublish = new NetStream(nc);

    var nsPublishClient:Object = new Object();
    nsPublish.client = nsPublishClient;

    // Set the H.264 encoding parameters
    if (testVersion(11,0,0,0))
    {
        initH264Recording(nsPublish);
    }
    else
    {
        prompt.text = "Flash player 11 or greater is required for H.264 encoding (" + Capabilities.version + ").";

    }// trace the NetStream status information
    nsPublish.addEventListener(NetStatusEvent.NET_STATUS, nsPublicOnStatus);

    // publish the stream by name;
    nsPublish.publish(nameStr.text, (AppendCheckbox.selected?"append":"record"));

    // add custom metadata to the header of the .flv file;
    var metaData:Object = new Object();
    metaData["description"] = "Recorded using WebcamRecording example.";
    nsPublish.send("@setDataFrame", "onMetaData", metaData);

    // attach the camera and microphone to the server;
    nsPublish.attachCamera(camera);
    nsPublish.attachAudio(microphone);

    ExternalInterface.call("logBrowserStreaming", microphone);

    // set the buffer time to 20 seconds to buffer 20 seconds of video;
    // data for better performance and higher quality video
    nsPublish.bufferTime = 20;

    // Disable the audio choice dropdown
    aCb.enabled = false;

}

function doStreamStop()
{

    ExternalInterface.call("logBrowserStreaming", "stopping stream");

    // stop streaming video and audio to the publishing
    // NetStream object
    nsPublish.attachAudio(null);
    nsPublish.attachCamera(null);

    // After stopping the publishing we need to check if there is;
    // video content in the NetStream buffer. If there is data
    // we are going to monitor the video upload progress by calling
    // flushVideoBuffer every 250ms.  If the buffer length is 0
    // we close the recording immediately.
    var buffLen:Number = nsPublish.bufferLength;
    if (buffLen > 0)
    {
        flushVideoBufferTimer = setInterval(flushVideoBuffer,250);
        doPublish.label = 'Wait...';
    }
    else
    {
        trace("nsPublish.publish(null)");
        doCloseRecord();
        doPublish.label = 'Start';
    }

    // Disable the audio choice dropdown
    aCb.enabled = true;

}

// Test version function checks if the current flash version supports H.264 Encoding.
function testVersion(v0:Number, v1:Number, v2:Number, v3:Number):Boolean
{
    var version:String = Capabilities.version;
    var index:Number = version.indexOf(" ");
    version = version.substr(index+1);
    var verParts:Array = version.split(",");

    var i:Number;

    var ret:Boolean = true;
    while (true)
    {
        if (Number(verParts[0]) < v0)
        {
            ret = false;
            break;
        }
        else if (Number(verParts[0]) > v0)
        {
            break;

        }
        if (Number(verParts[1]) < v1)
        {
            ret = false;
            break;
        }
        else if (Number(verParts[1]) > v1)
        {
            break;

        }
        if (Number(verParts[2]) < v2)
        {
            ret = false;
            break;
        }
        else if (Number(verParts[2]) > v2)
        {
            break;

        }
        if (Number(verParts[3]) < v3)
        {
            ret = false;
            break;
        }
        break;
    }
    trace("testVersion: "+Capabilities.version+">="+v0+","+v1+","+v2+","+v3+": "+ret);

    return ret;
}


// External trigger from Javascript;

// Allow stream to start with startBrowserStreaming call from js
ExternalInterface.addCallback("startBrowserStreaming", doStreamStart);

// Allow stream to stop with stopBrowserStreaming call from js;
ExternalInterface.addCallback("stopBrowserStreaming", doStreamStop);

stage.align = "TL";
stage.scaleMode = "noScale";

startCamera();

Answer 1

您可以切换音频源，而无需触摸 NetConnection 和/或 NetStream。

举这个简单的例子，我使用一个按钮来更改我的音频源:

const server:String = 'rtmp://localhost/live';
const stream:String = 'live';

var nc:NetConnection;
var ns_publish:NetStream;

nc = new NetConnection();
nc.addEventListener(
    NetStatusEvent.NET_STATUS,
    function(e:NetStatusEvent):void {
        if(e.info.code == 'NetConnection.Connect.Success'){
            publish();
        }
    }
)
nc.addEventListener(AsyncErrorEvent.ASYNC_ERROR, function(e:AsyncErrorEvent):void {})
nc.connect(server);

function publish():void {

    var cam:Camera = Camera.getCamera();

    // for my case, I have 2 mic, and I start with the first
    var mic:Microphone = Microphone.getMicrophone(0);
    ns_publish = new NetStream(nc);
    ns_publish.attachAudio(mic);
    ns_publish.attachCamera(cam);
    ns_publish.publish(stream, 'record');
}

btn_switch_mic.addEventListener(MouseEvent.CLICK, function(e){
    // I can switch to the second mic without initialize my NetConnection and/or my NetStream
    var mic:Microphone = Microphone.getMicrophone(1);
    ns_publish.attachAudio(mic);
})

我使用 Wowza Streaming Engine 4.1.1(当然没有 Wowza Transcoder AddOn 的免费版本)和 Flash Media Server 4.5 测试了此代码，并且工作正常。

注意:我们可以使用相同的方式来更改视频源(相机)。

希望以上内容对您有所帮助。