我正在开发一个HTML5应用程序,该应用程序需要与Flash接口才能访问本地媒体(例如,网络摄像头和麦克风),并在远程浏览器之间传输音频视频。但是在这个应用程序中,我需要本地网络摄像头显示在屏幕的一部分,由远程网络摄像头显示的各种HTML元素分隔。我很确定这意味着我需要运行多个Flash应用实例。但我认为你一次只能抓取一个网络摄像头实例,这意味着我需要能够在Flash实例之间共享这些网络摄像头和麦克风对象:一个显示本地网络摄像头,另一个与远程网络摄像头通信并显示远程网络摄像头。这可能吗?例如,我可以通过ExternalInterface将相机和麦克风实例传递给JavaScript,然后将它们传递回我的Flash对象的单独实例吗?
换句话说,我正在考虑有一个ActionScript类,看起来像这样(当然简化了):
public class MediaController
{
public function MediaController()
{
ExternalInterface.addCallback('getUserMedia', this.getUserMedia);
ExternalInterface.addCallback('getCamera', this.getCamera);
ExternalInterface.addCallback('setCamera', this.setCamera);
ExternalInterface.addCallback('getMicrophone', this.getMicrophone);
ExternalInterface.addCallback('setMicrophone', this.setMicrophone);
}
private var _mic:Microphone;
private var _cam:Camera;
public function getUserMedia()
{
_mic = Microphone.getMicrophone();
_cam = Camera.getCamera();
}
public function getCamera():Camera
{
return this._cam;
}
public function setCamera(cam:Camera):void
{
this._cam = cam;
}
public function getMicrophone():Microphone
{
return this._mic;
}
public function setMicrophone(mic:Microphone):void
{
this._mic = mic;
}
}
我在JavaScript中像这样检索它们
var localUser = $('#localUser')[0];
localUser.getUserMedia();
var mic = localUser.getMicrophone();
var cam = localUser.getCamera();
然后将它们传递回实际与远程用户通信的实例,就像这样:
var remoteUser = $('#remoteUser')[0];
remoteUser.setMicrophone(mic);
remoteUser.setCamera(cam);
这样做有什么已知的陷阱吗?有更好的处理方法吗?(在你问之前,是的,在没有其他建议的情况下,我计划将其编码,并且我会让每个人知道我的发现-只是想知道在开始之前是否有任何已知的陷阱或替代方案。: -)
你不能通过ExternalInterface
传递像Camera
和Microphone
这样的对象给Javascript。当您使用ExternalInterface
与Javascript通信时,您传递的任何数据都被编组为XML格式。因此,在这一点上,相机/麦克风不再是Flash的Camera
和Microphone
对象。
你可能会发现,在某些浏览器/操作系统中,试图同时从两个独立的SWF访问同一个摄像头。然而,在其他国家,它失败了。我在两个完全不相关的网站上看到过这种行为。
SWF可以使用LocalConnection类相互通信,尽管我从未尝试过这样的相机或麦克风。
无论如何,这就是我最终采取的方法(或多或少),而且它很有效。很复杂,而且有点脆弱,但它有效:
// A typical 1:1 communication will involve four instances of the FlashMediaObject class:
// Instance1 (Initiator Sender): Displays local video, streams local video out to Instance4
// Instance2 (Initiator Receiver): Receives and displays video from Instance3
// Instance3 (Responder Sender): Displays local video, streams local video out to Instance2
// Instance4 (Responder Receiver): Receives and displays video from Instance1
// The workflow needs to go something like this:
// (1) Both: Room.onSessionAdded():
// SignalR makes both the JS clients for both the Initiator and the Responder aware of each other (i.e., their SessionId's).
// (2) Initiator: writeLocalMediaElement() -> fmo1.Connect():
// Instance1 connects to Adobe's rtmfp service, gets its nearId, and passes it up to JS.
// (3) Responder: writeLocalMediaElement() -> fmo3.connect():
// Instance3 connects to Adobe's rtmfp service, gets its peerId, and passes it up to JS.
// (4) Responder: prepareForCall() -> fmo4.connect():
// Instance4 connects to Adobe's rtmfp service, gets its peerId, and passes it up to JS.
// (5) Initiator: call() -> prepareForCall() -> fmo2.Connect():
// Instance2 connects to Adbobe's rtmfp service, gets its nearId, and passes it up to JS.
// (6) Initiator: call() -> server.flashOffer():
// The Initiator's JS controller contacts the Responder's JS (via SignalR), and passes it the two rtmfp ID's.
// (7) Responder: handleFlashOffer() -> fmo3.call():
// The Responder's JS controller passes the peerId for Instance2 (Initiator Receiver) to Instance3 (Responder Sender).
// Instance3 begins publishing its video to Instance 2.
// (8) Responder: handleFlashOffer() -> fmo4.prepareForCall():
// The Responder's JS controller passes the peerId for Instance1 (Initiator Sender) to Instance4 (Responder Receiver)
// Instance4 prepares to receive a call from Instance1.
// (10) Responder: handleFlashOffer() -> server.flashAnswer():
// The Responder's JS controller contacts the Initiator's JS (via SignalR), and passes it the two peer ID's.
// (11) Initiator: handleFlashAnswer() -> fmo1.call():
// The Initiator's JS controller passes the peerId for Instance4 (Responder Receiver) to Instance1 (Initiator Sender).
// Instance1 connects to Instance4 and begins streaming video.
// (12) Initiator: handleFlashAnswer() -> fmo2.prepareForCall()
// The Responder's JS controller passes the peerID for Instance3 (Responder Sender) to Instance2
// Instance2 prepares to receive video from Instance3
// (9) Initiator: fmo2.onCall():
// Instance2 begins playing video from Instance3.
// (13) Responder: fmo4.onCall():
// Instance4 begins playing video from Instance1