C# 实现Windows Media Encoder音视频捕捉

C# 实现Windows Media Encoder音视频捕捉 收藏 http://blog.csdn.net/lhfzd2004/archive/2007/08/24/1757410.aspx
我的博客中讲述过WMS9，可以实现流媒体服务器，但没有WME（windows media encoder）的支持，总觉得缺少点什么，这里就讲述一下如何通过.net实现WME获取设备视频音频流，并推送到远程（本地当然可以）流媒体广播发布点。

一.下载了wme9的SDK，安装完毕：这一步主要体验一下WME能够实现那些功能。

读者可以自行安装试试。

二.创建.net winform Application，添加引用
using WMEncoderLib;

WMEncoderLib是一个assemble，通过它，我们可以方便实现WME的操作。

三.获取本地屏幕，并转换为视频信号
IWMEncSource SrcAud = SrcGrp.AddSource(WMENC_SOURCE_TYPE.WMENC_AUDIO);
IWMEncSource SrcVid = SrcGrp.AddSource(WMENC_SOURCE_TYPE.WMENC_VIDEO);
SrcAud.SetInput("Default_Audio_Device", "Device", "");
SrcVid.SetInput("ScreenCapture1", "ScreenCap", "");

四.启动Encoder，推送到远程WMS服务器
//Set up the push broadcast.
IWMEncPushDistribution PushDist = (IWMEncPushDistribution)Encoder.Broadcast;
string strServerName = this.TB_ServerName.Text.Trim() + ":" + this.TB_Port.Text.Trim();
string strPubPoint = "TmpBroadCastPubPoint";
// Remove the publishing point when the broadcast is over.
PushDist.AutoRemovePublishingPoint = true;
// Set the push distribution variables.
PushDist.ServerName = strServerName;
PushDist.PublishingPoint = strPubPoint;
// PushDist.Template = strPubTemplate;
// Initialize the encoding process.
Encoder.PrepareToEncode(true);

注意：在这里，直接推送到远程服务器，如果服务器不在同一域内，或在不可信任区域，推送时应该会需要验证用户名和密码。因此我们需要创建一个委托：
Encoder.OnAcquireCredentials += new _IWMEncoderEvents_OnAcquireCredentialsEventHandler(OnUserAuth);

public void OnUserAuth(string bstrRealm, string bstrSite, ref object pvarUser, ref object pvarPassword, ref object plFlags)
...{
pvarUser = "administrator";
pvarPassword = "622316";
plFlags = 4;
}

五.到这里就差不多了，完整代码贴出来：
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using WMEncoderLib;

namespace Project2
...{
public partial class Form1 : Form
...{
static bool bDone;
private WMEncoder Encoder;
public Form1()
...{
InitializeComponent();
Encoder = new WMEncoder();
Encoder.OnStateChange += new _IWMEncoderEvents_OnStateChangeEventHandler(OnWmeStatusChange);
Encoder.OnError += new _IWMEncoderEvents_OnErrorEventHandler(Encoder_OnError);
Encoder.OnAcquireCredentials += new _IWMEncoderEvents_OnAcquireCredentialsEventHandler(OnUserAuth);
}

private void Btn_Start_Click(object sender, EventArgs e)
...{
this.StartBroadCast();
}

private void Btn_Close_Click(object sender, EventArgs e)
...{
this.StopBroadCast();
}

/**////
/// 停止广播服务
///
public void StopBroadCast()
...{
this.Encoder.Stop();
}

/**////
/// 启动广播服务
///
public void StartBroadCast()
...{
if (Encoder != null)
...{

// Retrieve the source group collection.
IWMEncSourceGroupCollection SrcGrpColl = Encoder.SourceGroupCollection;

// Add a source group to the collection.
IWMEncSourceGroup SrcGrp = SrcGrpColl.Add("SG_2");

IWMEncSource SrcAud = SrcGrp.AddSource(WMENC_SOURCE_TYPE.WMENC_AUDIO);
IWMEncSource SrcVid = SrcGrp.AddSource(WMENC_SOURCE_TYPE.WMENC_VIDEO);
SrcAud.SetInput("Default_Audio_Device", "Device", "");
SrcVid.SetInput("ScreenCapture1", "ScreenCap", "");

// Choose a profile from the collection.
IWMEncProfileCollection ProColl = Encoder.ProfileCollection;
IWMEncProfile Pro;
for (int i = 0; i < ProColl.Count; i++)
...{
Pro = ProColl.Item(i);
if (Pro.Name == "Windows Media Video 8 for Local Area Network (384 Kbps)")
...{
SrcGrp.set_Profile(Pro);
break;
}
}

//Set up the push broadcast.
IWMEncPushDistribution PushDist = (IWMEncPushDistribution)Encoder.Broadcast;

// Specify the push distribution variables, including the Windows Media
// server name, publishing point, and announcement files.
string strServerName = this.TB_ServerName.Text.Trim() + ":" + this.TB_Port.Text.Trim();
string strPubPoint = "TmpBroadCastPubPoint";
//string strPubTemplate = "AnotherPubPoint";
//string MyNSCFile = "//localhost/test/MyPubPoint.nsc";
//string MyNSCURL = "//localhost/MyPubPoint.nsc";
//string MyASXFile = @"C:InetpubwwwrootMyPubPoint.asx";

// Remove the publishing point when the broadcast is over.
PushDist.AutoRemovePublishingPoint = true;
// Set the push distribution variables.
PushDist.ServerName = strServerName;

PushDist.PublishingPoint = strPubPoint;
// PushDist.Template = strPubTemplate;
// Initialize the encoding process.

Encoder.PrepareToEncode(true);

// Generate the announcement file.
//PushDist.GenerateMulticastInfoFile(MyNSCFile);
//PushDist.GenerateAnnouncementFile(MyNSCURL, MyASXFile);

// Start the encoding process.
Encoder.Start();
// wmp.openPlayer("mms://LIH-M/test");
this.wmp.URL = "mms://192.168.1.108/TmpBroadCastPubPoint";
}
}

public void OnUserAuth(string bstrRealm, string bstrSite, ref object pvarUser, ref object pvarPassword, ref object plFlags)
...{
pvarUser = "administrator";
pvarPassword = "622316";
plFlags = 4;
}

public void Encoder_OnError(int Result)
...{
this.RTB_Error.Text = "运行状态：出错代码 " + Result + " 【" + Encoder.ErrorState.ToString() + "】";
}

public void OnWmeStatusChange(WMENC_ENCODER_STATE enumState)
...{

switch (enumState)
...{
case WMENC_ENCODER_STATE.WMENC_ENCODER_RUNNING:
RTB_Error.Text += " 运行状态：Encoder正在运行";
break;

case WMENC_ENCODER_STATE.WMENC_ENCODER_STOPPED:
// TODO: Handle stopped state.
bDone = true;
RTB_Error.Text += " 运行状态：Encoder已经停止";
break;

case WMENC_ENCODER_STATE.WMENC_ENCODER_STARTING:
RTB_Error.Text += " 运行状态：Encoder正在启动";
break;

case WMENC_ENCODER_STATE.WMENC_ENCODER_PAUSING:
// TODO: Handle pausing state.
RTB_Error.Text += " 运行状态：Encoder正在暂停";
break;

case WMENC_ENCODER_STATE.WMENC_ENCODER_STOPPING:
// TODO: Handle stopping state.
RTB_Error.Text += " 运行状态：Encoder正在停止";
break;

case WMENC_ENCODER_STATE.WMENC_ENCODER_PAUSED:
// TODO: Handle paused state.
RTB_Error.Text += " 运行状态：Encoder已暂停";
break;

case WMENC_ENCODER_STATE.WMENC_ENCODER_END_PREPROCESS:
// TODO: Handle end preprocess state.
RTB_Error.Text += " 运行状态：Encoder正在处理结束前操作";
break;
}

}
}
}

WME可以捕捉机器音频和视频等设备，如：摄像头，桌面，光驱，声卡，电视卡等等。因此我们可以通过它实现网上电视直播，视频、音频捕捉等等功能。有兴趣的话可以研究一下。