cscの作法 その396

# 概要
cscの作法、調べてみた。
練習問題、やってみた。

# 練習問題
directshowlibでマイクをキャプチャしてwmaファイルを作成せよ。

# サンプルコード

```


using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.Collections;
using System.Runtime.InteropServices;
using System.Diagnostics;
using System.Windows.Forms;
using System.Threading;
using DirectShowLib;
using System.ComponentModel;
using System.Data;

namespace Write
{
	internal class Capture: IDisposable {
		private IFilterGraph2 m_FilterGraph = null;
		IMediaControl m_mediaCtrl = null;
		private bool m_bRunning = false;
		DsROTEntry m_rot = null;
		public void Dispose() {
			GC.SuppressFinalize(this);
			CloseInterfaces();
		}
		~Capture() {
			Dispose();
		}
		public Capture(int iDeviceNum, string szOutputFileName) {
			DsDevice [] capDevices;
			capDevices = DsDevice.GetDevicesOfCat(FilterCategory.AudioInputDevice);
			if (iDeviceNum + 1 > capDevices.Length)
			{
				throw new Exception("No video capture devices found at that index!");
			}
			try
			{
				SetupGraph(capDevices[iDeviceNum], szOutputFileName);
				m_bRunning = false;
			}
			catch
			{
				Dispose();
				throw;
			}
		}
		public void Start() {
			if (!m_bRunning)
			{
				int hr = m_mediaCtrl.Run();
				Marshal.ThrowExceptionForHR(hr);
				m_bRunning = true;
			}
		}
		public void Pause() {
			if (m_bRunning)
			{
				IMediaControl mediaCtrl = m_FilterGraph as IMediaControl;
				int hr = mediaCtrl.Pause();
				Marshal.ThrowExceptionForHR(hr);
				m_bRunning = false;
			}
		}
		private void SetupGraph(DsDevice dev, string szOutputFileName) {
			int hr;
			IBaseFilter capFilter = null;
			IBaseFilter asfWriter = null;
			ICaptureGraphBuilder2 capGraph = null;
			m_FilterGraph = (IFilterGraph2) new FilterGraph();
			m_rot = new DsROTEntry(m_FilterGraph);
			try
			{
				capGraph = (ICaptureGraphBuilder2) new CaptureGraphBuilder2();
				hr = capGraph.SetFiltergraph(m_FilterGraph);
				Marshal.ThrowExceptionForHR(hr);
				hr = m_FilterGraph.AddSourceFilterForMoniker(dev.Mon, null, dev.Name, out capFilter);
				Marshal.ThrowExceptionForHR(hr);
				asfWriter = ConfigAsf(capGraph, szOutputFileName);
				hr = capGraph.RenderStream(null, null, capFilter, null, asfWriter);
				Marshal.ThrowExceptionForHR(hr);
				m_mediaCtrl = m_FilterGraph as IMediaControl;
			}
			finally
			{
				if (capFilter != null)
				{
					Marshal.ReleaseComObject(capFilter);
					capFilter = null;
				}
				if (asfWriter != null)
				{
					Marshal.ReleaseComObject(asfWriter);
					asfWriter = null;
				}
				if (capGraph != null)
				{
					Marshal.ReleaseComObject(capGraph);
					capGraph = null;
				}
			}
		}
		private IBaseFilter ConfigAsf(ICaptureGraphBuilder2 capGraph, string szOutputFileName) {
			IFileSinkFilter pTmpSink = null;
			IBaseFilter asfWriter = null;
			int hr = capGraph.SetOutputFileName(MediaSubType.Asf, szOutputFileName, out asfWriter, out pTmpSink);
			Marshal.ThrowExceptionForHR(hr);
			try
			{
				IConfigAsfWriter lConfig = asfWriter as IConfigAsfWriter;
				Guid cat = new Guid("7EA3126D-E1BA-4716-89AF-F65CEE0C0C67");
				hr = lConfig.ConfigureFilterUsingProfileGuid(cat);
				Marshal.ThrowExceptionForHR(hr);
			}
			finally
			{
				Marshal.ReleaseComObject(pTmpSink);
			}
			return asfWriter;
		}
		private void CloseInterfaces() {
			int hr;
			try
			{
				if (m_mediaCtrl != null)
				{
					hr = m_mediaCtrl.Stop();
					m_bRunning = false;
				}
			}
			catch
			{
			}
			if (m_rot != null)
			{
				m_rot.Dispose();
				m_rot = null;
			}
			if (m_FilterGraph != null)
			{
				Marshal.ReleaseComObject(m_FilterGraph);
				m_FilterGraph = null;
			}
		}
	}
	public class Form1: Form {
		private Button button1;
		private TextBox textBox1;
		private Label label1;
		private System.ComponentModel.Container components = null;
		Capture cam = null;
		public Form1() {
			InitializeComponent();
		}
		protected override void Dispose(bool disposing) {
			if (disposing)
			{
				if (cam != null)
				{
					cam.Dispose();
					cam = null;
				}
				if (components != null)
				{
					components.Dispose();
				}
			}
			base.Dispose(disposing);
		}
		private void InitializeComponent() {
			this.button1 = new Button();
			this.textBox1 = new TextBox();
			this.label1 = new Label();
			this.SuspendLayout();
			this.button1.Location = new Point(88, 80);
			this.button1.Name = "button1";
			this.button1.Size = new Size(75, 48);
			this.button1.TabIndex = 0;
			this.button1.Text = "Start";
			this.button1.Click += new System.EventHandler(this.button1_Click);
			this.textBox1.Location = new Point(16, 40);
			this.textBox1.Name = "textBox1";
			this.textBox1.Size = new Size(160, 20);
			this.textBox1.TabIndex = 1;
			this.textBox1.Text = "test0.wma";
			this.label1.Location = new Point(16, 24);
			this.label1.Name = "label1";
			this.label1.Size = new Size(56, 16);
			this.label1.TabIndex = 2;
			this.label1.Text = "Output file";
			this.AcceptButton = this.button1;
			this.AutoScaleBaseSize = new Size(5, 13);
			this.ClientSize = new Size(248, 162);
			this.Controls.Add(this.label1);
			this.Controls.Add(this.textBox1);
			this.Controls.Add(this.button1);
			this.FormBorderStyle = FormBorderStyle.FixedDialog;
			this.MaximizeBox = false;
			this.Name = "Form1";
			this.Text = "AsfFilter";
			this.ResumeLayout(false);
			this.PerformLayout();
		}
		private void button1_Click(object sender, System.EventArgs e) {
			const int VIDEODEVICE = 0;
			Cursor.Current = Cursors.WaitCursor;
			if (cam == null)
			{
				cam = new Capture(VIDEODEVICE, textBox1.Text);
				cam.Start();
				button1.Text = "Stop";
				textBox1.ReadOnly = true;
			}
			else
			{
				button1.Text = "Start";
				textBox1.ReadOnly = false;
				cam.Pause();
				cam.Dispose();
				cam = null;
			}
			Cursor.Current = Cursors.Default;
		}
		[STAThread]
		static void Main() {
			Application.Run(new Form1());
		}
	}
}







```

以上。