# DirectShow Filter and SDK Registration Guide

DirectShow filters and SDK components often require proper registration to function correctly within your applications. This guide provides detailed implementation methods for registering DirectShow filters across multiple programming languages.

# Registration Overview

Most DirectShow filters in the SDK can be registered using the IVFRegister interface. This standardized approach works consistently across development environments. However, some specialized filters (like RGB2YUV converters) are designed to work without explicit registration.

# Registration Methods by Language

# C++ Implementation

The following C++ code demonstrates how to access the registration interface:

// {59E82754-B531-4A8E-A94D-57C75F01DA30}
DEFINE_GUID(IID_IVFRegister,
    0x59E82754, 0xB531, 0x4A8E, 0xA9, 0x4D, 0x57, 0xC7, 0x5F, 0x01, 0xDA, 0x30);

/// <summary>
/// Filter registration interface.
/// </summary>
DECLARE_INTERFACE_(IVFRegister, IUnknown)
{
    /// <summary>
    /// Sets registered.
    /// </summary>
    /// <param name="licenseKey">
    /// License Key.
    /// </param>
    STDMETHOD(SetLicenseKey)
        (THIS_
            WCHAR * licenseKey
            )PURE;
};

# C# Implementation

For .NET developers, the registration interface can be imported using the following C# code:

    /// <summary>
    /// Public filter registration interface.
    /// </summary>
    [ComImport]
    [System.Security.SuppressUnmanagedCodeSecurity]
    [Guid("59E82754-B531-4A8E-A94D-57C75F01DA30")]
    [InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
    public interface IVFRegister
    {
        /// <summary>
        /// Sets registered.
        /// </summary>
        /// <param name="licenseKey">
        /// License Key.
        /// </param>
        [PreserveSig]
        void SetLicenseKey([In, MarshalAs(UnmanagedType.LPWStr)] string licenseKey);
    }

# Delphi Implementation

For Delphi developers, implement the registration interface as follows:

const
  IID_IVFRegister: TGUID = '{59E82754-B531-4A8E-A94D-57C75F01DA30}';

type
  /// <summary>
  /// Public filter registration interface.
  /// </summary>
  IVFRegister = interface(IUnknown)
    /// <summary>
    /// Sets registered.
    /// </summary>
    /// <param name="licenseKey">
    /// License Key.
    /// </param>
    procedure SetLicenseKey(licenseKey: PWideChar); stdcall;
  end;

# Alternative Registration Approaches

Beyond the IVFRegister interface, several other registration methods are available:

# System Registry Registration

DirectShow filters can be registered directly in the Windows registry using appropriate registry keys. This approach is particularly useful for system-wide filter availability.

# Custom Build Integration

For specialized deployment scenarios, custom build processes can automate the registration of DirectShow filters during application installation or initialization.

# COM Registration

Standard COM registration techniques can also be applied to DirectShow filters, leveraging tools like regsvr32 for DLL-based filters.

# Best Practices for Filter Registration

When implementing DirectShow filter registration:

  1. Consider application permission requirements
  2. Handle registration failures gracefully
  3. Implement unregistration logic for clean application removal
  4. Test registration under various user permission scenarios