CS_CHANNEL_DESCRIPTOR描述符

CS_CHANNEL_DESCRIPTOR描述符结构体定义如下：

#pragma pack(1)

    typedef struct {
                        UCHAR bMethod;
                        UCHAR bMethodVariant;
    } CS_METHOD_AND_VARIANT;

    typedef struct {
                        UCHAR bLength;
                        UCHAR bDescriptorType;
                        UCHAR bChannelID;
                        UCHAR bmAttributes;
                        UCHAR bRecipient;
                        UCHAR bRecipientAlt;
                        UCHAR bRecipientLogicalUnit;
                        CS_METHOD_AND_VARIANT methodAndVariant[0];
    } CS_CHANNEL_DESCRIPTOR;
#pragma pack()

其中描述符类型固定为0x22。

#define CS_DESCRIPTOR_TYPE_CHANNEL    0x22

其中CS_METHOD_AND_VARIANT指定了方法类型。一其有以下几种：

#define CSM_BASIC           1       // Microsoft
#define CSM_DTCP            2       // Intel
#define CSM_OCPS            3       // Philips
#define CSM_ELLIPTIC_CURVE  4

文档定义如下：