/* Configuration 1 */
0x09, /* bLength */
USB_DESC_TYPE_CONFIGURATION, /* bDescriptorType */
LOBYTE(USB_AUDIO_CONFIG_DESC_SIZ), /* wTotalLength 109 bytes*/
HIBYTE(USB_AUDIO_CONFIG_DESC_SIZ),
0x02, /* bNumInterfaces */
0x01, /* bConfigurationValue */
0x00, /* iConfiguration */
0xC0, /* bmAttributes BUS Powred*/
0x32, /* bMaxPower = 100 mA*/
/* 09 byte*/

/* USB Speaker Standard interface descriptor */
AUDIO_INTERFACE_DESC_SIZE, /* bLength */
USB_DESC_TYPE_INTERFACE, /* bDescriptorType */
0x00, /* bInterfaceNumber */
0x00, /* bAlternateSetting */
0x00, /* bNumEndpoints */
USB_DEVICE_CLASS_AUDIO, /* bInterfaceClass */
AUDIO_SUBCLASS_AUDIOCONTROL, /* bInterfaceSubClass */
AUDIO_PROTOCOL_UNDEFINED, /* bInterfaceProtocol */
0x00, /* iInterface */
/* 09 byte*/

/* USB Speaker Class-specific AC Interface Descriptor */
AUDIO_INTERFACE_DESC_SIZE, /* bLength */
AUDIO_INTERFACE_DESCRIPTOR_TYPE, /* bDescriptorType */
AUDIO_CONTROL_HEADER, /* bDescriptorSubtype */
0x00, /* 1.00 */ /* bcdADC */
0x01,
0x27, /* wTotalLength = 39*/
0x00,
0x01, /* bInCollection */
0x01, /* baInterfaceNr */
/* 09 byte*/

/* USB Speaker Input Terminal Descriptor */
AUDIO_INPUT_TERMINAL_DESC_SIZE, /* bLength */
AUDIO_INTERFACE_DESCRIPTOR_TYPE, /* bDescriptorType */
AUDIO_CONTROL_INPUT_TERMINAL, /* bDescriptorSubtype */
0x01, /* bTerminalID */
0x01, /* wTerminalType AUDIO_TERMINAL_USB_STREAMING 0x0101 */
0x01,
0x00, /* bAssocTerminal */
0x02, /* bNrChannels */
0x03, /* wChannelConfig 0x0000 Mono */
0x00,
0x00, /* iChannelNames */
0x00, /* iTerminal */
/* 12 byte*/

/* USB Speaker Audio Feature Unit Descriptor */
0x09, /* bLength */
AUDIO_INTERFACE_DESCRIPTOR_TYPE, /* bDescriptorType */
AUDIO_CONTROL_FEATURE_UNIT, /* bDescriptorSubtype */
AUDIO_OUT_FEATURE_ID, /* bUnitID */
0x01, /* bSourceID */
0x01, /* bControlSize */
AUDIO_CONTROL_SUPPORT_MUTE | AUDIO_CONTROL_SUPPORT_VOLUME, /* bmaControls(0) */
0, /* bmaControls(1) */
0x00, /* iTerminal */
/* 09 byte*/

/*USB Speaker Output Terminal Descriptor */
0x09, /* bLength */
AUDIO_INTERFACE_DESCRIPTOR_TYPE, /* bDescriptorType */
AUDIO_CONTROL_OUTPUT_TERMINAL, /* bDescriptorSubtype */
0x03, /* bTerminalID */
0x01, /* wTerminalType 0x0301*/
0x03,
0x00, /* bAssocTerminal */
0x02, /* bSourceID */
0x00, /* iTerminal */
/* 09 byte*/

/* USB Speaker Standard AS Interface Descriptor - Audio Streaming Zero Bandwith */
/* Interface 1, Alternate Setting 0 */
AUDIO_INTERFACE_DESC_SIZE, /* bLength */
USB_DESC_TYPE_INTERFACE, /* bDescriptorType */
0x01, /* bInterfaceNumber */
0x00, /* bAlternateSetting */
0x00, /* bNumEndpoints */
USB_DEVICE_CLASS_AUDIO, /* bInterfaceClass */
AUDIO_SUBCLASS_AUDIOSTREAMING, /* bInterfaceSubClass */
AUDIO_PROTOCOL_UNDEFINED, /* bInterfaceProtocol */
0x00, /* iInterface */
/* 09 byte*/

/* USB Speaker Standard AS Interface Descriptor - Audio Streaming Operational */
/* Interface 1, Alternate Setting 1 */
AUDIO_INTERFACE_DESC_SIZE, /* bLength */
USB_DESC_TYPE_INTERFACE, /* bDescriptorType */
0x01, /* bInterfaceNumber */
0x01, /* bAlternateSetting */
0x01, /* bNumEndpoints */
USB_DEVICE_CLASS_AUDIO, /* bInterfaceClass */
AUDIO_SUBCLASS_AUDIOSTREAMING, /* bInterfaceSubClass */
AUDIO_PROTOCOL_UNDEFINED, /* bInterfaceProtocol */
0x00, /* iInterface */
/* 09 byte*/

/* USB Speaker Audio Streaming Interface Descriptor */
AUDIO_STREAMING_INTERFACE_DESC_SIZE, /* bLength */
AUDIO_INTERFACE_DESCRIPTOR_TYPE, /* bDescriptorType */
AUDIO_STREAMING_GENERAL, /* bDescriptorSubtype */
0x01, /* bTerminalLink */
0x01, /* bDelay */
0x01, /* wFormatTag AUDIO_FORMAT_PCM 0x0001*/
0x00,
/* 07 byte*/

/* USB Speaker Audio Type III Format Interface Descriptor */
11, /* bLength */
AUDIO_INTERFACE_DESCRIPTOR_TYPE, /* bDescriptorType */
AUDIO_STREAMING_FORMAT_TYPE, /* bDescriptorSubtype */
AUDIO_FORMAT_TYPE_I, /* bFormatType */
0x02, /* bNrChannels */
0x04, /* bSubFrameSize : 2 Bytes per frame (16bits) */
32, /* bBitResolution (16-bits per sample) */
0x01, /* bSamFreqType only one frequency supported */
AUDIO_SAMPLE_FREQ(USBD_AUDIO_FREQ),
/* 11 byte*/

/* Endpoint 1 - Standard Descriptor */
AUDIO_STANDARD_ENDPOINT_DESC_SIZE, /* bLength */
USB_DESC_TYPE_ENDPOINT, /* bDescriptorType */
AUDIO_OUT_EP, /* bEndpointAddress 1 out endpoint*/
USBD_EP_TYPE_ISOC, /* bmAttributes */
AUDIO_PACKET_SZE(MAX_USBD_AUDIO_FREQ), /* wMaxPacketSize in Bytes (Freq(Samples)*2(Stereo)*2(HalfWord)) */
0x01, /* bInterval */
0x00, /* bRefresh */
0x00, /* bSynchAddress */
/* 09 byte*/

/* Endpoint - Audio Streaming Descriptor*/
AUDIO_STREAMING_ENDPOINT_DESC_SIZE, /* bLength */
AUDIO_ENDPOINT_DESCRIPTOR_TYPE, /* bDescriptorType */
AUDIO_ENDPOINT_GENERAL, /* bDescriptor */
0x01, /* bmAttributes 0x01 sampling frequency control */
0x00, /* bLockDelayUnits */
0x00, /* wLockDelay */
0x00,
/* 07 byte*/