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STM32 USB音频麦克风实现

作者:互联网

最近项目进入收尾阶段,USB Microphone 部分代码不是我所实现,接口较为松散,所以决定优化这部分代码,啃一啃USB部分知识点,一两天肯定不能完全了解清晰,毕竟万能USB,其协议必然是复杂的,所以就先从音频麦克风的实现开始。

其实是币圈大跌,努力搬砖中…

调试工具

usbtreeview(一款方便查看USB设备相关信息的免安装绿色工具)
Audacity (音频频谱查看工具,可查看麦克风设备列表,进行音频录制)

资料书籍

<<圈圈教你玩USB 第二版>>

音频描述符中的简称及分类

拓扑图如下:
在这里插入图片描述
控制接口下,默认为端点0

接口描述符

查看位置:usbd_xxx.h,xxx代表某个功能如:audio
在这个文件中可以找到这个USB功能类的相关描述符定义

下图为一个speeaker即扬声器 USB拓扑
endpoint 以HOST为视角看待,即主机的输出口 endpoint1 的音频数据流,转入了设备端的输入口Terminal IN
在这里插入图片描述
那么麦克风的配置

usbd_audio.c

iConfiguration iTerminal iInterfaceiChannelNames其数值,都是在说明本描述符的字符串说明符,所在索引号,若为0则没有字符串说明(没有文字说明)

如果麦克风数据需要通过USB上传至PC那么:

麦克风数据 --》(USB设备)MCU -》(USB主机)PC

麦克风数据 --》 terminal IN -》terminal OUT -》 Endpoint IN

STM32配置

打开USB设备功能 FS( Full Speed 全速设备)
在这里插入图片描述
配置USB Audio库,配置音频的采样率
在这里插入图片描述
在这里插入图片描述
一般CubeMX会自动打开USB的全局中断,生成代码后,自己最好确认一下(位于usbd_config.c)。

以下usbd_audio.c和对应头文件可直接替换,自动生成的。
修改usbd_audio.c文件

/**
  ******************************************************************************
  * @file    usbd_audio.c
  * @author  MCD Application Team
  * @brief   This file provides the Audio core functions.
  *
  * @verbatim
  *
  *          ===================================================================
  *                                AUDIO Class  Description
  *          ===================================================================
  *           This driver manages the Audio Class 1.0 following the "USB Device Class Definition for
  *           Audio Devices V1.0 Mar 18, 98".
  *           This driver implements the following aspects of the specification:
  *             - Device descriptor management
  *             - Configuration descriptor management
  *             - Standard AC Interface Descriptor management
  *             - 1 Audio Streaming Interface (with single channel, PCM, Stereo mode)
  *             - 1 Audio Streaming Endpoint
  *             - 1 Audio Terminal Input (1 channel)
  *             - Audio Class-Specific AC Interfaces
  *             - Audio Class-Specific AS Interfaces
  *             - AudioControl Requests: only SET_CUR and GET_CUR requests are supported (for Mute)
  *             - Audio Feature Unit (limited to Mute control)
  *             - Audio Synchronization type: Asynchronous
  *             - Single fixed audio sampling rate (configurable in usbd_conf.h file)
  *          The current audio class version supports the following audio features:
  *             - Pulse Coded Modulation (PCM) format
  *             - sampling rate: 48KHz.
  *             - Bit resolution: 16
  *             - Number of channels: 2
  *             - No volume control
  *             - Mute/Unmute capability
  *             - Asynchronous Endpoints
  *
  * @note     In HS mode and when the DMA is used, all variables and data structures
  *           dealing with the DMA during the transaction process should be 32-bit aligned.
  *
  *
  *  @endverbatim
  *
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; Copyright (c) 2015 STMicroelectronics.
  * All rights reserved.</center></h2>
  *
  * This software component is licensed by ST under Ultimate Liberty license
  * SLA0044, the "License"; You may not use this file except in compliance with
  * the License. You may obtain a copy of the License at:
  *                      www.st.com/SLA0044
  *
  ******************************************************************************
  */

/* BSPDependencies
- "stm32xxxxx_{eval}{discovery}.c"
- "stm32xxxxx_{eval}{discovery}_io.c"
- "stm32xxxxx_{eval}{discovery}_audio.c"
EndBSPDependencies */

/* Includes ------------------------------------------------------------------*/
#include "usbd_audio.h"
#include "usbd_ctlreq.h"

/** @addtogroup STM32_USB_DEVICE_LIBRARY
  * @{
  */


/** @defgroup USBD_AUDIO
  * @brief usbd core module
  * @{
  */

/** @defgroup USBD_AUDIO_Private_TypesDefinitions
  * @{
  */
/**
  * @}
  */


/** @defgroup USBD_AUDIO_Private_Defines
  * @{
  */
/**
  * @}
  */


/** @defgroup USBD_AUDIO_Private_Macros
  * @{
  */
#define AUDIO_SAMPLE_FREQ(frq)         (uint8_t)(frq), (uint8_t)((frq >> 8)), (uint8_t)((frq >> 16))

#define AUDIO_PACKET_SZE(frq)          (uint8_t)(((frq * 2U * 2U)/1000U) & 0xFFU), \
                                       (uint8_t)((((frq * 2U * 2U)/1000U) >> 8) & 0xFFU)

/**
  * @}
  */


/** @defgroup USBD_AUDIO_Private_FunctionPrototypes
  * @{
  */
static uint8_t USBD_AUDIO_Init(USBD_HandleTypeDef *pdev, uint8_t cfgidx);
static uint8_t USBD_AUDIO_DeInit(USBD_HandleTypeDef *pdev, uint8_t cfgidx);

static uint8_t USBD_AUDIO_Setup(USBD_HandleTypeDef *pdev,
                                USBD_SetupReqTypedef *req);

static uint8_t *USBD_AUDIO_GetCfgDesc(uint16_t *length);
static uint8_t *USBD_AUDIO_GetDeviceQualifierDesc(uint16_t *length);
static uint8_t USBD_AUDIO_DataIn(USBD_HandleTypeDef *pdev, uint8_t epnum);
static uint8_t USBD_AUDIO_DataOut(USBD_HandleTypeDef *pdev, uint8_t epnum);
static uint8_t USBD_AUDIO_EP0_RxReady(USBD_HandleTypeDef *pdev);
static uint8_t USBD_AUDIO_EP0_TxReady(USBD_HandleTypeDef *pdev);
static uint8_t USBD_AUDIO_SOF(USBD_HandleTypeDef *pdev);

static uint8_t USBD_AUDIO_IsoINIncomplete(USBD_HandleTypeDef *pdev, uint8_t epnum);
static uint8_t USBD_AUDIO_IsoOutIncomplete(USBD_HandleTypeDef *pdev, uint8_t epnum);
static void AUDIO_REQ_GetCurrent(USBD_HandleTypeDef *pdev, USBD_SetupReqTypedef *req);
static void AUDIO_REQ_SetCurrent(USBD_HandleTypeDef *pdev, USBD_SetupReqTypedef *req);

/**
  * @}
  */

/** @defgroup USBD_AUDIO_Private_Variables
  * @{
  */

USBD_ClassTypeDef USBD_AUDIO =
{
  USBD_AUDIO_Init,
  USBD_AUDIO_DeInit,
  USBD_AUDIO_Setup,
  USBD_AUDIO_EP0_TxReady,
  USBD_AUDIO_EP0_RxReady,
  USBD_AUDIO_DataIn,
  USBD_AUDIO_DataOut,
  USBD_AUDIO_SOF,
  USBD_AUDIO_IsoINIncomplete,
  USBD_AUDIO_IsoOutIncomplete,
  USBD_AUDIO_GetCfgDesc,
  USBD_AUDIO_GetCfgDesc,
  USBD_AUDIO_GetCfgDesc,
  USBD_AUDIO_GetDeviceQualifierDesc,
};

/* USB AUDIO device Configuration Descriptor */
__ALIGN_BEGIN static uint8_t USBD_AUDIO_CfgDesc[USB_AUDIO_CONFIG_DESC_SIZ] __ALIGN_END =
{
  /* 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 */
#if (USBD_SELF_POWERED == 1U)
  0xC0,                                 /* bmAttributes: Bus Powered according to user configuration */
#else
  0x80,                                 /* bmAttributes: Bus Powered according to user configuration */
#endif
  USBD_MAX_POWER,                       /* bMaxPower = 100 mA */
  /* 09 byte*/

  /* USB Microphone 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 Microphone 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 Microphone Input Terminal Descriptor */
  AUDIO_INPUT_TERMINAL_DESC_SIZE,       /* bLength */
  AUDIO_INTERFACE_DESCRIPTOR_TYPE,      /* bDescriptorType */
  AUDIO_CONTROL_INPUT_TERMINAL,         /* bDescriptorSubtype */
  AUDIO_PORT_INPUT_TERMINAL_ID_1,       /* bTerminalID */ 
  AUDIO_PORT_MICRO_PHONE_TERMINAL_L,    /* wTerminalType AUDIO_TERMINAL_USB_Microphone   0x0201 */
  AUDIO_PORT_MICRO_PHONE_TERMINAL_H,
  0x00,                                 /* bAssocTerminal */
  AUDIO_PORT_CHANNEL_NUMS,              /* bNrChannels */
  AUDIO_PORT_CHANNEL_CONFIG_L,          /* wChannelConfig 0x0000  Mono or L+R or L or R*/
  AUDIO_PORT_CHANNEL_CONFIG_H,
  0x00,                                 /* iChannelNames */
  0x00,                                 /* iTerminal */
  /* 12 byte*/

  /* USB Microphone Audio Feature Unit Descriptor */
  0x09,                                 /* bLength */
  AUDIO_INTERFACE_DESCRIPTOR_TYPE,      /* bDescriptorType */
  AUDIO_CONTROL_FEATURE_UNIT,           /* bDescriptorSubtype */
  AUDIO_PORT_INPUT_CTL_ID_2,            /* bUnitID */
  AUDIO_PORT_INPUT_TERMINAL_ID_1,       /* bSourceID */
  0x01,                                 /* bControlSize */
  AUDIO_CONTROL_MUTE,                   /* bmaControls(0) */
  0,                                    /* bmaControls(1) */
  0x00,                                 /* iTerminal */
  /* 09 byte*/

  /*USB Microphone Output Terminal Descriptor */
  0x09,      /* bLength */
  AUDIO_INTERFACE_DESCRIPTOR_TYPE,      /* bDescriptorType */
  AUDIO_CONTROL_OUTPUT_TERMINAL,        /* bDescriptorSubtype */
  AUDIO_PORT_OUTPUT_TERMINAL_ID_3,      /* bTerminalID */
  AUDIO_PORT_STREAM_TERMINAL_TYPE_L,    /* wTerminalType  音频流0x0101*/
  AUDIO_PORT_STREAM_TERMINAL_TYPE_H,
  0x00,                                 /* bAssocTerminal */
  AUDIO_PORT_INPUT_CTL_ID_2,            /* bSourceID */
  0x00,                                 /* iTerminal */
  /* 09 byte*/

  /* USB Microphone Standard AS Interface Descriptor - Audio Streaming Zero Bandwidth */
  /* 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 Microphone 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 Microphone Audio Streaming Interface Descriptor */
  AUDIO_STREAMING_INTERFACE_DESC_SIZE,  /* bLength */
  AUDIO_INTERFACE_DESCRIPTOR_TYPE,      /* bDescriptorType */
  AUDIO_STREAMING_GENERAL,              /* bDescriptorSubtype */
  AUDIO_PORT_OUTPUT_TERMINAL_ID_3,      /* bTerminalLink */
  0x01,                                 /* bDelay */
  0x01,                                 /* wFormatTag AUDIO_FORMAT_PCM  0x0001 */
  0x00,
  /* 07 byte*/

  /* USB Microphone Audio Type III Format Interface Descriptor */
  0x0B,                                 /* bLength */
  AUDIO_INTERFACE_DESCRIPTOR_TYPE,      /* bDescriptorType */
  AUDIO_STREAMING_FORMAT_TYPE,          /* bDescriptorSubtype */
  AUDIO_FORMAT_TYPE_I,                  /* bFormatType */
  AUDIO_PORT_CHANNEL_NUMS,              /* bNrChannels */
  0x02,                                 /* bSubFrameSize :  2 Bytes per frame (16bits) */
  16,                                   /* bBitResolution (16-bits per sample) */
  0x01,                                 /* bSamFreqType only one frequency supported */
  AUDIO_SAMPLE_FREQ(USBD_AUDIO_FREQ),   /* Audio sampling frequency coded on 3 bytes */
  /* 11 byte*/

  /* Endpoint 1 - Standard Descriptor */
  AUDIO_STANDARD_ENDPOINT_DESC_SIZE,    /* bLength */
  USB_DESC_TYPE_ENDPOINT,               /* bDescriptorType */
  AUDIO_PORT_IN_EP_DIR_ID,              /* bEndpointAddress 1 in endpoint */
  USBD_EP_TYPE_ISOC,                    /* bmAttributes */
  AUDIO_PORT_PACKET_SZE(USBD_AUDIO_FREQ),/* wMaxPacketSize in Bytes (Freq(Samples)*2(Stereo)*2(HalfWord)) */
  AUDIO_PORT_FS_BINTERVAL,              /* 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 */
  0x00,                                 /* bmAttributes */
  0x00,                                 /* bLockDelayUnits */
  0x00,                                 /* wLockDelay */
  0x00,
  /* 07 byte*/
} ;

/* USB Standard Device Descriptor */
__ALIGN_BEGIN static uint8_t USBD_AUDIO_DeviceQualifierDesc[USB_LEN_DEV_QUALIFIER_DESC] __ALIGN_END =
{
  USB_LEN_DEV_QUALIFIER_DESC,
  USB_DESC_TYPE_DEVICE_QUALIFIER,
  0x00,
  0x02,
  0x00,
  0x00,
  0x00,
  0x40,
  0x01,
  0x00,
};

/**
  * @}
  */

/** @defgroup USBD_AUDIO_Private_Functions
  * @{
  */

/**
  * @brief  USBD_AUDIO_Init
  *         Initialize the AUDIO interface
  * @param  pdev: device instance
  * @param  cfgidx: Configuration index
  * @retval status
  */
static uint8_t USBD_AUDIO_Init(USBD_HandleTypeDef *pdev, uint8_t cfgidx)
{
  return USB_Audio_Port_EP_IN_Init(pdev, cfgidx);
}

/**
  * @brief  USBD_AUDIO_Init
  *         DeInitialize the AUDIO layer
  * @param  pdev: device instance
  * @param  cfgidx: Configuration index
  * @retval status
  */
static uint8_t USBD_AUDIO_DeInit(USBD_HandleTypeDef *pdev, uint8_t cfgidx)
{
  UNUSED(cfgidx);

  /* Open EP OUT */
  (void)USBD_LL_CloseEP(pdev, AUDIO_OUT_EP);
  pdev->ep_out[AUDIO_OUT_EP & 0xFU].is_used = 0U;
  pdev->ep_out[AUDIO_OUT_EP & 0xFU].bInterval = 0U;

  /* DeInit  physical Interface components */
  if (pdev->pClassData != NULL)
  {
    ((USBD_AUDIO_ItfTypeDef *)pdev->pUserData)->DeInit(0U);
    (void)USBD_free(pdev->pClassData);
    pdev->pClassData = NULL;
  }

  return (uint8_t)USBD_OK;
}

/**
  * @brief  USBD_AUDIO_Setup
  *         Handle the AUDIO specific requests
  * @param  pdev: instance
  * @param  req: usb requests
  * @retval status
  */
static uint8_t USBD_AUDIO_Setup(USBD_HandleTypeDef *pdev,
                                USBD_SetupReqTypedef *req)
{
  USBD_AUDIO_HandleTypeDef *haudio;
  uint16_t len;
  uint8_t *pbuf;
  uint16_t status_info = 0U;
  USBD_StatusTypeDef ret = USBD_OK;

  haudio = (USBD_AUDIO_HandleTypeDef *)pdev->pClassData;

  if (haudio == NULL)
  {
    return (uint8_t)USBD_FAIL;
  }

  switch (req->bmRequest & USB_REQ_TYPE_MASK)
  {
    case USB_REQ_TYPE_CLASS:
      switch (req->bRequest)
      {
        case AUDIO_REQ_GET_CUR:
          AUDIO_REQ_GetCurrent(pdev, req);
          break;

        case AUDIO_REQ_SET_CUR:
          AUDIO_REQ_SetCurrent(pdev, req);
          break;

        default:
          USBD_CtlError(pdev, req);
          ret = USBD_FAIL;
          break;
      }
      break;

    case USB_REQ_TYPE_STANDARD:
      switch (req->bRequest)
      {
        case USB_REQ_GET_STATUS:
          if (pdev->dev_state == USBD_STATE_CONFIGURED)
          {
            (void)USBD_CtlSendData(pdev, (uint8_t *)&status_info, 2U);
          }
          else
          {
            USBD_CtlError(pdev, req);
            ret = USBD_FAIL;
          }
          break;

        case USB_REQ_GET_DESCRIPTOR:
          if ((req->wValue >> 8) == AUDIO_DESCRIPTOR_TYPE)
          {
            pbuf = USBD_AUDIO_CfgDesc + 18;
            len = MIN(USB_AUDIO_DESC_SIZ, req->wLength);

            (void)USBD_CtlSendData(pdev, pbuf, len);
          }
          break;

        case USB_REQ_GET_INTERFACE:
          if (pdev->dev_state == USBD_STATE_CONFIGURED)
          {
            (void)USBD_CtlSendData(pdev, (uint8_t *)&haudio->alt_setting, 1U);
          }
          else
          {
            USBD_CtlError(pdev, req);
            ret = USBD_FAIL;
          }
          break;

        case USB_REQ_SET_INTERFACE:
          if (pdev->dev_state == USBD_STATE_CONFIGURED)
          {
            if ((uint8_t)(req->wValue) <= USBD_MAX_NUM_INTERFACES)
            {
              haudio->alt_setting = (uint8_t)(req->wValue);
            }
            else
            {
              /* Call the error management function (command will be NAKed */
              USBD_CtlError(pdev, req);
              ret = USBD_FAIL;
            }
          }
          else
          {
            USBD_CtlError(pdev, req);
            ret = USBD_FAIL;
          }
          break;

        case USB_REQ_CLEAR_FEATURE:
          break;

        default:
          USBD_CtlError(pdev, req);
          ret = USBD_FAIL;
          break;
      }
      break;
    default:
      USBD_CtlError(pdev, req);
      ret = USBD_FAIL;
      break;
  }

  return (uint8_t)ret;
}


/**
  * @brief  USBD_AUDIO_GetCfgDesc
  *         return configuration descriptor
  * @param  speed : current device speed
  * @param  length : pointer data length
  * @retval pointer to descriptor buffer
  */
static uint8_t *USBD_AUDIO_GetCfgDesc(uint16_t *length)
{
  *length = (uint16_t)sizeof(USBD_AUDIO_CfgDesc);

  return USBD_AUDIO_CfgDesc;
}

/**
  * @brief  USBD_AUDIO_DataIn
  *         handle data IN Stage
  * @param  pdev: device instance
  * @param  epnum: endpoint index
  * @retval status
  */
static uint8_t USBD_AUDIO_DataIn(USBD_HandleTypeDef *pdev, uint8_t epnum)
{
  return USB_Audio_Port_DataIn(pdev, epnum);
}

/**
  * @brief  USBD_AUDIO_EP0_RxReady
  *         handle EP0 Rx Ready event
  * @param  pdev: device instance
  * @retval status
  */
static uint8_t USBD_AUDIO_EP0_RxReady(USBD_HandleTypeDef *pdev)
{
  USBD_AUDIO_HandleTypeDef *haudio;
  haudio = (USBD_AUDIO_HandleTypeDef *)pdev->pClassData;

  if (haudio == NULL)
  {
    return (uint8_t)USBD_FAIL;
  }

  if (haudio->control.cmd == AUDIO_REQ_SET_CUR)
  {
    /* In this driver, to simplify code, only SET_CUR request is managed */

    if (haudio->control.unit == AUDIO_OUT_STREAMING_CTRL)
    {
      ((USBD_AUDIO_ItfTypeDef *)pdev->pUserData)->MuteCtl(haudio->control.data[0]);
      haudio->control.cmd = 0U;
      haudio->control.len = 0U;
    }
  }

  return (uint8_t)USBD_OK;
}
/**
  * @brief  USBD_AUDIO_EP0_TxReady
  *         handle EP0 TRx Ready event
  * @param  pdev: device instance
  * @retval status
  */
static uint8_t USBD_AUDIO_EP0_TxReady(USBD_HandleTypeDef *pdev)
{
  UNUSED(pdev);

  /* Only OUT control data are processed */
  return (uint8_t)USBD_OK;
}
/**
  * @brief  USBD_AUDIO_SOF
  *         handle SOF event
  * @param  pdev: device instance
  * @retval status
  */
static uint8_t USBD_AUDIO_SOF(USBD_HandleTypeDef *pdev)
{
  UNUSED(pdev);

  return (uint8_t)USBD_OK;
}

/**
  * @brief  USBD_AUDIO_SOF
  *         handle SOF event
  * @param  pdev: device instance
  * @retval status
  */
void USBD_AUDIO_Sync(USBD_HandleTypeDef *pdev, AUDIO_OffsetTypeDef offset)
{
  USBD_AUDIO_HandleTypeDef *haudio;
  uint32_t BufferSize = AUDIO_TOTAL_BUF_SIZE / 2U;

  if (pdev->pClassData == NULL)
  {
    return;
  }

  haudio = (USBD_AUDIO_HandleTypeDef *)pdev->pClassData;

  haudio->offset = offset;

  if (haudio->rd_enable == 1U)
  {
    haudio->rd_ptr += (uint16_t)BufferSize;

    if (haudio->rd_ptr == AUDIO_TOTAL_BUF_SIZE)
    {
      /* roll back */
      haudio->rd_ptr = 0U;
    }
  }

  if (haudio->rd_ptr > haudio->wr_ptr)
  {
    if ((haudio->rd_ptr - haudio->wr_ptr) < AUDIO_OUT_PACKET)
    {
      BufferSize += 4U;
    }
    else
    {
      if ((haudio->rd_ptr - haudio->wr_ptr) > (AUDIO_TOTAL_BUF_SIZE - AUDIO_OUT_PACKET))
      {
        BufferSize -= 4U;
      }
    }
  }
  else
  {
    if ((haudio->wr_ptr - haudio->rd_ptr) < AUDIO_OUT_PACKET)
    {
      BufferSize -= 4U;
    }
    else
    {
      if ((haudio->wr_ptr - haudio->rd_ptr) > (AUDIO_TOTAL_BUF_SIZE - AUDIO_OUT_PACKET))
      {
        BufferSize += 4U;
      }
    }
  }

  if (haudio->offset == AUDIO_OFFSET_FULL)
  {
    ((USBD_AUDIO_ItfTypeDef *)pdev->pUserData)->AudioCmd(&haudio->buffer[0],
                                                         BufferSize, AUDIO_CMD_PLAY);
    haudio->offset = AUDIO_OFFSET_NONE;
  }
}

/**
  * @brief  USBD_AUDIO_IsoINIncomplete
  *         handle data ISO IN Incomplete event
  * @param  pdev: device instance
  * @param  epnum: endpoint index
  * @retval status
  */
static uint8_t USBD_AUDIO_IsoINIncomplete(USBD_HandleTypeDef *pdev, uint8_t epnum)
{
  UNUSED(pdev);
  UNUSED(epnum);

  return (uint8_t)USBD_OK;
}
/**
  * @brief  USBD_AUDIO_IsoOutIncomplete
  *         handle data ISO OUT Incomplete event
  * @param  pdev: device instance
  * @param  epnum: endpoint index
  * @retval status
  */
static uint8_t USBD_AUDIO_IsoOutIncomplete(USBD_HandleTypeDef *pdev, uint8_t epnum)
{
  UNUSED(pdev);
  UNUSED(epnum);

  return (uint8_t)USBD_OK;
}
/**
  * @brief  USBD_AUDIO_DataOut
  *         handle data OUT Stage
  * @param  pdev: device instance
  * @param  epnum: endpoint index
  * @retval status
  */
static uint8_t USBD_AUDIO_DataOut(USBD_HandleTypeDef *pdev, uint8_t epnum)
{
  uint16_t PacketSize;
  USBD_AUDIO_HandleTypeDef *haudio;

  haudio = (USBD_AUDIO_HandleTypeDef *)pdev->pClassData;

  if (haudio == NULL)
  {
    return (uint8_t)USBD_FAIL;
  }

  if (epnum == AUDIO_OUT_EP)
  {
    /* Get received data packet length */
    PacketSize = (uint16_t)USBD_LL_GetRxDataSize(pdev, epnum);

    /* Packet received Callback */
    ((USBD_AUDIO_ItfTypeDef *)pdev->pUserData)->PeriodicTC(&haudio->buffer[haudio->wr_ptr],
                                                           PacketSize, AUDIO_OUT_TC);

    /* Increment the Buffer pointer or roll it back when all buffers are full */
    haudio->wr_ptr += PacketSize;

    if (haudio->wr_ptr == AUDIO_TOTAL_BUF_SIZE)
    {
      /* All buffers are full: roll back */
      haudio->wr_ptr = 0U;

      if (haudio->offset == AUDIO_OFFSET_UNKNOWN)
      {
        ((USBD_AUDIO_ItfTypeDef *)pdev->pUserData)->AudioCmd(&haudio->buffer[0],
                                                             AUDIO_TOTAL_BUF_SIZE / 2U,
                                                             AUDIO_CMD_START);
        haudio->offset = AUDIO_OFFSET_NONE;
      }
    }

    if (haudio->rd_enable == 0U)
    {
      if (haudio->wr_ptr == (AUDIO_TOTAL_BUF_SIZE / 2U))
      {
        haudio->rd_enable = 1U;
      }
    }

    /* Prepare Out endpoint to receive next audio packet */
    (void)USBD_LL_PrepareReceive(pdev, AUDIO_OUT_EP,
                                 &haudio->buffer[haudio->wr_ptr],
                                 AUDIO_OUT_PACKET);
  }

  return (uint8_t)USBD_OK;
}

/**
  * @brief  AUDIO_Req_GetCurrent
  *         Handles the GET_CUR Audio control request.
  * @param  pdev: instance
  * @param  req: setup class request
  * @retval status
  */
static void AUDIO_REQ_GetCurrent(USBD_HandleTypeDef *pdev, USBD_SetupReqTypedef *req)
{
  USBD_AUDIO_HandleTypeDef *haudio;
  haudio = (USBD_AUDIO_HandleTypeDef *)pdev->pClassData;

  if (haudio == NULL)
  {
    return;
  }

  (void)USBD_memset(haudio->control.data, 0, 64U);

  /* Send the current mute state */
  (void)USBD_CtlSendData(pdev, haudio->control.data, req->wLength);
}

/**
  * @brief  AUDIO_Req_SetCurrent
  *         Handles the SET_CUR Audio control request.
  * @param  pdev: instance
  * @param  req: setup class request
  * @retval status
  */
static void AUDIO_REQ_SetCurrent(USBD_HandleTypeDef *pdev, USBD_SetupReqTypedef *req)
{
  USBD_AUDIO_HandleTypeDef *haudio;
  haudio = (USBD_AUDIO_HandleTypeDef *)pdev->pClassData;

  if (haudio == NULL)
  {
    return;
  }

  if (req->wLength != 0U)
  {
    /* Prepare the reception of the buffer over EP0 */
    (void)USBD_CtlPrepareRx(pdev, haudio->control.data, req->wLength);

    haudio->control.cmd = AUDIO_REQ_SET_CUR;     /* Set the request value */
    haudio->control.len = (uint8_t)req->wLength; /* Set the request data length */
    haudio->control.unit = HIBYTE(req->wIndex);  /* Set the request target unit */
  }
}


/**
  * @brief  DeviceQualifierDescriptor
  *         return Device Qualifier descriptor
  * @param  length : pointer data length
  * @retval pointer to descriptor buffer
  */
static uint8_t *USBD_AUDIO_GetDeviceQualifierDesc(uint16_t *length)
{
  *length = (uint16_t)sizeof(USBD_AUDIO_DeviceQualifierDesc);

  return USBD_AUDIO_DeviceQualifierDesc;
}

/**
  * @brief  USBD_AUDIO_RegisterInterface
  * @param  fops: Audio interface callback
  * @retval status
  */
uint8_t USBD_AUDIO_RegisterInterface(USBD_HandleTypeDef *pdev,
                                     USBD_AUDIO_ItfTypeDef *fops)
{
  if (fops == NULL)
  {
    return (uint8_t)USBD_FAIL;
  }

  pdev->pUserData = fops;

  return (uint8_t)USBD_OK;
}
/**
  * @}
  */


/**
  * @}
  */


/**
  * @}
  */

/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/

usbd_audio.h
其内主要修改了 缓冲区大小,包含了接口头文件

/**
  ******************************************************************************
  * @file    usbd_audio.h
  * @author  MCD Application Team
  * @brief   header file for the usbd_audio.c file.
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; Copyright (c) 2015 STMicroelectronics.
  * All rights reserved.</center></h2>
  *
  * This software component is licensed by ST under Ultimate Liberty license
  * SLA0044, the "License"; You may not use this file except in compliance with
  * the License. You may obtain a copy of the License at:
  *                      www.st.com/SLA0044
  *
  ******************************************************************************
  */

/* Define to prevent recursive inclusion -------------------------------------*/
#ifndef __USB_AUDIO_H
#define __USB_AUDIO_H

#ifdef __cplusplus
extern "C" {
#endif

/* Includes ------------------------------------------------------------------*/
#include  "usbd_ioreq.h"
#include "USB_Audio_Port.h"
/** @addtogroup STM32_USB_DEVICE_LIBRARY
  * @{
  */

/** @defgroup USBD_AUDIO
  * @brief This file is the Header file for usbd_audio.c
  * @{
  */


/** @defgroup USBD_AUDIO_Exported_Defines
  * @{
  */
#ifndef USBD_AUDIO_FREQ
/* AUDIO Class Config */
#define USBD_AUDIO_FREQ                               48000U
#endif /* USBD_AUDIO_FREQ */

#ifndef USBD_MAX_NUM_INTERFACES
#define USBD_MAX_NUM_INTERFACES                       1U
#endif /* USBD_AUDIO_FREQ */

#ifndef AUDIO_HS_BINTERVAL
#define AUDIO_HS_BINTERVAL                            0x01U
#endif /* AUDIO_HS_BINTERVAL */

#ifndef AUDIO_FS_BINTERVAL
#define AUDIO_FS_BINTERVAL                            0x01U
#endif /* AUDIO_FS_BINTERVAL */

#define AUDIO_OUT_EP                                  0x01U
#define USB_AUDIO_CONFIG_DESC_SIZ                     0x6DU
#define AUDIO_INTERFACE_DESC_SIZE                     0x09U
#define USB_AUDIO_DESC_SIZ                            0x09U
#define AUDIO_STANDARD_ENDPOINT_DESC_SIZE             0x09U
#define AUDIO_STREAMING_ENDPOINT_DESC_SIZE            0x07U

#define AUDIO_DESCRIPTOR_TYPE                         0x21U
#define USB_DEVICE_CLASS_AUDIO                        0x01U
#define AUDIO_SUBCLASS_AUDIOCONTROL                   0x01U
#define AUDIO_SUBCLASS_AUDIOSTREAMING                 0x02U
#define AUDIO_PROTOCOL_UNDEFINED                      0x00U
#define AUDIO_STREAMING_GENERAL                       0x01U
#define AUDIO_STREAMING_FORMAT_TYPE                   0x02U

/* Audio Descriptor Types */
#define AUDIO_INTERFACE_DESCRIPTOR_TYPE               0x24U
#define AUDIO_ENDPOINT_DESCRIPTOR_TYPE                0x25U

/* Audio Control Interface Descriptor Subtypes */
#define AUDIO_CONTROL_HEADER                          0x01U
#define AUDIO_CONTROL_INPUT_TERMINAL                  0x02U
#define AUDIO_CONTROL_OUTPUT_TERMINAL                 0x03U
#define AUDIO_CONTROL_FEATURE_UNIT                    0x06U

#define AUDIO_INPUT_TERMINAL_DESC_SIZE                0x0CU
#define AUDIO_OUTPUT_TERMINAL_DESC_SIZE               0x09U
#define AUDIO_STREAMING_INTERFACE_DESC_SIZE           0x07U

#define AUDIO_CONTROL_MUTE                            0x0001U

#define AUDIO_FORMAT_TYPE_I                           0x01U
#define AUDIO_FORMAT_TYPE_III                         0x03U

#define AUDIO_ENDPOINT_GENERAL                        0x01U

#define AUDIO_REQ_GET_CUR                             0x81U
#define AUDIO_REQ_SET_CUR                             0x01U

#define AUDIO_OUT_STREAMING_CTRL                      0x02U

#define AUDIO_OUT_TC                                  0x01U
#define AUDIO_IN_TC                                   0x02U


#define AUDIO_OUT_PACKET                              AUDIO_PORT_OUT_SIZE
#define AUDIO_DEFAULT_VOLUME                          70U

/* Number of sub-packets in the audio transfer buffer. You can modify this value but always make sure
  that it is an even number and higher than 3 */
#define AUDIO_OUT_PACKET_NUM                          80U
/* Total size of the audio transfer buffer */
#define AUDIO_TOTAL_BUF_SIZE                          AUDIO_PORT_BUF_SIZE

/* Audio Commands enumeration */
typedef enum
{
  AUDIO_CMD_START = 1,
  AUDIO_CMD_PLAY,
  AUDIO_CMD_STOP,
} AUDIO_CMD_TypeDef;


typedef enum
{
  AUDIO_OFFSET_NONE = 0,
  AUDIO_OFFSET_HALF,
  AUDIO_OFFSET_FULL,
  AUDIO_OFFSET_UNKNOWN,
} AUDIO_OffsetTypeDef;
/**
  * @}
  */


/** @defgroup USBD_CORE_Exported_TypesDefinitions
  * @{
  */
typedef struct
{
  uint8_t cmd;
  uint8_t data[USB_MAX_EP0_SIZE];
  uint8_t len;
  uint8_t unit;
} USBD_AUDIO_ControlTypeDef;


typedef struct
{
  uint32_t alt_setting;
  uint8_t buffer[AUDIO_TOTAL_BUF_SIZE];
  AUDIO_OffsetTypeDef offset;
  uint8_t rd_enable;
  uint16_t rd_ptr;
  uint16_t wr_ptr;
  USBD_AUDIO_ControlTypeDef control;
} USBD_AUDIO_HandleTypeDef;


typedef struct
{
  int8_t (*Init)(uint32_t AudioFreq, uint32_t Volume, uint32_t options);
  int8_t (*DeInit)(uint32_t options);
  int8_t (*AudioCmd)(uint8_t *pbuf, uint32_t size, uint8_t cmd);
  int8_t (*VolumeCtl)(uint8_t vol);
  int8_t (*MuteCtl)(uint8_t cmd);
  int8_t (*PeriodicTC)(uint8_t *pbuf, uint32_t size, uint8_t cmd);
  int8_t (*GetState)(void);
} USBD_AUDIO_ItfTypeDef;
/**
  * @}
  */



/** @defgroup USBD_CORE_Exported_Macros
  * @{
  */

/**
  * @}
  */

/** @defgroup USBD_CORE_Exported_Variables
  * @{
  */

extern USBD_ClassTypeDef USBD_AUDIO;
#define USBD_AUDIO_CLASS &USBD_AUDIO
/**
  * @}
  */

/** @defgroup USB_CORE_Exported_Functions
  * @{
  */
uint8_t USBD_AUDIO_RegisterInterface(USBD_HandleTypeDef *pdev,
                                     USBD_AUDIO_ItfTypeDef *fops);

void USBD_AUDIO_Sync(USBD_HandleTypeDef *pdev, AUDIO_OffsetTypeDef offset);
/**
  * @}
  */

#ifdef __cplusplus
}
#endif

#endif  /* __USB_AUDIO_H */
/**
  * @}
  */

/**
  * @}
  */

/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/

实现部分

其内需要环形缓冲区,源码获取:https://blog.csdn.net/weixin_42892101/article/details/104886937

USB_Audio_Port.c

/**
 *  @file USB_Audio_Port.c
 *
 *  @date 2021-06-01
 *
 *  @author aron566
 *
 *  @copyright Copyright (c) 2021 aron566 <aron566@163.com>.
 *
 *  @brief USB音频类接口,对外提供音频更新及输出接口
 *
 *  @details 1、开启对应FS中断,中断处理和初始化位于usbd_conf.c
 *           2、16k采样,双声道,10ms出320点数据
 *           3、1ms间隔发送,10ms发送5次,每次发送320/5 = 64点数据
 *           4、接收来自MIC数据,10ms来一次每次双通道160点*2
 *  @version V1.0
 */
/** Includes -----------------------------------------------------------------*/
/* Private includes ----------------------------------------------------------*/
#include "USB_Audio_Port.h"
#include "main.h"
#include <arm_math.h>
#include "usbd_audio.h"
/** Use C compiler -----------------------------------------------------------*/
#ifdef __cplusplus ///<use C compiler
extern "C" {
#endif
/** Private typedef ----------------------------------------------------------*/
/** Private macros -----------------------------------------------------------*/
#define USB_RX_BUF_SIZE_MAX       1024 /**< 接收缓冲区设置1024*2Bytes*/

#define USB_PORT_AUDIO_OUT_PACKET AUDIO_PORT_OUT_SIZE    /**< 一次发送大小字节数*/
#define USB_PORT_AUDIO_BUF_SIZE   AUDIO_TOTAL_BUF_SIZE
#define USB_PORT_AUDIO_IN_EP      AUDIO_PORT_IN_EP_DIR_ID
#define USB_PORT_AUDIO_OUT_EP     AUDIO_PORT_OUT_EP_DIR_ID
/** Private constants --------------------------------------------------------*/
/** Public variables ---------------------------------------------------------*/
/** Private variables --------------------------------------------------------*/
/*音频缓冲区*/
static CQ_handleTypeDef USB_Audio_Data_Handle;
static int16_t USB_Audio_Receive_Buf[STEREO_FRAME_SIZE] = {0};
static uint16_t USB_Audio_Send_Buf[USB_RX_BUF_SIZE_MAX];
/** Private function prototypes ----------------------------------------------*/

/** Private user code --------------------------------------------------------*/

/** Private application code -------------------------------------------------*/
/*******************************************************************************
*
*       Static code
*
********************************************************************************
*/
/**
  ******************************************************************
  * @brief   USB音频接口初始化
  * @param   [in]None.
  * @return  None.
  * @author  aron566
  * @version V1.0
  * @date    2021-06-02
  ******************************************************************
  */
static void USB_Audio_Port_Init(void)
{
  /*初始化接收音频缓冲区*/
  CQ_16_init(&USB_Audio_Data_Handle, USB_Audio_Send_Buf, USB_RX_BUF_SIZE_MAX);
}

/**
  ******************************************************************
  * @brief   向USB缓冲区数据加入数据
  * @param   [in]Data 待加入数据.
  * @param   [in]Size 待加入数据长度Size个16Bit.
  * @return  None.
  * @author  aron566
  * @version V1.0
  * @date    2021-06-04
  ******************************************************************
  */
static inline void USB_Audio_Port_Put_Audio_Data(const int16_t *Data, uint32_t Size)
{
  CQ_16putData(&USB_Audio_Data_Handle, (const uint16_t *)Data, Size);
}

/** Public application code --------------------------------------------------*/
/*******************************************************************************
*
*       Public code
*
********************************************************************************
*/

/**
  ******************************************************************
  * @brief   USB缓冲区数据接收来自HOST
  * @param   [in]pdev device instance
  * @param   [in]epnum 端点号
  * @return  USBD_OK 正常.
  * @author  aron566
  * @version V1.0
  * @date    2021-06-01
  ******************************************************************
  */
uint8_t USB_Audio_Port_DataOut(void *xpdev, uint8_t epnum)
{
  uint16_t PacketSize;
  USBD_AUDIO_HandleTypeDef *haudio;
  USBD_HandleTypeDef *pdev = (USBD_HandleTypeDef *)xpdev;
  
  haudio = (USBD_AUDIO_HandleTypeDef *)pdev->pClassData;

  if (haudio == NULL)
  {
    return (uint8_t)USBD_FAIL;
  }

  if (epnum == USB_PORT_AUDIO_OUT_EP)
  {
    /* Get received data packet length */
    PacketSize = (uint16_t)USBD_LL_GetRxDataSize(pdev, epnum);

    /* Packet received Callback */
    ((USBD_AUDIO_ItfTypeDef *)pdev->pUserData)->PeriodicTC(&haudio->buffer[haudio->wr_ptr],
                                                           PacketSize, AUDIO_OUT_TC);

    /* Increment the Buffer pointer or roll it back when all buffers are full */
    haudio->wr_ptr += PacketSize;

    if (haudio->wr_ptr == AUDIO_TOTAL_BUF_SIZE)
    {
      /* All buffers are full: roll back */
      haudio->wr_ptr = 0U;

      if (haudio->offset == AUDIO_OFFSET_UNKNOWN)
      {
        ((USBD_AUDIO_ItfTypeDef *)pdev->pUserData)->AudioCmd(&haudio->buffer[0],
                                                             AUDIO_TOTAL_BUF_SIZE / 2U,
                                                             AUDIO_CMD_START);
        haudio->offset = AUDIO_OFFSET_NONE;
      }
    }

    if (haudio->rd_enable == 0U)
    {
      if (haudio->wr_ptr == (AUDIO_TOTAL_BUF_SIZE / 2U))
      {
        haudio->rd_enable = 1U;
      }
    }

    /* Prepare Out endpoint to receive next audio packet */
    (void)USBD_LL_PrepareReceive(pdev, USB_PORT_AUDIO_OUT_EP,
                                 &haudio->buffer[haudio->wr_ptr],
                                 AUDIO_OUT_PACKET);
  }

  return (uint8_t)USBD_OK;
}

/**
  ******************************************************************
  * @brief   USB缓冲区数据发送至HOST
  * @param   [in]pdev device instance
  * @param   [in]epnum 端点号
  * @return  USBD_OK 正常.
  * @author  aron566
  * @version V1.0
  * @date    2021-06-01
  ******************************************************************
  */
uint8_t USB_Audio_Port_DataIn(void *xpdev, uint8_t epnum)
{
  USBD_HandleTypeDef *pdev = (USBD_HandleTypeDef *)xpdev;
  USBD_AUDIO_HandleTypeDef *haudio = (USBD_AUDIO_HandleTypeDef*) pdev->pClassData;
  
	USBD_LL_FlushEP(pdev, USB_PORT_AUDIO_IN_EP);
  if(CQ_getLength(&USB_Audio_Data_Handle) < USB_PORT_AUDIO_OUT_PACKET/2)
  {
    return (uint8_t)USBD_BUSY;
  }
  CQ_16getData(&USB_Audio_Data_Handle, (uint16_t *)haudio->buffer, USB_PORT_AUDIO_OUT_PACKET/2);
  return USBD_LL_Transmit(pdev, USB_PORT_AUDIO_IN_EP, haudio->buffer, USB_PORT_AUDIO_OUT_PACKET);
}

/**
  ******************************************************************
  * @brief   反初始化音频输出端点
  * @param   [in]pdev
  * @param   [in]cfgidx
  * @return  USBD_OK 正常.
  * @author  aron566
  * @version V1.0
  * @date    2021-06-01
  ******************************************************************
  */
uint8_t USB_Audio_Port_EP_OUT_DeInit(void *xpdev, uint8_t cfgidx)
{
  UNUSED(cfgidx);
  USBD_HandleTypeDef *pdev = (USBD_HandleTypeDef *)xpdev;
  
  /* Open EP OUT */
  (void)USBD_LL_CloseEP(pdev, USB_PORT_AUDIO_OUT_EP);
  pdev->ep_out[USB_PORT_AUDIO_OUT_EP & 0xFU].is_used = 0U;
  pdev->ep_out[USB_PORT_AUDIO_OUT_EP & 0xFU].bInterval = 0U;

  /* DeInit  physical Interface components */
  if (pdev->pClassData != NULL)
  {
    ((USBD_AUDIO_ItfTypeDef *)pdev->pUserData)->DeInit(0U);
    (void)USBD_free(pdev->pClassData);
    pdev->pClassData = NULL;
  }

  return (uint8_t)USBD_OK;
}

/**
  ******************************************************************
  * @brief   反初始化音频输入端点
  * @param   [in]pdev
  * @param   [in]cfgidx
  * @return  USBD_OK 正常.
  * @author  aron566
  * @version V1.0
  * @date    2021-06-01
  ******************************************************************
  */
uint8_t USB_Audio_Port_EP_IN_DeInit(void *xpdev, uint8_t cfgidx)
{
  UNUSED(cfgidx);
  USBD_HandleTypeDef *pdev = (USBD_HandleTypeDef *)xpdev;
  
  /* Open EP OUT */  
  USBD_LL_CloseEP(pdev, USB_PORT_AUDIO_IN_EP);
  
  /* DeInit  physical Interface components */
  if (pdev->pClassData != NULL)
  {
    ((USBD_AUDIO_ItfTypeDef *)pdev->pUserData)->DeInit(0U);
    (void)USBD_free(pdev->pClassData);
    pdev->pClassData = NULL;
  }
  return (uint8_t)USBD_OK;
}

/**
  ******************************************************************
  * @brief   初始化为音频输出端点
  * @param   [in]pdev
  * @param   [in]cfgidx
  * @return  USBD_OK 正常.
  * @author  aron566
  * @version V1.0
  * @date    2021-06-01
  ******************************************************************
  */
uint8_t USB_Audio_Port_EP_OUT_Init(void *xpdev, uint8_t cfgidx)
{
  UNUSED(cfgidx);
  USBD_AUDIO_HandleTypeDef *haudio;
  USBD_HandleTypeDef *pdev = (USBD_HandleTypeDef *)xpdev;
  
  /* Allocate Audio structure */
  haudio = USBD_malloc(sizeof(USBD_AUDIO_HandleTypeDef));

  if (haudio == NULL)
  {
    pdev->pClassData = NULL;
    return (uint8_t)USBD_EMEM;
  }

  pdev->pClassData = (void *)haudio;
    
  if (pdev->dev_speed == USBD_SPEED_HIGH)
  {
    pdev->ep_out[USB_PORT_AUDIO_OUT_EP & 0xFU].bInterval = AUDIO_HS_BINTERVAL;
  }
  else   /* LOW and FULL-speed endpoints */
  {
    pdev->ep_out[USB_PORT_AUDIO_OUT_EP & 0xFU].bInterval = AUDIO_FS_BINTERVAL;
  }

  /* Open EP OUT */
  (void)USBD_LL_OpenEP(pdev, USB_PORT_AUDIO_OUT_EP, USBD_EP_TYPE_ISOC, USB_PORT_AUDIO_OUT_PACKET);
  pdev->ep_out[USB_PORT_AUDIO_OUT_EP & 0xFU].is_used = 1U;

  haudio->alt_setting = 0U;
  haudio->offset = AUDIO_OFFSET_UNKNOWN;
  haudio->wr_ptr = 0U;
  haudio->rd_ptr = 0U;
  haudio->rd_enable = 0U;

  /* Initialize the Audio output Hardware layer */
  if (((USBD_AUDIO_ItfTypeDef *)pdev->pUserData)->Init(USBD_AUDIO_FREQ,
                                                       AUDIO_DEFAULT_VOLUME,
                                                       0U) != 0U)
  {
    return (uint8_t)USBD_FAIL;
  }

  /* Prepare Out endpoint to receive 1st packet */
  (void)USBD_LL_PrepareReceive(pdev, USB_PORT_AUDIO_OUT_EP, haudio->buffer,
                               AUDIO_OUT_PACKET);
  return (uint8_t)USBD_OK; 
}

/**
  ******************************************************************
  * @brief   初始化为音频输入端点
  * @param   [in]pdev
  * @param   [in]cfgidx
  * @return  USBD_OK 正常.
  * @author  aron566
  * @version V1.0
  * @date    2021-06-01
  ******************************************************************
  */
uint8_t USB_Audio_Port_EP_IN_Init(void *xpdev, uint8_t cfgidx)
{
  UNUSED(cfgidx);
  USBD_AUDIO_HandleTypeDef *haudio;
  USBD_HandleTypeDef *pdev = (USBD_HandleTypeDef *)xpdev;
  
  /*USB接口初始化*/
  USB_Audio_Port_Init();
  
  /* Allocate Audio structure */
  haudio = USBD_malloc(sizeof(USBD_AUDIO_HandleTypeDef));

  if (haudio == NULL)
  {
    pdev->pClassData = NULL;
    return (uint8_t)USBD_EMEM;
  }

  pdev->pClassData = (void *)haudio;
  
  if (pdev->dev_speed == USBD_SPEED_HIGH)
  {
    pdev->ep_in[USB_PORT_AUDIO_IN_EP & 0xFU].bInterval = AUDIO_HS_BINTERVAL;
  }
  else   /* LOW and FULL-speed endpoints */
  {
    pdev->ep_in[USB_PORT_AUDIO_IN_EP & 0xFU].bInterval = AUDIO_FS_BINTERVAL;
  }
  
    /* Open EP IN */
  (void)USBD_LL_OpenEP(pdev, USB_PORT_AUDIO_IN_EP, USBD_EP_TYPE_ISOC, USB_PORT_AUDIO_OUT_PACKET); 
  pdev->ep_in[USB_PORT_AUDIO_IN_EP & 0xFU].is_used = 1U;
  
  haudio->alt_setting = 0U;
  haudio->offset = AUDIO_OFFSET_UNKNOWN;
  haudio->wr_ptr = 0U;
  haudio->rd_ptr = 0U;
  haudio->rd_enable = 0U;
  
  memset(haudio->buffer, 0, USB_PORT_AUDIO_BUF_SIZE);

  USBD_LL_Transmit(pdev, USB_PORT_AUDIO_IN_EP, haudio->buffer, USB_PORT_AUDIO_OUT_PACKET);
  return (uint8_t)USBD_OK;
}

/**
  ******************************************************************
  * @brief   更新USB音频数据
  * @param   [in]pdev
  * @param   [in]cfgidx
  * @return  USBD_OK 正常.
  * @author  aron566
  * @version V1.0
  * @date    2021-06-01
  ******************************************************************
  */
void USB_Audio_Port_Put_Data(const int16_t *Left_Audio, const int16_t *Right_Audio)
{
  /*更新USB音频数据*/
  int index = 0, i = 0;
  for(i = 0; i < STEREO_FRAME_SIZE;)
  {
    USB_Audio_Receive_Buf[i++] = Left_Audio[index++];/**< TO USB LEFT*/
    USB_Audio_Receive_Buf[i++] = Right_Audio[index];/**< TO USB RIGHT*/
  }
  
  USB_Audio_Port_Put_Audio_Data(USB_Audio_Receive_Buf, STEREO_FRAME_SIZE);
}

#ifdef __cplusplus ///<end extern c
}
#endif
/******************************** End of file *********************************/

USB_Audio_Port.h
文件中主要定义了相关宏,用于配置USB 麦克风描述符,如通道数,一次发送包大小,采样率(CubeMX配置),最大缓冲区

/**
 *  @file USB_Audio_Port.h
 *
 *  @date 2021-06-01
 *
 *  @author aron566
 *
 *  @brief 
 *  
 *  @version V1.0
 */
#ifndef USB_AUDIO_PORT_H
#define USB_AUDIO_PORT_H
/** Includes -----------------------------------------------------------------*/
#include <stdint.h> /**< need definition of uint8_t */
#include <stddef.h> /**< need definition of NULL    */
#include <stdbool.h>/**< need definition of BOOL    */
#include <stdio.h>  /**< if need printf             */
#include <stdlib.h>
#include <string.h>
#include <limits.h> /**< need variable max value    */
/** Exported macros-----------------------------------------------------------*/
#define AUDIO_PORT_CHANNEL_NUMS               2U      /**< MIC音频通道数*/
#define MONO_CHANNEL_SEL                      2U      /**< 0使用L声道 1使用R声道 2配置MONO*/
#define AUDIO_PORT_USBD_AUDIO_FREQ            16000U  /**< 设置音频采样率*/

/*音频类终端类型定义*/ 
#define AUDIO_PORT_INPUT_TERMINAL_ID_1        0x01
#define AUDIO_PORT_OUTPUT_TERMINAL_ID_3       0x03
#define AUDIO_PORT_INPUT_CTL_ID_2             0x02

#define AUDIO_PORT_SPEAKE_TERMINAL_TYPE_L     0x01U
#define AUDIO_PORT_SPEAKE_TERMINAL_TYPE_H     0x03U

#define AUDIO_PORT_STREAM_TERMINAL_TYPE_L     0x01U
#define AUDIO_PORT_STREAM_TERMINAL_TYPE_H     0x01U

#define AUDIO_PORT_MICRO_PHONE_TERMINAL_L     0x01U
#define AUDIO_PORT_MICRO_PHONE_TERMINAL_H     0x02U
  
#define AUDIO_PORT_IN_EP_DIR_ID               0x81  /**< (Direction=IN EndpointID=1)*/
#define AUDIO_PORT_OUT_EP_DIR_ID              0x01  /**< (Direction=OUT EndpointID=1)*/

/*立体声配置*/
#if AUDIO_PORT_CHANNEL_NUMS == 2
  /*使用L+R声道*/
  #define AUDIO_PORT_CHANNEL_CONFIG_L  0x03U
  #define AUDIO_PORT_CHANNEL_CONFIG_H  0x00U
/*单声道配置*/
#elif AUDIO_PORT_CHANNEL_NUMS == 1
  #if MONO_CHANNEL_SEL == 0
    /*使用L声道*/
    #define AUDIO_PORT_CHANNEL_CONFIG_L  0x01U
    #define AUDIO_PORT_CHANNEL_CONFIG_H  0x00U
  #elif MONO_CHANNEL_SEL == 1
    /*使用R声道*/
    #define AUDIO_PORT_CHANNEL_CONFIG_L  0x02U
    #define AUDIO_PORT_CHANNEL_CONFIG_H  0x00U
  #elif MONO_CHANNEL_SEL == 2
    /*使用默认MONO声道*/
    #define AUDIO_PORT_CHANNEL_CONFIG_L  0x00U
    #define AUDIO_PORT_CHANNEL_CONFIG_H  0x00U    
  #endif
#endif

/*轮询时间间隔*/
#define AUDIO_PORT_FS_BINTERVAL           1U     /**< 1ms一次轮询*/
/*音频传输大小设置*/
#define AUDIO_PORT_PACKET_SZE(frq)       (uint8_t)(((frq * 2U * 2U)/(1000U/AUDIO_PORT_FS_BINTERVAL)) & 0xFFU), \
                                         (uint8_t)((((frq * 2U * 2U)/(1000U/AUDIO_PORT_FS_BINTERVAL)) >> 8) & 0xFFU)
                                         
#define AUDIO_PORT_OUT_SIZE               ((AUDIO_PORT_USBD_AUDIO_FREQ * 2U * 2U)/(1000U/AUDIO_PORT_FS_BINTERVAL))   /**< 音频发送大小Byte*/                                         
#define AUDIO_PORT_BUF_SIZE               AUDIO_PORT_OUT_SIZE*4   /**< 音频缓冲区大小 大于3的倍数*/
/** Private includes ---------------------------------------------------------*/

/** Use C compiler -----------------------------------------------------------*/
#ifdef __cplusplus ///<use C compiler
extern "C" {
#endif
/** Private defines ----------------------------------------------------------*/

/** Exported typedefines -----------------------------------------------------*/

/** Exported constants -------------------------------------------------------*/


/** Exported variables -------------------------------------------------------*/
/** Exported functions prototypes --------------------------------------------*/

/*向USB缓冲区数据加入数据*/
void USB_Audio_Port_Put_Data(const int16_t *Left_Audio, const int16_t *Right_Audio);
/*初始化音频输出端点*/
uint8_t USB_Audio_Port_EP_IN_Init(void *xpdev, uint8_t cfgidx);
/*初始化音频输入端点*/
uint8_t USB_Audio_Port_EP_OUT_Init(void *xpdev, uint8_t cfgidx);
/*反初始化音频输出端点*/
uint8_t USB_Audio_Port_EP_IN_DeInit(void *xpdev, uint8_t cfgidx);
/*反初始化音频输入端点*/
uint8_t USB_Audio_Port_EP_OUT_DeInit(void *xpdev, uint8_t cfgidx);
/*USB缓冲区数据发送至HOST*/
uint8_t USB_Audio_Port_DataIn(void *xpdev, uint8_t epnum);
/*USB缓冲区数据接收来自HOST*/
uint8_t USB_Audio_Port_DataOut(void *xpdev, uint8_t epnum);

#ifdef __cplusplus ///<end extern c
}
#endif
#endif
/******************************** End of file *********************************/

如何使用

1、用usb_audio.c和对应头文件替换你原先的文件
2、工程添加USB_Audio_Port.cUSB_Audio_Port.h,环形缓冲区
3、调用接口添加新音频到缓冲区即可USB_Audio_Port_Put_Data

参考引用

https://blog.csdn.net/xiaowanbiao123/article/details/112611264#comments_15318445
https://my.oschina.net/u/2007478/blog/1204300

标签:haudio,USB,麦克风,uint8,STM32,USBD,pdev,AUDIO
来源: https://blog.csdn.net/weixin_42892101/article/details/116148454