USB Device UVC
usb_device_uvc 是用于 ESP32-S2/ESP32-S3 的 USB UVC 设备驱动程序，它支持将 JPEG 帧流传输到 USB 主机。用户可以通过回调函数将相机或任何设备包装成符合 UVC 标准的设备。
特性：
支持通过 UVC 流接口进行视频流传输
支持
Isochronous和Bulk模式支持多种分辨率和帧率
将组件添加到项目
请使用组件管理器命令 add-dependency 将 usb_device_uvc 添加到项目的依赖项中，在 CMake 步骤中会自动下载该组件
idf.py add-dependency "espressif/usb_device_uvc=*"
用户参考
该组件仅提供一个 API 用于配置 UVC 设备。由于驱动基于 TinyUSB 堆栈，因此未提供 deinit API。
#include "usb_device_uvc.h"
static esp_err_t camera_start_cb(uvc_format_t format, int width, int height, int rate, void *cb_ctx)
{
// 用户可以在这里初始化相机
// 相机应根据给定的格式、宽度、高度和帧率进行初始化
return ESP_OK;
}
static void camera_stop_cb(void *cb_ctx)
{
// 用户代码
return;
}
static uvc_fb_t* camera_fb_get_cb(void *cb_ctx)
{
// 用户代码以返回图像帧缓冲区
// 相机应准备下一帧，并返回帧缓冲区
return uvc_fb;
}
static void camera_fb_return_cb(uvc_fb_t *fb, void *cb_ctx)
{
// 在帧缓冲区被复制到传输缓冲区后返回
// 用户代码以回收帧缓冲区
return;
}
// 缓冲区用于存储要发送到主机的数据
const size_t buff_size = 30 * 1024;
uint8_t *uvc_buffer = (uint8_t *)heap_caps_malloc(buff_size, MALLOC_CAP_DEFAULT);
assert(uvc_buffer != NULL);
uvc_device_config_t config = {
.uvc_buffer = uvc_buffer,
.uvc_buffer_size = 40 * 1024,
.start_cb = camera_start_cb,
.fb_get_cb = camera_fb_get_cb,
.fb_return_cb = camera_fb_return_cb,
.stop_cb = camera_stop_cb,
.cb_ctx = NULL,
};
ESP_ERROR_CHECK(uvc_device_config(0, &config));
ESP_ERROR_CHECK(uvc_device_init());
示例
API 参考
Header File
Functions
-
esp_err_t uvc_device_config(int index, uvc_device_config_t *config)
Configure the UVC device by uvc device number.
- 参数
index – UVC device index number [0,1]
config – Configuration for the UVC device
- 返回
ESP_OK on success ESP_ERR_INVALID_ARG if the configuration is invalid ESP_FAIL if the UVC device could not be initialized
-
esp_err_t uvc_device_init(void)
Initialize the UVC device, after this function is called, the UVC device will be visible to the host and the host can open the UVC device with the specific format and resolution.
- 返回
ESP_OK on success ESP_FAIL if the UVC device could not be initialized
Structures
-
struct uvc_fb_t
Frame buffer structure.
Public Members
-
uint8_t *buf
Pointer to the frame data
-
size_t len
Length of the buffer in bytes
-
size_t width
Width of the image frame in pixels
-
size_t height
Height of the image frame in pixels
-
uvc_format_t format
Format of the frame data
-
struct timeval timestamp
Timestamp since boot of the frame
-
uint8_t *buf
-
struct uvc_device_config_t
Configuration for the UVC device.
Public Members
-
uint8_t *uvc_buffer
UVC transfer buffer
-
uint32_t uvc_buffer_size
UVC transfer buffer size, should bigger than one frame size
-
uvc_input_start_cb_t start_cb
callback function of host open the UVC device with the specific format and resolution
-
uvc_input_fb_get_cb_t fb_get_cb
callback function of host request a new frame buffer
-
uvc_input_fb_return_cb_t fb_return_cb
callback function of the frame buffer is no longer used
-
uvc_input_stop_cb_t stop_cb
callback function of host close the UVC device
-
void *cb_ctx
callback context, for user specific usage
-
uint8_t *uvc_buffer
Type Definitions
-
typedef esp_err_t (*uvc_input_start_cb_t)(uvc_format_t format, int width, int height, int rate, void *cb_ctx)
type of callback function when host open the UVC device
-
typedef uvc_fb_t *(*uvc_input_fb_get_cb_t)(void *cb_ctx)
type of callback function when host request a new frame buffer
-
typedef void (*uvc_input_fb_return_cb_t)(uvc_fb_t *fb, void *cb_ctx)
type of callback function when the frame buffer is no longer used
-
typedef void (*uvc_input_stop_cb_t)(void *cb_ctx)
type of callback function when host close the UVC device