UVCCamera向USB设备发送命令

Posted 2022-12-26 柳鲲鹏

改变亮度

• JAVA

UVCCameraHelper.setModelValue()

UVCCameraHandler.setValue()

UVCCamera.setBrightness()

nativeSetBrightness()

• nativeSetBrightness
  

static jint nativeSetBrightness(JNIEnv *env, jobject thiz,
	ID_TYPE id_camera, jint brightness) 

	jint result = JNI_ERR;
	ENTER();
	UVCCamera *camera = reinterpret_cast<UVCCamera *>(id_camera);
	if (LIKELY(camera)) 
		result = camera->setBrightness(brightness);
	
	RETURN(result, jint);

• setBrightness

int UVCCamera::setBrightness(int brightness) 
	ENTER();
	int ret = UVC_ERROR_IO;
	if (mPUSupports & PU_BRIGHTNESS) 
		ret = internalSetCtrlValue(mBrightness, brightness, uvc_get_brightness, uvc_set_brightness);
	
	RETURN(ret, int);

• uvc_set_brightness

uvc_error_t uvc_set_brightness(uvc_device_handle_t *devh, short brightness) 
	uint8_t data[2];
	uvc_error_t ret;

	SHORT_TO_SW(brightness, data);

	ret = libusb_control_transfer(devh->usb_devh, REQ_TYPE_SET, UVC_SET_CUR,
			UVC_PU_BRIGHTNESS_CONTROL << 8,
			devh->info->ctrl_if.processing_unit_descs->request,
			data, sizeof(data), CTRL_TIMEOUT_MILLIS);

	if (LIKELY(ret == sizeof(data)))
		return UVC_SUCCESS;
	else
		return ret;

• libusb_control_transfer

int API_EXPORTED libusb_control_transfer(libusb_device_handle *dev_handle,
	uint8_t bmRequestType, uint8_t bRequest, uint16_t wValue, uint16_t wIndex,
	unsigned char *data, uint16_t wLength, unsigned int timeout)

	struct libusb_transfer *transfer = libusb_alloc_transfer(0);
	unsigned char *buffer;
	int completed = 0;
	int r;

	if (UNLIKELY(!transfer))
		return LIBUSB_ERROR_NO_MEM;

	buffer = (unsigned char*) malloc(LIBUSB_CONTROL_SETUP_SIZE + wLength);
	if (UNLIKELY(!buffer)) 
		libusb_free_transfer(transfer);
		return LIBUSB_ERROR_NO_MEM;
	

	libusb_fill_control_setup(buffer, bmRequestType, bRequest, wValue, wIndex, wLength);
	if ((bmRequestType & LIBUSB_ENDPOINT_DIR_MASK) == LIBUSB_ENDPOINT_OUT)
		memcpy(buffer + LIBUSB_CONTROL_SETUP_SIZE, data, wLength);

	libusb_fill_control_transfer(transfer, dev_handle, buffer,
		sync_transfer_cb, &completed, timeout);
	transfer->flags = LIBUSB_TRANSFER_FREE_BUFFER;
	r = libusb_submit_transfer(transfer);
	if (UNLIKELY(r < 0)) 
		libusb_free_transfer(transfer);
		return r;
	

	sync_transfer_wait_for_completion(transfer);

	if ((bmRequestType & LIBUSB_ENDPOINT_DIR_MASK) == LIBUSB_ENDPOINT_IN)
		memcpy(data, libusb_control_transfer_get_data(transfer),
			transfer->actual_length);


	libusb_free_transfer(transfer);
	return r;

• libusb_submit_transfer

r = usbi_backend.submit_transfer(itransfer);

• op_submit_transfer

LIBUSB_TRANSFER_TYPE_BULK = 2U

submit_bulk_transfer

• submit_bulk_transfer

ioctl