# UVC 与视差

本示例演示如何将您的OAK设备用作UVC网络摄像头。UVC功能允许您在诸如OpenCV的cv2.VideoCapture()、原生相机应用等程序中将OAK设备作为常规网络摄像头使用。

### 工作原理：

[StereoDepth](https://docs.luxonis.com/software/depthai-components/nodes/stereo_depth.md)节点以UINT8格式输出图像数据。然而，[UVC](https://docs.luxonis.com/software/depthai-components/nodes/uvc.md)节点期望接收NV12格式的数据。为了桥接这一差异，使用一个中间节点[ImageManip](https://docs.luxonis.com/software/depthai-components/nodes/image_manip.md)将MonoCamera节点的GRAY8输出转换为NV12格式，然后传递给UVC节点进行流式传输。
这不适用于深度输出，因为深度是UINT16格式，无法转换为NV12。

如果启用亚像素视差功能，此示例将无法工作，因为该功能同样输出UINT16格式。

### 类似示例：

 * [UVC 与彩色相机](https://docs.luxonis.com/software/depthai/examples/uvc_rgb.md)
 * [UVC 与单目相机](https://docs.luxonis.com/software/depthai/examples/uvc_mono.md)

## 设置

请运行[安装脚本](https://github.com/luxonis/depthai-python/blob/main/examples/install_requirements.py)以下载所有必需的依赖项。请注意，此脚本必须在 git
上下文中运行，因此您需要先下载 [depthai-python](https://github.com/luxonis/depthai-python) 仓库，然后运行该脚本。

```bash
git clone https://github.com/luxonis/depthai-python.git
cd depthai-python/examples
python3 install_requirements.py
```

更多信息，请参考[安装指南](https://docs.luxonis.com/software/depthai/manual-install.md)。

## 用于测试的代码

```python
import cv2

# 初始化VideoCapture对象，使用默认相机（相机索引0为网络摄像头）
cap = cv2.VideoCapture(1)

# 检查相机是否成功打开
if not cap.isOpened():
    print("错误：无法打开相机。")
    exit()

# 循环持续从相机获取帧
while True:
    ret, frame = cap.read()

    if not ret:
        print("错误：无法读取帧。")
        break

    cv2.imshow('视频流', frame)

    if cv2.waitKey(1) & 0xFF == ord('q'):
        break

cap.release()
cv2.destroyAllWindows()
```

## 源代码

#### Python

```python
#!/usr/bin/env python3

import time

import depthai as dai

pipeline = dai.Pipeline()

# Define a source - two mono (grayscale) cameras
mono_left = pipeline.createMonoCamera()
mono_right = pipeline.createMonoCamera()

mono_left.setResolution(dai.MonoCameraProperties.SensorResolution.THE_720_P)
mono_left.setBoardSocket(dai.CameraBoardSocket.CAM_B)

mono_right.setResolution(dai.MonoCameraProperties.SensorResolution.THE_720_P)
mono_right.setBoardSocket(dai.CameraBoardSocket.CAM_C)

# Create stereo depth
stereo = pipeline.createStereoDepth()
stereo.initialConfig.setConfidenceThreshold(255)
stereo.setLeftRightCheck(True)
# 0.190 values, better for visualization
stereo.setExtendedDisparity(True)

# Create an UVC (USB Video Class) output node
uvc = pipeline.createUVC()

# Manip for frame type conversion
manip = pipeline.createImageManip()
manip.initialConfig.setResize(1280, 720)
manip.initialConfig.setFrameType(dai.RawImgFrame.Type.NV12)
manip.initialConfig.setColormap(dai.Colormap.STEREO_TURBO, stereo.initialConfig.getMaxDisparity())
manip.setMaxOutputFrameSize(int(1280*720*1.5))

# Linking
mono_left.out.link(stereo.left)
mono_right.out.link(stereo.right)
stereo.disparity.link(manip.inputImage)
manip.out.link(uvc.input)

# Note: if the pipeline is sent later to device (using startPipeline()),
# it is important to pass the device config separately when creating the device
config = dai.Device.Config()
config.board.uvc = dai.BoardConfig.UVC(1280, 720)
config.board.uvc.frameType = dai.ImgFrame.Type.NV12
# config.board.uvc.cameraName = "My Custom Cam"
pipeline.setBoardConfig(config.board)

# Standard UVC load with depthai
with dai.Device(pipeline) as device:
    # Dot projector
    device.setIrLaserDotProjectorBrightness(765)
    print("\nDevice started, please keep this process running")
    print("and open an UVC viewer to check the camera stream.")
    print("\nTo close: Ctrl+C")

    # Doing nothing here, just keeping the host feeding the watchdog
    while True:
        try:
            time.sleep(0.1)
        except KeyboardInterrupt:
            break
```

## 管道

### examples/uvc_disparity.pipeline.json

```json
{
  "pipeline": {
    "connections": [
      {
        "node1Id": 0,
        "node1Output": "out",
        "node1OutputGroup": "",
        "node2Id": 2,
        "node2Input": "left",
        "node2InputGroup": ""
      },
      {
        "node1Id": 1,
        "node1Output": "out",
        "node1OutputGroup": "",
        "node2Id": 2,
        "node2Input": "right",
        "node2InputGroup": ""
      },
      {
        "node1Id": 2,
        "node1Output": "disparity",
        "node1OutputGroup": "",
        "node2Id": 4,
        "node2Input": "inputImage",
        "node2InputGroup": ""
      },
      {
        "node1Id": 4,
        "node1Output": "out",
        "node1OutputGroup": "",
        "node2Id": 3,
        "node2Input": "in",
        "node2InputGroup": ""
      }
    ],
    "globalProperties": {
      "calibData": null,
      "cameraTuningBlobSize": null,
      "cameraTuningBlobUri": "",
      "leonCssFrequencyHz": 700000000.0,
      "leonMssFrequencyHz": 700000000.0,
      "pipelineName": null,
      "pipelineVersion": null,
      "sippBufferSize": 18432,
      "sippDmaBufferSize": 16384,
      "xlinkChunkSize": -1
    },
    "nodes": [
      [
        0,
        {
          "id": 0,
          "ioInfo": [
            [
              [
                "",
                "inputControl"
              ],
              {
                "blocking": true,
                "group": "",
                "id": 1,
                "name": "inputControl",
                "queueSize": 8,
                "type": 3,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "out"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 2,
                "name": "out",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "raw"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 3,
                "name": "raw",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "frameEvent"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 4,
                "name": "frameEvent",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ]
          ],
          "name": "MonoCamera",
          "properties": {
            "boardSocket": 1,
            "cameraName": "",
            "fps": 30.0,
            "imageOrientation": -1,
            "initialControl": {
              "aeLockMode": false,
              "aeMaxExposureTimeUs": 0,
              "aeRegion": {
                "height": 0,
                "priority": 0,
                "width": 0,
                "x": 0,
                "y": 0
              },
              "afRegion": {
                "height": 0,
                "priority": 0,
                "width": 0,
                "x": 0,
                "y": 0
              },
              "antiBandingMode": 0,
              "autoFocusMode": 3,
              "awbLockMode": false,
              "awbMode": 0,
              "brightness": 0,
              "captureIntent": 0,
              "chromaDenoise": 0,
              "cmdMask": 0,
              "contrast": 0,
              "controlMode": 0,
              "effectMode": 0,
              "expCompensation": 0,
              "expManual": {
                "exposureTimeUs": 0,
                "frameDurationUs": 0,
                "sensitivityIso": 0
              },
              "frameSyncMode": 0,
              "lensPosAutoInfinity": 0,
              "lensPosAutoMacro": 0,
              "lensPosition": 0,
              "lensPositionRaw": 0.0,
              "lowPowerNumFramesBurst": 0,
              "lowPowerNumFramesDiscard": 0,
              "lumaDenoise": 0,
              "saturation": 0,
              "sceneMode": 0,
              "sharpness": 0,
              "strobeConfig": {
                "activeLevel": 0,
                "enable": 0,
                "gpioNumber": 0
              },
              "strobeTimings": {
                "durationUs": 0,
                "exposureBeginOffsetUs": 0,
                "exposureEndOffsetUs": 0
              },
              "wbColorTemp": 0
            },
            "isp3aFps": 0,
            "numFramesPool": 3,
            "numFramesPoolRaw": 3,
            "rawPacked": null,
            "resolution": 0
          }
        }
      ],
      [
        1,
        {
          "id": 1,
          "ioInfo": [
            [
              [
                "",
                "inputControl"
              ],
              {
                "blocking": true,
                "group": "",
                "id": 5,
                "name": "inputControl",
                "queueSize": 8,
                "type": 3,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "out"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 6,
                "name": "out",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "raw"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 7,
                "name": "raw",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "frameEvent"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 8,
                "name": "frameEvent",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ]
          ],
          "name": "MonoCamera",
          "properties": {
            "boardSocket": 2,
            "cameraName": "",
            "fps": 30.0,
            "imageOrientation": -1,
            "initialControl": {
              "aeLockMode": false,
              "aeMaxExposureTimeUs": 0,
              "aeRegion": {
                "height": 0,
                "priority": 0,
                "width": 0,
                "x": 0,
                "y": 0
              },
              "afRegion": {
                "height": 0,
                "priority": 0,
                "width": 0,
                "x": 0,
                "y": 0
              },
              "antiBandingMode": 0,
              "autoFocusMode": 3,
              "awbLockMode": false,
              "awbMode": 0,
              "brightness": 0,
              "captureIntent": 0,
              "chromaDenoise": 0,
              "cmdMask": 0,
              "contrast": 0,
              "controlMode": 0,
              "effectMode": 0,
              "expCompensation": 0,
              "expManual": {
                "exposureTimeUs": 0,
                "frameDurationUs": 0,
                "sensitivityIso": 0
              },
              "frameSyncMode": 0,
              "lensPosAutoInfinity": 0,
              "lensPosAutoMacro": 0,
              "lensPosition": 0,
              "lensPositionRaw": 0.0,
              "lowPowerNumFramesBurst": 0,
              "lowPowerNumFramesDiscard": 0,
              "lumaDenoise": 0,
              "saturation": 0,
              "sceneMode": 0,
              "sharpness": 0,
              "strobeConfig": {
                "activeLevel": 0,
                "enable": 0,
                "gpioNumber": 0
              },
              "strobeTimings": {
                "durationUs": 0,
                "exposureBeginOffsetUs": 0,
                "exposureEndOffsetUs": 0
              },
              "wbColorTemp": 0
            },
            "isp3aFps": 0,
            "numFramesPool": 3,
            "numFramesPoolRaw": 3,
            "rawPacked": null,
            "resolution": 0
          }
        }
      ],
      [
        2,
        {
          "id": 2,
          "ioInfo": [
            [
              [
                "",
                "inputConfig"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 9,
                "name": "inputConfig",
                "queueSize": 4,
                "type": 3,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "left"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 10,
                "name": "left",
                "queueSize": 8,
                "type": 3,
                "waitForMessage": true
              }
            ],
            [
              [
                "",
                "debugExtDispLrCheckIt1"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 22,
                "name": "debugExtDispLrCheckIt1",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "right"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 11,
                "name": "right",
                "queueSize": 8,
                "type": 3,
                "waitForMessage": true
              }
            ],
            [
              [
                "",
                "syncedLeft"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 12,
                "name": "syncedLeft",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "depth"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 13,
                "name": "depth",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "disparity"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 14,
                "name": "disparity",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "syncedRight"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 15,
                "name": "syncedRight",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "debugDispCostDump"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 20,
                "name": "debugDispCostDump",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "debugDispLrCheckIt2"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 21,
                "name": "debugDispLrCheckIt2",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "rectifiedLeft"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 16,
                "name": "rectifiedLeft",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "debugExtDispLrCheckIt2"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 23,
                "name": "debugExtDispLrCheckIt2",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "rectifiedRight"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 17,
                "name": "rectifiedRight",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "confidenceMap"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 24,
                "name": "confidenceMap",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "outConfig"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 18,
                "name": "outConfig",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "debugDispLrCheckIt1"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 19,
                "name": "debugDispLrCheckIt1",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ]
          ],
          "name": "StereoDepth",
          "properties": {
            "alphaScaling": null,
            "baseline": null,
            "depthAlignCamera": -1,
            "depthAlignmentUseSpecTranslation": null,
            "disparityToDepthUseSpecTranslation": null,
            "enableRectification": true,
            "enableRuntimeStereoModeSwitch": false,
            "focalLength": null,
            "focalLengthFromCalibration": true,
            "height": null,
            "initialConfig": {
              "algorithmControl": {
                "centerAlignmentShiftFactor": null,
                "customDepthUnitMultiplier": 1000.0,
                "depthAlign": 0,
                "depthUnit": 2,
                "disparityShift": 0,
                "enableExtended": true,
                "enableLeftRightCheck": true,
                "enableSubpixel": false,
                "leftRightCheckThreshold": 10,
                "numInvalidateEdgePixels": 0,
                "subpixelFractionalBits": 3
              },
              "censusTransform": {
                "enableMeanMode": true,
                "kernelMask": 0,
                "kernelSize": -1,
                "threshold": 0
              },
              "costAggregation": {
                "divisionFactor": 1,
                "horizontalPenaltyCostP1": 250,
                "horizontalPenaltyCostP2": 500,
                "verticalPenaltyCostP1": 250,
                "verticalPenaltyCostP2": 500
              },
              "costMatching": {
                "confidenceThreshold": 255,
                "disparityWidth": 1,
                "enableCompanding": false,
                "invalidDisparityValue": 0,
                "linearEquationParameters": {
                  "alpha": 0,
                  "beta": 2,
                  "threshold": 127
                }
              },
              "postProcessing": {
                "bilateralSigmaValue": 0,
                "brightnessFilter": {
                  "maxBrightness": 256,
                  "minBrightness": 0
                },
                "decimationFilter": {
                  "decimationFactor": 1,
                  "decimationMode": 0
                },
                "median": 5,
                "spatialFilter": {
                  "alpha": 0.5,
                  "delta": 0,
                  "enable": false,
                  "holeFillingRadius": 2,
                  "numIterations": 1
                },
                "speckleFilter": {
                  "enable": false,
                  "speckleRange": 50
                },
                "temporalFilter": {
                  "alpha": 0.4000000059604645,
                  "delta": 0,
                  "enable": false,
                  "persistencyMode": 3
                },
                "thresholdFilter": {
                  "maxRange": 65535,
                  "minRange": 0
                }
              }
            },
            "mesh": {
              "meshLeftUri": "",
              "meshRightUri": "",
              "meshSize": null,
              "stepHeight": 16,
              "stepWidth": 16
            },
            "numFramesPool": 3,
            "numPostProcessingMemorySlices": -1,
            "numPostProcessingShaves": -1,
            "outHeight": null,
            "outKeepAspectRatio": true,
            "outWidth": null,
            "rectificationUseSpecTranslation": null,
            "rectifyEdgeFillColor": 0,
            "useHomographyRectification": null,
            "width": null
          }
        }
      ],
      [
        3,
        {
          "id": 3,
          "ioInfo": [
            [
              [
                "",
                "in"
              ],
              {
                "blocking": true,
                "group": "",
                "id": 25,
                "name": "in",
                "queueSize": 8,
                "type": 3,
                "waitForMessage": true
              }
            ]
          ],
          "name": "UVC",
          "properties": {
            "gpioInit": [],
            "gpioStreamOff": [],
            "gpioStreamOn": []
          }
        }
      ],
      [
        4,
        {
          "id": 4,
          "ioInfo": [
            [
              [
                "",
                "inputConfig"
              ],
              {
                "blocking": true,
                "group": "",
                "id": 26,
                "name": "inputConfig",
                "queueSize": 8,
                "type": 3,
                "waitForMessage": false
              }
            ],
            [
              [
                "",
                "inputImage"
              ],
              {
                "blocking": true,
                "group": "",
                "id": 27,
                "name": "inputImage",
                "queueSize": 8,
                "type": 3,
                "waitForMessage": true
              }
            ],
            [
              [
                "",
                "out"
              ],
              {
                "blocking": false,
                "group": "",
                "id": 28,
                "name": "out",
                "queueSize": 8,
                "type": 0,
                "waitForMessage": false
              }
            ]
          ],
          "name": "ImageManip",
          "properties": {
            "initialConfig": {
              "cropConfig": {
                "cropRatio": 1.0,
                "cropRect": {
                  "xmax": 0.0,
                  "xmin": 0.0,
                  "ymax": 0.0,
                  "ymin": 0.0
                },
                "cropRotatedRect": {
                  "angle": 0.0,
                  "center": {
                    "x": 0.0,
                    "y": 0.0
                  },
                  "size": {
                    "height": 0.0,
                    "width": 0.0
                  }
                },
                "enableCenterCropRectangle": false,
                "enableRotatedRect": false,
                "normalizedCoords": true,
                "widthHeightAspectRatio": 1.0
              },
              "enableCrop": false,
              "enableFormat": true,
              "enableResize": true,
              "formatConfig": {
                "colormap": 3,
                "colormapMax": 190,
                "colormapMin": 0,
                "flipHorizontal": false,
                "flipVertical": false,
                "type": 22
              },
              "interpolation": -1,
              "resizeConfig": {
                "bgBlue": 0,
                "bgGreen": 0,
                "bgRed": 0,
                "enableRotation": false,
                "enableWarp4pt": false,
                "enableWarpMatrix": false,
                "height": 720,
                "keepAspectRatio": true,
                "lockAspectRatioFill": false,
                "normalizedCoords": true,
                "rotationAngleDeg": 0.0,
                "warpBorderReplicate": false,
                "warpFourPoints": [],
                "warpMatrix3x3": [],
                "width": 1280
              },
              "reusePreviousImage": false,
              "skipCurrentImage": false
            },
            "meshHeight": 0,
            "meshUri": "",
            "meshWidth": 0,
            "numFramesPool": 4,
            "outputFrameSize": 1382400
          }
        }
      ]
    ]
  }
}
```

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