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ON THIS PAGE

  • DepthAI V3 Porting Guide
  • What's new in the v3 API
  • Minimal changes required
  • Quick port: simple RGB stream example
  • Porting
  • Porting the old
  • v2 example
  • v3 equivalent:

DepthAI V3 Porting Guide

This document describes the changes between the v2 and v3 APIs of DepthAI and how to migrate existing code.

What's new in the v3 API

  • No more explicit XLink nodes - the XLink “bridges” are created automatically.
  • Host nodes - nodes that run on the host machine now work cleanly with device-side nodes.
  • Custom host nodes - users can create custom nodes that run on the host machine
    • Both ThreadedHostNode and HostNode are supported.
    • ThreadedHostNode works similarly to ScriptNode; the user specifies a run function that executes in a separate thread.
    • HostNode exposes an input map inputs whose entries are implicitly synced.
    • Available in both Python and C++.
  • Record-and-replay nodes.
  • Pipeline now has a live device that can be queried during pipeline creation.
  • Support for the new Model Zoo.
  • ImageManip has a refreshed API with better-defined behaviour.
  • ColorCamera and MonoCamera are deprecated in favour of the new Camera node.

Minimal changes required

  • Remove the explicit creation of dai.Device (unless you intentionally pass a live device handle via the pipeline constructor – a rare edge case).
  • Remove explicit XLink nodes.
  • Replace dai.Device(pipeline) with pipeline.start().
  • Replace any .getOutputQueue() calls with output.createOutputQueue().
  • Replace any .getInputQueue() calls with input.createInputQueue().

Quick port: simple RGB stream example

Below, the old v2 code is commented with # ORIG and the new code with # NEW.
Python
1#!/usr/bin/env python3
2
3import cv2
4import depthai as dai
5
6# Create pipeline
7pipeline = dai.Pipeline()
8
9# Define source and output
10camRgb = pipeline.create(dai.node.ColorCamera)
11
12# ORIG – explicit XLink removed in v3
13# xoutVideo = pipeline.create(dai.node.XLinkOut)
14# xoutVideo.setStreamName("video")
15
16# Properties
17camRgb.setBoardSocket(dai.CameraBoardSocket.CAM_A)
18camRgb.setResolution(dai.ColorCameraProperties.SensorResolution.THE_1080_P)
19camRgb.setVideoSize(1920, 1080)
20
21# Linking
22# ORIG
23# camRgb.video.link(xoutVideo.input)
24# NEW – output queue straight from the node
25videoQueue = camRgb.video.createOutputQueue()
26
27# ORIG – entire `with dai.Device` block removed
28# with dai.Device(pipeline) as device:
29#   video = device.getOutputQueue(name="video", maxSize=1, blocking=False)
30#   while True:
31# NEW – start the pipeline
32pipeline.start()
33while pipeline.isRunning():
34    videoIn = videoQueue.get()  # blocking
35    cv2.imshow("video", videoIn.getCvFrame())
36    if cv2.waitKey(1) == ord('q'):
37        break
This runs on RVC2 devices. Note that ColorCamera/MonoCamera nodes are deprecated on RVC4; see the next section for using Camera instead.

Porting ColorCamera / MonoCamera usage to Camera

The new Camera node can expose as many outputs as you request.
Python
1camRgb = pipeline.create(dai.node.ColorCamera)
2camRgb.setPreviewSize(300, 300)
3camRgb.setInterleaved(False)
4camRgb.setColorOrder(dai.ColorCameraProperties.ColorOrder.RGB)
5outputQueue = camRgb.preview.createOutputQueue()
turns into
Python
1camRgb = pipeline.create(dai.node.Camera).build()  # don’t forget .build()
2cameraOutput = camRgb.requestOutput((300, 300), type=dai.ImgFrame.Type.RGB888p)  # replaces .preview
3outputQueue = cameraOutput.createOutputQueue()
Request multiple outputs simply by calling requestOutput again. For full‑resolution use‑cases that previously used .isp, call requestFullResolutionOutput() instead.For former MonoCamera pipelines, replace the .out output with requestOutput, e.g.
Python
1mono = pipeline.create(dai.node.Camera).build()
2monoOut = mono.requestOutput((1280, 720), type=dai.ImgFrame.Type.GRAY8)

Porting the old ImageManip to the new API

The new API tracks every transformation in sequence and separates how the final image is resized. See the official documentation for full details.

v2 example

Python
1#!/usr/bin/env python3
2
3import cv2
4import depthai as dai
5
6# Create pipeline
7pipeline = dai.Pipeline()
8
9camRgb = pipeline.create(dai.node.ColorCamera)
10camRgb.setPreviewSize(1000, 500)
11camRgb.setInterleaved(False)
12maxFrameSize = camRgb.getPreviewHeight() * camRgb.getPreviewWidth() * 3
13
14# In this example we use 2 imageManips for splitting the original 1000x500
15# preview frame into 2 500x500 frames
16manip1 = pipeline.create(dai.node.ImageManip)
17manip1.initialConfig.setCropRect(0, 0, 0.5, 1)
18manip1.setMaxOutputFrameSize(maxFrameSize)
19camRgb.preview.link(manip1.inputImage)
20
21manip2 = pipeline.create(dai.node.ImageManip)
22manip2.initialConfig.setCropRect(0.5, 0, 1, 1)
23manip2.setMaxOutputFrameSize(maxFrameSize)
24camRgb.preview.link(manip2.inputImage)
25
26xout1 = pipeline.create(dai.node.XLinkOut)
27xout1.setStreamName('out1')
28manip1.out.link(xout1.input)
29
30xout2 = pipeline.create(dai.node.XLinkOut)
31xout2.setStreamName('out2')
32manip2.out.link(xout2.input)
33
34# Connect to device and start pipeline
35with dai.Device(pipeline) as device:
36    # Output queue will be used to get the rgb frames from the output defined above
37    q1 = device.getOutputQueue(name="out1", maxSize=4, blocking=False)
38    q2 = device.getOutputQueue(name="out2", maxSize=4, blocking=False)
39
40    while True:
41        if q1.has():
42            cv2.imshow("Tile 1", q1.get().getCvFrame())
43
44        if q2.has():
45            cv2.imshow("Tile 2", q2.get().getCvFrame())
46
47        if cv2.waitKey(1) == ord('q'):
48            break

v3 equivalent:

Python
1#!/usr/bin/env python3
2
3import cv2
4import depthai as dai
5
6# Create pipeline
7pipeline = dai.Pipeline()
8
9camRgb = pipeline.create(dai.node.Camera).build()
10preview = camRgb.requestOutput((1000, 500), type=dai.ImgFrame.Type.RGB888p)
11
12# In this example we use 2 imageManips for splitting the original 1000x500
13# preview frame into 2 500x500 frames
14manip1 = pipeline.create(dai.node.ImageManip)
15manip1.initialConfig.addCrop(0, 0, 500, 500)
16preview.link(manip1.inputImage)
17
18manip2 = pipeline.create(dai.node.ImageManip)
19manip2.initialConfig.addCrop(500, 0, 500, 500)
20preview.link(manip2.inputImage)
21
22q1 = manip1.out.createOutputQueue()
23q2 = manip2.out.createOutputQueue()
24
25pipeline.start()
26with pipeline:
27    while pipeline.isRunning():
28        if q1.has():
29            cv2.imshow("Tile 1", q1.get().getCvFrame())
30
31        if q2.has():
32            cv2.imshow("Tile 2", q2.get().getCvFrame())
33
34        if cv2.waitKey(1) == ord('q'):
35            break