#!/usr/bin/env python3

"""

This example demonstrates use of queue events to block a thread until a message

arrives to any (of the specified) queue

"""

import cv2

import depthai as dai

# Create pipeline

pipeline = dai.Pipeline()

# Define sources and outputs

camRgb = pipeline.create(dai.node.ColorCamera)

camMono = pipeline.create(dai.node.MonoCamera)

xoutRgb = pipeline.create(dai.node.XLinkOut)

xoutMono = pipeline.create(dai.node.XLinkOut)

xoutRgb.setStreamName("rgb")

xoutMono.setStreamName("mono")

# Properties

camRgb.setInterleaved(True)

camRgb.setPreviewSize(300, 300)

# Linking

camRgb.preview.link(xoutRgb.input)

camMono.out.link(xoutMono.input)

# Connect to device and start pipeline

with dai.Device(pipeline) as device:

# Clear queue events

device.getQueueEvents()

while True:

# Block until a message arrives to any of the specified queues

queueName = device.getQueueEvent(("rgb", "mono"))

# Getting that message from queue with name specified by the event

# Note: number of events doesn't necessarily match number of messages in queues

# because queues can be set to non-blocking (overwriting) behavior

message = device.getOutputQueue(queueName).get()

# Display arrived frames

if type(message) == dai.ImgFrame:

cv2.imshow(queueName, message.getCvFrame())

if cv2.waitKey(1) == ord('q'):

break