Skip to content

NetGear_Async Examples⚓

 

Using NetGear_Async with WebGear⚓

The complete usage example is as follows:

New in v0.2.2

This example was added in v0.2.2.

Client + WebGear Server⚓

Open a terminal on Client System where you want to display the input frames (and setup WebGear server) received from the Server and execute the following python code:

After running this code, Make sure to open Browser immediately otherwise NetGear_Async will soon exit with TimeoutError. You can also try setting timeout parameter to a higher value to extend this timeout.

Make sure you use different port value for NetGear_Async and WebGear API.

High CPU utilization may occur on Client's end. User discretion is advised.

Note down the IP-address of this system (required at Server's end) by executing the hostname -I command and also replace it in the following code."

# import libraries
from vidgear.gears.asyncio import NetGear_Async
from vidgear.gears.asyncio import WebGear
from vidgear.gears.asyncio.helper import reducer
import uvicorn, asyncio, cv2

# Define NetGear_Async Client at given IP address and define parameters
# !!! change following IP address '192.168.x.xxx' with yours !!!
client = NetGear_Async(
    receive_mode=True,
    pattern=1,
    logging=True,
).launch()

# create your own custom frame producer
async def my_frame_producer():

    # loop over Client's Asynchronous Frame Generator
    async for frame in client.recv_generator():

        # {do something with received frames here}

        # reducer frames size if you want more performance otherwise comment this line
        frame = await reducer(
            frame, percentage=30, interpolation=cv2.INTER_AREA
        )  # reduce frame by 30%

        # handle JPEG encoding
        encodedImage = cv2.imencode(".jpg", frame)[1].tobytes()
        # yield frame in byte format
        yield (b"--frame\r\nContent-Type:image/jpeg\r\n\r\n" + encodedImage + b"\r\n")
        await asyncio.sleep(0)


if __name__ == "__main__":
    # Set event loop to client's
    asyncio.set_event_loop(client.loop)

    # initialize WebGear app without any source
    web = WebGear(logging=True)

    # add your custom frame producer to config with adequate IP address
    web.config["generator"] = my_frame_producer

    # run this app on Uvicorn server at address http://localhost:8000/
    uvicorn.run(web(), host="localhost", port=8000)

    # safely close client
    client.close()

    # close app safely
    web.shutdown()

On successfully running this code, the output stream will be displayed at address http://localhost:8000/ in your Client's Browser.

Server⚓

Now, Open the terminal on another Server System (with a webcam connected to it at index 0), and execute the following python code:

Replace the IP address in the following code with Client's IP address you noted earlier.

# import library
from vidgear.gears.asyncio import NetGear_Async
import cv2, asyncio

# initialize Server without any source
server = NetGear_Async(
    source=None,
    address="192.168.x.xxx",
    port="5454",
    protocol="tcp",
    pattern=1,
    logging=True,
)

# Create a async frame generator as custom source
async def my_frame_generator():

    # !!! define your own video source here !!!
    # Open any video stream such as live webcam
    # video stream on first index(i.e. 0) device
    stream = cv2.VideoCapture(0)

    # loop over stream until its terminated
    while True:

        # read frames
        (grabbed, frame) = stream.read()

        # check if frame empty
        if not grabbed:
            break

        # do something with the frame to be sent here

        # yield frame
        yield frame
        # sleep for sometime
        await asyncio.sleep(0)

    # close stream
    stream.release()


if __name__ == "__main__":
    # set event loop
    asyncio.set_event_loop(server.loop)
    # Add your custom source generator to Server configuration
    server.config["generator"] = my_frame_generator()
    # Launch the Server
    server.launch()
    try:
        # run your main function task until it is complete
        server.loop.run_until_complete(server.task)
    except (KeyboardInterrupt, SystemExit):
        # wait for interrupts
        pass
    finally:
        # finally close the server
        server.close()

 


Last update: October 7, 2021