Background-Substractor-Video-Capturer

Background Substractor Video Capturer

This sample application shows how to use a video capturer being used by a publisher in your application. It is important to note that a custom video capturer always belongs to a given publisher. The video capturer captures video frames from the default video camera, removes its background and provides them to the SDK so they are sent to participants in the session.

This sample builds upon the Publisher Only sample, but with a publisher that uses a backgroung substractor stream video capturer where background subtraction is performed through OpenCV.

You will need a valid Vonage Video API account to build this app. (Note that OpenTok is now the Vonage Video API.)

Setting up your environment

OpenTok SDK

Building this sample application requires having a local installation of the OpenTok Linux SDK.

On Debian-based Linuxes

The OpenTok Linux SDK for x86_64 is available as a Debian package. For Debian we support Debian 11 (Bullseye). We maintain our own Debian repository on packagecloud. Follow these steps to install the packages from our repository.

• Add packagecloud repository:

curl -s https://packagecloud.io/install/repositories/tokbox/debian/script.deb.sh | sudo bash

• Install the OpenTok Linux SDK packages.

sudo apt install libopentok-dev

On non-Debian-based Linuxes

Download the OpenTok SDK from https://tokbox.com/developer/sdks/linux/ and extract it and set the LIBOPENTOK_PATH environment variable to point to the path where you extracted the SDK. For example:

wget https://tokbox.com/downloads/libopentok_linux_llvm_x86_64-2.28.2
tar xvf libopentok_linux_llvm_x86_64-2.28.2
export LIBOPENTOK_PATH=<path_to_SDK>

Other dependencies

Before building the sample application you will need to install the following dependencies

On Debian-based Linuxes

sudo apt install build-essential cmake clang libc++-dev libc++abi-dev \
    pkg-config libasound2 libpulse-dev libsdl2-dev libopencv-dev

On Fedora

sudo dnf groupinstall "Development Tools" "Development Libraries"
sudo dnf install SDL2-devel clang pkg-config libcxx-devel libcxxabi-devel cmake opencv-devel

Building and running the sample app

Once you have installed the dependencies, you can build the sample application. Since it's good practice to create a build folder, let's go ahead and create it in the project directory:

mkdir Background-Substractor-Video-Capturer/build

Copy the config-sample.h file as config.h at Background-Substractor-Video-Capturer/:

cp common/src/config-sample.h  Background-Substractor-Video-Capturer/config.h

Edit the config.h file and add your OpenTok API key, an OpenTok session ID, and token for that session. For test purposes, you can obtain a session ID and token from the project page in your Vonage Video API account. However, in a production application, you will need to dynamically obtain the session ID and token from a web service that uses one of the Vonage Video API server SDKs.

Next, create the building bits using cmake:

cd Background-Substractor-Video-Capturer/build
CC=clang CXX=clang++ cmake ..

Note we are using clang/clang++ compilers.

Use make to build the code:

make

When the background_substractor_video_capturer binary is built, run it:

./background_substractor_video_capturer

You can use the OpenTok Playground to connect to the OpenTok session in a web browser, view the stream published by the Background Substractor Video Capturer app, and publish a stream that the app can subscribe to.

You can end the sample application by typing Control + C in the console.

Next steps

See the Vonage Video API developer center for more information on the OpenTok Linux SDK.