December 2021 Summaries

In this tutorial, we will develop a web application that supports speech-to-text transcription and translation using JavaScript's Web Speech API, the Agora Web SDK, the Agora RTM SDK, and the Google Cloud Translation API. The aim is to create a real-time translation service for video calls without relying on interpreters or revealing confidential information. We will build upon an existing project called Building Your Own Transcription Service Within a Video Call Web App. Prerequisites include basic knowledge of JavaScript, JQuery, Bootstrap, and Font Awesome, as well as Agora Developer Account, Google Cloud account, and understanding how to make requests and receive responses from REST APIs. The tutorial guides users through setting up the project, adding real-time translation functionality, and testing the application using multiple browser tabs. The final code is available on GitHub, and a demo can be viewed online.

Agora has released Voice and Video SDK v3.6.0 for native mobile and desktop platforms on December 7, 2021. The update includes new features such as following system default audio settings automatically on macOS and Windows, improved CDN live streaming with optimized API design and handling of network issues, and bug fixes related to audio issues, feed freeze, multiple screen sharers, remote user screen flicker, and Bluetooth detection. For more information about the updates for specific platforms, visit Agora's downloads page.

In this tutorial, we learn how to mute audio and adjust volume during a video call using the Agora SDK in an Android application. The prerequisites include an Agora developer account, knowledge of creating live-streaming Android applications with Agora, basic Android development skills, Android Studio, and an Android device. We start by adding dependencies in Gradle and permissions in the Manifest.xml file. Then we create an RtcEngine instance and set up the video call profile. To adjust volume during a video call, we use a SeekBar object and implement its methods. Finally, to mute audio, we use the adjustPlaybackSignalVolume() and adjustAudioMixingVolume() methods. The tutorial also provides guidance on integrating these features with an Agora Video Call SDK and testing the app demo.

Senior Architect Ben Weekes at Agora has developed a solution for displaying large video call grids in a browser environment, which was previously believed to be impossible due to varying CPU/GPU capacity across devices. The technology could be useful for virtual events and company meetings where the energy of a large group contributes to the experience. The main challenges include processor load, lack of hardware information from browsers, and changing network conditions. To tackle these issues, Weekes ensures that only necessary pixels are delivered, monitors volatility in render frame rates and outgoing frame rates, and stays ahead of changing network conditions by monitoring real-time estimations of available downlink bandwidth and NACK rate. The open-source algorithm for this large WebRTC grid experiment is available on GitHub through Agora's Multichannel SDK.

This article provides a step-by-step guide on how to implement a voice-changing feature in an Android application using the Agora Android Video Call SDK and Voicemod extension from Extensions Marketplace. The process involves setting up a basic video calling app, activating the Voicemod extension, linking it to the local project, making necessary code modifications, and running the app. The article also covers prerequisites needed for the project setup, such as basic knowledge of Java/Kotlin and Android SDK, Android Studio, Agora Developer Account, and more.

In this tutorial, we learn how to implement a feature that highlights a speaker in a call using the Agora Flutter SDK. The prerequisites include basic knowledge of Flutter and an Agora Developer Account. We create a dart file with the name home_page.dart for taking the channel name as input from the user, and another dart file with the name call_page.dart for showing the surface views in grid view and highlighting the speaker in the call. The tutorial covers various methods such as initialize(), enableVideo(), setChannelProfile(), enableAudioVolumeIndication(), _addAgoraEventHandler(), error(), joinChannelSuccess(), leaveChannel(), userJoined(), userOffline(), audioVolumeIndication(), activeSpeaker(), and more. We also learn how to update the UI based on the _userMap data, add user interactive buttons at the bottom of the screen for ending the call, mic mute/unmute, and switching the camera. Finally, we test the app on a device and conclude by successfully using the Agora Flutter SDK to implement the Flutter video calling app with a feature highlighting the speaking person in a call.

This blog by Prakhar Soni demonstrates how to integrate admin features into a video calling application using Agora RTC and RTM SDKs. The tutorial provides a step-by-step guide on creating a bare-bones React application for adding admin functions to a basic video calling app. It covers the application architecture, data storage, event listeners, and important functions of the components involved. The code base for this tutorial is available on GitHub, and additional features can be found in the official docs.

In this tutorial by Akshat Gupta, an Agora Developer Evangelist Intern, a web application is developed where users can request for role promotion and hosts can accept or decline the requests. The application uses the Agora Web SDK and the Agora RTM SDK to integrate live video streaming capabilities with user interaction features. Users can raise their hand by clicking on a button, which sends a channel message using the Agora RTM SDK. Hosts receive these messages and decide whether to promote or reject the requesting user. The tutorial provides detailed instructions for setting up the project, coding the application, and testing it. The complete code is available on GitHub, along with a demo of the application in action.

In this tutorial by Akshat Gupta, an Agora Developer Evangelist Intern, learn how to fetch tokens from a server and use them to join a video/voice channel in React. The author provides instructions on deploying the token server using Node or GoLang examples and offers a basic understanding of React. The tutorial also covers connecting with tokens, staying connected by handling expired tokens, and implementing the same in Vanilla JavaScript using fetch.

This tutorial teaches developers how to use the Agora SDK to play audio files during a video call on Android devices. The author provides step-by-step instructions, including adding dependencies in Gradle, adding permissions in the Manifest.xml file, creating an instance of RtcEngine, loading and playing audio files, adjusting volume, and stopping or resuming audio playback. The tutorial also explains how to integrate the play audio feature with the Agora Video Call SDK and provides additional resources for further learning.