Create a Twilio Programmable Video flutter package for Android

Problem to solve

To be able to use Twilio Programmable Video in Flutter a package should be created since there isn't an existing package already.

Use-cases

• Video calling on Android

Proposal

Create a Flutter package that wraps the SDK and exposes some of it's API to be able to create the first PoC example application.

Links/references

• Twilio Programmable Video - Android docs
• Video Tuorials
• Android Quickstart Example

Tasks

• Create documentation on howto use within the README.md
• Add the latest Twilio Programmable Video Android SDK to the Flutter package: https://www.twilio.com/docs/video/android-getting-started-v5#gradle
• Make sure to add the proguard rules as well (add to readme): https://www.twilio.com/docs/video/android-getting-started-v5#proguard
• Make sure to set the minimum API level to 16 or higher: https://www.twilio.com/docs/video/android-getting-started-v5#supported-devices
• Create methods for:
  • Connect to a room
  • Join a room
  • Publishing microphone and camera
    • Audio only
    • Video only
    • Add audio or video to a session from above
    • Directly start with audio/video
    • https://www.twilio.com/docs/video/android-getting-started-v5#display-a-camera-preview
  • Setting up listeners
    • Handle Connected Participants
    • Handle Participant Connection Events
    • Room reconnection
  • Display a Remote Participant's Video
  • Switching camera
  • Mute/unmute microphone
  • Mute/unmute camera
  • Disconnect from a Room

Audio improvements / notices when tested on Android

• We need control over setting speaker phone or not and default set to speaker phone: https://www.twilio.com/docs/video/android-configuring-audio-video-input-and-output-devices-v5#selecting-a-specific-audio-output. If we could toggle this in Dart maybe we could use the proximity sensor to switch to audio only and through headphone instead of speaker.
• This should get implemented: https://github.com/twilio/video-quickstart-android#configuring-audiomanager. During the test I only tested setting the audioManager.setMode(AudioManager.MODE_IN_COMMUNICATION); Also check the React Native plugin which has a lot of working implementations of the audioManager: https://github.com/blackuy/react-native-twilio-video-webrtc/blob/master/android/src/main/java/com/twiliorn/library/CustomTwilioVideoView.java
• Pixel 2 phone needs software echo cancellation, see https://github.com/twilio/video-quickstart-android#configuring-hardware-audio-effects.
  • List of models that needs software echo cancellation: https://github.com/signalapp/Signal-Android/blob/72e10ac5974eddd03d48a8bd4c12581db9c4b50b/app/src/main/java/org/thoughtcrime/securesms/ApplicationContext.java#L297
• Wrap android widget

Quirks/Bugs

• There is currently a bug with gradle: https://github.com/twilio/video-quickstart-android/issues/430
  • Temporary fix, add android.enableDexingArtifactTransform.desugaring=false to project gradle.properties.