AntMediaInferencePlugin

This is a plugin that enables Ant Media servers to stream frames to DirectAI's object detection inference pipeline. Your object detection model(s) are defined entirely in text via a JSON. No training required.

Prerequisites

• You’ll need access to DirectAI Credentials. These are generated by navigating to DirectAi’s landing page and clicking the “Get API Access” button. Click “Get New Credentials” after the signup/login flow to grab your client_id & client_secret.
• You’ll need Dashboard AND SSH access to a development Ant Media Server. The plugin installation process initiates a restart of the Ant Media Server. That server should be running Ant Media Server Enterprise Edition v2.7.0 or above. Here's a quickstart guide for getting one running on AWS.

Configuring the Ant Media Server

• We'll need to modify settings in your Ant Media Dashboard to get started.
  • Choose your webrtc streaming application. For testing purposes, we’ll use WebRTCAppEE.
    
  • Select the settings for this application.
    
  • Enable Adaptive Bit Rate (see Before and After). This allows for ease of stream decomposition into individual frames.
    • Before:
      
      
    • After:
      
      
  • Enable the IP Filter for RESTful API and add 127.0.0.1. You'll be making curl requests to the local Ant Media Server.
    
    

Installing the Plugin

• Clone this repository into the root directory of your Ant Media Server.
• Install Java-related packages: sudo apt update && sudo apt install maven openjdk-11-jdk.
• Build and Install the DirectAI plugin from inside the AntMediaInferencePlugin directory. DANGEROUS: This will restart the Ant Media server: ./redeploy.sh
  • Note: The DirectAI plugin installation process also includes an installation of OpenCV 4.7.0

Getting Started on Inference:

• Take a look at the trailing logs of the Ant Media Server. This will show us when the DirectAI object detector starts logging information. tail -f /usr/local/antmedia/log/ant-media-server.log
• Run cp AntMediaInferencePlugin/params.json.template AntMediaInferencePlugin/params.json. Open up the latter file in a text editor.
  • Copy in your DirectAI Credentials to the values of directaiClientID and directaiClientSecret.
  • Define the clientWebhook value with a webhook endpoint of your choice. Detection results will be dumped to this endpoint where you’ll be able to process them on your own.
  • Optional: If you want to copy individual frames to S3 while we perform inference, follow the S3 Credentials Generation Instructions here. You’ll need to programmatically populate s3Bucket, s3AccessKey, and s3SecretKey with temporary S3 Write Credentials. You'll also need to set downloadFramesToS3 to true.
• From the Ant Media Server, start a sample WebRTC Stream. Take note of the stream ID (e.g. “stream_1”)
  • The sample stream builder should be available from https://AMS_IP/WebRTCAppEE
  • Before Starting:
    
    
  • After Starting:
    
    
• Start the object detection process on an Ant Media Stream from the Ant Media Server:

curl --location --request POST 'http://localhost:5080/{appName}/rest/v2/inference/{STREAM_ID}/start' \
  --header 'Accept: Application/json' \
  --header 'Content-Type: application/json' \
  -d @params.json

• When you're ready to stop the object detection process on the Ant Media Stream:

curl --location --request POST 'http://localhost:5080/{appName}/rest/v2/inference/{STREAM_ID}/stop' \
  --header 'Accept: Application/json' \
  --header 'Content-Type: application/json'

More Context on Inference Parameters:

• The clientWebhook allows you to pick a place where all that object detection information should be dumped. You can make use of it as necessary on the server that hosts that webhook.
• Models are defined inside model_config.
  • Unique object detectors are stored as items in the detectors list.
  • name describes the label of that object detector, not the function.
  • We use examples_to_include and examples_to_exclude to describe what the object detector should and should not identify. Building the model is really just about describing it in plain language.
  • The detection_threshold parameter define minimum bound for identifying candidate objects in individual frames. We recommend modifying the inclusion/exclusion lists before attempting to change the numerical threshold. Come chat with us in Discord or send us an email (ben@directai.io) if you're having trouble!