strai

Stream AI content to the world

• Prerequisites
• Getting started
  • OBS setup
• Concept
• Under the hood
  • OBS: How it works

Prerequisites

Before running the application, make sure you have the following prerequisites installed:

• Node.js (version 18.16 or higher) (run nvm use if you use NVM or similar tools)
• Twitch account with stream key for streaming
• OBS > 28.0.0 because it includes the obs-websocket plugin

Getting started

1. Clone the repo to your computer:

git clone https://github.com/failfa-st/strai.git

2. Go into the strai folder

cd strai

3. Install dependencies

npm i

4. Create the .env based on .env.example

cp .env.example .env

5. Fill out the .env

# You get this password in the next step "OBS Setup"
OBS_WEBSOCKET_SERVER_PASSWORD=

# The full path to the video that gets looped as a default when nothing is visible
OBS_DEFAULT_VIDEO=

OBS setup

You need to create the following base setup:

• A scene named default with an Sources > Media Source named defaultVideo with the following configuration
  • Local file: true
  • Loop: true
  • Restart playback when source becomes available: true
  • Use hardware decoding when available: true
  • Show nothing when playback ends: false
  • Close file when inactive: false
  • Leave all other settings on their defaults
• A scene named queue with
• A scene named stream with
  • Sources > Group named setup
  • Sources > Scene and select default and put it into the group setup
  • Sources > Scene and select queue and put it into the group setup
  • Make sure that the scenes inside the group are in this order:
    • queue
    • default

Then you can also configure the Websocket-Server:

• Tools > WebSocket Server Settings
  • Set the server port to 4455, as this is the default here
  • Enable Authentication: true
  • Click on the "Show Connect Info" to get the Server Password

Concept

graph TB
  A[Stable Diffusion WebUI] -->|Generates Picture| D[SadTalker]
  B[Twitch Chat] -->|Extracts Messages| E{System Prompt to OpenAI GPT}
  E -->|Generates Text| F[Bark]
  F -->|Generates WAV File| D
  D -->|Generates MP4 Video| G[OBS via obs-websocket-js]
  G -->|Streams Video| H[Twitch]

This diagram describes the following steps:

1. Stable Diffusion WebUI generates a picture of a person which is used by SadTalker.
2. Messages are extracted from Twitch Chat and transformed into an API call to OpenAI GPT using strong system prompt that represents a specific persona.
3. The system prompt to OpenAI GPT generates a response to the chat message which is fed to Bark.
4. Bark generates a WAV file based on the provided text.
5. SadTalker combines the picture from Stable Diffusion WebUI and the WAV file from Bark to generate an MP4 video, which contains a face that speaks
6. The generated MP4 video is then input into OBS using obs-websocket-js.
7. OBS streams the video to Twitch.

Under the hood

OBS: How it works

• Enable the defaultVideo
  • This makes sure that we have a loop constantly running when nothing is happening
• When OBSRemoteControl.addVideo is called:
  • Add the video to a video queue
    • This creates a new Media Source inside of queue using the same transform settings that were used to position the defaultVideo. It will also set the audio output to "Monitor and Output" so that the video's audio is hearable in the stream
• The oldest video from the video queue will be played
  • Once the video is playing in OBS, it will be removed from the video queue
• Once the video playback ended in OBS, the video will be removed from OBS