Real-Time Conversational AI (Zen-Live)
Zen-Live -- low-latency streaming model for real-time voice conversation, live video understanding, and interactive tutoring
ZIP-0417: Real-Time Conversational AI (Zen-Live)
Abstract
This proposal specifies Zen-Live, the real-time conversational variant of the Zen model family. Zen-Live enables sub-200ms latency voice conversations with AI agents, live video understanding (e.g., pointing a camera at a bird and asking "what species is this?"), and interactive tutoring sessions. The model uses speculative decoding, streaming output, and an optimized audio codec to achieve real-time performance while maintaining the quality of the Zen-Pro model.
Motivation
The whitepaper's vision (Section 08) of conversational AI companions requires real-time interaction -- not the multi-second latency typical of API-based LLM calls. When a user is on a nature walk with their Zoo companion app, they need:
- Instant voice responses (< 200ms end-to-end latency)
- Live video understanding (identify species from camera feed)
- Interruptible conversation (user can speak while agent is responding)
- Emotional expressiveness (tone of voice conveys excitement about a rare sighting)
Specification
Architecture
Microphone ─> Audio Codec ─> Token Encoder ─> ┐
Camera ─> Frame Sampler ─> Vision Encoder ─> ─┤
Text Input ─> Tokenizer ─────────────────────> ├─> Zen-Live Model ─> Streaming Output
│ (speculative ├─> Audio Codec ─> Speaker
│ decoding) ├─> Text Stream
└─────────────────────└─> Video Annotations
Latency Budget
| Component | Budget |
|---|---|
| Audio capture + encoding | 20ms |
| Network (edge inference) | 10ms |
| Model inference (first token) | 80ms |
| Audio synthesis (first chunk) | 40ms |
| Network (return) | 10ms |
| Audio playback buffer | 40ms |
| Total end-to-end | < 200ms |
Speculative Decoding
Zen-Live uses a small draft model (1.5B params) to generate candidate continuations, which the main model (7B+ params) verifies in a single forward pass. This achieves 3-4x throughput improvement for real-time streaming.
Audio Codec
Custom neural audio codec with:
- 24kHz sample rate, 16-bit depth
- 1.5 kbps encoding rate (extremely efficient for voice)
- Emotional encoding: tone, pace, emphasis encoded as separate streams
- Speaker identity preservation for consistent agent voice
Capabilities
- Voice conversation: Natural back-and-forth voice dialogue
- Live video QA: Real-time visual question answering from camera feed
- Interruption handling: Graceful handling of user interruptions mid-response
- Multilingual voice: Real-time conversation in 30+ languages
- Emotional expression: Agent voice conveys appropriate emotions
Research Papers
- zen-live_whitepaper -- Zen-Live real-time model whitepaper
- zen-audio-architecture -- Audio encoder/decoder architecture
- zen-voice-clone -- Voice cloning and synthesis technology
Implementation
- hanzo/jin: Jin multimodal framework with real-time streaming
- hanzo/llm: LLM Gateway with streaming inference support
- hanzo/chat: Chat interface with voice conversation mode
Timeline
- Originated: May 2024 (Zen-Live architecture)
- Research:
zen-live_whitepaperpublished Q3 2024 - Implementation: Zen-Live deployed via Hanzo LLM Gateway Q4 2024