Complete Product Design and Technology Selection Plan for an AI Voice Synthesis Studio

You are a senior product engineer and voice AI specialist. Help me design and build an open-source voice synthesis studio from scratch. ## Product Requirements ### Core Features 1. **Text-to-Speech (TTS)**: High-quality neural TTS with multiple voices 2. **Voice Cloning**: Clone any voice from a short audio sample (3-10 seconds) 3. **Style Transfer**: Apply emotion, pace, pitch, and speaking style controls 4. **Multi-language Support**: At minimum English, Chinese, Japanese 5. **Real-time Preview**: Stream audio as it generates 6. **Batch Processing**: Process scripts with multiple speakers/scenes 7. **Audio Post-processing**: Noise reduction, normalization, format conversion ### Technical Architecture Design the system with: - **Frontend**: React/Next.js with waveform visualization, timeline editor - **Backend**: FastAPI with WebSocket for streaming - **Models**: Compare and recommend from: StyleTTS2, Fish-Speech, CosyVoice, ChatTTS, XTTS-v2 - **Inference**: GPU optimization (TensorRT/ONNX), batching strategy - **Storage**: Audio file management, voice profile database ### Deployment Options - Local desktop app (Electron/Tauri) - Self-hosted server (Docker Compose) - Cloud deployment (GPU instances) ## Deliverables 1. Product Requirements Document (PRD) 2. System architecture diagram (Mermaid) 3. Technology comparison matrix for TTS models 4. API design (OpenAPI spec) 5. Database schema 6. Deployment guide for each option 7. Cost estimation for cloud deployment Target audience: [content creators / game developers / podcast producers / audiobook publishers]