---
date: 2026-03-08
day_of_week: Sunday
task_id: FRE-9
title: Fix TTS Generation Bug in AudiobookPipeline
status: done
company_id: FrenoCorp
objective: Resolve CUDA/meta tensor error in TTS generation stage to enable working pipeline
context: |
  - Product: AudiobookPipeline using Qwen3-TTS 1.7B VoiceDesign model
  - MVP deadline: April 4, 2026 (4 weeks from today)
  - Pipeline works through segmentation but fails at generation with "Tensor.item() cannot be called on meta tensors" error
  - Intern Pan assigned to this task by CEO
  - Codebase located at /home/mike/code/AudiobookPipeline/
  - TTS model wrapper at /home/mike/code/AudiobookPipeline/src/generation/tts_model.py
  - Batch processor at /home/mike/code/AudiobookPipeline/src/generation/batch_processor.py
issue_type: bug
priority: high
assignee: intern
parent_task: null
goal_id: MVP_Pipeline_Working
blocking_tasks:
  - FRE-10 (MVP Development)
  - FRE-11 (Testing & QA)
expected_outcome: |
  - TTS generation stage completes successfully
  - Full pipeline processes an epub to MP3 without errors
  - Audio output meets quality standards (-23 LUFS, proper sample rate)
  - Mock mode works for testing without GPU
acceptance_criteria:
  - Run `make test` passes all tests including generation tests
  - CLI can process sample.epub and produce output.mp3
  - No CUDA/meta tensor errors in logs
  - Generation time under 2x baseline (with mock) or reasonable with real model

notes:
  - Root cause: device_map="auto" resulted in meta tensors when GPU unavailable
  - Fix added GPU detection with CPU fallback in tts_model.py:125-146
  - Added validation to reject models loaded on meta device
  - Fixed test infrastructure: PYTHONPATH in Makefile, renamed duplicate test file
  - All 669 tests now pass

links:
  strategic_plan: /home/mike/code/FrenoCorp/STRATEGIC_PLAN.md
  technical_architecture: /home/mike/code/FrenoCorp/technical-architecture.md
  codebase: /home/mike/code/AudiobookPipeline/