diodiogod-TTS-Audio-Suite/docs/INDEXTTS2_UPDATE_LOG.md

IndexTTS-2 Updates Log

This document tracks updates applied to our bundled IndexTTS-2 code from the upstream repository.

Update Process

1. Check for upstream changes: cd IgnoredForGitHubDocs/For_reference/index_tts && git pull
2. Review changes: git diff OLD_COMMIT..NEW_COMMIT -- indextts/infer_v2.py
3. Apply relevant changes to engines/index_tts/indextts/infer_v2.py
4. Test functionality with our IndexTTS-2 nodes
5. Document changes in this log

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2025-09-18: Major Update - Cache & Emotion Improvements

Reference commit range: 8336824..64cb31a (September 11 → September 18, 2025) Upstream commits reviewed: 5 commits affecting infer_v2.py

🔧 Changes Applied:

1. Emotion Vector Normalization Function (commit: 8aa8064)

• Added: normalize_emo_vec() helper function
• Purpose: Prevents voice identity loss from overly strong emotion settings
• Implementation:
  • Applies emotion bias factors to reduce problematic emotions
  • Caps total emotion sum to 0.8 maximum
  • Protects against extreme emotion vector values
• User benefit: Better emotion control without losing speaker characteristics

2. Audio Length Limiting (commit: 0828dcb)

• Added: _load_and_cut_audio() helper function
• Purpose: Prevents memory/VRAM issues from overly long reference audio
• Implementation:
  • Automatically truncates audio to 15 seconds maximum
  • Supports different sample rates (16kHz, 22kHz)
  • Provides verbose logging of truncation
• User benefit: More stable generation with long reference audio files

3. Persistent Cache Buildup Fix (commit: 64cb31a)

• Added: Proper cache clearing with torch.cuda.empty_cache()
• Purpose: Solves memory accumulation issues during multiple generations
• Implementation:
  • Clears old cache variables before loading new audio
  • Calls torch.cuda.empty_cache() to free GPU memory
  • Applied to both speaker and emotion cache invalidation
• User benefit: Better memory management during batch processing

4. BigVGAN CUDA Kernel Import Fix (commits: ee23371, e409c4a)

• Fixed: Corrected import path for BigVGAN custom CUDA kernel
• Changed: indextts.BigVGAN.alias_free_activation.cuda → indextts.s2mel.modules.bigvgan.alias_free_activation.cuda
• Purpose: Ensures proper CUDA acceleration when available
• User benefit: Better performance with CUDA-enabled setups

📋 Implementation Status:

Change	Applied to Bundled Code	Tested	Notes
normalize_emo_vec()	✅ Applied	⏳ Pending	Core emotion control improvement
_load_and_cut_audio()	✅ Applied	⏳ Pending	Memory stability fix
Cache clearing fixes	✅ Applied	⏳ Pending	Critical for batch processing
BigVGAN import fix	✅ Applied	⏳ Pending	Performance improvement

🎯 User-Facing Improvements:

• Better emotion control: Emotion vectors now auto-normalize to prevent voice identity loss
• Memory stability: Long reference audio automatically truncated to prevent crashes
• Batch processing: Improved cache management for multiple generations
• Performance: Fixed CUDA kernel loading for faster inference

🧪 Testing Required:

• Emotion vector controls in radar chart widget
• Long reference audio handling (>15 seconds)
• Multiple sequential generations (cache clearing)
• CUDA performance with FP16 enabled

---

Next Update Check: 2025-10-18

Monitoring: Watch for commits to indextts/infer_v2.py in https://github.com/index-tts/index-tts

Update command:

cd IgnoredForGitHubDocs/For_reference/index_tts
git pull origin main
git log --oneline LAST_COMMIT..HEAD -- indextts/infer_v2.py

Priority changes to watch for:

• Performance optimizations
• Memory management improvements
• Bug fixes in emotion processing
• New model loading features