VOICE REQUEST
    |
    |-- Have reference audio of target voice?
    |   |-- Yes (5+ seconds) → Chatterbox (MIT, paralinguistic tags)
    |   |-- Yes (10-15 seconds) → F5-TTS (fastest zero-shot)
    |   |-- Yes (10+ minutes) → RVC training (highest fidelity)
    |   |-- Yes (any length, budget) → ElevenLabs (production quality)
    |
    |-- No reference audio?
    |   |-- Need emotion control → IndexTTS-2 (8-emotion vectors)
    |   |-- Need multi-language → TTS Audio Suite (23 languages)
    |   |-- Need voice design → ElevenLabs Voice Design (describe voice)
    |   |-- Quick prototype → Any TTS with default voice
    |
    |-- Need multi-speaker dialog?
    |   |-- Chatterbox (4 voices) or TTS Audio Suite (character switching)
    |
    |-- Need lip-sync?
    |   |-- Best accuracy → Wav2Lip + CodeFormer
    |   |-- Need head movement → SadTalker
    |   |-- Full expression control → LivePortrait
    |   |-- Unlimited length → InfiniteTalk

Tool Reference

Chatterbox (Recommended Open-Source)

Strengths: MIT license, beats ElevenLabs 63.8% in blind tests, 5-second sample, emotion control, sub-200ms latency.

Paralinguistic tags:

[laugh] [chuckle] [sigh] [gasp] [cough] [clear throat]
[whisper] [excited] [sad] [angry] [surprised]

Key parameter: exaggeration (0.25-2.0) controls expressiveness.

Limit: 40-second generation cap. Split longer content.

F5-TTS

Strengths: Fastest zero-shot cloning, <15 second samples, MIT license, multi-language.

Requirements: Reference audio must be paired with .wav + .txt (matching transcription).

Languages: English, German, Spanish, French, Japanese, Hindi, Thai, Portuguese.

TTS Audio Suite

Strengths: Unified multi-engine platform, 23 languages, character switching.

Special features:

Character switching: [CharacterName] tags
Language switching: [de:Alice], [fr:Bob]
Pause control: [pause:1s]
SRT timing sync

Integrates: F5-TTS, Chatterbox, Higgs Audio 2, VibeVoice, IndexTTS-2, RVC.

IndexTTS-2

Strengths: 8-emotion vector control with per-segment parameters.

Emotions: happy, angry, sad, surprised, afraid, disgusted, calm, melancholic.

RVC (Voice Conversion)

Use case: Train a model on target voice (10+ min audio), then convert any TTS output.

Pipeline: Text → Any TTS → Base Audio → RVC Model → Character Voice

Training: 300-500 epochs, RMVPE feature extraction.

ElevenLabs (Commercial)

Tiers:

Instant Clone: 1-minute sample, good quality
Professional Clone: 30+ minutes (3h ideal), near-indistinguishable
Voice Design: Describe voice in text (no sample needed)

Voice Profile Setup

For each character, establish a voice profile in projects/{project}/characters/{name}/profile.yaml:

voice:
  cloned: true
  model: "chatterbox"
  sample_file: "references/voice_sample.wav"
  settings:
    exaggeration: 1.2
    default_emotion: "neutral"
  notes: "Warm, confident tone. Slight Italian-American undertones."

Script Preparation

Text Formatting for TTS

Punctuation matters: Commas create pauses, periods create stops
Phonetic hints: Spell unusual words phonetically if mispronounced
Emotion cues: Use Chatterbox tags or split by emotion for IndexTTS-2
Length: Split into 30-40 second segments for Chatterbox limit

Multi-Speaker Script

[Sage] Hello! *laughs* I've been looking forward to this.
[pause:0.5s]
[Alex] [excited] Same here! Let's dive right in.
[Sage] [whisper] But first, I need to tell you something...

Audio Post-Processing

Requirements for Lip-Sync Input

Sample rate: 16-24kHz (model dependent)
Format: WAV (uncompressed)
Mono channel
Trim leading silence
Add 0.2s trailing silence
Normalize to -3dB peak

FFmpeg Processing

# Convert to mono 24kHz WAV, normalized
ffmpeg -i input.wav -ac 1 -ar 24000 -af "loudnorm=I=-16:TP=-3" output.wav

# Trim silence from start/end
ffmpeg -i input.wav -af "silenceremove=start_periods=1:start_threshold=-50dB,areverse,silenceremove=start_periods=1:start_threshold=-50dB,areverse" trimmed.wav

# Concatenate segments
ffmpeg -f concat -safe 0 -i filelist.txt -c copy combined.wav

Lip-Sync Methods

Wav2Lip (Best Accuracy)

Settings:

wav2lip_model: "wav2lip_gan.pth"  # Better than wav2lip.pth
face_detect_batch: 16
nosmooth: false
pad_bottom: 10

MUST post-process: CodeFormer (fidelity 0.7) after Wav2Lip output.

SadTalker (Head Movement)

Settings:

preprocess: "full"     # Better for novel faces
enhancer: "gfpgan"
pose_style: 10-20      # Natural conversation range

LivePortrait (Expression Control)

Settings:

lip_zero: 0.03         # Reduces unnatural lip movement
stitching: true        # Seamless face blending

Best for: Premium avatar creation, expression transfer from driving video.

LatentSync 1.6 (Newest, Highest Quality)

ByteDance model trained at 512x512 with TREPA modules for temporal consistency.

InfiniteTalk (Unlimited Length)

For videos longer than standard lip-sync limits. Integrates with Wan for joint generation.

Complete Talking Head Workflow

Pipeline A: Quick (Image → Talk)

1. [Text] → Chatterbox/F5-TTS → audio.wav
2. [Character Image] + audio.wav → SadTalker → video.mp4
3. video.mp4 → GFPGAN/CodeFormer → final.mp4

Time: ~2 minutes. Quality: Good.

Pipeline B: Quality (Image → Video → Lip-Sync)

1. [Text] → Chatterbox → audio.wav
2. [Character Image] → Wan I2V → base_video.mp4
   Prompt: "person talking, slight head movement, indoor"
3. base_video.mp4 + audio.wav → Wav2Lip → lipsync.mp4
4. lipsync.mp4 → FaceDetailer batch → enhanced.mp4
5. enhanced.mp4 → Color correct + Deflicker → final.mp4

Time: ~10 minutes. Quality: Production.

Pipeline C: Premium (Expression Transfer)

1. Record driving video (actor performing lines)
2. [Text] → Voice Clone TTS → audio.wav
3. [Character Image] + driving.mp4 → LivePortrait → expression_video.mp4
4. expression_video.mp4 + audio.wav → Wav2Lip → lipsync.mp4
5. lipsync.mp4 → CodeFormer → final.mp4

Time: ~15 minutes. Quality: Premium.

Troubleshooting

Issue	Solution
Audio out of sync	Offset with ffmpeg: `ffmpeg -itsoffset 0.1 -i audio.wav ...`
Subtle mouth movements	Use wav2lip_gan.pth, increase audio volume
Face artifacts	Post-process with CodeFormer (fidelity 0.6-0.8)
Robotic voice clone	Use longer/cleaner reference, increase exaggeration
Unnatural head movement	Lower SadTalker pose_style to 0-10

Reference

references/voice-synthesis.md - Full voice tool documentation
references/models.md - Voice model download links
Character voice profiles in projects/{project}/characters/

comfyui-voice-pipeline

ComfyUI Voice Pipeline

Voice Generation Decision Tree