Text processing before TTS:
- dictionary.txt rewrites words and phrases (km/h, np., units). Rules compile
into one alternation applied in a single pass, so replacements never chain
and longest-literal wins. Case-sensitive, whole-word.
- A per-queue second dictionary, written by the GUI into the first video's job
folder and merged with the shared one (--dictionary-extra).
- ALL-CAPS blocks become Title Case rather than sentence case: lowercasing
destroyed proper nouns inside captions ("NASA - MARGO MADISON") and invited
the normalizer to "correct" the name. Paired clips in output/clips/all-caps
showed the TTS reads both casings the same.
normalizer/ — digits to spoken Polish, in its own venv because it needs
transformers>=5, which must not touch ComfyUI's pinned versions:
- Two backends. Plain integers go to num2words for the value and a general
Polish LLM for the case; times, dates, decimals and identifiers go to a 0.6B
fine-tune. Measured on 40 real subtitle lines, each is clearly better than
the other on its half. 74% of numbered blocks take the first leg.
- Guards on every answer: runaway length, repetition loops, invalid bytes,
leftover digits, a lost minus sign, a changed number, a lost word. A failure
falls back to num2words, which is nominative but never wrong about the value.
- ComfyUI is asked to unload before normalizing; a normalizer that does not fit
in VRAM is spilled to RAM silently at 5x the cost.
Backend lifecycle:
- ComfyUI is found by port through /proc, so a backend started by hand is
managed too. SIGTERM escalates to SIGKILL, and a suspended process is killed
outright since it never runs its handlers.
- A clip that kills the backend is retried three times, each with a different
seed (the aborts are seed-dependent, not text-dependent), then skipped and
reported so an overnight queue keeps moving.
- start_comfyui.sh execs python, so the script's PID is ComfyUI's.
- GUI gains ComfyUI and Queue dictionary buttons; quitting stops the backend.
--resume-from now reuses the job folder's tts_input.srt instead of reparsing
the subtitles, so block N still pairs with clip_NNNN.flac.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
6.7 KiB
Requirements
Hardware
| Minimum | Notes | |
|---|---|---|
| GPU | NVIDIA, 12 GB VRAM | Developed on an RTX 4070 Ti SUPER (16 GB) |
| Driver | 525+ | Needed by the CUDA 12.8 wheels |
| Disk | ~35 GB free | ~22 GB installed (+8 GB with the number normalizer) |
| RAM | 16 GB | The final mux briefly peaks around 2.6 GB |
The CUDA toolkit is not required. The PyTorch cu128 wheels bundle their own
CUDA runtime, so the system nvcc version is irrelevant — this machine has CUDA
11.5 installed system-wide while PyTorch runs cu128 perfectly well. Only the
driver version matters.
CPU-only inference technically works but is slow enough to be impractical for a feature-length film.
Disk footprint
~/miniforge3/envs/comfy-tts 9.7 GB conda env (PyTorch and ~233 packages)
~/comfy-tts-app/ComfyUI 3.2 GB application code and dependencies
└── models/TTS 8.8 GB Higgs Audio V3 weights
------
21.7 GB
lektor_ai/normalizer/venv 6.9 GB optional: number normalizer env
lektor_ai/normalizer/model 1.1 GB optional: its weights
Output is roughly the size of the source video, since video is stream-copied. A 60-minute 10 Mbit/s episode produces about 5 GB. Intermediate FLAC clips add a few hundred MB per film and are kept deliberately, so individual clips can be regenerated without redoing a whole run (see usage.md).
Software
| Component | Version here | Notes |
|---|---|---|
| OS | Linux (Ubuntu 22.04) | Only Linux is supported by the installer |
| ComfyUI | 0.26.0 (7cb784e0) |
Pinned |
| TTS-Audio-Suite | v5.3.0 (09df1681) |
The only custom node installed |
| Higgs Audio V3 | bosonai/higgs-audio-v3-tts-4b |
8.7 GB, auto-downloaded |
| Python (ComfyUI) | 3.12.13 | conda-forge, in the comfy-tts env |
| PyTorch | 2.11.0+cu128 | With torchvision 0.26.0, torchaudio 2.11.0 |
| Python (script) | 3.8+ | System Python; 3.10.12 here |
| ffmpeg / ffprobe | 4.4+ | System install; 4.4.2 here |
Dependency surface
This is the point most worth internalising, because it makes debugging much simpler: the three parts have almost nothing in common.
lektor_ai_comfy.py — standard library only
argparse configparser json os queue random re shlex shutil subprocess
sys threading time uuid pathlib.Path urllib.request
No third-party packages. No conda environment. No virtualenv. It runs on the system Python:
/usr/bin/python3 lektor_ai_comfy.py --help # works, nothing installed
Its only external requirements are ffmpeg and ffprobe on PATH, and a
reachable ComfyUI instance. It talks to ComfyUI over plain HTTP with
urllib.request — there is no ComfyUI client library involved.
requirements.txtin the project root does not apply here. It belongs to the olderlektor_ai.py, which used the hosted Boson AI API and neededopenai>=1.0.0.lektor_ai_comfy.pyrequires nothing from it.normalizer/requirements.txtis a different file and does apply — to the normalizer's own venv, never to the system Python.
normalizer/ — optional third environment
torch 2.11.0+cu128 transformers 5.15.0 accelerate 1.14.0
num2words 0.5.x (fallback path only)
Its own venv at normalizer/venv (~6.9 GB — the cu128 wheels bundle their
own CUDA runtime, again) plus normalizer/model (1.1 GB).
Separate from ComfyUI's environment because it hard-requires transformers >= 5
— 4.x tokenizes the Qwen3 chat template differently and silently produces wrong
output. lektor_ai_comfy.py never imports it; it starts it as a subprocess and
talks JSON lines over a pipe, so the version conflict never has to be resolved.
Entirely optional: without it the pipeline uses a num2words fallback, and with
numbers = no it is not started at all.
ComfyUI — a large, isolated environment
233 pip packages in the comfy-tts conda env. The important ones:
torch 2.11.0+cu128 torchaudio 2.11.0+cu128 torchvision 0.26.0+cu128
transformers 5.12.1 tokenizers 0.22.2 accelerate 1.14.0
numpy 2.2.6 scipy 1.18.0 librosa 0.11.0
soundfile 0.14.0 safetensors 0.8.0 einops 0.8.2
The conda environment itself holds only the 27 base conda-forge packages that
make up the Python runtime. Everything else arrives via pip. In particular,
portaudio, libsamplerate, ffmpeg and espeak-ng are not installed in
the environment despite appearing in the original planning notes — the system
ffmpeg is used and espeak-ng is absent entirely. Everything works without them.
TTS-Audio-Suite installs its dependencies through its own install.py, not
through its requirements.txt. That file deliberately omits packages needing
special handling — librosa, descript-audio-codec, onnxruntime,
opencv-python and others are installed with --no-deps because pip would
otherwise drag numpy backwards and break the rest of the environment. Never
substitute pip install -r requirements.txt for python install.py.
Input requirements
Video — anything ffmpeg can demux. MKV and MP4 are the usual cases. The container must support what gets muxed back in; output is always MKV, which accepts every codec involved.
Subtitles — either an external .srt, or a text-based track inside the
video (subrip, ass, ssa, webvtt, mov_text). Image-based tracks
(hdmv_pgs_subtitle from Blu-ray, dvd_subtitle) contain bitmaps rather than
text and cannot drive TTS without OCR; the --embedded-subs picker marks them
as unusable. They are still copied to the output untouched.
Voice reference — a .wav plus a .txt holding its exact transcript, both
in voices/. Three are bundled:
| Voice | Length | Format |
|---|---|---|
gudowski |
2:10 | 44.1 kHz stereo |
gudowski_short (default) |
0:52 | 44.1 kHz stereo |
gudowski_short_2 |
0:28 | 44.1 kHz stereo |
The transcript matters as much as the audio — voice cloning quality drops
noticeably without an accurate one. The script warns if the .txt is missing.
Network
Needed only at install time, for the ComfyUI and TTS-Audio-Suite clones, the pip downloads, and the 8.7 GB model. Generation afterwards is entirely local; no API keys, no accounts, no per-use cost.
The model is published under a research / non-commercial licence and may require
accepting its terms on huggingface.co, then hf auth login, before it will
download.
The number normalizer's model is gated in the same way and needs an
HF_TOKEN for its one-time download; see
installation.md. Runs
set HF_HUB_OFFLINE=1 and TRANSFORMERS_OFFLINE=1, so it never reaches the
network afterwards.