| name | localvideo |
| description | Local LongCat-Video on Windows (high-VRAM NVIDIA) with identity-first flow (hero still → I2V → lengthen → upscale). Use for /localvideo; never text-only T2V for celebrity/character likeness finals. |
localvideo
Stack
Resolve install roots from the environment (do not invent a publisher path):
| Piece | Path |
|---|
| Code + venv | $env:LONGCAT_ROOT (LongCat-Video checkout) |
| Weights | $env:LONGCAT_WEIGHTS |
| Short T2V | run_sample_windows.py |
| Long T2V+VC | run_long_windows.py |
| Windows I2V | run_i2v_windows.py (prefer --no-distill) |
| Official I2V demo | run_demo_image_to_video.py |
| Python | $env:LONGCAT_ROOT\.venv\Scripts\python.exe |
| Stills | /localimage → style-routed ComfyUI (default Flux photoreal) |
| Docs | WINDOWS_SETUP.md, windows_vram.py (--gpu-heavy) |
After gen → local-media-router. Before gen → run local-media-router/discover.ps1 and match motion-prompt style to the still’s model/style (no Pixar words on a Flux photo hero).
I2V note
Distill LoRA + accelerate CPU offload / gpu-heavy can crash with Tensor on device meta. Until fixed: run_i2v_windows.py --no-distill (e.g. --steps 20).
Canonical quality flow (mandatory mindset)
Hero still (Flux / ref) → still QA
→ I2V @ 3s → frame identity QA
→ only then 6s/10s (continuation)
→ upscale → NVENC final
→ stranger-test QA (identity FAIL = BLOCKER)
When pure T2V is OK
Landscapes, products, vehicles, abstract, non-likeness stylized scenes.
When pure T2V is NOT OK for finals
Named people, celebrities, recurring characters, “must look like X”. Use ref + I2V. Lesson learned: MJ stage text-only distill → wrong face.
Preconditions
Test-Path "$env:LONGCAT_ROOT\run_sample_windows.py"
Test-Path "$env:LONGCAT_ROOT\run_long_windows.py"
Test-Path "$env:LONGCAT_WEIGHTS\dit"
ffmpeg -hide_banner -encoders 2>&1 | Select-String "h264_nvenc"
nvidia-smi --query-gpu=memory.free,memory.total --format=csv,noheader
If free VRAM < 6GB: warn — do not start ComfyUI in parallel with LongCat.
Arg grammar
/localvideo [3s|6s|10s] [best|gpu-heavy] [ref <image>] <prompt>
/localvideo edit <path> [extend|restyle|trim|upscale] [prompt...]
Also accept: 3 sec, ~10s, --gpu-heavy, --best, --ref.
Decision tree — identity (before duration)
- Prompt names a person / character / celebrity OR user cares about likeness?
- Yes → need
ref <image> or produce still via /localimage and stop for approval.
- User says “text only anyway” → warn, then T2V only if they confirm.
- Else → T2V allowed.
Decision tree — duration
edit → EDIT mode (below).- Duration token present → use table.
- Else → ASK: 3s / 6s / 10s.
- If user asks 10s but no approved 3s keeper for likeness jobs → recommend 3s first; only skip if they explicitly say so.
| Token | Runner | Notes |
|---|
3s | sample · 49 frames | Default iterate |
6s | long · 93f · cont=0 | After 3s OK |
10s | long · cont=1 · trim 10s | After 3s OK for likeness |
Decision tree — quality flags
| Token | Maps to |
|---|
gpu-heavy | --gpu-heavy --gpu-gib 20 |
best | --gpu-heavy --gpu-gib 20 --no-distill --steps 40 (or 50 if user accepts time) + plan upscale after |
| (default) | distill + cpu_offload (fast / draft) |
Draft vs final: draft may use distill; likeness finals should use best or at least gpu-heavy + more steps.
I2V vs T2V
| Mode | When | How (this PC) |
|---|
| I2V | ref present or approved still in pack refs/ / raw/hero.png | Prefer LongCat image-to-video path; if Windows I2V runner not yet wrapped, say so and either wrap from run_demo_image_to_video.py or use Comfy I2V — do not silently fall back to T2V for likeness |
| T2V | No likeness requirement | run_sample_windows.py / run_long_windows.py |
Pack should store: refs/hero.png (approved still), raw/, keep/, final/.
Edit modes
| Mode | Behavior |
|---|
extend | Lengthen (seeded VC when CLI exists; else new segment + optional concat) |
restyle | New gen with prompt; keep source |
trim | ffmpeg cut |
upscale | lanczos+NVENC default; SeedVR2/ESRGAN if installed and user asks |
Invocation examples
$py = "$env:LONGCAT_ROOT\.venv\Scripts\python.exe"
# Draft 3s T2V (non-likeness)
& $py run_sample_windows.py --output_dir $out --output_name clip.mp4 --prompt '...' --num_frames 49 --steps 16 --distill
# Best-ish 3s
& $py run_sample_windows.py ... --num_frames 49 --no-distill --steps 40 --gpu-heavy --gpu-gib 20
# 10s after approval
& $py run_long_windows.py ... --continuations 1 --gpu-heavy
ffmpeg -y -i raw\clip.mp4 -t 10 -c:v h264_nvenc -preset p5 -cq 19 -an final\clip_10s.mp4
Post + QA
- Promote to
keep/ + NVENC final/ via local-media-router
- Extract start/mid/end (or 6 frames) → Read each
- Identity stranger test for people/characters — FAIL = BLOCKER
manifest.json includes ref, mode: t2v|i2v, quality: draft|best- Report paths + elapsed; never claim ship on identity FAIL
Constraints
- Local only from this skill
- Never delete keepers/finals
- One GPU heavy job at a time
- Honest ceiling: local likeness < Flow/Veo; still→I2V is the way to close the gap
