Field	Value
Model family	`lingbotworld2`
First scope	`robbyant/lingbot-world-v2-14b-causal-fast`, I2V causal-fast inference
Workload types	I2V: text + first image + camera/action path to video
Official reference	`/mnt/weka/shrd/wm/junda/fv-hub/lingbot-world-v2`
HF weights	`robbyant/lingbot-world-v2-14b-causal-fast`
Raw weights	`/mnt/weka/shrd/wm/junda/fv-hub/lingbot-world-v2/ckpts/lingbot-world-v2-14b-causal-fast`
FastVideo bundle	`/mnt/weka/shrd/wm/junda/fv-hub/lingbot-world-v2/ckpts/lingbot-world-v2-14b-causal-fast-fastvideo`
Source layout	`raw_official`
Needs conversion	`yes`
Token env var	none recorded

Do not write token values in this file.

Shared Environment Setup

Use the existing venv and do not rebuild FlashAttention:

/mnt/weka/shrd/wm/junda/fv-hub/.venv/bin/pip install -r /mnt/weka/shrd/wm/junda/fv-hub/lingbot-world-v2/requirements.txt
/mnt/weka/shrd/wm/junda/fv-hub/.venv/bin/pip install --no-deps -e /mnt/weka/shrd/wm/junda/fv-hub/fastvideo-port-lingbot

The current environment already has the FastVideo editable install pointing at:

/mnt/weka/shrd/wm/junda/fv-hub/fastvideo-port-lingbot

Runtime cache and temporary paths used by the matrix scripts:

/mnt/weka/shrd/wm/junda/fv-hub/lingbot-world-v2/.cache

Conversion

The converter writes a FastVideo-loadable bundle with native component configs, the exact LingBot World 2 Wan VAE checkpoint, and symlinked raw LingBot World 2 transformer/T5 assets:

cd /mnt/weka/shrd/wm/junda/fv-hub/fastvideo-port-lingbot
/mnt/weka/shrd/wm/junda/fv-hub/.venv/bin/python scripts/checkpoint_conversion/convert_lingbotworld2_causal_fast.py \
  --source-dir /mnt/weka/shrd/wm/junda/fv-hub/lingbot-world-v2/ckpts/lingbot-world-v2-14b-causal-fast \
  --output-dir /mnt/weka/shrd/wm/junda/fv-hub/lingbot-world-v2/ckpts/lingbot-world-v2-14b-causal-fast-fastvideo

Strict-load checks already run locally:

Component	Status	Notes
VAE	pass	`LingBotWorld2WanVAE` loads the original `Wan2.1_VAE.pth` checkpoint.
Text encoder	pass	Native `LingBotWorld2T5EncoderModel` strict-load from symlinked `.pt`.
Transformer	pass	Full 14B load and 8-GPU causal-fast generation pass.

Official Frame-Count Constraint

The requested verification frame counts are 5, 9, 17, 33, 65. The official causal-fast source uses default chunk_size=4, then truncates latent frames to a multiple of the chunk size. This makes 5 and 9 source-impossible and changes the generated frame counts for the remaining values.

Requested frames	Official effective frames	Status
`5`	`-3`	official source fails
`9`	`-3`	official source fails
`17`	`13`	runs with truncated output
`33`	`29`	runs with truncated output
`65`	`61`	runs with truncated output

Evidence: /mnt/weka/shrd/wm/junda/fv-hub/lingbot-world-v2/wan/image2video.py rounds frame_num to 4n+1, computes latent frames, truncates lat_f by chunk_size, and resets F = (lat_f - 1) * 4 + 1.

Local Tests

cd /mnt/weka/shrd/wm/junda/fv-hub/fastvideo-port-lingbot
/mnt/weka/shrd/wm/junda/fv-hub/.venv/bin/python -m pytest \
  tests/local_tests/lingbotworld2/test_lingbotworld2_causal_fast_preflight.py \
  tests/local_tests/pipelines/test_lingbotworld2_causal_fast_pipeline_smoke.py \
  tests/local_tests/pipelines/test_lingbotworld2_causal_fast_pipeline_parity.py \
  -q -rs

Current result:

2026-07-10: 5 passed, 1 skipped.
Skipped test: opt-in 14B heavy smoke gated by LINGBOTWORLD2_RUN_HEAVY_SMOKE=1.

Heavy smoke is opt-in because it loads the 14B model:

cd /mnt/weka/shrd/wm/junda/fv-hub/fastvideo-port-lingbot
LINGBOTWORLD2_RUN_HEAVY_SMOKE=1 /mnt/weka/shrd/wm/junda/fv-hub/.venv/bin/python -m pytest \
  tests/local_tests/pipelines/test_lingbotworld2_causal_fast_pipeline_smoke.py \
  -q -rs

Current heavy result:

2026-07-10: 2 passed in 3:15 on 8 H200 GPUs.

Matrix Verification

Reference generation:

/mnt/weka/shrd/wm/junda/fv-hub/lingbot-world-v2/scripts/run_reference_matrix.sh

FastVideo generation:

/mnt/weka/shrd/wm/junda/fv-hub/.venv/bin/python \
  /mnt/weka/shrd/wm/junda/fv-hub/lingbot-world-v2/scripts/run_fastvideo_matrix.py

Decoded-frame comparison:

/mnt/weka/shrd/wm/junda/fv-hub/.venv/bin/python \
  /mnt/weka/shrd/wm/junda/fv-hub/lingbot-world-v2/scripts/compare_matrix_outputs.py

Current comparison result:

2026-07-09: all 9 official-supported FastVideo videos are exactly equal to the
reference videos after decoded-frame comparison: max abs 0, mean abs 0.0.
The requested 5-frame and 9-frame cases are recorded as official_unsupported for
both reference and FastVideo.

Expected output roots:

Output type	Path
Reference	`/mnt/weka/shrd/wm/junda/fv-hub/lingbot-world-v2/outputs/reference`
FastVideo	`/mnt/weka/shrd/wm/junda/fv-hub/lingbot-world-v2/outputs/fastvideo`
Verification	`/mnt/weka/shrd/wm/junda/fv-hub/lingbot-world-v2/outputs/verification`

Generated-output parity test:

cd /mnt/weka/shrd/wm/junda/fv-hub/fastvideo-port-lingbot
/mnt/weka/shrd/wm/junda/fv-hub/.venv/bin/python -m pytest \
  tests/local_tests/pipelines/test_lingbotworld2_causal_fast_pipeline_parity.py \
  -q -rs