sgl-project/sglang · error · ValueError

keyframe denoising requires one encoded keyframe per…

Error message

keyframe denoising requires one encoded keyframe per semantic anchor

What it means

Keyframe denoising requires exactly one encoded keyframe per semantic anchor. Align the keyframe encodings with the anchors.

Solutions

1. Ensure exactly len(semantic_frame_indices) dict entries in keyframes
2. Wrap non-mapping entries with dataclasses.asdict()/dict(...) or skip failures upstream by reducing anchors
3. Fail the whole request if any keyframe source can't be encoded, rather than emitting a short list

Example fix

# before
payload["keyframes"] = [enc0]  # 2 anchors, 1 entry
# after
payload["keyframes"] = [enc0, enc1]  # one per semantic anchor

kfs = keyframe.get("keyframes")
assert isinstance(kfs, list) and len(kfs) == len(sem) and all(isinstance(e, Mapping) for e in kfs)

def keyframes_valid(kf) -> bool:
    kfs = kf.get("keyframes")
    sem = kf.get("semantic_frame_indices") or ()
    return isinstance(kfs, list) and len(kfs) == len(sem) and all(isinstance(e, Mapping) for e in kfs)

When it happens

Trigger: An empty keyframes list with 2 anchors, 3 entries for 2 anchors, entries as tuples/classes instead of dicts, or the field missing (None).

Common situations: Dropping one encoded keyframe when its source image failed to load; producers emitting dataclasses or namedtuples instead of dict-like entries.

Related errors

• encoded keyframe condition rows must be a mapping
• keyframe payload requires an integer frame_count
• fl2va denoising requires encoded keyframe condition rows
• hybrid ref2va layout only supports first/last keyframe…
• keyframe condition rows require plan.task='fl2va' or…

AI-assisted analysis of sgl-project/sglang@0132848349 (2026-08-28). Data as JSON: /api/errors/aeeecdfae61b1f37. Report an issue: GitHub.

Appendix: source

Thrown at python/sglang/multimodal_gen/runtime/pipelines_core/stages/model_specific_stages/minimax_h3/stages/denoising.py:126

        raise ValueError("keyframe payload frame_count must be greater than one")
    pixel_indices = keyframe.get("pixel_frame_indices")
    expected_pixel_indices = [
        frame_count - 1 if index == -1 else index for index in semantic_indices
    ]
    if pixel_indices != expected_pixel_indices:
        raise ValueError(
            "keyframe denoising requires pixel_frame_indices resolved from the "
            "semantic anchors, "
            f"got {pixel_indices!r} for frame_count={frame_count}"
        )

    entries = keyframe.get("keyframes")
    if (
        not isinstance(entries, list)
        or len(entries) != len(semantic_indices)
        or any(not isinstance(entry, Mapping) for entry in entries)
    ):
        raise ValueError(
            "keyframe denoising requires one encoded keyframe per semantic anchor"
        )
    if [entry.get("frame_index") for entry in entries] != list(semantic_indices):
        raise ValueError("encoded keyframes must remain in semantic anchor order")
    if [
        entry.get("resolved_frame_index") for entry in entries
    ] != expected_pixel_indices:
        raise ValueError(
            "encoded keyframes must carry matching resolved_frame_index values"
        )

    latent_h = int(keyframe.get("latent_h") or 0)
    latent_w = int(keyframe.get("latent_w") or 0)
    rows = keyframe.get("rows")
    expected_rows = len(semantic_indices) * (latent_h // 2) * (latent_w // 2)
    if (
        latent_h <= 0
        or latent_w <= 0

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