Files
facok-ComfyUI-LCS/core/sampling.py
T
facok ec9941b5fc Use model's latent_format for space conversion instead of hardcoded FLUX constants
Replaces hardcoded SCALE_FACTOR/SHIFT_FACTOR with model.latent_format.process_in/out
so LCS works with any model (FLUX, LTXV, SD, etc). Adds LTXAV packed tensor
unpack/repack support for audio+video models. All hooks (color, tone, sharpness,
observer) now use the model-aware conversion from args["model"].
2026-03-21 21:30:22 +08:00

95 lines
3.4 KiB
Python

"""Shared sampling utilities for LCS intervention hooks."""
import torch
# Legacy FLUX constants — kept for backward compatibility with observe.py preview
SCALE_FACTOR = 0.3611
SHIFT_FACTOR = 0.1159
def find_step_index(sigma, sigmas):
"""Find the step index for a given sigma value in the sigma schedule.
Uses torch.isclose for robust matching across dtype differences (e.g. bfloat16
sigma vs float32 sample_sigmas), with argmin fallback for edge cases.
"""
sigma_val = sigma.flatten()[0].float()
sigmas_f = sigmas.float()
matched = torch.isclose(sigmas_f, sigma_val, rtol=1e-3, atol=1e-5).nonzero()
if len(matched) > 0:
return matched[0].item()
return (sigmas_f - sigma_val).abs().argmin().item()
def denoised_to_raw(denoised, model):
"""Convert denoised tensor from process_in space to raw VAE space.
Uses the model's latent_format.process_out (inverse of process_in).
Works for any model: FLUX (scale+shift), LTXV (identity), SD (scale), etc.
"""
return model.latent_format.process_out(denoised)
def raw_to_denoised(raw, model):
"""Convert raw VAE space tensor back to process_in space.
Uses the model's latent_format.process_in.
"""
return model.latent_format.process_in(raw)
def unpack_video_if_needed(denoised, args):
"""Unpack LTXAV-style packed latents if detected.
LTXAV packs video [B,128,F,H,W] + audio [B,ch,T,freq] into [B,1,flat].
Returns (tensor_to_process, pack_info) where pack_info is None for
non-packed formats or a dict for repacking.
"""
# Detect packed format: shape [B, 1, flat] with very large last dim
if denoised.ndim == 3 and denoised.shape[1] == 1:
# Try to find latent_shapes from cond data
cond = args.get("cond")
latent_shapes = _extract_latent_shapes(cond)
if latent_shapes is not None and len(latent_shapes) > 1:
import comfy.utils
tensors = comfy.utils.unpack_latents(denoised, latent_shapes)
# tensors[0] = video [B, 128, F, H, W], tensors[1] = audio [B, ch, T, freq]
return tensors[0], {"packed": True, "latent_shapes": latent_shapes,
"other_tensors": tensors[1:], "original": denoised}
return denoised, None
def repack_video_if_needed(modified, original_denoised, pack_info):
"""Repack video tensor back into LTXAV packed format if it was unpacked.
modified: the video tensor after intervention [B, 128, F, H, W]
original_denoised: the original packed tensor (for audio portion)
pack_info: from unpack_video_if_needed
"""
if pack_info is None:
return modified
import comfy.utils
all_tensors = [modified] + pack_info["other_tensors"]
packed, _ = comfy.utils.pack_latents(all_tensors)
return packed
def _extract_latent_shapes(cond):
"""Try to extract latent_shapes from conditioning data.
After convert_cond, cond is a list of dicts with 'model_conds' containing
CONDConstant-wrapped values like 'latent_shapes'.
"""
if cond is None:
return None
for c in cond:
if isinstance(c, dict):
model_conds = c.get('model_conds', {})
if 'latent_shapes' in model_conds:
ls = model_conds['latent_shapes']
# CONDConstant wraps the value in .cond
if hasattr(ls, 'cond'):
return ls.cond
return ls
return None