from comfy_api.latest import ComfyExtension, io
from typing_extensions import override
class TextGenerate(io.ComfyNode):
@classmethod
def define_schema(cls):
# Define dynamic combo options for sampling mode
sampling_options = [
io.DynamicCombo.Option(
key="on",
inputs=[
io.Float.Input("temperature", default=0.7, min=0.01, max=2.0, step=0.000001),
io.Int.Input("top_k", default=64, min=0, max=1000),
io.Float.Input("top_p", default=0.95, min=0.0, max=1.0, step=0.01),
io.Float.Input("min_p", default=0.05, min=0.0, max=1.0, step=0.01),
io.Float.Input("repetition_penalty", default=1.05, min=0.0, max=5.0, step=0.01),
io.Int.Input("seed", default=0, min=0, max=0xffffffffffffffff),
io.Float.Input("presence_penalty", optional=True, default=0.0, min=0.0, max=5.0, step=0.01),
]
),
io.DynamicCombo.Option(
key="off",
inputs=[]
),
]
return io.Schema(
node_id="TextGenerate",
category="textgen",
search_aliases=["LLM", "gemma"],
inputs=[
io.Clip.Input("clip"),
io.String.Input("prompt", multiline=True, dynamic_prompts=True, default=""),
io.Image.Input("image", optional=True),
io.Image.Input("video", optional=True, tooltip="Video frames as image batch (1 FPS recommended)."),
io.Audio.Input("audio", optional=True),
io.Int.Input("max_length", default=256, min=1, max=2048),
io.DynamicCombo.Input("sampling_mode", options=sampling_options, display_name="Sampling Mode"),
io.Boolean.Input("thinking", optional=True, default=False, tooltip="Operate in thinking mode if the model supports it."),
],
outputs=[
io.String.Output(display_name="generated_text"),
],
)
@classmethod
def execute(cls, clip, prompt, max_length, sampling_mode, image=None, video=None, audio=None, thinking=False) -> io.NodeOutput:
tokens = clip.tokenize(prompt, image=image, video=video, audio=audio, skip_template=False, min_length=1, thinking=thinking)
# Get sampling parameters from dynamic combo
do_sample = sampling_mode.get("sampling_mode") == "on"
temperature = sampling_mode.get("temperature", 1.0)
top_k = sampling_mode.get("top_k", 50)
top_p = sampling_mode.get("top_p", 1.0)
min_p = sampling_mode.get("min_p", 0.0)
seed = sampling_mode.get("seed", None)
repetition_penalty = sampling_mode.get("repetition_penalty", 1.0)
presence_penalty = sampling_mode.get("presence_penalty", 0.0)
generated_ids = clip.generate(
tokens,
do_sample=do_sample,
max_length=max_length,
temperature=temperature,
top_k=top_k,
top_p=top_p,
min_p=min_p,
repetition_penalty=repetition_penalty,
presence_penalty=presence_penalty,
seed=seed
)
generated_text = clip.decode(generated_ids, skip_special_tokens=not thinking)
if thinking:
# Translate Gemma4 thinking channel markers to standard / tags
generated_text = generated_text.replace("<|channel>thought\n", "\n")
generated_text = generated_text.replace("", "")
# Strip remaining special tokens
generated_text = generated_text.replace("", "").replace("", "").strip()
return io.NodeOutput(generated_text)
LTX2_T2V_SYSTEM_PROMPT = """You are a Creative Assistant. Given a user's raw input prompt describing a scene or concept, expand it into a detailed video generation prompt with specific visuals and integrated audio to guide a text-to-video model.
#### Guidelines
- Strictly follow all aspects of the user's raw input: include every element requested (style, visuals, motions, actions, camera movement, audio).
- If the input is vague, invent concrete details: lighting, textures, materials, scene settings, etc.
- For characters: describe gender, clothing, hair, expressions. DO NOT invent unrequested characters.
- Use active language: present-progressive verbs ("is walking," "speaking"). If no action specified, describe natural movements.
- Maintain chronological flow: use temporal connectors ("as," "then," "while").
- Audio layer: Describe complete soundscape (background audio, ambient sounds, SFX, speech/music when requested). Integrate sounds chronologically alongside actions. Be specific (e.g., "soft footsteps on tile"), not vague (e.g., "ambient sound is present").
- Speech (only when requested):
- For ANY speech-related input (talking, conversation, singing, etc.), ALWAYS include exact words in quotes with voice characteristics (e.g., "The man says in an excited voice: 'You won't believe what I just saw!'").
- Specify language if not English and accent if relevant.
- Style: Include visual style at the beginning: "Style: