app.py

"""
Sulphur — Image to Video (HF Spaces).
Clones Wan2GP and downloads models on first run.
Generation is handled by generate.py called as a subprocess inside @spaces.GPU.
"""

import os
import sys
import subprocess
import shutil
import tempfile
import threading
import json
from pathlib import Path

import gradio as gr
import spaces

_HF_TOKEN    = os.environ.get("HF_TOKEN")
_PERSISTENT  = Path("/data") if Path("/data").exists() else Path(tempfile.gettempdir())
WAN2GP_ROOT  = _PERSISTENT / "Wan2GP"
CKPTS_DIR    = WAN2GP_ROOT / "ckpts"
LORAS_DIR    = WAN2GP_ROOT / "loras" / "ltx2"
FINETUNES_DIR = WAN2GP_ROOT / "finetunes"
GENERATE_PY  = Path(__file__).parent / "generate.py"

SULPHUR_ASSETS = [
    ("SulphurAI/Sulphur-2-base", "sulphur_distil_bf16.safetensors", CKPTS_DIR),
]
LTX_ASSETS = [
    ("SulphurAI/Sulphur-2-base", "distill_loras/ltx-2.3-22b-distilled-lora-1.1_fro90_ceil72_condsafe.safetensors", LORAS_DIR),
    ("DeepBeepMeep/LTX-2", "ltx-2.3-22b_vae.safetensors",                    CKPTS_DIR),
    ("DeepBeepMeep/LTX-2", "ltx-2.3-22b_text_embedding_projection.safetensors", CKPTS_DIR),
    ("DeepBeepMeep/LTX-2", "ltx-2.3-22b_embeddings_connector.safetensors",   CKPTS_DIR),
]

SULPHUR_FINETUNE = {
    "model": {
        "name": "Sulphur 2 Base",
        "visible": True,
        "architecture": "ltx2_22B",
        "parent_model_type": "ltx2_22B",
        "description": "LTX-2.3 fine-tuned i2v. Distilled checkpoint.",
        # Full distilled model — do NOT also preload the rank-768 LoRA (README: use one or the other)
        "URLs": [str(CKPTS_DIR / "sulphur_distil_bf16.safetensors")],
        "preload_URLs": [],
    },
    "num_inference_steps": 8,
    "video_length": 81,
    "resolution": "832x480",
    "guidance_scale": 3.5,
    "alt_guidance_scale": 3.5,
}

_setup_lock = threading.Lock()
_setup_done = False


def _download(repo_id, filename, dest_dir):
    from huggingface_hub import hf_hub_download
    dest_dir.mkdir(parents=True, exist_ok=True)
    dest = dest_dir / Path(filename).name  # flat — strip any subfolder
    if dest.exists():
        print(f"[download] cached: {dest.name}")
        return
    print(f"[download] {repo_id}/{filename}")
    hf_hub_download(repo_id=repo_id, filename=filename,
                    local_dir=str(dest_dir), token=_HF_TOKEN)
    # hf_hub_download preserves subfolder structure; flatten to dest_dir root
    downloaded = dest_dir / filename
    if downloaded.exists() and not dest.exists():
        shutil.move(str(downloaded), str(dest))


def setup():
    global _setup_done
    with _setup_lock:
        if _setup_done:
            return
        _setup_done = True

    if not (WAN2GP_ROOT / "shared" / "api.py").exists():
        WAN2GP_ROOT.mkdir(parents=True, exist_ok=True)
        print("[setup] Cloning Wan2GP...")
        subprocess.run(
            ["git", "clone", "--depth=1",
             "https://github.com/deepbeepmeep/Wan2GP.git", str(WAN2GP_ROOT)],
            check=True,
        )

    for repo, fname, dest in SULPHUR_ASSETS + LTX_ASSETS:
        _download(repo, fname, dest)

    # Gemma text encoder — must stay in its subfolder (Wan2GP looks there by name)
    _gemma_folder = "gemma-3-12b-it-qat-q4_0-unquantized"
    _gemma_file = f"{_gemma_folder}_quanto_bf16_int8.safetensors"
    gemma_dest = CKPTS_DIR / _gemma_folder / _gemma_file
    if not gemma_dest.exists():
        from huggingface_hub import hf_hub_download
        print("[download] Gemma text encoder...")
        hf_hub_download(
            repo_id="DeepBeepMeep/LTX-2",
            filename=f"{_gemma_folder}/{_gemma_file}",
            local_dir=str(CKPTS_DIR),
            token=_HF_TOKEN,
        )
    else:
        print("[download] cached: Gemma text encoder")

    FINETUNES_DIR.mkdir(parents=True, exist_ok=True)
    (FINETUNES_DIR / "sulphur_2_base.json").write_text(json.dumps(SULPHUR_FINETUNE, indent=2))
    print("[setup] Done.")


setup()

RESOLUTIONS = ["832x480", "480x832", "640x640", "1024x576", "576x1024"]


@spaces.GPU(duration=120)
def generate_video(image, prompt, resolution, steps, guidance_scale, frames, seed):
    if image is None:
        raise gr.Error("Please upload an image.")
    if not prompt.strip():
        raise gr.Error("Please enter a prompt.")

    out_file = Path(tempfile.mkdtemp()) / "output.mp4"
    env = {**os.environ, "WAN2GP_ROOT": str(WAN2GP_ROOT)}

    cmd = [
        sys.executable, str(GENERATE_PY),
        "--image",  image,
        "--prompt", prompt,
        "--output", str(out_file),
        "--model",  "sulphur-2",
        "--seed",   str(int(seed)),
        "--resolution", resolution,
        "--steps",  str(int(steps)),
        "--guidance_scale", str(float(guidance_scale)),
        "--frames", str(int(frames)),
    ]

    log_lines = []
    proc = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT,
                            text=True, bufsize=0, env=env)

    buf = ""
    while True:
        chunk = proc.stdout.read(256)
        if not chunk:
            break
        buf += chunk
        # Split on \r or \n — tqdm uses \r to overwrite progress lines
        parts = buf.replace("\r", "\n").split("\n")
        buf = parts[-1]
        for part in parts[:-1]:
            stripped = part.strip()
            if not stripped:
                continue
            # Overwrite last line if it looks like a progress bar update
            if log_lines and ("%" in stripped or "it/s" in stripped or "step" in stripped.lower()):
                log_lines[-1] = stripped
            else:
                log_lines.append(stripped)
            print(stripped)
            yield None, "\n".join(log_lines[-30:])

    proc.wait()
    log = "\n".join(log_lines)

    if proc.returncode != 0 or not out_file.exists():
        yield None, log + "\n\n[ERROR] Generation failed."
        return

    final = tempfile.NamedTemporaryFile(suffix=".mp4", delete=False)
    shutil.copy2(out_file, final.name)
    yield final.name, log + "\n\n[DONE]"


with gr.Blocks(title="Sulphur — Image to Video") as demo:
    gr.Markdown("# Sulphur — Image to Video\nPowered by Wan2GP · Sulphur-2 distilled finetune")
    with gr.Row():
        with gr.Column(scale=1):
            image_in  = gr.Image(type="filepath", label="Input Image")
            prompt_in = gr.Textbox(label="Prompt", placeholder="Describe the motion…", lines=3)
            with gr.Accordion("Advanced", open=False):
                resolution_dd = gr.Dropdown(RESOLUTIONS, value="832x480", label="Resolution")
                steps_sl      = gr.Slider(1, 50, value=8,   step=1,   label="Steps")
                guidance_sl   = gr.Slider(1.0, 10.0, value=5.0, step=0.5, label="Guidance Scale")
                frames_sl     = gr.Slider(17, 257, value=81, step=8,  label="Frames")
                seed_num      = gr.Number(value=-1, label="Seed (-1 = random)", precision=0)
            run_btn = gr.Button("Generate", variant="primary")
        with gr.Column(scale=1):
            video_out = gr.Video(label="Output Video")
            log_out   = gr.Textbox(label="Log", lines=10, interactive=False)

    run_btn.click(
        fn=generate_video,
        inputs=[image_in, prompt_in, resolution_dd, steps_sl, guidance_sl, frames_sl, seed_num],
        outputs=[video_out, log_out],
    )

if __name__ == "__main__":
    demo.launch(theme=gr.themes.Soft())