Function generate_alphas

clip_manager.py:217–299

(
    clips,
    device=None,
    *,
    on_clip_start: Callable[[str, int], None] | None = None,
)

def generate_alphas(
    clips,
    device=None,
    *,
    on_clip_start: Callable[[str, int], None] | None = None,
):
    clips_to_process = [c for c in clips if c.alpha_asset is None]

    if not clips_to_process:
        logger.info("All clips have valid Alpha assets. No generation needed.")
        return

    logger.info(f"Found {len(clips_to_process)} clips missing Alpha.")

    if device is None:
        device = resolve_device()

    try:
        processor = get_gvm_processor(device=device)
    except ImportError as e:
        logger.error(f"GVM Import Error: {e}")
        logger.error("Skipping GVM generation. Please install GVM requirements if you wish to use this feature.")
        return
    except Exception as e:
        logger.error(f"GVM Initialization Error: {e}")
        return

    for clip in clips_to_process:
        logger.info(f"Generating Alpha for: {clip.name}")
        if on_clip_start:
            on_clip_start(clip.name, len(clips_to_process))

        alpha_output_dir = os.path.join(clip.root_path, "AlphaHint")
        if os.path.exists(alpha_output_dir):
            shutil.rmtree(alpha_output_dir)
        os.makedirs(alpha_output_dir, exist_ok=True)

        try:
            processor.process_sequence(
                input_path=clip.input_asset.path,
                output_dir=None,
                num_frames_per_batch=1,
                decode_chunk_size=1,
                denoise_steps=1,
                mode="matte",
                write_video=False,
                direct_output_dir=alpha_output_dir,
            )

            # Post-Process: Naming Convention
            generated_files = sorted([f for f in os.listdir(alpha_output_dir) if f.endswith(".png")])

            if not generated_files:
                logger.error(f"GVM finished but no PNGs found in {alpha_output_dir}")
                continue

            if clip.input_asset.type == "sequence":
                in_files = sorted([f for f in os.listdir(clip.input_asset.path) if is_image_file(f)])