[Core] Unified quantization framework (#1764)

benchmarks/diffusion/quantization_quality.py

@@ -0,0 +1,460 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+
+"""
+Benchmark quantization quality loss for diffusion models (image & video).
+
+Generates outputs with BF16 (baseline) and a quantized config using the same
+seed, then computes LPIPS perceptual distance between them. Results are printed
+as a Markdown table ready to paste into a PR description.
+
+Requirements:
+    pip install lpips Pillow numpy
+
+Image example (text-to-image):
+    python benchmarks/diffusion/quantization_quality.py \
+        --model Tongyi-MAI/Z-Image-Turbo \
+        --task t2i \
+        --quantization fp8 \
+        --prompts \
+            "an aerial view of a coral reef with crystal clear turquoise water" \
+            "a campfire in a dark forest with sparks rising into a starry sky" \
+            "a gourmet dessert plate with chocolate mousse and gold leaf" \
+        --height 1024 --width 1024 \
+        --num-inference-steps 50 --seed 42
+
+Video example (text-to-video):
+    python benchmarks/diffusion/quantization_quality.py \
+        --model Wan-AI/Wan2.2-T2V-A14B-Diffusers \
+        --task t2v \
+        --quantization fp8 \
+        --prompts \
+            "A serene lakeside sunrise with mist over the water" \
+            "A cat walking across a wooden bridge in autumn" \
+        --height 720 --width 1280 \
+        --num-frames 81 --num-inference-steps 40 --seed 42
+
+Multiple quantization methods:
+    python benchmarks/diffusion/quantization_quality.py \
+        --model Tongyi-MAI/Z-Image-Turbo \
+        --task t2i \
+        --quantization fp8 int8 bitsandbytes \
+        --prompts "a cup of coffee on the table" \
+        --height 1024 --width 1024 \
+        --num-inference-steps 50 --seed 42
+
+Output directory structure (--output-dir, default: ./quant_bench_output):
+    quant_bench_output/
+        baseline/           # BF16 outputs
+        <method>/           # Quantized outputs per method
+        results.md          # Markdown table
+"""
+
+import argparse
+import gc
+import time
+from pathlib import Path
+
+import numpy as np
+import torch
+
+
+def compute_lpips_images(
+    baseline_images: list,
+    quantized_images: list,
+    net: str = "alex",
+) -> list[float]:
+    """Compute LPIPS between paired lists of PIL images."""
+    import lpips
+    from torchvision import transforms
+
+    loss_fn = lpips.LPIPS(net=net).eval()
+    if torch.cuda.is_available():
+        loss_fn = loss_fn.cuda()
+
+    transform = transforms.Compose(
+        [
+            transforms.Resize((256, 256)),
+            transforms.ToTensor(),
+            transforms.Normalize(mean=[0.5, 0.5, 0.5], std=[0.5, 0.5, 0.5]),
+        ]
+    )
+
+    scores = []
+    for img_bl, img_qt in zip(baseline_images, quantized_images):
+        t_bl = transform(img_bl.convert("RGB")).unsqueeze(0)
+        t_qt = transform(img_qt.convert("RGB")).unsqueeze(0)
+        if torch.cuda.is_available():
+            t_bl, t_qt = t_bl.cuda(), t_qt.cuda()
+        with torch.no_grad():
+            score = loss_fn(t_bl, t_qt).item()
+        scores.append(score)
+    return scores
+
+
+def compute_lpips_video(
+    baseline_frames: np.ndarray,
+    quantized_frames: np.ndarray,
+    net: str = "alex",
+) -> float:
+    """Compute mean per-frame LPIPS for a video pair.
+
+    Args:
+        baseline_frames: (F, H, W, C) float array in [0, 1].
+        quantized_frames: same shape.
+
+    Returns:
+        Mean LPIPS across all frames.
+    """
+    import lpips
+
+    loss_fn = lpips.LPIPS(net=net).eval()
+    if torch.cuda.is_available():
+        loss_fn = loss_fn.cuda()
+
+    num_frames = min(len(baseline_frames), len(quantized_frames))
+    scores = []
+    for i in range(num_frames):
+        # Convert (H, W, C) float [0,1] -> (1, C, H, W) float [-1, 1]
+        f_bl = torch.from_numpy(baseline_frames[i]).permute(2, 0, 1).unsqueeze(0).float() * 2 - 1
+        f_qt = torch.from_numpy(quantized_frames[i]).permute(2, 0, 1).unsqueeze(0).float() * 2 - 1
+        if torch.cuda.is_available():
+            f_bl, f_qt = f_bl.cuda(), f_qt.cuda()
+        with torch.no_grad():
+            score = loss_fn(f_bl, f_qt).item()
+        scores.append(score)
+    return float(np.mean(scores))
+
+
+def _build_omni_kwargs(args, quantization=None):
+    """Build kwargs dict for Omni() constructor."""
+    from vllm_omni.diffusion.data import DiffusionParallelConfig
+
+    parallel_config = DiffusionParallelConfig(
+        ulysses_degree=args.ulysses_degree,
+        ring_degree=args.ring_degree,
+        tensor_parallel_size=args.tensor_parallel_size,
+    )
+    kwargs = {
+        "model": args.model,
+        "parallel_config": parallel_config,
+        "enforce_eager": args.enforce_eager,
+    }
+    if quantization:
+        kwargs["quantization_config"] = quantization
+    return kwargs
+
+
+def _generate_image(omni, args, prompt, seed):
+    """Generate a single image and return (PIL.Image, time_seconds, memory_gib)."""
+    from vllm_omni.inputs.data import OmniDiffusionSamplingParams
+    from vllm_omni.platforms import current_omni_platform
+
+    generator = torch.Generator(device=current_omni_platform.device_type).manual_seed(seed)
+    torch.cuda.reset_peak_memory_stats()
+    start = time.perf_counter()
+    outputs = omni.generate(
+        {"prompt": prompt},
+        OmniDiffusionSamplingParams(
+            height=args.height,
+            width=args.width,
+            generator=generator,
+            num_inference_steps=args.num_inference_steps,
+        ),
+    )
+    elapsed = time.perf_counter() - start
+    peak_mem = torch.cuda.max_memory_allocated() / (1024**3)
+
+    first = outputs[0]
+    req_out = first.request_output[0] if hasattr(first, "request_output") else first
+    img = req_out.images[0]
+    return img, elapsed, peak_mem
+
+
+def _generate_video(omni, args, prompt, seed):
+    """Generate a video and return (np.ndarray [F,H,W,C], time_seconds, memory_gib)."""
+    from vllm_omni.inputs.data import OmniDiffusionSamplingParams
+    from vllm_omni.outputs import OmniRequestOutput
+    from vllm_omni.platforms import current_omni_platform
+
+    generator = torch.Generator(device=current_omni_platform.device_type).manual_seed(seed)
+    torch.cuda.reset_peak_memory_stats()
+    start = time.perf_counter()
+    outputs = omni.generate(
+        {"prompt": prompt, "negative_prompt": ""},
+        OmniDiffusionSamplingParams(
+            height=args.height,
+            width=args.width,
+            generator=generator,
+            guidance_scale=args.guidance_scale,
+            num_inference_steps=args.num_inference_steps,
+            num_frames=args.num_frames,
+        ),
+    )
+    elapsed = time.perf_counter() - start
+    peak_mem = torch.cuda.max_memory_allocated() / (1024**3)
+
+    first = outputs[0]
+    if hasattr(first, "request_output") and isinstance(first.request_output, list):
+        inner = first.request_output[0]
+        if isinstance(inner, OmniRequestOutput) and hasattr(inner, "images"):
+            frames = inner.images[0] if inner.images else None
+        else:
+            frames = inner
+    elif hasattr(first, "images") and first.images:
+        frames = first.images
+    else:
+        raise ValueError("Could not extract video frames from output.")
+
+    if isinstance(frames, torch.Tensor):
+        video = frames.detach().cpu()
+        if video.dim() == 5:
+            video = video[0].permute(1, 2, 3, 0) if video.shape[1] in (3, 4) else video[0]
+        elif video.dim() == 4 and video.shape[0] in (3, 4):
+            video = video.permute(1, 2, 3, 0)
+        if video.is_floating_point():
+            video = video.clamp(-1, 1) * 0.5 + 0.5
+        frames_array = video.float().numpy()
+    else:
+        frames_array = np.asarray(frames)
+        if frames_array.ndim == 5:
+            frames_array = frames_array[0]
+
+    return frames_array, elapsed, peak_mem
+
+
+def _unload_omni(omni):
+    """Delete Omni instance and free GPU memory."""
+    del omni
+    gc.collect()
+    if torch.cuda.is_available():
+        torch.cuda.empty_cache()
+        torch.cuda.synchronize()
+
+
+def run_benchmark(args):
+    from vllm_omni.entrypoints.omni import Omni
+
+    output_dir = Path(args.output_dir)
+    output_dir.mkdir(parents=True, exist_ok=True)
+
+    is_video = args.task == "t2v"
+    prompts = args.prompts
+    seed = args.seed
+
+    # Determine configs to benchmark
+    configs = []  # list of (label, quantization_method)
+    for method in args.quantization:
+        configs.append((method, method))
+
+    # --- Baseline run ---
+    print("\n" + "=" * 60)
+    print("Running BF16 baseline...")
+    print("=" * 60)
+    bl_kwargs = _build_omni_kwargs(args, quantization=None)
+    omni_bl = Omni(**bl_kwargs)
+
+    baseline_outputs = {}  # prompt -> (output, time, mem)
+    for prompt in prompts:
+        print(f"  Generating: {prompt[:60]}...")
+        if is_video:
+            out, t, mem = _generate_video(omni_bl, args, prompt, seed)
+        else:
+            out, t, mem = _generate_image(omni_bl, args, prompt, seed)
+        baseline_outputs[prompt] = (out, t, mem)
+
+    bl_avg_time = np.mean([v[1] for v in baseline_outputs.values()])
+    bl_mem = baseline_outputs[prompts[0]][2]  # use first prompt's memory
+    _unload_omni(omni_bl)
+
+    # Save baseline outputs
+    bl_dir = output_dir / "baseline"
+    bl_dir.mkdir(parents=True, exist_ok=True)
+    for i, prompt in enumerate(prompts):
+        out = baseline_outputs[prompt][0]
+        if is_video:
+            try:
+                from diffusers.utils import export_to_video
+
+                frames_list = list(out) if isinstance(out, np.ndarray) and out.ndim == 4 else out
+                export_to_video(frames_list, str(bl_dir / f"prompt_{i}.mp4"), fps=args.fps)
+            except ImportError:
+                np.save(bl_dir / f"prompt_{i}.npy", out)
+        else:
+            out.save(bl_dir / f"prompt_{i}.png")
+
+    # --- Quantized runs ---
+    all_results = []  # list of dicts
+
+    for config_label, quant_method in configs:
+        print(f"\n{'=' * 60}")
+        print(f"Running: {config_label}...")
+        print("=" * 60)
+
+        qt_kwargs = _build_omni_kwargs(args, quantization=quant_method)
+        omni_qt = Omni(**qt_kwargs)
+
+        qt_outputs = {}
+        for prompt in prompts:
+            print(f"  Generating: {prompt[:60]}...")
+            if is_video:
+                out, t, mem = _generate_video(omni_qt, args, prompt, seed)
+            else:
+                out, t, mem = _generate_image(omni_qt, args, prompt, seed)
+            qt_outputs[prompt] = (out, t, mem)
+
+        qt_avg_time = np.mean([v[1] for v in qt_outputs.values()])
+        qt_mem = qt_outputs[prompts[0]][2]
+        _unload_omni(omni_qt)
+
+        # Save quantized outputs
+        qt_dir = output_dir / config_label.replace(" ", "_")
+        qt_dir.mkdir(parents=True, exist_ok=True)
+
+        # Compute LPIPS per prompt
+        per_prompt = []
+        for i, prompt in enumerate(prompts):
+            bl_out = baseline_outputs[prompt][0]
+            qt_out = qt_outputs[prompt][0]
+            if is_video:
+                lpips_score = compute_lpips_video(bl_out, qt_out, net=args.lpips_net)
+                try:
+                    from diffusers.utils import export_to_video
+
+                    frames_list = list(qt_out) if isinstance(qt_out, np.ndarray) and qt_out.ndim == 4 else qt_out
+                    export_to_video(frames_list, str(qt_dir / f"prompt_{i}.mp4"), fps=args.fps)
+                except ImportError:
+                    np.save(qt_dir / f"prompt_{i}.npy", qt_out)
+            else:
+                lpips_score = compute_lpips_images([bl_out], [qt_out], net=args.lpips_net)[0]
+                qt_out.save(qt_dir / f"prompt_{i}.png")
+            per_prompt.append({"prompt": prompt, "lpips": lpips_score})
+
+        mean_lpips = np.mean([p["lpips"] for p in per_prompt])
+        speedup = bl_avg_time / qt_avg_time if qt_avg_time > 0 else float("inf")
+        mem_reduction = (bl_mem - qt_mem) / bl_mem * 100
+
+        all_results.append(
+            {
+                "config": config_label,
+                "avg_time": qt_avg_time,
+                "speedup": speedup,
+                "memory_gib": qt_mem,
+                "mem_reduction_pct": mem_reduction,
+                "mean_lpips": mean_lpips,
+                "per_prompt": per_prompt,
+            }
+        )
+
+    # --- Print results ---
+    print("\n\n")
+    print("=" * 80)
+    print("RESULTS")
+    print("=" * 80)
+
+    # Summary table
+    lines = []
+    lines.append(f"## Quantization Quality Benchmark — {args.model.split('/')[-1]}")
+    lines.append(
+        f"Setup: {args.height}x{args.width}, {args.num_inference_steps} steps, "
+        f"seed={args.seed}, LPIPS ({args.lpips_net})"
+    )
+    if is_video:
+        lines.append(f"Video: {args.num_frames} frames")
+    lines.append("")
+    lines.append("### Summary")
+    lines.append("")
+    lines.append("| Config | Avg Time | Speedup | Memory (GiB) | Mem Reduction | Mean LPIPS |")
+    lines.append("|--------|----------|---------|--------------|---------------|------------|")
+    lines.append(f"| BF16 baseline | {bl_avg_time:.2f}s | 1.00x | {bl_mem:.2f} | — | (ref) |")
+    for r in all_results:
+        lines.append(
+            f"| {r['config']} | {r['avg_time']:.2f}s | {r['speedup']:.2f}x "
+            f"| {r['memory_gib']:.2f} | {r['mem_reduction_pct']:.0f}% "
+            f"| {r['mean_lpips']:.4f} |"
+        )
+    lines.append("")
+    lines.append("> LPIPS < 0.01 = imperceptible, > 0.1 = clearly noticeable.")
+    lines.append("")
+
+    # Per-prompt table
+    if len(prompts) > 1:
+        lines.append("### Per-Prompt LPIPS")
+        lines.append("")
+        header = "| Prompt |"
+        sep = "|--------|"
+        for r in all_results:
+            header += f" {r['config']} |"
+            sep += "--------|"
+        lines.append(header)
+        lines.append(sep)
+        for i, prompt in enumerate(prompts):
+            short = prompt[:50] + "..." if len(prompt) > 50 else prompt
+            row = f"| {short} |"
+            for r in all_results:
+                row += f" {r['per_prompt'][i]['lpips']:.4f} |"
+            lines.append(row)
+        lines.append("")
+
+    md = "\n".join(lines)
+    print(md)
+
+    # Save markdown
+    results_path = output_dir / "results.md"
+    results_path.write_text(md, encoding="utf-8")
+    print(f"\nResults saved to {results_path}")
+    print(f"Baseline outputs in {bl_dir}")
+    for r in all_results:
+        qt_dir = output_dir / r["config"].replace(" ", "_")
+        print(f"Quantized outputs in {qt_dir}")
+
+
+def parse_args():
+    parser = argparse.ArgumentParser(
+        description="Benchmark quantization quality loss for diffusion models.",
+        formatter_class=argparse.RawDescriptionHelpFormatter,
+    )
+    parser.add_argument("--model", required=True, help="Model name or local path.")
+    parser.add_argument(
+        "--task",
+        default="t2i",
+        choices=["t2i", "t2v"],
+        help="Task type: t2i (text-to-image) or t2v (text-to-video).",
+    )
+    parser.add_argument(
+        "--quantization",
+        nargs="+",
+        required=True,
+        help="One or more quantization methods to benchmark (e.g. fp8 int8 bitsandbytes).",
+    )
+    parser.add_argument(
+        "--prompts",
+        nargs="+",
+        default=["a cup of coffee on the table"],
+        help="One or more prompts to generate.",
+    )
+    parser.add_argument("--seed", type=int, default=42)
+    parser.add_argument("--height", type=int, default=1024)
+    parser.add_argument("--width", type=int, default=1024)
+    parser.add_argument("--num-inference-steps", type=int, default=50)
+    parser.add_argument("--num-frames", type=int, default=81, help="Number of video frames (t2v only).")
+    parser.add_argument("--fps", type=int, default=24, help="Video FPS for saving (t2v only).")
+    parser.add_argument("--guidance-scale", type=float, default=4.0, help="CFG scale (used for video).")
+    parser.add_argument("--output-dir", type=str, default="./quant_bench_output", help="Directory to save outputs.")
+    parser.add_argument(
+        "--lpips-net",
+        type=str,
+        default="alex",
+        choices=["alex", "vgg", "squeeze"],
+        help="LPIPS backbone network.",
+    )
+    parser.add_argument("--ulysses-degree", type=int, default=1)
+    parser.add_argument("--ring-degree", type=int, default=1)
+    parser.add_argument("--tensor-parallel-size", type=int, default=1)
+    parser.add_argument("--enforce-eager", action="store_true")
+    return parser.parse_args()
+
+
+if __name__ == "__main__":
+    args = parse_args()
+    run_benchmark(args)