[Model] Add Stable Audio Open support for text-to-audio generation

examples/offline_inference/text_to_audio/text_to_audio.py

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+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+
+"""
+Example script for text-to-audio generation using Stable Audio Open.
+
+This script demonstrates how to generate audio from text prompts using
+the Stable Audio Open model with vLLM-Omni.
+
+Usage:
+    python text_to_audio.py --prompt "The sound of a dog barking"
+    python text_to_audio.py --prompt "A piano playing a gentle melody" --audio_length 10.0
+    python text_to_audio.py --prompt "Thunder and rain sounds" --negative_prompt "Low quality"
+"""
+
+import argparse
+import time
+from pathlib import Path
+
+import numpy as np
+import torch
+
+from vllm_omni.entrypoints.omni import Omni
+from vllm_omni.utils.platform_utils import detect_device_type
+
+
+def parse_args() -> argparse.Namespace:
+    parser = argparse.ArgumentParser(description="Generate audio with Stable Audio Open.")
+    parser.add_argument(
+        "--model",
+        default="stabilityai/stable-audio-open-1.0",
+        help="Stable Audio model name or local path.",
+    )
+    parser.add_argument(
+        "--prompt",
+        default="The sound of a hammer hitting a wooden surface.",
+        help="Text prompt for audio generation.",
+    )
+    parser.add_argument(
+        "--negative_prompt",
+        default="Low quality.",
+        help="Negative prompt for classifier-free guidance.",
+    )
+    parser.add_argument(
+        "--seed",
+        type=int,
+        default=42,
+        help="Random seed for deterministic results.",
+    )
+    parser.add_argument(
+        "--guidance_scale",
+        type=float,
+        default=7.0,
+        help="Classifier-free guidance scale.",
+    )
+    parser.add_argument(
+        "--audio_start",
+        type=float,
+        default=0.0,
+        help="Audio start time in seconds.",
+    )
+    parser.add_argument(
+        "--audio_length",
+        type=float,
+        default=10.0,
+        help="Audio length in seconds (max ~47s for stable-audio-open-1.0).",
+    )
+    parser.add_argument(
+        "--num_inference_steps",
+        type=int,
+        default=100,
+        help="Number of denoising steps for the diffusion sampler.",
+    )
+    parser.add_argument(
+        "--num_waveforms",
+        type=int,
+        default=1,
+        help="Number of audio waveforms to generate for the given prompt.",
+    )
+    parser.add_argument(
+        "--output",
+        type=str,
+        default="stable_audio_output.wav",
+        help="Path to save the generated audio (WAV format).",
+    )
+    parser.add_argument(
+        "--sample_rate",
+        type=int,
+        default=44100,
+        help="Sample rate for output audio (Stable Audio uses 44100 Hz).",
+    )
+    return parser.parse_args()
+
+
+def save_audio(audio_data: np.ndarray, output_path: str, sample_rate: int = 44100):
+    """Save audio data to a WAV file."""
+    try:
+        import soundfile as sf
+
+        sf.write(output_path, audio_data, sample_rate)
+    except ImportError:
+        try:
+            import scipy.io.wavfile as wav
+
+            # Ensure audio is in the correct format for scipy
+            if audio_data.dtype == np.float32 or audio_data.dtype == np.float64:
+                # Normalize to int16 range
+                audio_data = np.clip(audio_data, -1.0, 1.0)
+                audio_data = (audio_data * 32767).astype(np.int16)
+            wav.write(output_path, sample_rate, audio_data)
+        except ImportError:
+            raise ImportError(
+                "Either 'soundfile' or 'scipy' is required to save audio files. "
+                "Install with: pip install soundfile or pip install scipy"
+            )
+
+
+def main():
+    args = parse_args()
+    device = detect_device_type()
+    generator = torch.Generator(device=device).manual_seed(args.seed)
+
+    print(f"\n{'=' * 60}")
+    print("Stable Audio Open - Text-to-Audio Generation")
+    print(f"{'=' * 60}")
+    print(f"  Model: {args.model}")
+    print(f"  Prompt: {args.prompt}")
+    print(f"  Negative prompt: {args.negative_prompt}")
+    print(f"  Audio length: {args.audio_length}s")
+    print(f"  Inference steps: {args.num_inference_steps}")
+    print(f"  Guidance scale: {args.guidance_scale}")
+    print(f"  Seed: {args.seed}")
+    print(f"{'=' * 60}\n")
+
+    # Initialize Omni with Stable Audio model
+    omni = Omni(model=args.model)
+
+    # Calculate audio end time
+    audio_end_in_s = args.audio_start + args.audio_length
+
+    # Time profiling for generation
+    generation_start = time.perf_counter()
+
+    # Generate audio
+    audio = omni.generate(
+        args.prompt,
+        negative_prompt=args.negative_prompt,
+        generator=generator,
+        guidance_scale=args.guidance_scale,
+        num_inference_steps=args.num_inference_steps,
+        num_outputs_per_prompt=args.num_waveforms,
+        extra={
+            "audio_start_in_s": args.audio_start,
+            "audio_end_in_s": audio_end_in_s,
+        },
+    )
+
+    generation_end = time.perf_counter()
+    generation_time = generation_end - generation_start
+
+    print(f"Total generation time: {generation_time:.2f} seconds")
+
+    # Process and save audio
+    output_path = Path(args.output)
+    output_path.parent.mkdir(parents=True, exist_ok=True)
+    suffix = output_path.suffix or ".wav"
+    stem = output_path.stem or "stable_audio_output"
+
+    # Handle different output formats
+    if isinstance(audio, torch.Tensor):
+        audio = audio.cpu().float().numpy()
+
+    # Audio shape is typically [batch, channels, samples] or [channels, samples]
+    if audio.ndim == 3:
+        # [batch, channels, samples]
+        if args.num_waveforms <= 1:
+            audio_data = audio[0].T  # [samples, channels]
+            save_audio(audio_data, str(output_path), args.sample_rate)
+            print(f"Saved generated audio to {output_path}")
+        else:
+            for idx in range(audio.shape[0]):
+                audio_data = audio[idx].T  # [samples, channels]
+                save_path = output_path.parent / f"{stem}_{idx}{suffix}"
+                save_audio(audio_data, str(save_path), args.sample_rate)
+                print(f"Saved generated audio to {save_path}")
+    elif audio.ndim == 2:
+        # [channels, samples]
+        audio_data = audio.T  # [samples, channels]
+        save_audio(audio_data, str(output_path), args.sample_rate)
+        print(f"Saved generated audio to {output_path}")
+    else:
+        # [samples] - mono audio
+        save_audio(audio, str(output_path), args.sample_rate)
+        print(f"Saved generated audio to {output_path}")
+
+    print(f"\nGenerated {args.audio_length}s of audio at {args.sample_rate} Hz")
+
+
+if __name__ == "__main__":
+    main()

vllm_omni/diffusion/models/stable_audio/__init__.py

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+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+
+"""Stable Audio Open model support for vLLM-Omni."""
+
+from vllm_omni.diffusion.models.stable_audio.pipeline_stable_audio import (
+    StableAudioPipeline,
+    get_stable_audio_post_process_func,
+)
+from vllm_omni.diffusion.models.stable_audio.stable_audio_transformer import (
+    StableAudioDiTModel,
+)
+
+__all__ = [
+    "StableAudioDiTModel",
+    "StableAudioPipeline",
+    "get_stable_audio_post_process_func",
+]