[Core][Frontend] Unified Full-duplex Framework (#7413)

Signed-off-by: chickeyton <ngton2014@gmail.com>
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>

vllm_omni/entrypoints/duplex/audio_encoding.py

@@ -0,0 +1,55 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM-Omni project
+
+"""Audio encoding for duplex model output (entrypoint layer, injected into ``DuplexOmniEngine``)."""
+
+from __future__ import annotations
+
+import numpy as np
+from vllm.logger import init_logger
+
+logger = init_logger(__name__)
+
+
+def encode_audio(
+    audio_data: object,
+    sample_rate_hz: int,
+    response_format: str,
+    speed: float | None,
+) -> str | None:
+    """Encode a model audio tensor/array into base64 in ``response_format``.
+
+    Moved from the serving runtime bridge; uses the shared ``AudioMixin``
+    encoder directly instead of going through the chat service.
+    """
+    if audio_data is None:
+        return None
+    try:
+        import torch
+
+        from vllm_omni.entrypoints.openai.audio_utils_mixin import AudioMixin
+        from vllm_omni.entrypoints.openai.protocol.audio import CreateAudio
+
+        if isinstance(audio_data, torch.Tensor):
+            audio_tensor = audio_data.detach().cpu().float().numpy()
+        else:
+            audio_tensor = np.asarray(audio_data, dtype=np.float32)
+        if audio_tensor.ndim > 1:
+            audio_tensor = audio_tensor.reshape(-1)
+        audio_response = AudioMixin().create_audio(
+            CreateAudio(
+                audio_tensor=audio_tensor,
+                sample_rate=sample_rate_hz,
+                response_format=response_format,
+                speed=float(speed) if isinstance(speed, int | float) and speed > 0 else 1.0,
+                stream_format="audio",
+                base64_encode=True,
+            )
+        )
+        return str(audio_response.audio_data)
+    except Exception:
+        logger.exception("Failed to encode duplex data-plane audio output")
+        return None
+
+
+__all__ = ["encode_audio"]