[WebRTC音频底座]：完成全双工音频基础模块，包含环形缓冲、APM接口和fake回声抑制测试

src/owner_voice_pet/models.py

@@ -23,6 +23,10 @@ class ErrorCode(str, Enum):
     AUDIO_PERMISSION_DENIED = "AUDIO_PERMISSION_DENIED"
     AUDIO_STREAM_UNDERRUN = "AUDIO_STREAM_UNDERRUN"
     AUDIO_FORMAT_UNSUPPORTED = "AUDIO_FORMAT_UNSUPPORTED"
+    AUDIO_APM_UNAVAILABLE = "AUDIO_APM_UNAVAILABLE"
+    AUDIO_APM_FORMAT_MISMATCH = "AUDIO_APM_FORMAT_MISMATCH"
+    AUDIO_APM_PROCESS_FAILED = "AUDIO_APM_PROCESS_FAILED"
+    AUDIO_BUFFER_OVERRUN = "AUDIO_BUFFER_OVERRUN"
     CONFIG_MISSING_VALUE = "CONFIG_MISSING_VALUE"
     WAKE_MODEL_MISSING = "WAKE_MODEL_MISSING"
     WAKE_MODEL_LOAD_FAILED = "WAKE_MODEL_LOAD_FAILED"
@@ -78,6 +82,38 @@ class AudioFrame:
         if self.frame_id < 0:
             raise ValueError("frame_id must be non-negative")
 
+    @property
+    def duration_ms(self) -> int:
+        metadata_duration = self.metadata.get("duration_ms")
+        if isinstance(metadata_duration, int):
+            return metadata_duration
+        bytes_per_sample = 2
+        if self.channels <= 0:
+            return 0
+        sample_count = len(self.pcm) // (bytes_per_sample * self.channels)
+        return round(sample_count * 1000 / self.sample_rate)
+
+    def to_fixture(self) -> dict[str, Any]:
+        return {
+            "pcm_hex": self.pcm.hex(),
+            "sample_rate": self.sample_rate,
+            "channels": self.channels,
+            "timestamp_ms": self.timestamp_ms,
+            "frame_id": self.frame_id,
+            "metadata": dict(self.metadata),
+        }
+
+    @classmethod
+    def from_fixture(cls, data: Mapping[str, Any]) -> "AudioFrame":
+        return cls(
+            pcm=bytes.fromhex(str(data["pcm_hex"])),
+            sample_rate=int(data["sample_rate"]),
+            channels=int(data["channels"]),
+            timestamp_ms=int(data["timestamp_ms"]),
+            frame_id=int(data["frame_id"]),
+            metadata=dict(data.get("metadata") or {}),
+        )
+
 
 @dataclass(frozen=True, slots=True)
 class AudioSegment: