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wov-node-whisper/wov_node_whisper/__main__.py
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Python

"""faster-whisper ASR 节点入口。
使用 faster-whisper 加载 Whisper 模型,将音频转写为带时间轴的 SRT 文件。
模型、设备与计算类型均可通过参数或环境变量配置。
"""
from __future__ import annotations
import json
import os
from pathlib import Path
from wov_sdk.models import InvokeRequest, InvokeResponse, NodeManifest
from wov_sdk.server import run_node
def format_timestamp(seconds: float) -> str:
"""把秒数格式化为 SRT 时间戳,例如 01:00:00,500。"""
# 先换算成毫秒再逐级拆分为时/分/秒/毫秒,避免浮点误差。
total_ms = int(seconds * 1000)
hours, remainder = divmod(total_ms, 3600000)
minutes, remainder = divmod(remainder, 60000)
secs, millis = divmod(remainder, 1000)
return f"{hours:02d}:{minutes:02d}:{secs:02d},{millis:03d}"
def invoke(request: InvokeRequest) -> InvokeResponse:
"""转写音频并生成 SRT 字幕,产物为 transcript.srt。"""
audio_uri = request.inputs.get("audio_uri")
if not audio_uri:
return InvokeResponse(status="failed", error="audio_uri is required")
# 文件不存在时提前失败,避免进入耗时的模型加载流程。
audio_path = Path(audio_uri)
if not audio_path.is_file():
return InvokeResponse(status="failed", error="audio file not found")
try:
# 延迟导入 faster-whisper,保证健康检查等轻量路径不依赖重型依赖。
from faster_whisper import WhisperModel
# 参数优先于环境变量;模型路径缺省使用 faster-whisper 的 large-v3。
model_path = str(
request.params.get("model_path")
or os.getenv("WHISPER_MODEL_PATH", "large-v3")
)
device = str(request.params.get("device") or os.getenv("WHISPER_DEVICE", "auto"))
# auto 让 faster-whisper 根据硬件自动选择 float16/int8 等计算类型。
compute_type = str(request.params.get("compute_type") or "auto")
model = WhisperModel(
model_path,
device=device,
compute_type=compute_type,
)
# language 默认日语,vad_filter 过滤静音段以提升转写质量。
segments, _info = model.transcribe(
str(audio_path),
language=str(request.params.get("language", "ja")),
beam_size=int(request.params.get("beam_size", 1)),
vad_filter=bool(request.params.get("vad_filter", True)),
)
output_dir = Path(request.output_dir)
output_dir.mkdir(parents=True, exist_ok=True)
output_path = output_dir / "transcript.srt"
# 按 SRT 标准输出:序号、时间轴、文本和空行交替。
lines: list[str] = []
for index, segment in enumerate(segments, start=1):
lines.extend(
[
str(index),
f"{format_timestamp(segment.start)} --> {format_timestamp(segment.end)}",
segment.text.strip(),
"",
]
)
output_path.write_text("\n".join(lines), encoding="utf-8")
return InvokeResponse(status="completed", outputs={"srt_uri": str(output_path)})
except Exception as exc: # noqa: BLE001
# 模型加载或转写异常统一转换为 failed 响应,不让节点进程退出。
return InvokeResponse(status="failed", error=str(exc))
def main() -> None:
"""加载节点清单并以本模块的 invoke 处理器启动服务。"""
manifest_path = Path(__file__).resolve().parent.parent / "node.manifest.json"
with open(manifest_path, "r", encoding="utf-8") as f:
manifest = NodeManifest.from_dict(json.load(f))
run_node(manifest, invoke)
if __name__ == "__main__":
main()