Initial commit: audio2text 双语字幕生成服务

- 音频/视频转双语(英/中)SRT 字幕，Docker 容器化，CPU 开发/GPU 生产同一份代码
- faster-whisper ASR(词级时间戳) + 断句时间戳重算 + NLLB 翻译(模型不共驻)
- 分片上传(断点续传) + SQLite 持久化 + 主页/历史/日志页面
- 历史页文件名搜索；缓存定时清理(默认保留7天，可配置)
- 双 Dockerfile(cpu/gpu) + setup/start/stop 脚本

app/config.py

@@ -0,0 +1,136 @@
+"""运行时配置：所有参数从 config.yaml 读取，对齐 server/config.py 的风格。
+
+CPU dev / GPU prod 仅靠 device / model / compute_type 三项切换，代码完全不变。
+"""
+
+from __future__ import annotations
+
+import os
+from functools import lru_cache
+from pathlib import Path
+
+import yaml
+from pydantic import BaseModel, Field, field_validator
+
+PROJECT_ROOT = Path(__file__).resolve().parent.parent
+DEFAULT_CONFIG_PATH = PROJECT_ROOT / "config.yaml"
+
+
+class ServerConfig(BaseModel):
+    host: str = "0.0.0.0"
+    port: int = 8000
+    workers: int = 1
+
+
+class StorageConfig(BaseModel):
+    upload_dir: str = "/data/uploads"
+    work_dir: str = "/data/.work"
+    output_dir: str = "/data/outputs"
+    chunk_bytes: int = 1024 * 1024
+    chunk_session_ttl_seconds: int = 300
+    # 缓存保留：超期任务产物（输出字幕 / 中间音频 / 保留的原始视频）连同 DB 记录一并清理
+    cache_retention_days: int = 7
+    # 定时清理间隔（小时）：启动时跑一次，之后按此间隔循环
+    cache_cleanup_interval_hours: int = 24
+
+
+class ProcessingConfig(BaseModel):
+    delete_original_after_extract: bool = True
+    keep_audio: bool = False
+
+
+class AsrConfig(BaseModel):
+    model: str = "small"
+    device: str = "cpu"            # cpu | cuda
+    compute_type: str = "int8"     # cpu: int8；gpu: float16
+    language: str = "en"
+    word_timestamps: bool = True
+    vad_filter: bool = True
+
+
+class TranslationConfig(BaseModel):
+    model: str = "facebook/nllb-200-distilled-1.3B"
+    device: str = "cpu"            # cpu | cuda
+    src_lang: str = "eng_Latn"
+    tgt_lang: str = "zho_Hans"
+    batch_size: int = 16
+    max_length: int = 256
+
+
+class SegmentationConfig(BaseModel):
+    max_words_per_line: int = 14
+    max_duration_seconds: float = 7.0
+    min_duration_seconds: float = 1.0
+    max_chars_per_line: int = 42
+
+
+class LoggingConfig(BaseModel):
+    """日志配置：控制台 + 内存缓冲的最低级别，以及缓冲条数。
+
+    分层语义：
+    - debug：详细（ffmpeg 命令、模型加载/卸载、转写逐段、翻译逐批进度）
+    - info：简略（仅任务阶段转换，如 "任务 N [transcribing 55%]"）
+    - error：详细错误（完整 traceback，由 logger.exception 自带）
+    """
+
+    level: str = "info"            # debug | info | warning | error
+    buffer_size: int = 2000        # /logs 页面内存缓冲条数
+
+    @field_validator("level", mode="before")
+    @classmethod
+    def _normalize_level(cls, v):
+        return str(v).lower() if v else "info"
+
+
+class DocsConfig(BaseModel):
+    """/docs Basic Auth 凭据（明文，对齐 server）。"""
+
+    enabled: bool = True
+    username: str = "admin"
+    password: str = ""
+    realm: str = "audio2text docs"
+
+    @field_validator("password", mode="before")
+    @classmethod
+    def _coerce(cls, v):
+        return "" if v is None else str(v)
+
+
+class Settings(BaseModel):
+    server: ServerConfig = ServerConfig()
+    storage: StorageConfig = StorageConfig()
+    processing: ProcessingConfig = ProcessingConfig()
+    asr: AsrConfig = AsrConfig()
+    translation: TranslationConfig = TranslationConfig()
+    segmentation: SegmentationConfig = SegmentationConfig()
+    logging: LoggingConfig = LoggingConfig()
+    docs: DocsConfig = DocsConfig()
+
+    def upload_dir(self) -> Path:
+        return Path(self.storage.upload_dir)
+
+    def work_dir(self) -> Path:
+        return Path(self.storage.work_dir)
+
+    def output_dir(self) -> Path:
+        return Path(self.storage.output_dir)
+
+
+def _load_yaml(path: Path) -> dict:
+    if not path.exists():
+        raise FileNotFoundError(
+            f"未找到配置文件 {path}；请先 cp config.example.yaml config.yaml 并填值。"
+        )
+    return yaml.safe_load(path.read_text(encoding="utf-8")) or {}
+
+
+@lru_cache(maxsize=1)
+def get_settings() -> Settings:
+    path = Path(os.getenv("CONFIG_PATH", str(DEFAULT_CONFIG_PATH)))
+    return Settings.model_validate(_load_yaml(path))
+
+
+def reload_settings() -> Settings:
+    """清缓存并重新读取，供脚本与测试使用。"""
+    get_settings.cache_clear()
+    return get_settings()