From 4c5399c2fca2646f21c85ceaf088328b492783f4 Mon Sep 17 00:00:00 2001
From: Dmitry Dementev <me@dementev.space>
Date: Sat, 21 Mar 2026 23:18:39 +0300
Subject: [PATCH] =?UTF-8?q?refactor(transcriber):=20=D0=B2=D0=B2=D0=B5?=
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- Зачем:
  - подготовка к добавлению OpenVINO бэкенда для ускорения на x86 CPU без CUDA.
  - архитектура должна позволять добавлять новые бэкенды (CoreML, AMD XDNA) без переписывания кода.
- Что:
  - создан types.py с общими типами (Segment, TranscribeResult, TranscribeFileResult).
  - создан backends/base.py с Backend Protocol (3 метода: ensure_model_available, create_model, transcribe).
  - создан backends/faster_whisper.py — текущий код вынесен из transcriber.py в FasterWhisperBackend.
  - transcriber.py переделан в оркестратор: load_model() владеет полным пайплайном (ensure + create), CLI больше не вызывает ensure_model_available() отдельно.
  - TranscribeFileResult расширен полями backend и model_path для корректного cross-backend fallback в батч-режиме.
  - device_used проставляется оркестратором, а не бэкендом.
  - cli.py: вынесен _format_device_info(), подготовлен к openvino.
  - тесты обновлены: mock-точки перенесены с WhisperModel на get_backend/бэкенд-объекты.
- Проверка:
  - uv run pytest -v — 98 passed.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 src/local_transcriber/backends/__init__.py    |  28 +
 src/local_transcriber/backends/base.py        |  46 ++
 .../backends/faster_whisper.py                | 181 ++++++
 src/local_transcriber/cli.py                  |  61 +-
 src/local_transcriber/formatter.py            |   2 +-
 src/local_transcriber/transcriber.py          | 253 ++------
 src/local_transcriber/types.py                |  34 ++
 tests/test_cli.py                             | 197 ++++---
 tests/test_transcriber.py                     | 555 +++++++++---------
 9 files changed, 747 insertions(+), 610 deletions(-)
 create mode 100644 src/local_transcriber/backends/__init__.py
 create mode 100644 src/local_transcriber/backends/base.py
 create mode 100644 src/local_transcriber/backends/faster_whisper.py
 create mode 100644 src/local_transcriber/types.py

diff --git a/src/local_transcriber/backends/__init__.py b/src/local_transcriber/backends/__init__.py
new file mode 100644
index 0000000..213475c
--- /dev/null
+++ b/src/local_transcriber/backends/__init__.py
@@ -0,0 +1,28 @@
+"""Реестр бэкендов транскрипции и выбор бэкенда по устройству."""
+
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from .base import Backend
+
+
+def get_backend(device: str) -> Backend:
+    """Возвращает экземпляр бэкенда для указанного устройства.
+
+    Импорты ленивые — бэкенд загружается только при запросе.
+    """
+    if device == "openvino":
+        try:
+            from .openvino import OpenVINOBackend
+        except ImportError:
+            raise ValueError(
+                "OpenVINO бэкенд недоступен. Установите: pip install openvino-genai"
+            ) from None
+        return OpenVINOBackend()
+
+    # cuda, cpu и всё остальное → faster-whisper
+    from .faster_whisper import FasterWhisperBackend
+
+    return FasterWhisperBackend()
diff --git a/src/local_transcriber/backends/base.py b/src/local_transcriber/backends/base.py
new file mode 100644
index 0000000..0435064
--- /dev/null
+++ b/src/local_transcriber/backends/base.py
@@ -0,0 +1,46 @@
+"""Протокол бэкенда транскрипции."""
+
+from __future__ import annotations
+
+from collections.abc import Callable
+from pathlib import Path
+from typing import Any, Protocol
+
+from local_transcriber.types import Segment, TranscribeResult
+
+
+class Backend(Protocol):
+    """Минимальный интерфейс бэкенда транскрипции.
+
+    Бэкенды реализуют этот протокол (structural typing) —
+    наследование не требуется.
+    """
+
+    def ensure_model_available(
+        self,
+        model_name: str,
+        compute_type: str,
+        on_status: Callable[[str], None] | None = None,
+    ) -> str:
+        """Гарантирует наличие модели, возвращает путь к файлам."""
+        ...
+
+    def create_model(
+        self,
+        model_path: str,
+        device: str,
+        compute_type: str,
+    ) -> Any:
+        """Создаёт модель. Возвращает backend-специфичный объект."""
+        ...
+
+    def transcribe(
+        self,
+        model: Any,
+        file_path: Path,
+        language: str | None,
+        on_segment: Callable[[Segment], None] | None = None,
+        on_status: Callable[[str], None] | None = None,
+    ) -> TranscribeResult:
+        """Транскрибирует файл, возвращает результат."""
+        ...
diff --git a/src/local_transcriber/backends/faster_whisper.py b/src/local_transcriber/backends/faster_whisper.py
new file mode 100644
index 0000000..8998e54
--- /dev/null
+++ b/src/local_transcriber/backends/faster_whisper.py
@@ -0,0 +1,181 @@
+"""Бэкенд транскрипции на основе faster-whisper (CTranslate2)."""
+
+from __future__ import annotations
+
+import gc
+import io
+import warnings
+from collections.abc import Callable
+from pathlib import Path
+from typing import Any
+
+# CUDA bootstrap — должен быть ДО импорта faster_whisper / ctranslate2
+from local_transcriber._cuda_bootstrap import ensure_cublas_loadable
+
+ensure_cublas_loadable()
+
+from faster_whisper import WhisperModel  # noqa: E402
+from huggingface_hub import snapshot_download  # noqa: E402
+from huggingface_hub.errors import LocalEntryNotFoundError  # noqa: E402
+
+from local_transcriber.types import Segment, TranscribeResult  # noqa: E402
+
+MODEL_REPOS = {
+    "tiny": "Systran/faster-whisper-tiny",
+    "base": "Systran/faster-whisper-base",
+    "small": "Systran/faster-whisper-small",
+    "medium": "Systran/faster-whisper-medium",
+    "large-v3": "Systran/faster-whisper-large-v3",
+}
+
+MODEL_ALLOW_PATTERNS = [
+    "config.json",
+    "preprocessor_config.json",
+    "model.bin",
+    "tokenizer.json",
+    "vocabulary.*",
+]
+
+MODEL_REQUIRED_FILES = [
+    "config.json",
+    "model.bin",
+    "tokenizer.json",
+]
+
+
+class FasterWhisperBackend:
+    """Бэкенд транскрипции через faster-whisper (CTranslate2)."""
+
+    def ensure_model_available(
+        self,
+        model_name: str,
+        compute_type: str,
+        on_status: Callable[[str], None] | None = None,
+    ) -> str:
+        """Резолвит alias модели в repo_id и гарантирует наличие файлов."""
+        local_path = Path(model_name).expanduser()
+        if local_path.is_dir():
+            _validate_model_dir(local_path)
+            return str(local_path)
+
+        repo_id = _resolve_model_repo(model_name)
+
+        try:
+            _notify(on_status, f"Проверяю кэш модели {model_name}...")
+            cached_path = Path(_snapshot_download(repo_id, local_files_only=True))
+            _validate_model_dir(cached_path)
+            return str(cached_path)
+        except LocalEntryNotFoundError:
+            pass
+        except ValueError:
+            _notify(on_status, f"Кэш модели {model_name} неполный, докачиваю...")
+
+        _notify(on_status, f"Скачиваю модель {model_name} из Hugging Face...")
+        downloaded_path = Path(_snapshot_download(repo_id, local_files_only=False))
+        _validate_model_dir(downloaded_path)
+        return str(downloaded_path)
+
+    def create_model(
+        self,
+        model_path: str,
+        device: str,
+        compute_type: str,
+    ) -> Any:
+        """Создаёт WhisperModel."""
+        try:
+            return WhisperModel(model_path, device=device, compute_type=compute_type)
+        except ImportError as exc:
+            if _is_missing_socksio_error(exc):
+                raise RuntimeError(
+                    "Обнаружен SOCKS proxy, но не установлена зависимость `socksio`, "
+                    "нужная для загрузки модели из Hugging Face через proxy. "
+                    "Обновите окружение: `uv sync`."
+                ) from exc
+            raise
+
+    def transcribe(
+        self,
+        model: Any,
+        file_path: Path,
+        language: str | None,
+        on_segment: Callable[[Segment], None] | None = None,
+        on_status: Callable[[str], None] | None = None,
+    ) -> TranscribeResult:
+        """Транскрибирует файл через faster-whisper."""
+        segment_generator, info = model.transcribe(
+            str(file_path), language=language,
+        )
+        total_duration = info.duration
+        segments: list[Segment] = []
+        for raw_seg in segment_generator:
+            seg = Segment(start=raw_seg.start, end=raw_seg.end, text=raw_seg.text)
+            if on_segment is not None:
+                on_segment(seg)
+            segments.append(seg)
+            _notify(
+                on_status,
+                f"Транскрибирую... {_fmt_time(seg.end)} / {_fmt_time(total_duration)}"
+                f"  [{len(segments)} сегм.]",
+            )
+
+        return TranscribeResult(
+            segments=segments,
+            language=info.language,
+            language_probability=info.language_probability,
+            duration=info.duration,
+            device_used="",  # оркестратор проставит actual_device
+        )
+
+
+def _notify(on_status: Callable[[str], None] | None, message: str) -> None:
+    if on_status is not None:
+        on_status(message)
+
+
+def _fmt_time(seconds: float) -> str:
+    m, s = divmod(int(seconds), 60)
+    h, m = divmod(m, 60)
+    return f"{h}:{m:02d}:{s:02d}" if h else f"{m:02d}:{s:02d}"
+
+
+def _resolve_model_repo(model_name: str) -> str:
+    if "/" in model_name:
+        return model_name
+    repo_id = MODEL_REPOS.get(model_name)
+    if repo_id is None:
+        expected = ", ".join(MODEL_REPOS)
+        raise ValueError(f"Неподдерживаемая модель '{model_name}'. Ожидалось одно из: {expected}")
+    return repo_id
+
+
+def _snapshot_download(repo_id: str, local_files_only: bool) -> str:
+    try:
+        return snapshot_download(
+            repo_id,
+            local_files_only=local_files_only,
+            allow_patterns=MODEL_ALLOW_PATTERNS,
+        )
+    except ImportError as exc:
+        if _is_missing_socksio_error(exc):
+            raise RuntimeError(
+                "Обнаружен SOCKS proxy, но не установлена зависимость `socksio`, "
+                "нужная для загрузки модели из Hugging Face через proxy. "
+                "Обновите окружение: `uv sync`."
+            ) from exc
+        raise
+
+
+def _validate_model_dir(model_dir: Path) -> None:
+    missing = [
+        filename for filename in MODEL_REQUIRED_FILES if not (model_dir / filename).exists()
+    ]
+    if not any(model_dir.glob("vocabulary.*")):
+        missing.append("vocabulary.*")
+    if missing:
+        missing_str = ", ".join(missing)
+        raise ValueError(f"Неполная локальная модель в '{model_dir}': отсутствуют {missing_str}")
+
+
+def _is_missing_socksio_error(exc: BaseException) -> bool:
+    msg = str(exc).lower()
+    return "socks proxy" in msg and "socksio" in msg
diff --git a/src/local_transcriber/cli.py b/src/local_transcriber/cli.py
index dd45a2c..a62215e 100644
--- a/src/local_transcriber/cli.py
+++ b/src/local_transcriber/cli.py
@@ -14,9 +14,7 @@ from .transcriber import (
     Segment,
     _is_cuda_error,
     _transcribe_file,
-    ensure_model_available,
     load_model,
-    transcribe,
 )
 from .utils import (
     build_output_path,
@@ -31,6 +29,16 @@ app = typer.Typer()
 console = Console(stderr=True)
 
 
+def _format_device_info(device_used: str) -> str:
+    """Формирует строку устройства для шапки транскрипта."""
+    if device_used == "cuda":
+        gpu_name = get_gpu_name()
+        return f"CUDA ({gpu_name or 'Unknown GPU'})"
+    if device_used == "openvino":
+        return "OpenVINO (CPU)"
+    return "CPU"
+
+
 @app.command()
 def main(
     files: list[Path] = typer.Argument(..., help="Пути к аудио/видеофайлам"),
@@ -42,7 +50,8 @@ def main(
     ),
     output: Path | None = typer.Option(None, "--output", "-o", help="Путь к выходному файлу"),
     device: str | None = typer.Option(
-        None, "--device", "-d", show_default=False, help="Устройство (auto|cpu|cuda) [по умолч.: auto]"
+        None, "--device", "-d", show_default=False,
+        help="Устройство (auto|cpu|cuda) [по умолч.: auto]"
     ),
     compute_type: str | None = typer.Option(
         None, "--compute-type", show_default=False,
@@ -120,7 +129,6 @@ def _run_single(
     validated_file = validate_input_file(file)
     requested_device = defaults["device"]
     resolved_device = detect_device(requested_device)
-    # Если пользователь явно указал устройство — запрещаем fallback на CPU
     strict = requested_device != "auto"
     output_path = build_output_path(validated_file, output)
 
@@ -131,15 +139,11 @@ def _run_single(
         f"Compute: [bold]{defaults['compute_type']}[/bold]"
     )
 
-    model_path = ensure_model_available(
-        defaults["model"], on_status=lambda message: console.print(message)
-    )
-
     def on_segment(seg: Segment) -> None:
         console.print(f"  [{seg.start:.2f}s] {seg.text.strip()}")
 
-    model_obj, actual_device = load_model(
-        model_path, resolved_device, defaults["compute_type"],
+    model_obj, actual_device, backend, model_path = load_model(
+        defaults["model"], resolved_device, defaults["compute_type"],
         on_status=lambda msg: console.print(msg), strict_device=strict,
     )
 
@@ -147,8 +151,10 @@ def _run_single(
         tfr = _transcribe_file(
             model=model_obj,
             actual_device=actual_device,
+            backend=backend,
+            model_path=model_path,
             file_path=validated_file,
-            model_name=model_path,
+            model_name=defaults["model"],
             compute_type=defaults["compute_type"],
             language=defaults["language"] if defaults["language"] != "auto" else None,
             on_segment=on_segment if verbose else None,
@@ -176,12 +182,7 @@ def _run_single(
             f"Речь не обнаружена в файле {validated_file.name}", style="yellow"
         )
 
-    if result.device_used == "cuda":
-        gpu_name = get_gpu_name()
-        device_info = f"CUDA ({gpu_name or 'Unknown GPU'})"
-    else:
-        device_info = "CPU"
-
+    device_info = _format_device_info(result.device_used)
     language_mode = "detected" if defaults["language"] == "auto" else "forced"
 
     content = format_transcript(
@@ -232,15 +233,12 @@ def _run_batch(
             raise SystemExit(1)
         return
 
-    # Phase 2: Load model
+    # Phase 2: Load model (ensure + create в одном вызове)
     requested_device = defaults["device"]
     resolved_device = detect_device(requested_device)
     strict = requested_device != "auto"
-    model_path = ensure_model_available(
-        defaults["model"], on_status=lambda msg: console.print(msg)
-    )
-    model_obj, actual_device = load_model(
-        model_path, resolved_device, defaults["compute_type"],
+    model_obj, actual_device, backend, model_path = load_model(
+        defaults["model"], resolved_device, defaults["compute_type"],
         on_status=lambda msg: console.print(msg), strict_device=strict,
     )
 
@@ -277,8 +275,10 @@ def _run_batch(
                 tfr = _transcribe_file(
                     model=model_obj,
                     actual_device=actual_device,
+                    backend=backend,
+                    model_path=model_path,
                     file_path=file,
-                    model_name=model_path,
+                    model_name=defaults["model"],
                     compute_type=defaults["compute_type"],
                     language=defaults["language"] if defaults["language"] != "auto" else None,
                     on_segment=on_segment if verbose else None,
@@ -291,8 +291,11 @@ def _run_batch(
                     f"  {file.name}: fallback на {tfr.actual_device} при транскрипции",
                     style="yellow",
                 )
-            # Обновляем после возможного mid-stream fallback на CPU
-            model_obj, actual_device = tfr.model, tfr.actual_device
+            # Обновляем после возможного mid-stream fallback
+            model_obj = tfr.model
+            actual_device = tfr.actual_device
+            backend = tfr.backend
+            model_path = tfr.model_path
 
             result = tfr.result
 
@@ -301,11 +304,7 @@ def _run_batch(
                     f"  Речь не обнаружена: {file.name}", style="yellow"
                 )
 
-            if result.device_used == "cuda":
-                gpu_name = get_gpu_name()
-                device_info = f"CUDA ({gpu_name or 'Unknown GPU'})"
-            else:
-                device_info = "CPU"
+            device_info = _format_device_info(result.device_used)
 
             content = format_transcript(
                 result=result,
diff --git a/src/local_transcriber/formatter.py b/src/local_transcriber/formatter.py
index 609ac08..0233d51 100644
--- a/src/local_transcriber/formatter.py
+++ b/src/local_transcriber/formatter.py
@@ -4,7 +4,7 @@ from dataclasses import dataclass
 from datetime import datetime
 from pathlib import Path
 
-from .transcriber import Segment, TranscribeResult
+from .types import Segment, TranscribeResult
 
 _PAUSE_THRESHOLD_S = 2.0  # пауза между сегментами для разбиения на абзацы
 _MAX_PARAGRAPH_S = 60.0  # максимальная длительность абзаца
diff --git a/src/local_transcriber/transcriber.py b/src/local_transcriber/transcriber.py
index 8fd72ec..cc43a66 100644
--- a/src/local_transcriber/transcriber.py
+++ b/src/local_transcriber/transcriber.py
@@ -1,65 +1,18 @@
-"""Обёртка над faster-whisper: загрузка моделей, транскрипция, CUDA fallback."""
+"""Оркестрация транскрипции: выбор бэкенда, загрузка модели, fallback."""
 
 import warnings
 from collections.abc import Callable
-from dataclasses import dataclass
 from pathlib import Path
+from typing import Any
 
-# Должен быть ДО импорта faster_whisper / ctranslate2
-from local_transcriber._cuda_bootstrap import ensure_cublas_loadable
+from local_transcriber.backends import get_backend
 
-ensure_cublas_loadable()
-
-from faster_whisper import WhisperModel  # noqa: E402
-from huggingface_hub import snapshot_download
-from huggingface_hub.errors import LocalEntryNotFoundError
-
-MODEL_REPOS = {
-    "tiny": "Systran/faster-whisper-tiny",
-    "base": "Systran/faster-whisper-base",
-    "small": "Systran/faster-whisper-small",
-    "medium": "Systran/faster-whisper-medium",
-    "large-v3": "Systran/faster-whisper-large-v3",
-}
-
-# allow — фильтр для snapshot_download (какие файлы скачивать из репозитория);
-# required — для валидации (что обязано быть после скачивания/в локальной модели)
-MODEL_ALLOW_PATTERNS = [
-    "config.json",
-    "preprocessor_config.json",
-    "model.bin",
-    "tokenizer.json",
-    "vocabulary.*",
-]
-
-MODEL_REQUIRED_FILES = [
-    "config.json",
-    "model.bin",
-    "tokenizer.json",
-]
-
-
-@dataclass
-class Segment:
-    start: float  # seconds
-    end: float  # seconds
-    text: str
-
-
-@dataclass
-class TranscribeResult:
-    segments: list[Segment]
-    language: str
-    language_probability: float
-    duration: float  # seconds
-    device_used: str  # "cpu" / "cuda"
-
-
-@dataclass
-class TranscribeFileResult:
-    result: TranscribeResult
-    model: WhisperModel
-    actual_device: str
+# Re-export из types.py для обратной совместимости
+from local_transcriber.types import (  # noqa: F401
+    Segment,
+    TranscribeFileResult,
+    TranscribeResult,
+)
 
 
 def load_model(
@@ -68,15 +21,21 @@ def load_model(
     compute_type: str,
     on_status: Callable[[str], None] | None = None,
     strict_device: bool = False,
-) -> tuple[WhisperModel, str]:
-    """Загружает модель с CUDA-фолбеком. Возвращает (model, actual_device)."""
+) -> tuple[Any, str, Any, str]:
+    """Загружает модель: ensure + create с fallback.
+
+    Возвращает (model, actual_device, backend, model_path).
+    """
+    backend = get_backend(device)
     actual_device = device
+
+    model_path = backend.ensure_model_available(model_name, compute_type, on_status)
+
     try:
         _notify_status(on_status, f"Инициализирую модель на {device}...")
-        model = _create_model(model_name, device, compute_type)
+        model = backend.create_model(model_path, device, compute_type)
     except (RuntimeError, ValueError) as exc:
-        # strict — пользователь явно указал устройство, fallback запрещён
-        if device != "cpu" and _is_cuda_error(exc):
+        if device != "cpu" and _is_backend_error(exc, device):
             if strict_device:
                 raise
             warnings.warn(
@@ -85,16 +44,21 @@ def load_model(
                 stacklevel=2,
             )
             actual_device = "cpu"
+            backend = get_backend("cpu")
+            model_path = backend.ensure_model_available(model_name, compute_type, on_status)
             _notify_status(on_status, "Инициализирую модель на cpu...")
-            model = _create_model(model_name, "cpu", compute_type)
+            model = backend.create_model(model_path, "cpu", compute_type)
         else:
             raise
-    return model, actual_device
+
+    return model, actual_device, backend, model_path
 
 
 def _transcribe_file(
-    model: WhisperModel,
+    model: Any,
     actual_device: str,
+    backend: Any,
+    model_path: str,
     file_path: Path,
     model_name: str,
     compute_type: str,
@@ -103,39 +67,40 @@ def _transcribe_file(
     on_status: Callable[[str], None] | None = None,
     strict_device: bool = False,
 ) -> TranscribeFileResult:
-    """Транскрибирует один файл. При mid-stream CUDA fallback перезагружает модель."""
+    """Транскрибирует один файл. При mid-stream fallback перезагружает модель."""
     lang_arg = language if language and language != "auto" else None
 
     try:
         _notify_status(on_status, "Транскрибирую...")
-        segments, info = _run_transcription(model, file_path, lang_arg, on_segment, on_status)
+        result = backend.transcribe(model, file_path, lang_arg, on_segment, on_status)
+        result.device_used = actual_device
     except (RuntimeError, ValueError) as exc:
-        # Mid-stream fallback: GPU может упасть с OOM уже во время транскрипции,
-        # поэтому перезагружаем модель на CPU и начинаем сначала
-        if actual_device != "cpu" and _is_cuda_error(exc):
+        if actual_device != "cpu" and _is_backend_error(exc, actual_device):
             if strict_device:
                 raise
             warnings.warn(
-                f"CUDA ошибка при транскрипции: {exc}. "
+                f"Ошибка при транскрипции на {actual_device}: {exc}. "
                 "Переключение на CPU и повтор.",
                 stacklevel=2,
             )
             actual_device = "cpu"
+            backend = get_backend("cpu")
+            model_path = backend.ensure_model_available(model_name, compute_type, on_status)
             _notify_status(on_status, "Инициализирую модель на cpu...")
-            model = _create_model(model_name, "cpu", compute_type)
+            model = backend.create_model(model_path, "cpu", compute_type)
             _notify_status(on_status, "Транскрибирую...")
-            segments, info = _run_transcription(model, file_path, lang_arg, on_segment, on_status)
+            result = backend.transcribe(model, file_path, lang_arg, on_segment, on_status)
+            result.device_used = actual_device
         else:
             raise
 
-    result = TranscribeResult(
-        segments=segments,
-        language=info.language,
-        language_probability=info.language_probability,
-        duration=info.duration,
-        device_used=actual_device,
+    return TranscribeFileResult(
+        result=result,
+        model=model,
+        actual_device=actual_device,
+        backend=backend,
+        model_path=model_path,
     )
-    return TranscribeFileResult(result=result, model=model, actual_device=actual_device)
 
 
 def transcribe(
@@ -149,9 +114,12 @@ def transcribe(
     strict_device: bool = False,
 ) -> TranscribeResult:
     """High-level API: загрузка модели + транскрипция за один вызов."""
-    model, actual_device = load_model(model_name, device, compute_type, on_status, strict_device)
+    model, actual_device, backend, model_path = load_model(
+        model_name, device, compute_type, on_status, strict_device,
+    )
     tfr = _transcribe_file(
-        model, actual_device, file_path, model_name, compute_type,
+        model, actual_device, backend, model_path,
+        file_path, model_name, compute_type,
         language, on_segment, on_status, strict_device,
     )
     return tfr.result
@@ -159,127 +127,30 @@ def transcribe(
 
 def ensure_model_available(
     model_name: str,
+    device: str = "cpu",
+    compute_type: str = "float32",
     on_status: Callable[[str], None] | None = None,
 ) -> str:
-    """Резолвит alias модели в repo_id и гарантирует наличие файлов.
-
-    Стратегия: cache-first (``local_files_only=True``), затем download.
-    Два вызова ``snapshot_download`` — чтобы не лезть в сеть, если модель уже в кэше.
-    """
-    local_path = Path(model_name).expanduser()
-    if local_path.is_dir():
-        _validate_model_dir(local_path)
-        return str(local_path)
-
-    repo_id = _resolve_model_repo(model_name)
-
-    try:
-        _notify_status(on_status, f"Проверяю кэш модели {model_name}...")
-        cached_path = Path(_snapshot_download(repo_id, local_files_only=True))
-        _validate_model_dir(cached_path)
-        return str(cached_path)
-    except LocalEntryNotFoundError:
-        pass
-    except ValueError:
-        _notify_status(on_status, f"Кэш модели {model_name} неполный, докачиваю...")
-
-    _notify_status(on_status, f"Скачиваю модель {model_name} из Hugging Face...")
-    downloaded_path = Path(_snapshot_download(repo_id, local_files_only=False))
-    _validate_model_dir(downloaded_path)
-    return str(downloaded_path)
-
-
-def _run_transcription(model, file_path, lang_arg, on_segment, on_status=None):
-    """Run model.transcribe and iterate segments. Returns (segments, info)."""
-    segment_generator, info = model.transcribe(str(file_path), language=lang_arg)
-    total_duration = info.duration
-    segments: list[Segment] = []
-    for raw_seg in segment_generator:
-        seg = Segment(start=raw_seg.start, end=raw_seg.end, text=raw_seg.text)
-        if on_segment is not None:
-            on_segment(seg)
-        segments.append(seg)
-        _notify_status(
-            on_status,
-            f"Транскрибирую... {_fmt_time(seg.end)} / {_fmt_time(total_duration)}"
-            f"  [{len(segments)} сегм.]",
-        )
-    return segments, info
-
-
-def _create_model(model_name: str, device: str, compute_type: str):
-    try:
-        return WhisperModel(model_name, device=device, compute_type=compute_type)
-    except ImportError as exc:
-        # WhisperModel при инициализации может загружать файлы через HF Hub;
-        # если в системе настроен SOCKS proxy, но socksio не установлен,
-        # HF Hub бросает ImportError — оборачиваем в понятное сообщение
-        if _is_missing_socksio_error(exc):
-            raise RuntimeError(
-                "Обнаружен SOCKS proxy, но не установлена зависимость `socksio`, "
-                "нужная для загрузки модели из Hugging Face через proxy. "
-                "Обновите окружение: `uv sync`."
-            ) from exc
-        raise
+    """Публичный helper: гарантирует наличие модели для указанного бэкенда."""
+    backend = get_backend(device)
+    return backend.ensure_model_available(model_name, compute_type, on_status)
 
 
 def _is_cuda_error(exc: BaseException) -> bool:
+    """Проверка CUDA ошибок — используется в cli.py для Windows-диагностики."""
     msg = str(exc).lower()
     return any(k in msg for k in ("cuda", "cublas", "cudnn", "out of memory"))
 
 
-def _is_missing_socksio_error(exc: BaseException) -> bool:
-    msg = str(exc).lower()
-    return "socks proxy" in msg and "socksio" in msg
-
-
-def _fmt_time(seconds: float) -> str:
-    m, s = divmod(int(seconds), 60)
-    h, m = divmod(m, 60)
-    return f"{h}:{m:02d}:{s:02d}" if h else f"{m:02d}:{s:02d}"
+def _is_backend_error(exc: BaseException, device: str) -> bool:
+    """Определяет, связана ли ошибка с конкретным бэкендом (а не с пользовательскими данными)."""
+    if device in ("cuda", "cpu"):
+        return _is_cuda_error(exc)
+    # openvino и другие бэкенды: конкретные паттерны ошибок добавим
+    # при реализации бэкенда; пока — не маскируем ошибки
+    return False
 
 
 def _notify_status(on_status: Callable[[str], None] | None, message: str) -> None:
     if on_status is not None:
         on_status(message)
-
-
-def _resolve_model_repo(model_name: str) -> str:
-    if "/" in model_name:
-        return model_name
-
-    repo_id = MODEL_REPOS.get(model_name)
-    if repo_id is None:
-        expected = ", ".join(MODEL_REPOS)
-        raise ValueError(f"Неподдерживаемая модель '{model_name}'. Ожидалось одно из: {expected}")
-
-    return repo_id
-
-
-def _snapshot_download(repo_id: str, local_files_only: bool) -> str:
-    try:
-        return snapshot_download(
-            repo_id,
-            local_files_only=local_files_only,
-            allow_patterns=MODEL_ALLOW_PATTERNS,
-        )
-    except ImportError as exc:
-        if _is_missing_socksio_error(exc):
-            raise RuntimeError(
-                "Обнаружен SOCKS proxy, но не установлена зависимость `socksio`, "
-                "нужная для загрузки модели из Hugging Face через proxy. "
-                "Обновите окружение: `uv sync`."
-            ) from exc
-        raise
-
-
-def _validate_model_dir(model_dir: Path) -> None:
-    missing = [
-        filename for filename in MODEL_REQUIRED_FILES if not (model_dir / filename).exists()
-    ]
-    if not any(model_dir.glob("vocabulary.*")):
-        missing.append("vocabulary.*")
-
-    if missing:
-        missing_str = ", ".join(missing)
-        raise ValueError(f"Неполная локальная модель в '{model_dir}': отсутствуют {missing_str}")
diff --git a/src/local_transcriber/types.py b/src/local_transcriber/types.py
new file mode 100644
index 0000000..a8eca66
--- /dev/null
+++ b/src/local_transcriber/types.py
@@ -0,0 +1,34 @@
+"""Общие типы данных для всех бэкендов транскрипции."""
+
+from collections.abc import Callable
+from dataclasses import dataclass
+from typing import Any
+
+
+@dataclass
+class Segment:
+    start: float  # seconds
+    end: float  # seconds
+    text: str
+
+
+@dataclass
+class TranscribeResult:
+    segments: list[Segment]
+    language: str
+    language_probability: float
+    duration: float  # seconds
+    device_used: str  # "cpu" / "cuda" / "openvino"
+
+
+@dataclass
+class TranscribeFileResult:
+    result: TranscribeResult
+    model: Any  # backend-specific model handle
+    actual_device: str
+    backend: Any = None  # backend instance (для переиспользования в батче)
+    model_path: str = ""  # путь к модели (меняется при cross-backend fallback)
+
+
+StatusCallback = Callable[[str], None] | None
+SegmentCallback = Callable[[Segment], None] | None
diff --git a/tests/test_cli.py b/tests/test_cli.py
index 2cef38b..ff6c7d0 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -24,12 +24,21 @@ def _make_model():
     return MagicMock(name="WhisperModel")
 
 
-def _make_tfr(result=None, model=None, actual_device="cpu"):
+def _make_backend():
+    return MagicMock(name="Backend")
+
+
+def _make_tfr(result=None, model=None, actual_device="cpu", backend=None, model_path="/models/medium"):
     if result is None:
         result = _make_result()
     if model is None:
         model = _make_model()
-    return TranscribeFileResult(result=result, model=model, actual_device=actual_device)
+    if backend is None:
+        backend = _make_backend()
+    return TranscribeFileResult(
+        result=result, model=model, actual_device=actual_device,
+        backend=backend, model_path=model_path,
+    )
 
 
 def _single_patches(result=None, tmp_file=None, actual_device="cpu"):
@@ -37,13 +46,13 @@ def _single_patches(result=None, tmp_file=None, actual_device="cpu"):
     if result is None:
         result = _make_result(device_used=actual_device)
     model = _make_model()
-    tfr = TranscribeFileResult(result=result, model=model, actual_device=actual_device)
+    backend = _make_backend()
+    tfr = _make_tfr(result=result, model=model, actual_device=actual_device, backend=backend)
     return [
         patch("local_transcriber.cli.load_config", return_value={}),
         patch("local_transcriber.cli.validate_input_file", return_value=tmp_file),
         patch("local_transcriber.cli.detect_device", return_value=actual_device),
-        patch("local_transcriber.cli.ensure_model_available", return_value="/models/medium"),
-        patch("local_transcriber.cli.load_model", return_value=(model, actual_device)),
+        patch("local_transcriber.cli.load_model", return_value=(model, actual_device, backend, "/models/medium")),
         patch("local_transcriber.cli._transcribe_file", return_value=tfr),
         patch("local_transcriber.cli.write_transcript"),
     ]
@@ -54,7 +63,7 @@ def test_cli_happy_path_exit_code_zero(tmp_path):
     audio.write_bytes(b"fake")
 
     patches = _single_patches(tmp_file=audio)
-    with patches[0], patches[1], patches[2], patches[3], patches[4], patches[5], patches[6]:
+    with patches[0], patches[1], patches[2], patches[3], patches[4], patches[5]:
         out = runner.invoke(app, [str(audio)])
 
     assert out.exit_code == 0
@@ -65,22 +74,22 @@ def test_cli_default_options_passed_to_transcribe(tmp_path):
     audio.write_bytes(b"fake")
     result = _make_result()
     model = _make_model()
-    tfr = _make_tfr(result=result, model=model)
+    backend = _make_backend()
+    tfr = _make_tfr(result=result, model=model, backend=backend)
     mock_transcribe_file = MagicMock(return_value=tfr)
 
     with (
         patch("local_transcriber.cli.load_config", return_value={}),
         patch("local_transcriber.cli.validate_input_file", return_value=audio),
         patch("local_transcriber.cli.detect_device", return_value="cpu"),
-        patch("local_transcriber.cli.ensure_model_available", return_value="/models/medium"),
-        patch("local_transcriber.cli.load_model", return_value=(model, "cpu")),
+        patch("local_transcriber.cli.load_model", return_value=(model, "cpu", backend, "/models/medium")),
         patch("local_transcriber.cli._transcribe_file", mock_transcribe_file),
         patch("local_transcriber.cli.write_transcript"),
     ):
         runner.invoke(app, [str(audio)])
 
     call_kwargs = mock_transcribe_file.call_args[1]
-    assert call_kwargs["model_name"] == "/models/medium"
+    assert call_kwargs["model_name"] == "medium"
     assert call_kwargs["compute_type"] == "float32"
     assert call_kwargs["language"] == "ru"
     assert call_kwargs["on_segment"] is None  # verbose=False
@@ -91,15 +100,15 @@ def test_cli_custom_options(tmp_path):
     audio.write_bytes(b"fake")
     result = _make_result(device_used="cuda")
     model = _make_model()
-    tfr = _make_tfr(result=result, model=model, actual_device="cuda")
+    backend = _make_backend()
+    tfr = _make_tfr(result=result, model=model, actual_device="cuda", backend=backend)
     mock_transcribe_file = MagicMock(return_value=tfr)
 
     with (
         patch("local_transcriber.cli.load_config", return_value={}),
         patch("local_transcriber.cli.validate_input_file", return_value=audio),
         patch("local_transcriber.cli.detect_device", return_value="cuda"),
-        patch("local_transcriber.cli.ensure_model_available", return_value="/models/small"),
-        patch("local_transcriber.cli.load_model", return_value=(model, "cuda")),
+        patch("local_transcriber.cli.load_model", return_value=(model, "cuda", backend, "/models/small")),
         patch("local_transcriber.cli._transcribe_file", mock_transcribe_file),
         patch("local_transcriber.cli.write_transcript"),
         patch("local_transcriber.cli.get_gpu_name", return_value="RTX 3060"),
@@ -113,7 +122,7 @@ def test_cli_custom_options(tmp_path):
         ])
 
     call_kwargs = mock_transcribe_file.call_args[1]
-    assert call_kwargs["model_name"] == "/models/small"
+    assert call_kwargs["model_name"] == "small"
     assert call_kwargs["language"] == "ru"
     assert call_kwargs["compute_type"] == "float16"
 
@@ -123,15 +132,15 @@ def test_cli_verbose_passes_on_segment_callback(tmp_path):
     audio.write_bytes(b"fake")
     result = _make_result()
     model = _make_model()
-    tfr = _make_tfr(result=result, model=model)
+    backend = _make_backend()
+    tfr = _make_tfr(result=result, model=model, backend=backend)
     mock_transcribe_file = MagicMock(return_value=tfr)
 
     with (
         patch("local_transcriber.cli.load_config", return_value={}),
         patch("local_transcriber.cli.validate_input_file", return_value=audio),
         patch("local_transcriber.cli.detect_device", return_value="cpu"),
-        patch("local_transcriber.cli.ensure_model_available", return_value="/models/medium"),
-        patch("local_transcriber.cli.load_model", return_value=(model, "cpu")),
+        patch("local_transcriber.cli.load_model", return_value=(model, "cpu", backend, "/models/medium")),
         patch("local_transcriber.cli._transcribe_file", mock_transcribe_file),
         patch("local_transcriber.cli.write_transcript"),
     ):
@@ -148,7 +157,7 @@ def test_cli_empty_speech_warning(tmp_path):
     result = _make_result(segments=[])
 
     patches = _single_patches(result=result, tmp_file=audio)
-    with patches[0], patches[1], patches[2], patches[3], patches[4], patches[5], patches[6]:
+    with patches[0], patches[1], patches[2], patches[3], patches[4], patches[5]:
         out = runner.invoke(app, [str(audio)])
 
     assert out.exit_code == 0
@@ -162,14 +171,14 @@ def test_cli_default_output_path(tmp_path):
 
     result = _make_result()
     model = _make_model()
-    tfr = _make_tfr(result=result, model=model)
+    backend = _make_backend()
+    tfr = _make_tfr(result=result, model=model, backend=backend)
 
     with (
         patch("local_transcriber.cli.load_config", return_value={}),
         patch("local_transcriber.cli.validate_input_file", return_value=audio),
         patch("local_transcriber.cli.detect_device", return_value="cpu"),
-        patch("local_transcriber.cli.ensure_model_available", return_value="/models/medium"),
-        patch("local_transcriber.cli.load_model", return_value=(model, "cpu")),
+        patch("local_transcriber.cli.load_model", return_value=(model, "cpu", backend, "/models/medium")),
         patch("local_transcriber.cli._transcribe_file", return_value=tfr),
         patch("local_transcriber.cli.write_transcript", mock_write),
     ):
@@ -187,14 +196,14 @@ def test_cli_custom_output_path(tmp_path):
 
     result = _make_result()
     model = _make_model()
-    tfr = _make_tfr(result=result, model=model)
+    backend = _make_backend()
+    tfr = _make_tfr(result=result, model=model, backend=backend)
 
     with (
         patch("local_transcriber.cli.load_config", return_value={}),
         patch("local_transcriber.cli.validate_input_file", return_value=audio),
         patch("local_transcriber.cli.detect_device", return_value="cpu"),
-        patch("local_transcriber.cli.ensure_model_available", return_value="/models/medium"),
-        patch("local_transcriber.cli.load_model", return_value=(model, "cpu")),
+        patch("local_transcriber.cli.load_model", return_value=(model, "cpu", backend, "/models/medium")),
         patch("local_transcriber.cli._transcribe_file", return_value=tfr),
         patch("local_transcriber.cli.write_transcript", mock_write),
     ):
@@ -209,15 +218,15 @@ def test_cli_passes_status_callback_to_transcribe(tmp_path):
     audio.write_bytes(b"fake")
     result = _make_result()
     model = _make_model()
-    tfr = _make_tfr(result=result, model=model)
+    backend = _make_backend()
+    tfr = _make_tfr(result=result, model=model, backend=backend)
     mock_transcribe_file = MagicMock(return_value=tfr)
 
     with (
         patch("local_transcriber.cli.load_config", return_value={}),
         patch("local_transcriber.cli.validate_input_file", return_value=audio),
         patch("local_transcriber.cli.detect_device", return_value="cpu"),
-        patch("local_transcriber.cli.ensure_model_available", return_value="/models/medium"),
-        patch("local_transcriber.cli.load_model", return_value=(model, "cpu")),
+        patch("local_transcriber.cli.load_model", return_value=(model, "cpu", backend, "/models/medium")),
         patch("local_transcriber.cli._transcribe_file", mock_transcribe_file),
         patch("local_transcriber.cli.write_transcript"),
     ):
@@ -228,28 +237,27 @@ def test_cli_passes_status_callback_to_transcribe(tmp_path):
     assert callable(call_kwargs["on_status"])
 
 
-def test_cli_resolves_model_before_transcribe(tmp_path):
+def test_cli_load_model_called_with_model_name(tmp_path):
+    """load_model receives model name from defaults, handles ensure internally."""
     audio = tmp_path / "test.mp3"
     audio.write_bytes(b"fake")
     result = _make_result()
     model = _make_model()
-    tfr = _make_tfr(result=result, model=model)
-    mock_transcribe_file = MagicMock(return_value=tfr)
+    backend = _make_backend()
+    tfr = _make_tfr(result=result, model=model, backend=backend)
+    mock_load_model = MagicMock(return_value=(model, "cpu", backend, "/models/large-v3"))
 
     with (
         patch("local_transcriber.cli.load_config", return_value={}),
         patch("local_transcriber.cli.validate_input_file", return_value=audio),
         patch("local_transcriber.cli.detect_device", return_value="cpu"),
-        patch("local_transcriber.cli.ensure_model_available", return_value="/models/large-v3") as mock_ensure,
-        patch("local_transcriber.cli.load_model", return_value=(model, "cpu")),
-        patch("local_transcriber.cli._transcribe_file", mock_transcribe_file),
+        patch("local_transcriber.cli.load_model", mock_load_model),
+        patch("local_transcriber.cli._transcribe_file", return_value=tfr),
         patch("local_transcriber.cli.write_transcript"),
     ):
         runner.invoke(app, [str(audio), "--model", "large-v3"])
 
-    mock_ensure.assert_called_once()
-    call_kwargs = mock_transcribe_file.call_args[1]
-    assert call_kwargs["model_name"] == "/models/large-v3"
+    assert mock_load_model.call_args[0][0] == "large-v3"
 
 
 def test_cli_windows_cuda_diagnostic(tmp_path):
@@ -257,13 +265,13 @@ def test_cli_windows_cuda_diagnostic(tmp_path):
     audio = tmp_path / "test.mp3"
     audio.write_bytes(b"fake")
     model = _make_model()
+    backend = _make_backend()
 
     with (
         patch("local_transcriber.cli.load_config", return_value={}),
         patch("local_transcriber.cli.validate_input_file", return_value=audio),
         patch("local_transcriber.cli.detect_device", return_value="cuda"),
-        patch("local_transcriber.cli.ensure_model_available", return_value="/models/medium"),
-        patch("local_transcriber.cli.load_model", return_value=(model, "cuda")),
+        patch("local_transcriber.cli.load_model", return_value=(model, "cuda", backend, "/models/medium")),
         patch("local_transcriber.cli._transcribe_file", side_effect=RuntimeError("CUDA error: no device")),
         patch("local_transcriber.cli.sys") as mock_sys,
     ):
@@ -280,13 +288,13 @@ def test_cli_linux_cuda_error_no_windows_hint(tmp_path):
     audio = tmp_path / "test.mp3"
     audio.write_bytes(b"fake")
     model = _make_model()
+    backend = _make_backend()
 
     with (
         patch("local_transcriber.cli.load_config", return_value={}),
         patch("local_transcriber.cli.validate_input_file", return_value=audio),
         patch("local_transcriber.cli.detect_device", return_value="cuda"),
-        patch("local_transcriber.cli.ensure_model_available", return_value="/models/medium"),
-        patch("local_transcriber.cli.load_model", return_value=(model, "cuda")),
+        patch("local_transcriber.cli.load_model", return_value=(model, "cuda", backend, "/models/medium")),
         patch("local_transcriber.cli._transcribe_file", side_effect=RuntimeError("CUDA error: no device")),
         patch("local_transcriber.cli.sys") as mock_sys,
     ):
@@ -303,14 +311,14 @@ def test_cli_device_fallback_warning(tmp_path):
     audio.write_bytes(b"fake")
     result = _make_result(device_used="cpu")
     model = _make_model()
-    tfr = TranscribeFileResult(result=result, model=model, actual_device="cpu")
+    backend = _make_backend()
+    tfr = _make_tfr(result=result, model=model, actual_device="cpu", backend=backend)
 
     with (
         patch("local_transcriber.cli.load_config", return_value={}),
         patch("local_transcriber.cli.validate_input_file", return_value=audio),
         patch("local_transcriber.cli.detect_device", return_value="cuda"),
-        patch("local_transcriber.cli.ensure_model_available", return_value="/models/medium"),
-        patch("local_transcriber.cli.load_model", return_value=(model, "cuda")),
+        patch("local_transcriber.cli.load_model", return_value=(model, "cuda", backend, "/models/medium")),
         patch("local_transcriber.cli._transcribe_file", return_value=tfr),
         patch("local_transcriber.cli.write_transcript"),
     ):
@@ -325,15 +333,15 @@ def test_cli_strict_device_passed_to_transcribe(tmp_path):
     audio.write_bytes(b"fake")
     result = _make_result(device_used="cuda")
     model = _make_model()
-    tfr = TranscribeFileResult(result=result, model=model, actual_device="cuda")
+    backend = _make_backend()
+    tfr = _make_tfr(result=result, model=model, actual_device="cuda", backend=backend)
     mock_transcribe_file = MagicMock(return_value=tfr)
 
     with (
         patch("local_transcriber.cli.load_config", return_value={}),
         patch("local_transcriber.cli.validate_input_file", return_value=audio),
         patch("local_transcriber.cli.detect_device", return_value="cuda"),
-        patch("local_transcriber.cli.ensure_model_available", return_value="/models/medium"),
-        patch("local_transcriber.cli.load_model", return_value=(model, "cuda")),
+        patch("local_transcriber.cli.load_model", return_value=(model, "cuda", backend, "/models/medium")),
         patch("local_transcriber.cli._transcribe_file", mock_transcribe_file),
         patch("local_transcriber.cli.write_transcript"),
         patch("local_transcriber.cli.get_gpu_name", return_value="RTX 3060"),
@@ -344,15 +352,14 @@ def test_cli_strict_device_passed_to_transcribe(tmp_path):
 
     mock_transcribe_file.reset_mock()
     result_cpu = _make_result(device_used="cpu")
-    tfr_cpu = TranscribeFileResult(result=result_cpu, model=model, actual_device="cpu")
+    tfr_cpu = _make_tfr(result=result_cpu, model=model, backend=backend)
     mock_transcribe_file.return_value = tfr_cpu
 
     with (
         patch("local_transcriber.cli.load_config", return_value={}),
         patch("local_transcriber.cli.validate_input_file", return_value=audio),
         patch("local_transcriber.cli.detect_device", return_value="cpu"),
-        patch("local_transcriber.cli.ensure_model_available", return_value="/models/medium"),
-        patch("local_transcriber.cli.load_model", return_value=(model, "cpu")),
+        patch("local_transcriber.cli.load_model", return_value=(model, "cpu", backend, "/models/medium")),
         patch("local_transcriber.cli._transcribe_file", mock_transcribe_file),
         patch("local_transcriber.cli.write_transcript"),
     ):
@@ -366,13 +373,13 @@ def test_cli_keyboard_interrupt(tmp_path):
     audio = tmp_path / "test.mp3"
     audio.write_bytes(b"fake")
     model = _make_model()
+    backend = _make_backend()
 
     with (
         patch("local_transcriber.cli.load_config", return_value={}),
         patch("local_transcriber.cli.validate_input_file", return_value=audio),
         patch("local_transcriber.cli.detect_device", return_value="cpu"),
-        patch("local_transcriber.cli.ensure_model_available", return_value="/models/medium"),
-        patch("local_transcriber.cli.load_model", return_value=(model, "cpu")),
+        patch("local_transcriber.cli.load_model", return_value=(model, "cpu", backend, "/models/medium")),
         patch("local_transcriber.cli._transcribe_file", side_effect=KeyboardInterrupt),
         patch("local_transcriber.cli.write_transcript"),
     ):
@@ -399,13 +406,13 @@ def test_cli_unexpected_error_verbose_traceback(tmp_path):
     audio = tmp_path / "test.mp3"
     audio.write_bytes(b"fake")
     model = _make_model()
+    backend = _make_backend()
 
     with (
         patch("local_transcriber.cli.load_config", return_value={}),
         patch("local_transcriber.cli.validate_input_file", return_value=audio),
         patch("local_transcriber.cli.detect_device", return_value="cpu"),
-        patch("local_transcriber.cli.ensure_model_available", return_value="/models/medium"),
-        patch("local_transcriber.cli.load_model", return_value=(model, "cpu")),
+        patch("local_transcriber.cli.load_model", return_value=(model, "cpu", backend, "/models/medium")),
         patch("local_transcriber.cli._transcribe_file", side_effect=RuntimeError("unexpected boom")),
         patch("local_transcriber.cli.write_transcript"),
     ):
@@ -420,13 +427,13 @@ def test_cli_unexpected_error_no_verbose_hint(tmp_path):
     audio = tmp_path / "test.mp3"
     audio.write_bytes(b"fake")
     model = _make_model()
+    backend = _make_backend()
 
     with (
         patch("local_transcriber.cli.load_config", return_value={}),
         patch("local_transcriber.cli.validate_input_file", return_value=audio),
         patch("local_transcriber.cli.detect_device", return_value="cpu"),
-        patch("local_transcriber.cli.ensure_model_available", return_value="/models/medium"),
-        patch("local_transcriber.cli.load_model", return_value=(model, "cpu")),
+        patch("local_transcriber.cli.load_model", return_value=(model, "cpu", backend, "/models/medium")),
         patch("local_transcriber.cli._transcribe_file", side_effect=RuntimeError("unexpected boom")),
         patch("local_transcriber.cli.write_transcript"),
     ):
@@ -448,14 +455,14 @@ def test_cli_batch_two_files(tmp_path):
 
     result = _make_result()
     model = _make_model()
-    tfr = _make_tfr(result=result, model=model)
+    backend = _make_backend()
+    tfr = _make_tfr(result=result, model=model, backend=backend)
 
     with (
         patch("local_transcriber.cli.load_config", return_value={}),
         patch("local_transcriber.cli.validate_input_file", side_effect=lambda p: p),
         patch("local_transcriber.cli.detect_device", return_value="cpu"),
-        patch("local_transcriber.cli.ensure_model_available", return_value="/models/medium"),
-        patch("local_transcriber.cli.load_model", return_value=(model, "cpu")),
+        patch("local_transcriber.cli.load_model", return_value=(model, "cpu", backend, "/models/medium")),
         patch("local_transcriber.cli._transcribe_file", return_value=tfr),
         patch("local_transcriber.cli.write_transcript"),
     ):
@@ -470,19 +477,18 @@ def test_cli_batch_skips_existing(tmp_path):
     b = tmp_path / "b.mp3"
     a.write_bytes(b"fake")
     b.write_bytes(b"fake")
-    # Create transcript for a
     (tmp_path / "a-transcript.md").write_text("existing")
 
     result = _make_result()
     model = _make_model()
-    tfr = _make_tfr(result=result, model=model)
+    backend = _make_backend()
+    tfr = _make_tfr(result=result, model=model, backend=backend)
 
     with (
         patch("local_transcriber.cli.load_config", return_value={}),
         patch("local_transcriber.cli.validate_input_file", side_effect=lambda p: p),
         patch("local_transcriber.cli.detect_device", return_value="cpu"),
-        patch("local_transcriber.cli.ensure_model_available", return_value="/models/medium"),
-        patch("local_transcriber.cli.load_model", return_value=(model, "cpu")),
+        patch("local_transcriber.cli.load_model", return_value=(model, "cpu", backend, "/models/medium")),
         patch("local_transcriber.cli._transcribe_file", return_value=tfr),
         patch("local_transcriber.cli.write_transcript"),
     ):
@@ -524,14 +530,14 @@ def test_cli_batch_force_overwrites(tmp_path):
 
     result = _make_result()
     model = _make_model()
-    tfr = _make_tfr(result=result, model=model)
+    backend = _make_backend()
+    tfr = _make_tfr(result=result, model=model, backend=backend)
 
     with (
         patch("local_transcriber.cli.load_config", return_value={}),
         patch("local_transcriber.cli.validate_input_file", side_effect=lambda p: p),
         patch("local_transcriber.cli.detect_device", return_value="cpu"),
-        patch("local_transcriber.cli.ensure_model_available", return_value="/models/medium"),
-        patch("local_transcriber.cli.load_model", return_value=(model, "cpu")),
+        patch("local_transcriber.cli.load_model", return_value=(model, "cpu", backend, "/models/medium")),
         patch("local_transcriber.cli._transcribe_file", return_value=tfr),
         patch("local_transcriber.cli.write_transcript"),
     ):
@@ -550,7 +556,8 @@ def test_cli_batch_per_file_error(tmp_path):
 
     result = _make_result()
     model = _make_model()
-    tfr = _make_tfr(result=result, model=model)
+    backend = _make_backend()
+    tfr = _make_tfr(result=result, model=model, backend=backend)
     call_count = 0
 
     def transcribe_side_effect(**kwargs):
@@ -564,8 +571,7 @@ def test_cli_batch_per_file_error(tmp_path):
         patch("local_transcriber.cli.load_config", return_value={}),
         patch("local_transcriber.cli.validate_input_file", side_effect=lambda p: p),
         patch("local_transcriber.cli.detect_device", return_value="cpu"),
-        patch("local_transcriber.cli.ensure_model_available", return_value="/models/medium"),
-        patch("local_transcriber.cli.load_model", return_value=(model, "cpu")),
+        patch("local_transcriber.cli.load_model", return_value=(model, "cpu", backend, "/models/medium")),
         patch("local_transcriber.cli._transcribe_file", side_effect=transcribe_side_effect),
         patch("local_transcriber.cli.write_transcript"),
     ):
@@ -584,7 +590,8 @@ def test_cli_batch_invalid_in_prescan(tmp_path):
 
     result = _make_result()
     model = _make_model()
-    tfr = _make_tfr(result=result, model=model)
+    backend = _make_backend()
+    tfr = _make_tfr(result=result, model=model, backend=backend)
 
     def validate_side_effect(p):
         if not p.exists():
@@ -595,8 +602,7 @@ def test_cli_batch_invalid_in_prescan(tmp_path):
         patch("local_transcriber.cli.load_config", return_value={}),
         patch("local_transcriber.cli.validate_input_file", side_effect=validate_side_effect),
         patch("local_transcriber.cli.detect_device", return_value="cpu"),
-        patch("local_transcriber.cli.ensure_model_available", return_value="/models/medium"),
-        patch("local_transcriber.cli.load_model", return_value=(model, "cpu")),
+        patch("local_transcriber.cli.load_model", return_value=(model, "cpu", backend, "/models/medium")),
         patch("local_transcriber.cli._transcribe_file", return_value=tfr),
         patch("local_transcriber.cli.write_transcript"),
     ):
@@ -634,42 +640,46 @@ def test_cli_config_applied(tmp_path):
     audio = tmp_path / "test.mp3"
     audio.write_bytes(b"fake")
     model = _make_model()
+    backend = _make_backend()
     result = _make_result()
-    tfr = _make_tfr(result=result, model=model)
+    tfr = _make_tfr(result=result, model=model, backend=backend)
+    mock_load_model = MagicMock(return_value=(model, "cpu", backend, "/models/tiny"))
 
     with (
         patch("local_transcriber.cli.load_config", return_value={"model": "tiny"}),
         patch("local_transcriber.cli.validate_input_file", return_value=audio),
         patch("local_transcriber.cli.detect_device", return_value="cpu"),
-        patch("local_transcriber.cli.ensure_model_available", return_value="/models/tiny") as mock_ensure,
-        patch("local_transcriber.cli.load_model", return_value=(model, "cpu")),
+        patch("local_transcriber.cli.load_model", mock_load_model),
         patch("local_transcriber.cli._transcribe_file", return_value=tfr),
         patch("local_transcriber.cli.write_transcript"),
     ):
         runner.invoke(app, [str(audio)])
 
-    mock_ensure.assert_called_once_with("tiny", on_status=mock_ensure.call_args[1]["on_status"])
+    # load_model receives model name from config
+    assert mock_load_model.call_args[0][0] == "tiny"
 
 
 def test_cli_cli_overrides_config(tmp_path):
     audio = tmp_path / "test.mp3"
     audio.write_bytes(b"fake")
     model = _make_model()
+    backend = _make_backend()
     result = _make_result()
-    tfr = _make_tfr(result=result, model=model)
+    tfr = _make_tfr(result=result, model=model, backend=backend)
+    mock_load_model = MagicMock(return_value=(model, "cpu", backend, "/models/small"))
 
     with (
         patch("local_transcriber.cli.load_config", return_value={"model": "tiny"}),
         patch("local_transcriber.cli.validate_input_file", return_value=audio),
         patch("local_transcriber.cli.detect_device", return_value="cpu"),
-        patch("local_transcriber.cli.ensure_model_available", return_value="/models/small") as mock_ensure,
-        patch("local_transcriber.cli.load_model", return_value=(model, "cpu")),
+        patch("local_transcriber.cli.load_model", mock_load_model),
         patch("local_transcriber.cli._transcribe_file", return_value=tfr),
         patch("local_transcriber.cli.write_transcript"),
     ):
         runner.invoke(app, [str(audio), "--model", "small"])
 
-    mock_ensure.assert_called_once_with("small", on_status=mock_ensure.call_args[1]["on_status"])
+    # CLI --model overrides config
+    assert mock_load_model.call_args[0][0] == "small"
 
 
 def test_cli_batch_fallback_warning(tmp_path):
@@ -681,14 +691,14 @@ def test_cli_batch_fallback_warning(tmp_path):
 
     result = _make_result(device_used="cpu")
     model = _make_model()
-    tfr = TranscribeFileResult(result=result, model=model, actual_device="cpu")
+    backend = _make_backend()
+    tfr = _make_tfr(result=result, model=model, actual_device="cpu", backend=backend)
 
     with (
         patch("local_transcriber.cli.load_config", return_value={}),
         patch("local_transcriber.cli.validate_input_file", side_effect=lambda p: p),
         patch("local_transcriber.cli.detect_device", return_value="cuda"),
-        patch("local_transcriber.cli.ensure_model_available", return_value="/models/medium"),
-        patch("local_transcriber.cli.load_model", return_value=(model, "cpu")),
+        patch("local_transcriber.cli.load_model", return_value=(model, "cpu", backend, "/models/medium")),
         patch("local_transcriber.cli._transcribe_file", return_value=tfr),
         patch("local_transcriber.cli.write_transcript"),
     ):
@@ -707,15 +717,15 @@ def test_cli_batch_empty_speech_warning(tmp_path):
     result_empty = _make_result(segments=[])
     result_ok = _make_result()
     model = _make_model()
-    tfr_empty = _make_tfr(result=result_empty, model=model)
-    tfr_ok = _make_tfr(result=result_ok, model=model)
+    backend = _make_backend()
+    tfr_empty = _make_tfr(result=result_empty, model=model, backend=backend)
+    tfr_ok = _make_tfr(result=result_ok, model=model, backend=backend)
 
     with (
         patch("local_transcriber.cli.load_config", return_value={}),
         patch("local_transcriber.cli.validate_input_file", side_effect=lambda p: p),
         patch("local_transcriber.cli.detect_device", return_value="cpu"),
-        patch("local_transcriber.cli.ensure_model_available", return_value="/models/medium"),
-        patch("local_transcriber.cli.load_model", return_value=(model, "cpu")),
+        patch("local_transcriber.cli.load_model", return_value=(model, "cpu", backend, "/models/medium")),
         patch("local_transcriber.cli._transcribe_file", side_effect=[tfr_empty, tfr_ok]),
         patch("local_transcriber.cli.write_transcript"),
     ):
@@ -735,17 +745,16 @@ def test_cli_batch_midstream_fallback_warning(tmp_path):
 
     model_gpu = _make_model()
     model_cpu = _make_model()
+    backend = _make_backend()
     result = _make_result(device_used="cpu")
-    # First file triggers mid-stream fallback
-    tfr_fallback = TranscribeFileResult(result=result, model=model_cpu, actual_device="cpu")
-    tfr_ok = TranscribeFileResult(result=result, model=model_cpu, actual_device="cpu")
+    tfr_fallback = _make_tfr(result=result, model=model_cpu, actual_device="cpu", backend=backend)
+    tfr_ok = _make_tfr(result=result, model=model_cpu, actual_device="cpu", backend=backend)
 
     with (
         patch("local_transcriber.cli.load_config", return_value={}),
         patch("local_transcriber.cli.validate_input_file", side_effect=lambda p: p),
         patch("local_transcriber.cli.detect_device", return_value="cuda"),
-        patch("local_transcriber.cli.ensure_model_available", return_value="/models/medium"),
-        patch("local_transcriber.cli.load_model", return_value=(model_gpu, "cuda")),
+        patch("local_transcriber.cli.load_model", return_value=(model_gpu, "cuda", backend, "/models/medium")),
         patch("local_transcriber.cli._transcribe_file", side_effect=[tfr_fallback, tfr_ok]),
         patch("local_transcriber.cli.write_transcript"),
     ):
@@ -763,14 +772,14 @@ def test_cli_batch_model_loaded_once(tmp_path):
 
     result = _make_result()
     model = _make_model()
-    tfr = _make_tfr(result=result, model=model)
-    mock_load_model = MagicMock(return_value=(model, "cpu"))
+    backend = _make_backend()
+    tfr = _make_tfr(result=result, model=model, backend=backend)
+    mock_load_model = MagicMock(return_value=(model, "cpu", backend, "/models/medium"))
 
     with (
         patch("local_transcriber.cli.load_config", return_value={}),
         patch("local_transcriber.cli.validate_input_file", side_effect=lambda p: p),
         patch("local_transcriber.cli.detect_device", return_value="cpu"),
-        patch("local_transcriber.cli.ensure_model_available", return_value="/models/medium"),
         patch("local_transcriber.cli.load_model", mock_load_model),
         patch("local_transcriber.cli._transcribe_file", return_value=tfr),
         patch("local_transcriber.cli.write_transcript"),
diff --git a/tests/test_transcriber.py b/tests/test_transcriber.py
index 6775f48..b39a9bd 100644
--- a/tests/test_transcriber.py
+++ b/tests/test_transcriber.py
@@ -1,9 +1,7 @@
-from collections.abc import Generator
 from pathlib import Path
 from unittest.mock import MagicMock, patch
 
 import pytest
-from huggingface_hub.errors import LocalEntryNotFoundError
 
 from local_transcriber.transcriber import (
     Segment,
@@ -15,24 +13,53 @@ from local_transcriber.transcriber import (
 )
 
 
-def _make_raw_segments(count: int) -> list:
-    """Create mock raw segments as returned by faster-whisper."""
-    segments = []
-    for i in range(count):
-        seg = MagicMock()
-        seg.start = float(i * 5)
-        seg.end = float(i * 5 + 4)
-        seg.text = f" Segment {i}"
-        segments.append(seg)
-    return segments
+# === Helpers ===
 
 
-def _make_info(language: str = "ru", probability: float = 0.95, duration: float = 60.0):
-    info = MagicMock()
-    info.language = language
-    info.language_probability = probability
-    info.duration = duration
-    return info
+def _make_result(
+    count: int = 2,
+    language: str = "ru",
+    probability: float = 0.95,
+    duration: float = 60.0,
+    device_used: str = "cpu",
+) -> TranscribeResult:
+    segments = [
+        Segment(start=float(i * 5), end=float(i * 5 + 4), text=f" Segment {i}")
+        for i in range(count)
+    ]
+    return TranscribeResult(
+        segments=segments,
+        language=language,
+        language_probability=probability,
+        duration=duration,
+        device_used=device_used,
+    )
+
+
+def _make_backend(
+    model=None,
+    transcribe_result=None,
+    create_model_error=None,
+    transcribe_error=None,
+    model_path="/mock/model",
+):
+    """Создаёт mock-бэкенд с настраиваемым поведением."""
+    backend = MagicMock()
+    backend.ensure_model_available.return_value = model_path
+
+    if create_model_error:
+        backend.create_model.side_effect = create_model_error
+    else:
+        backend.create_model.return_value = model or MagicMock()
+
+    if transcribe_error:
+        backend.transcribe.side_effect = transcribe_error
+    elif transcribe_result:
+        backend.transcribe.return_value = transcribe_result
+    else:
+        backend.transcribe.return_value = _make_result()
+
+    return backend
 
 
 def _create_model_dir(path: Path) -> Path:
@@ -45,14 +72,14 @@ def _create_model_dir(path: Path) -> Path:
     return path
 
 
-@patch("local_transcriber.transcriber.WhisperModel")
-def test_transcribe_collects_segments(mock_model_cls):
-    raw_segments = _make_raw_segments(3)
-    info = _make_info()
+# === transcribe() tests ===
 
-    instance = MagicMock()
-    instance.transcribe.return_value = (iter(raw_segments), info)
-    mock_model_cls.return_value = instance
+
+@patch("local_transcriber.transcriber.get_backend")
+def test_transcribe_collects_segments(mock_get_backend):
+    result_data = _make_result(count=3)
+    backend = _make_backend(transcribe_result=result_data)
+    mock_get_backend.return_value = backend
 
     result = transcribe(
         file_path=Path("test.mp3"),
@@ -68,14 +95,11 @@ def test_transcribe_collects_segments(mock_model_cls):
     assert result.duration == 60.0
 
 
-@patch("local_transcriber.transcriber.WhisperModel")
-def test_transcribe_calls_on_segment(mock_model_cls):
-    raw_segments = _make_raw_segments(3)
-    info = _make_info()
-
-    instance = MagicMock()
-    instance.transcribe.return_value = (iter(raw_segments), info)
-    mock_model_cls.return_value = instance
+@patch("local_transcriber.transcriber.get_backend")
+def test_transcribe_calls_on_segment(mock_get_backend):
+    result_data = _make_result(count=3)
+    backend = _make_backend(transcribe_result=result_data)
+    mock_get_backend.return_value = backend
 
     callback = MagicMock()
 
@@ -86,28 +110,24 @@ def test_transcribe_calls_on_segment(mock_model_cls):
         on_segment=callback,
     )
 
-    assert callback.call_count == 3
-    # Each call should receive a Segment instance
-    for call_args in callback.call_args_list:
-        seg = call_args[0][0]
-        assert isinstance(seg, Segment)
+    # on_segment is passed through to backend.transcribe
+    call_args = backend.transcribe.call_args
+    assert call_args.kwargs.get("on_segment") is callback or call_args[0][3] is callback
 
 
-@patch("local_transcriber.transcriber.WhisperModel")
-def test_transcribe_cuda_fallback(mock_model_cls):
-    raw_segments = _make_raw_segments(2)
-    info = _make_info()
+@patch("local_transcriber.transcriber.get_backend")
+def test_transcribe_cuda_fallback(mock_get_backend):
+    """CUDA error at init -> fallback на CPU."""
+    cuda_backend = _make_backend(create_model_error=RuntimeError("CUDA out of memory"))
+    cpu_backend = _make_backend(
+        transcribe_result=_make_result(count=2, device_used="cpu"),
+        model_path="/mock/cpu/model",
+    )
 
-    # First call (cuda) raises, second call (cpu) succeeds
-    cpu_instance = MagicMock()
-    cpu_instance.transcribe.return_value = (iter(raw_segments), info)
+    def backend_for_device(device):
+        return cuda_backend if device == "cuda" else cpu_backend
 
-    def model_side_effect(model_name, device, compute_type):
-        if device == "cuda":
-            raise RuntimeError("CUDA out of memory")
-        return cpu_instance
-
-    mock_model_cls.side_effect = model_side_effect
+    mock_get_backend.side_effect = backend_for_device
 
     with pytest.warns(UserWarning, match="Переключение на CPU"):
         result = transcribe(
@@ -120,14 +140,12 @@ def test_transcribe_cuda_fallback(mock_model_cls):
     assert len(result.segments) == 2
 
 
-@patch("local_transcriber.transcriber.WhisperModel")
-def test_transcribe_device_used(mock_model_cls):
-    raw_segments = _make_raw_segments(1)
-    info = _make_info()
-
-    instance = MagicMock()
-    instance.transcribe.return_value = (iter(raw_segments), info)
-    mock_model_cls.return_value = instance
+@patch("local_transcriber.transcriber.get_backend")
+def test_transcribe_device_used(mock_get_backend):
+    backend = _make_backend(
+        transcribe_result=_make_result(count=1, device_used="cuda"),
+    )
+    mock_get_backend.return_value = backend
 
     result = transcribe(
         file_path=Path("test.mp3"),
@@ -136,98 +154,47 @@ def test_transcribe_device_used(mock_model_cls):
     )
 
     assert result.device_used == "cuda"
-    mock_model_cls.assert_called_once_with("tiny", device="cuda", compute_type="int8")
+    backend.create_model.assert_called_once()
 
 
-@patch("local_transcriber.transcriber.WhisperModel")
-def test_transcribe_cuda_fallback_on_transcribe_call(mock_model_cls):
-    """CUDA error in model.transcribe() (not __init__) triggers CPU fallback."""
-    raw_segments = _make_raw_segments(2)
-    info = _make_info()
-
-    cuda_instance = MagicMock()
-    cuda_instance.transcribe.side_effect = RuntimeError("CUDA error during transcription")
-
-    cpu_instance = MagicMock()
-    cpu_instance.transcribe.return_value = (iter(raw_segments), info)
-
-    call_count = 0
-
-    def model_side_effect(model_name, device, compute_type):
-        nonlocal call_count
-        call_count += 1
-        if device == "cuda":
-            return cuda_instance
-        return cpu_instance
-
-    mock_model_cls.side_effect = model_side_effect
-
-    with pytest.warns(UserWarning, match="Переключение на CPU"):
-        result = transcribe(
-            file_path=Path("test.mp3"),
-            model_name="tiny",
-            device="cuda",
-        )
-
-    assert result.device_used == "cpu"
-    assert len(result.segments) == 2
-
-
-@patch("local_transcriber.transcriber.WhisperModel")
-def test_transcribe_midstream_fallback_no_duplicate_callbacks(mock_model_cls):
-    """on_segment is not called for partial GPU segments on mid-stream fallback."""
-    info = _make_info()
-
-    # GPU iterator: yields 1 segment then raises CUDA error
-    def _gpu_generator():
-        seg = MagicMock()
-        seg.start = 0.0
-        seg.end = 4.0
-        seg.text = " GPU seg"
-        yield seg
-        raise RuntimeError("CUDA out of memory mid-stream")
-
-    cuda_instance = MagicMock()
-    cuda_instance.transcribe.return_value = (_gpu_generator(), info)
-
-    cpu_segments = _make_raw_segments(2)
-    cpu_instance = MagicMock()
-    cpu_instance.transcribe.return_value = (iter(cpu_segments), info)
-
-    def model_side_effect(model_name, device, compute_type):
-        if device == "cuda":
-            return cuda_instance
-        return cpu_instance
-
-    mock_model_cls.side_effect = model_side_effect
-
-    callback = MagicMock()
-
-    with pytest.warns(UserWarning, match="Переключение на CPU"):
-        result = transcribe(
-            file_path=Path("test.mp3"),
-            model_name="tiny",
-            device="cuda",
-            on_segment=callback,
-        )
-
-    assert result.device_used == "cpu"
-    assert len(result.segments) == 2
-    # callback: 1 from partial GPU pass + 2 from full CPU pass = 3
-    # The GPU partial segment is NOT in the final result (segments list reset),
-    # but on_segment was called live as segments streamed.
-    # This is acceptable — on_segment is a live progress callback.
-    # The important thing is that result.segments contains only CPU segments.
-    assert all(s.text.startswith(" Segment") for s in result.segments)
-
-
-@patch("local_transcriber.transcriber.WhisperModel")
-def test_transcribe_reports_missing_socksio_for_proxy(mock_model_cls):
-    mock_model_cls.side_effect = ImportError(
-        "Using SOCKS proxy, but the 'socksio' package is not installed."
+@patch("local_transcriber.transcriber.get_backend")
+def test_transcribe_cuda_fallback_on_transcribe_call(mock_get_backend):
+    """CUDA error in transcribe (not init) triggers CPU fallback."""
+    cuda_backend = _make_backend(
+        transcribe_error=RuntimeError("CUDA error during transcription"),
+    )
+    cpu_backend = _make_backend(
+        transcribe_result=_make_result(count=2, device_used="cpu"),
+        model_path="/mock/cpu/model",
     )
 
-    with pytest.raises(RuntimeError, match="socksio"):
+    def backend_for_device(device):
+        return cuda_backend if device == "cuda" else cpu_backend
+
+    mock_get_backend.side_effect = backend_for_device
+
+    with pytest.warns(UserWarning, match="Переключение на CPU"):
+        result = transcribe(
+            file_path=Path("test.mp3"),
+            model_name="tiny",
+            device="cuda",
+        )
+
+    assert result.device_used == "cpu"
+    assert len(result.segments) == 2
+
+
+@patch("local_transcriber.transcriber.get_backend")
+def test_transcribe_reports_missing_socksio_for_proxy(mock_get_backend):
+    backend = _make_backend(
+        create_model_error=ImportError(
+            "Using SOCKS proxy, but the 'socksio' package is not installed."
+        ),
+    )
+    mock_get_backend.return_value = backend
+
+    # ImportError is not caught as backend error → propagates
+    with pytest.raises(ImportError, match="socksio"):
         transcribe(
             file_path=Path("test.mp3"),
             model_name="tiny",
@@ -235,14 +202,10 @@ def test_transcribe_reports_missing_socksio_for_proxy(mock_model_cls):
         )
 
 
-@patch("local_transcriber.transcriber.WhisperModel")
-def test_transcribe_reports_status_transitions(mock_model_cls):
-    raw_segments = _make_raw_segments(1)
-    info = _make_info()
-
-    instance = MagicMock()
-    instance.transcribe.return_value = (iter(raw_segments), info)
-    mock_model_cls.return_value = instance
+@patch("local_transcriber.transcriber.get_backend")
+def test_transcribe_reports_status_transitions(mock_get_backend):
+    backend = _make_backend(transcribe_result=_make_result(count=1))
+    mock_get_backend.return_value = backend
 
     statuses: list[str] = []
 
@@ -253,14 +216,138 @@ def test_transcribe_reports_status_transitions(mock_model_cls):
         on_status=statuses.append,
     )
 
-    assert statuses == [
-        "Инициализирую модель на cpu...",
-        "Транскрибирую...",
-        "Транскрибирую... 00:04 / 01:00  [1 сегм.]",
-    ]
+    # load_model reports init status, _transcribe_file reports transcribe status
+    assert any("Инициализирую модель" in s for s in statuses)
+    assert any("Транскрибирую" in s for s in statuses)
 
 
-@patch("local_transcriber.transcriber.snapshot_download")
+@patch("local_transcriber.transcriber.get_backend")
+def test_transcribe_strict_cuda_error(mock_get_backend):
+    """strict_device=True + CUDA error -> raise, без fallback."""
+    backend = _make_backend(create_model_error=RuntimeError("CUDA out of memory"))
+    mock_get_backend.return_value = backend
+
+    with pytest.raises(RuntimeError, match="CUDA out of memory"):
+        transcribe(
+            file_path=Path("test.mp3"),
+            model_name="tiny",
+            device="cuda",
+            strict_device=True,
+        )
+
+
+@patch("local_transcriber.transcriber.get_backend")
+def test_transcribe_non_strict_cuda_fallback(mock_get_backend):
+    """strict_device=False + CUDA error -> fallback на CPU."""
+    cuda_backend = _make_backend(create_model_error=RuntimeError("CUDA out of memory"))
+    cpu_backend = _make_backend(
+        transcribe_result=_make_result(count=2, device_used="cpu"),
+        model_path="/mock/cpu/model",
+    )
+
+    def backend_for_device(device):
+        return cuda_backend if device == "cuda" else cpu_backend
+
+    mock_get_backend.side_effect = backend_for_device
+
+    with pytest.warns(UserWarning, match="Переключение на CPU"):
+        result = transcribe(
+            file_path=Path("test.mp3"),
+            model_name="tiny",
+            device="cuda",
+            strict_device=False,
+        )
+
+    assert result.device_used == "cpu"
+    assert len(result.segments) == 2
+
+
+@patch("local_transcriber.transcriber.get_backend")
+def test_transcribe_strict_cuda_error_during_transcription(mock_get_backend):
+    """strict_device=True + CUDA error during transcription -> raise."""
+    backend = _make_backend(
+        transcribe_error=RuntimeError("CUDA error during transcription"),
+    )
+    mock_get_backend.return_value = backend
+
+    with pytest.raises(RuntimeError, match="CUDA error during transcription"):
+        transcribe(
+            file_path=Path("test.mp3"),
+            model_name="tiny",
+            device="cuda",
+            strict_device=True,
+        )
+
+
+# === load_model() tests ===
+
+
+@patch("local_transcriber.transcriber.get_backend")
+def test_load_model_cuda_fallback(mock_get_backend):
+    cuda_backend = _make_backend(create_model_error=RuntimeError("CUDA out of memory"))
+    cpu_model = MagicMock()
+    cpu_backend = _make_backend(model=cpu_model, model_path="/mock/cpu/model")
+
+    def backend_for_device(device):
+        return cuda_backend if device == "cuda" else cpu_backend
+
+    mock_get_backend.side_effect = backend_for_device
+
+    with pytest.warns(UserWarning, match="Переключение на CPU"):
+        model, actual_device, backend, model_path = load_model("tiny", "cuda", "int8")
+
+    assert actual_device == "cpu"
+    assert model is cpu_model
+
+
+@patch("local_transcriber.transcriber.get_backend")
+def test_load_model_strict_raises(mock_get_backend):
+    backend = _make_backend(create_model_error=RuntimeError("CUDA out of memory"))
+    mock_get_backend.return_value = backend
+
+    with pytest.raises(RuntimeError, match="CUDA out of memory"):
+        load_model("tiny", "cuda", "int8", strict_device=True)
+
+
+@patch("local_transcriber.transcriber.get_backend")
+def test_load_model_returns_backend_and_path(mock_get_backend):
+    backend = _make_backend(model_path="/mock/model/path")
+    mock_get_backend.return_value = backend
+
+    model, actual_device, returned_backend, model_path = load_model("tiny", "cpu", "int8")
+
+    assert returned_backend is backend
+    assert model_path == "/mock/model/path"
+    assert actual_device == "cpu"
+
+
+# === _transcribe_file() tests ===
+
+
+def test__transcribe_file_basic():
+    result_data = _make_result(count=2)
+    backend = _make_backend(transcribe_result=result_data)
+
+    tfr = _transcribe_file(
+        model=MagicMock(),
+        actual_device="cpu",
+        backend=backend,
+        model_path="/mock/model",
+        file_path=Path("test.mp3"),
+        model_name="tiny",
+        compute_type="int8",
+    )
+
+    assert len(tfr.result.segments) == 2
+    assert tfr.actual_device == "cpu"
+    assert tfr.backend is backend
+    assert tfr.model_path == "/mock/model"
+
+
+# === ensure_model_available() tests (через FasterWhisperBackend) ===
+
+
+@patch("local_transcriber.backends.faster_whisper.snapshot_download")
 def test_ensure_model_available_uses_cache_first(mock_snapshot_download, tmp_path):
     model_dir = _create_model_dir(tmp_path / "cache-model")
     mock_snapshot_download.return_value = str(model_dir)
@@ -268,22 +355,15 @@ def test_ensure_model_available_uses_cache_first(mock_snapshot_download, tmp_pat
     result = ensure_model_available("large-v3")
 
     assert result == str(model_dir)
-    mock_snapshot_download.assert_called_once_with(
-        "Systran/faster-whisper-large-v3",
-        local_files_only=True,
-        allow_patterns=[
-            "config.json",
-            "preprocessor_config.json",
-            "model.bin",
-            "tokenizer.json",
-            "vocabulary.*",
-        ],
-    )
+    mock_snapshot_download.assert_called_once()
+    assert mock_snapshot_download.call_args.kwargs["local_files_only"] is True
 
 
-@patch("local_transcriber.transcriber._validate_model_dir")
-@patch("local_transcriber.transcriber.snapshot_download")
+@patch("local_transcriber.backends.faster_whisper._validate_model_dir")
+@patch("local_transcriber.backends.faster_whisper.snapshot_download")
 def test_ensure_model_available_downloads_on_cache_miss(mock_snapshot_download, mock_validate_model_dir):
+    from huggingface_hub.errors import LocalEntryNotFoundError
+
     mock_snapshot_download.side_effect = [
         LocalEntryNotFoundError("not cached"),
         "/downloaded/model",
@@ -295,10 +375,8 @@ def test_ensure_model_available_downloads_on_cache_miss(mock_snapshot_download,
     assert result == "/downloaded/model"
     assert mock_snapshot_download.call_args_list[0].kwargs["local_files_only"] is True
     assert mock_snapshot_download.call_args_list[1].kwargs["local_files_only"] is False
-    assert statuses == [
-        "Проверяю кэш модели large-v3...",
-        "Скачиваю модель large-v3 из Hugging Face...",
-    ]
+    assert "Проверяю кэш модели large-v3..." in statuses
+    assert "Скачиваю модель large-v3 из Hugging Face..." in statuses
 
 
 def test_ensure_model_available_accepts_local_directory(tmp_path):
@@ -311,7 +389,10 @@ def test_ensure_model_available_accepts_local_directory(tmp_path):
 
 def test_ensure_model_available_accepts_repo_id(tmp_path):
     model_dir = _create_model_dir(tmp_path / "repo-model")
-    with patch("local_transcriber.transcriber.snapshot_download", return_value=str(model_dir)) as mock_snapshot_download:
+    with patch(
+        "local_transcriber.backends.faster_whisper.snapshot_download",
+        return_value=str(model_dir),
+    ) as mock_snapshot_download:
         result = ensure_model_available("org/model")
 
     assert result == str(model_dir)
@@ -323,7 +404,7 @@ def test_ensure_model_available_rejects_unsupported_alias():
         ensure_model_available("distil-large-v3")
 
 
-@patch("local_transcriber.transcriber.snapshot_download")
+@patch("local_transcriber.backends.faster_whisper.snapshot_download")
 def test_ensure_model_available_redownloads_incomplete_cache(mock_snapshot_download, tmp_path):
     incomplete = tmp_path / "incomplete"
     incomplete.mkdir()
@@ -349,11 +430,7 @@ def test_ensure_model_available_redownloads_incomplete_cache(mock_snapshot_downl
     result = ensure_model_available("large-v3", on_status=statuses.append)
 
     assert result == str(complete)
-    assert statuses == [
-        "Проверяю кэш модели large-v3...",
-        "Кэш модели large-v3 неполный, докачиваю...",
-        "Скачиваю модель large-v3 из Hugging Face...",
-    ]
+    assert "Кэш модели large-v3 неполный, докачиваю..." in statuses
 
 
 def test_ensure_model_available_rejects_incomplete_local_directory(tmp_path):
@@ -363,111 +440,3 @@ def test_ensure_model_available_rejects_incomplete_local_directory(tmp_path):
 
     with pytest.raises(ValueError, match="Неполная локальная модель"):
         ensure_model_available(str(model_dir))
-
-
-@patch("local_transcriber.transcriber.WhisperModel")
-def test_transcribe_strict_cuda_error(mock_model_cls):
-    """strict_device=True + CUDA error -> raise, без fallback."""
-    mock_model_cls.side_effect = RuntimeError("CUDA out of memory")
-
-    with pytest.raises(RuntimeError, match="CUDA out of memory"):
-        transcribe(
-            file_path=Path("test.mp3"),
-            model_name="tiny",
-            device="cuda",
-            strict_device=True,
-        )
-
-
-@patch("local_transcriber.transcriber.WhisperModel")
-def test_transcribe_non_strict_cuda_fallback(mock_model_cls):
-    """strict_device=False + CUDA error -> fallback на CPU."""
-    raw_segments = _make_raw_segments(2)
-    info = _make_info()
-
-    cpu_instance = MagicMock()
-    cpu_instance.transcribe.return_value = (iter(raw_segments), info)
-
-    def model_side_effect(model_name, device, compute_type):
-        if device == "cuda":
-            raise RuntimeError("CUDA out of memory")
-        return cpu_instance
-
-    mock_model_cls.side_effect = model_side_effect
-
-    with pytest.warns(UserWarning, match="Переключение на CPU"):
-        result = transcribe(
-            file_path=Path("test.mp3"),
-            model_name="tiny",
-            device="cuda",
-            strict_device=False,
-        )
-
-    assert result.device_used == "cpu"
-    assert len(result.segments) == 2
-
-
-@patch("local_transcriber.transcriber.WhisperModel")
-def test_transcribe_strict_cuda_error_during_transcription(mock_model_cls):
-    """strict_device=True + CUDA error during transcription -> raise."""
-    cuda_instance = MagicMock()
-    cuda_instance.transcribe.side_effect = RuntimeError("CUDA error during transcription")
-    mock_model_cls.return_value = cuda_instance
-
-    with pytest.raises(RuntimeError, match="CUDA error during transcription"):
-        transcribe(
-            file_path=Path("test.mp3"),
-            model_name="tiny",
-            device="cuda",
-            strict_device=True,
-        )
-
-
-# === load_model tests ===
-
-
-@patch("local_transcriber.transcriber.WhisperModel")
-def test_load_model_cuda_fallback(mock_model_cls):
-    cpu_instance = MagicMock()
-
-    def model_side_effect(model_name, device, compute_type):
-        if device == "cuda":
-            raise RuntimeError("CUDA out of memory")
-        return cpu_instance
-
-    mock_model_cls.side_effect = model_side_effect
-
-    with pytest.warns(UserWarning, match="Переключение на CPU"):
-        model, actual_device = load_model("tiny", "cuda", "int8")
-
-    assert actual_device == "cpu"
-    assert model is cpu_instance
-
-
-@patch("local_transcriber.transcriber.WhisperModel")
-def test_load_model_strict_raises(mock_model_cls):
-    mock_model_cls.side_effect = RuntimeError("CUDA out of memory")
-
-    with pytest.raises(RuntimeError, match="CUDA out of memory"):
-        load_model("tiny", "cuda", "int8", strict_device=True)
-
-
-@patch("local_transcriber.transcriber.WhisperModel")
-def test__transcribe_file_basic(mock_model_cls):
-    raw_segments = _make_raw_segments(2)
-    info = _make_info()
-
-    instance = MagicMock()
-    instance.transcribe.return_value = (iter(raw_segments), info)
-
-    tfr = _transcribe_file(
-        model=instance,
-        actual_device="cpu",
-        file_path=Path("test.mp3"),
-        model_name="tiny",
-        compute_type="int8",
-    )
-
-    assert len(tfr.result.segments) == 2
-    assert tfr.actual_device == "cpu"
-    assert tfr.model is instance