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aitrailer/tests/test_deep_scan.py
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2026-05-02 09:07:41 +02:00

141 lines
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Python

"""
tests/test_deep_scan.py — Unit tests for frame_extractor and deep_scan
Uses synthetic in-memory videos (cv2.VideoWriter → temp file) so no real
video files are required. Tests cover the pure logic, not hardware decoding.
"""
from __future__ import annotations
import tempfile
from pathlib import Path
import cv2
import numpy as np
import pytest
from src.cv.frame_extractor import (
get_video_info,
grab_frame_at,
iter_frames_stepped,
open_video,
)
from src.cv.fingerprinting import text_safe_crop
# ---------------------------------------------------------------------------
# Helpers: build a tiny synthetic video on disk
# ---------------------------------------------------------------------------
FPS = 24
WIDTH = 320
HEIGHT = 240
SECS = 3
def _make_synthetic_video(path: Path, color_bgr: tuple[int, int, int] = (0, 128, 255)) -> Path:
"""Write a 3-second single-colour video to *path*."""
fourcc = cv2.VideoWriter_fourcc(*"mp4v")
writer = cv2.VideoWriter(str(path), fourcc, float(FPS), (WIDTH, HEIGHT))
frame = np.full((HEIGHT, WIDTH, 3), color_bgr, dtype=np.uint8)
for _ in range(FPS * SECS):
writer.write(frame)
writer.release()
return path
@pytest.fixture
def synthetic_video(tmp_path: Path) -> Path:
return _make_synthetic_video(tmp_path / "test.mp4")
# ---------------------------------------------------------------------------
# open_video
# ---------------------------------------------------------------------------
class TestOpenVideo:
def test_opens_valid_file(self, synthetic_video: Path) -> None:
with open_video(synthetic_video) as cap:
assert cap.isOpened()
def test_raises_on_missing_file(self, tmp_path: Path) -> None:
with pytest.raises(FileNotFoundError):
with open_video(tmp_path / "ghost.mp4"):
pass
# ---------------------------------------------------------------------------
# get_video_info
# ---------------------------------------------------------------------------
class TestGetVideoInfo:
def test_returns_correct_fps(self, synthetic_video: Path) -> None:
info = get_video_info(synthetic_video)
assert info["fps"] == pytest.approx(FPS, rel=0.05)
def test_duration_approx(self, synthetic_video: Path) -> None:
info = get_video_info(synthetic_video)
assert info["duration_s"] == pytest.approx(SECS, rel=0.1)
def test_resolution(self, synthetic_video: Path) -> None:
info = get_video_info(synthetic_video)
assert info["width"] == WIDTH
assert info["height"] == HEIGHT
# ---------------------------------------------------------------------------
# grab_frame_at
# ---------------------------------------------------------------------------
class TestGrabFrameAt:
def test_returns_ndarray(self, synthetic_video: Path) -> None:
with open_video(synthetic_video) as cap:
frame = grab_frame_at(cap, 1.0)
assert frame is not None
assert isinstance(frame, np.ndarray)
assert frame.shape == (HEIGHT, WIDTH, 3)
def test_returns_none_past_end(self, synthetic_video: Path) -> None:
with open_video(synthetic_video) as cap:
frame = grab_frame_at(cap, 9999.0)
# May return None or a repeated last frame depending on codec;
# we only assert no exception is raised.
assert frame is None or isinstance(frame, np.ndarray)
# ---------------------------------------------------------------------------
# iter_frames_stepped
# ---------------------------------------------------------------------------
class TestIterFramesStepped:
def test_yields_correct_count(self, synthetic_video: Path) -> None:
with open_video(synthetic_video) as cap:
frames = list(iter_frames_stepped(cap, 0.0, 1.0, 0.5))
# Expect timestamps: 0.0, 0.5, 1.0 → 3 frames
assert len(frames) == 3
def test_timestamps_increasing(self, synthetic_video: Path) -> None:
with open_video(synthetic_video) as cap:
frames = list(iter_frames_stepped(cap, 0.0, 2.0, 0.5))
timestamps = [t for t, _ in frames]
assert timestamps == sorted(timestamps)
def test_invalid_step_raises(self, synthetic_video: Path) -> None:
with open_video(synthetic_video) as cap:
with pytest.raises(ValueError, match="step_s"):
list(iter_frames_stepped(cap, 0.0, 1.0, 0.0))
# ---------------------------------------------------------------------------
# text_safe_crop integration (sanity: cropped height consistent)
# ---------------------------------------------------------------------------
class TestCropSanity:
def test_crop_reduces_height(self, synthetic_video: Path) -> None:
with open_video(synthetic_video) as cap:
frame = grab_frame_at(cap, 0.5)
assert frame is not None
cropped = text_safe_crop(frame, 0.15, 0.30)
assert cropped.shape[0] < frame.shape[0]
assert cropped.shape[1] == frame.shape[1] # width unchanged