test: lock speechbrain lengths and identity camera filter

Filter --cameras 1,5 by cam-NN identity instead of discovery index.

tests/test_discovery.py

@@ -0,0 +1,49 @@
+import re
+
+from discovery import Camera, discover_cameras, select_cameras
+
+CARD_RE = re.compile(r"\s*(\d+)\s+\[([A-Za-z0-9_]+)\s*\]:\s*(.*)")
+
+
+def test_padded_c920_card_line_matches():
+    line = " 2 [C920            ]: USB-Audio - HD Pro Webcam C920"
+    m = CARD_RE.match(line)
+    assert m is not None
+    assert int(m.group(1)) == 2
+    assert m.group(2) == "C920"
+
+
+def test_naive_word_regex_misses_padding():
+    line = " 2 [C920            ]: USB-Audio - HD Pro Webcam C920"
+    assert re.match(r"\s*(\d+)\s+\[(\w+)\]:", line) is None
+
+
+def test_live_discover_present_cameras():
+    cams = discover_cameras()
+    assert len(cams) >= 1
+    assert all(c.audio_card is not None for c in cams)
+    assert all(c.serial for c in cams)
+    assert all(re.match(r"cam-\d{2}$", c.identity) for c in cams)
+    ids = [c.identity for c in cams]
+    assert ids == sorted(ids)
+
+
+def test_select_cameras_by_identity_not_index():
+    cams = [
+        Camera(index=0, identity="cam-01", video_device="/dev/cam01",
+               audio_card=2, serial="A"),
+        Camera(index=1, identity="cam-05", video_device="/dev/cam05",
+               audio_card=6, serial="B"),
+        Camera(index=2, identity="cam-20", video_device="/dev/cam20",
+               audio_card=21, serial="C"),
+    ]
+    out = select_cameras(cams, ["1", "5"])
+    assert [c.identity for c in out] == ["cam-01", "cam-05"]
+
+
+def test_select_cameras_all():
+    cams = [
+        Camera(index=0, identity="cam-01", video_device="/dev/cam01",
+               audio_card=2, serial="A"),
+    ]
+    assert select_cameras(cams, ["all"]) == cams