fix(manifests): flag DASH audio using the standard description role

tests/core/test_dash_descriptive_audio.py

@@ -0,0 +1,39 @@
+import xml.etree.ElementTree as ET
+
+import pytest
+
+from unshackle.core.manifests.dash import DASH
+
+
+def adaptation_set(scheme: str, value: str) -> ET.Element:
+    return ET.fromstring(f'<AdaptationSet><Accessibility schemeIdUri="{scheme}" value="{value}"/></AdaptationSet>')
+
+
+@pytest.mark.parametrize(
+    "scheme,value",
+    [
+        # "description" is the value the DASH role scheme defines. Stan writes it, and reading only
+        # "descriptive" left every audio-description track unflagged.
+        ("urn:mpeg:dash:role:2011", "description"),
+        ("urn:mpeg:dash:role:2011", "descriptive"),
+        ("urn:tva:metadata:cs:AudioPurposeCS:2007", "1"),
+    ],
+)
+def test_descriptive_accessibility_values(scheme: str, value: str) -> None:
+    assert DASH.is_descriptive(adaptation_set(scheme, value)) is True
+
+
+@pytest.mark.parametrize(
+    "scheme,value",
+    [
+        ("urn:mpeg:dash:role:2011", "main"),
+        ("urn:mpeg:dash:role:2011", "caption"),
+        ("urn:tva:metadata:cs:AudioPurposeCS:2007", "2"),
+    ],
+)
+def test_non_descriptive_accessibility_values(scheme: str, value: str) -> None:
+    assert DASH.is_descriptive(adaptation_set(scheme, value)) is False
+
+
+def test_no_accessibility_element() -> None:
+    assert DASH.is_descriptive(ET.fromstring("<AdaptationSet/>")) is False

unshackle/core/manifests/dash.py

@@ -1111,7 +1111,11 @@ class DASH:
         """Whether the Adaptation Set is Descriptive."""
         return any(
             (x.get("schemeIdUri"), x.get("value"))
-            in (("urn:mpeg:dash:role:2011", "descriptive"), ("urn:tva:metadata:cs:AudioPurposeCS:2007", "1"))
+            in (
+                ("urn:mpeg:dash:role:2011", "description"),
+                ("urn:mpeg:dash:role:2011", "descriptive"),
+                ("urn:tva:metadata:cs:AudioPurposeCS:2007", "1"),
+            )
             for x in adaptation_set.findall("Accessibility")
         )