1 files changed, 48 insertions, 0 deletions
diff --git a/packages/meshbay-node/tests/test_stream_video_transcode.py b/packages/meshbay-node/tests/test_stream_video_transcode.py
index b165af4..0fd12c6 100644
--- a/packages/meshbay-node/tests/test_stream_video_transcode.py
+++ b/packages/meshbay-node/tests/test_stream_video_transcode.py
@@ -35,6 +35,7 @@ from cryptography.hazmat.primitives.asymmetric.ed25519 import Ed25519PrivateKey
 
 from meshbay_common.crypto import generate_gek
 from meshbay_common.webcrypto import chunk_key_aes, decrypt_chunk_aes
+from meshbay_node import hwaccel
 from meshbay_node.indexer.group_index import GroupIndex
 from meshbay_node.transport.webrtc_server import WebRTCPeerSession, _probe_video
 
@@ -271,3 +272,50 @@ async def test_the_operator_can_refuse_the_re_encode_and_says_so(tmp_path):
         f"the refusal must point at the setting that caused it: {detail!r}")
     assert not [m for m in session.sent if m.get("type") == "stream_init"], (
         "a stream_init went out with no codec string the client could check")
+
+
+@needs_mp3
+async def test_a_hardware_encoder_that_does_not_work_costs_the_viewer_nothing(
+        tmp_path, monkeypatch):
+    """A VA-API mode that fails falls through to libx264 and the film plays.
+
+    This is the failure that cannot be prevented by probing: `hwaccel.py`
+    proves the *encoder* with a test encode at startup, and nothing proves the
+    GPU can decode a particular source until it is asked to — iHD has no
+    MPEG-4 Part 2 decoder at all, which is exactly the file used here.
+
+    The encoder is faked onto `/dev/null` rather than skipped for want of a
+    GPU, so this runs identically on a machine with one and on a machine
+    without: both hardware modes fail instantly, and what is tested is that
+    the viewer sees one working stream and not an error. The demotions are
+    checked too — a library of Xvid files must not pay for the first one's two
+    dead spawns again and again.
+    """
+    clip = tmp_path / "clip.avi"
+    _make_mpeg4_clip(clip)
+    gek = generate_gek()
+    session, file_id = _session(clip, gek)
+
+    hwaccel._reset_for_tests()
+
+    async def _broken_encoder():
+        vaapi = next(c for c in hwaccel.CANDIDATES if c.name == "vaapi")
+        return hwaccel.Encoder(candidate=vaapi, variant="standard", extra=(),
+                               device="/dev/null")
+
+    monkeypatch.setattr(hwaccel, "encoder", _broken_encoder)
+    try:
+        await session._stream_video_inner({"file_id": file_id, "start": 0, "credits": 0})
+
+        assert not [m for m in session.sent if m.get("type") == "error"], (
+            "a hardware encoder that does not work must cost the viewer nothing")
+        remuxed = _reassemble(session.sent, gek, file_id)
+        out_path = tmp_path / "out.mp4"
+        out_path.write_bytes(remuxed)
+        assert _output_video_codec(out_path) == "h264", \
+            "the software fallback must still deliver a playable H264 stream"
+
+        assert ("mpeg4", hwaccel.HW) in hwaccel._demoted
+        assert ("mpeg4", hwaccel.HWENC) in hwaccel._demoted
+    finally:
+        hwaccel._reset_for_tests()