player: NV12 zero-copy SDL upload path for Rockchip MPP hardware decode

- _Frame: add pixel_format ('BGRA'|'NV12'), uv_pixels, uv_pitch fields
- _create_appsink: accept NV12 caps when R36S_HW_DECODE=1 (NV12;BGRA fallback)
- render(): choose SDL_PIXELFORMAT_NV12 texture + SDL_UpdateNVTexture for NV12
  frames, avoiding any software colourspace conversion on the CPU
- _on_new_sample: detect format via VideoInfo.finfo.name, extract Y+UV planes
  separately from NV12 GStreamer buffers
- _destroy_texture: reset _texture_format to 'BGRA'
- deploy/arkos/MatHacks.sh: set R36S_HW_DECODE=1 to activate the path
- tests/test_player.py: add finfo mock, pixel_format to SimpleNamespace frame

tests/test_player.py

@@ -188,11 +188,17 @@ class FakeGst:
     Caps = SimpleNamespace(from_string=lambda value: value)
 
 
+class _FakeFinfo:
+    def __init__(self, name):
+        self.name = name
+
+
 class FakeVideoInfoValue:
-    def __init__(self, width, height, stride):
+    def __init__(self, width, height, stride, fmt="BGRA"):
         self.width = width
         self.height = height
-        self.stride = [stride]
+        self.stride = [stride, stride]
+        self.finfo = _FakeFinfo(fmt)
 
 
 class FakeVideoInfo:
@@ -201,7 +207,12 @@ class FakeVideoInfo:
         structure = caps.get_structure(0)
         width = structure.get_value("width")
         height = structure.get_value("height")
-        return FakeVideoInfoValue(width, height, width * 4)
+        fmt = "BGRA"
+        try:
+            fmt = structure.get_value("format") or fmt
+        except Exception:
+            pass
+        return FakeVideoInfoValue(width, height, width * 4, fmt)
 
 
 class FakeGstVideo:
@@ -341,7 +352,7 @@ class TestGStreamerBackend:
 
     def test_render_uploads_latest_frame_and_clears_dirty_flag(self, monkeypatch):
         backend, _pipeline, _sink = self._make_backend()
-        backend._latest_frame = SimpleNamespace(width=320, height=180, pitch=1280, pixels=b"\x00" * (320 * 180 * 4))
+        backend._latest_frame = SimpleNamespace(width=320, height=180, pitch=1280, pixels=b"\x00" * (320 * 180 * 4), pixel_format="BGRA", uv_pixels=None, uv_pitch=0)
         backend._frame_dirty = True
 
         calls = []