player: probe Rockchip MPP/V4L2 HW decoders at pipeline init, add setup_hw_decode.sh

src/r36s_dlna_browser/player/gstreamer_backend.py

@@ -25,6 +25,72 @@ log = logging.getLogger(__name__)
 
 Gst.init(None)
 
+# GStreamer element names for hardware video decoders, in priority order.
+# mppvideodec: Rockchip MPP plugin (gst-mpp), uses /dev/vpu_service on kernel 4.4 BSP.
+# v4l2*dec:    Linux V4L2 stateful decoders, available on kernel 5.4+ (rkvdec/hantro).
+_HW_DECODER_ELEMENTS = [
+    "mppvideodec",
+    "v4l2h264dec",
+    "v4l2h265dec",
+    "v4l2vp8dec",
+    "v4l2vp9dec",
+]
+
+# VPU device nodes that must be accessible for hardware decode on RK3326.
+_HW_VPU_DEVICES = [
+    "/dev/vpu_service",   # kernel 4.4 BSP (RK3326 / PX30)
+    "/dev/mpp_service",   # newer BSP variants
+    "/dev/video10",       # V4L2 vcodec on mainline/5.10+ kernels
+    "/dev/video11",
+]
+
+
+def _vpu_device_accessible() -> bool:
+    """Return True if at least one VPU device node can be opened by this process."""
+    for path in _HW_VPU_DEVICES:
+        try:
+            fd = os.open(path, os.O_RDWR | os.O_NONBLOCK)
+            os.close(fd)
+            log.info("HW decode: VPU device accessible: %s", path)
+            return True
+        except OSError:
+            pass
+    return False
+
+
+def _probe_hw_decoders(gst_module) -> list:
+    """
+    Probe for available hardware video decoder GStreamer elements and boost
+    their rank so that playbin's internal decodebin prefers them over software
+    decoders.  Returns the list of element names that were found and boosted.
+    If no VPU device node is accessible the probe is skipped entirely so that
+    a half-initialised hardware element cannot stall the pipeline.
+    """
+    if not _vpu_device_accessible():
+        log.info(
+            "HW decode: no accessible VPU device node — using software decode. "
+            "Run deploy/arkos/setup_hw_decode.sh as root to fix permissions."
+        )
+        return []
+
+    found = []
+    for name in _HW_DECODER_ELEMENTS:
+        factory = gst_module.ElementFactory.find(name)
+        if factory is not None:
+            try:
+                factory.set_rank(gst_module.Rank.PRIMARY + 1)
+                found.append(name)
+                log.info("HW decode: boosted rank of %s", name)
+            except Exception as exc:  # pragma: no cover
+                log.warning("HW decode: could not boost rank of %s: %s", name, exc)
+
+    if not found:
+        log.info(
+            "HW decode: VPU device is accessible but no gst-mpp / V4L2 plugin found. "
+            "Run deploy/arkos/setup_hw_decode.sh to install gstreamer1.0-rockchip-mpp."
+        )
+    return found
+
 
 def _wm_subsystem_name(subsystem: int) -> str:
     mapping = {
@@ -116,6 +182,7 @@ class GStreamerBackend(PlayerBackend):
         self._texture_renderer = None
         self._texture_size = (0, 0)
         self._resolution = ""
+        self._hw_decoders: list | None = None  # None = not yet probed
 
     def attach_window(self, window: object) -> None:
         self._window = window
@@ -259,6 +326,9 @@ class GStreamerBackend(PlayerBackend):
             if self._pipeline is not None:
                 return self._pipeline
 
+            if self._hw_decoders is None:
+                self._hw_decoders = _probe_hw_decoders(self._gst)
+
             self._pipeline = self._playbin_factory()
             self._configure_playbin_flags(self._pipeline)
             self._video_sink = self._create_appsink()