fix(video_rca): allow setting the video encoder

examples/01_vtk/vtk_cone_simple_video.py

@@ -22,6 +22,11 @@
 class ConeApp(TrameApp):
     def __init__(self, server=None):
         super().__init__(server)
+
+        self.server.cli.add_argument("--encoder", default="auto")
+        args, _ = self.server.cli.parse_known_args()
+
+        self.encoder = args.encoder
         self.render_window = self.setup_vtk()
 
         self._build_ui()
@@ -76,7 +81,9 @@ def _build_ui(self):
 
             with layout.content:
                 view = rca.RemoteControlledArea(display="video-decoder")
-                self.view_handler = view.create_view_handler(self.render_window)
+                self.view_handler = view.create_view_handler(
+                    self.render_window, encoder=self.encoder
+                )
 
 
 # -----------------------------------------------------------------------------

src/trame_rca/encoders/__init__.py

@@ -3,12 +3,14 @@
 from .image_encoder import RcaImageEncoder
 
 try:
-    from .video_encoder import RcaVideoEncoder
+    from .video_encoder import RcaVideoEncoder, VideoEncoderType
 except ModuleNotFoundError:
+    RcaVideoEncoder = object
+    VideoEncoderType = object
     logger = logging.getLogger(__name__)
     logger.warning(
         "VTKStreaming Video encoding is NOT AVAILABLE (missing Python package)"
     )
 
 
-__all__ = ["RcaVideoEncoder", "RcaImageEncoder"]
+__all__ = ["RcaVideoEncoder", "RcaImageEncoder", "VideoEncoderType"]

src/trame_rca/encoders/video_encoder.py

@@ -1,4 +1,5 @@
 import logging
+from enum import Enum, auto
 from time import time_ns
 from typing import Callable
 
@@ -50,19 +51,33 @@ def encode(
     return (bytes(frame_data), meta, now_ms)
 
 
+class VideoEncoderType(Enum):
+    AUTO = auto()
+    NVENC = auto()
+    VP9 = auto()
+
+
 class RcaVideoEncoder:
     def __init__(
         self,
         render_window: vtkRenderWindow,
         push_callback: Callable[[bytes, dict, int], None],
+        rca_encoder: VideoEncoderType | str | None = None,
     ) -> None:
         self._render_window = render_window
         self.encoder = None
         self.frame = None
         self._push_callback = push_callback
         self._window_size = None
 
-        if vtkNvEncoderGL.CheckAvailability():
+        rca_encoder = rca_encoder or VideoEncoderType.AUTO
+        if isinstance(rca_encoder, str):
+            rca_encoder = VideoEncoderType[rca_encoder.upper()]
+
+        if vtkNvEncoderGL.CheckAvailability() and rca_encoder in [
+            VideoEncoderType.AUTO,
+            VideoEncoderType.NVENC,
+        ]:
             logger.info("Using H264 through NVENC")
             self._create_encoder = create_nvenc_encoder
         else:

src/trame_rca/schedulers/video_scheduler.py

@@ -10,7 +10,7 @@
 
     from trame_rca.rca import VtkRemoteControlledArea
 
-from trame_rca.encoders import RcaVideoEncoder
+from trame_rca.encoders import RcaVideoEncoder, VideoEncoderType
 from trame_rca.rca import window_wrapper
 
 
@@ -33,10 +33,11 @@ def __init__(
         *,
         push_callback: Callable[[bytes, dict]] | None = None,
         target_fps: float = 30.0,
+        rca_encoder: VideoEncoderType | None = None,
     ):
         self._rca: VtkRemoteControlledArea = window_wrapper(window)
         self._rca_encoder = RcaVideoEncoder(
-            self._rca.render_window, push_callback=self._push
+            self._rca.render_window, push_callback=self._push, rca_encoder=rca_encoder
         )
         self._is_closing = False
         self._render_requested = False

src/trame_rca/widgets/rca.py

@@ -11,7 +11,7 @@
 if TYPE_CHECKING:
     from vtkmodules.vtkRenderingCore import vtkRenderWindow
 
-from trame_rca.encoders import RcaImageEncoder
+from trame_rca.encoders import RcaImageEncoder, VideoEncoderType
 from trame_rca.rca import RemoteControlledAreaProtocol, window_wrapper
 from trame_rca.schedulers import RcaImageRenderScheduler
 from trame_rca.utils import RcaViewAdapter
@@ -101,7 +101,7 @@ def add_view_handler(self, view_handler):
     def create_view_handler(
         self,
         window: RemoteControlledAreaProtocol | vtkRenderWindow,
-        encoder: RcaImageEncoder | str | None = None,
+        encoder: RcaImageEncoder | VideoEncoderType | str | None = None,
         target_fps: float = 30.0,
         interactive_quality: int = 60,
         still_quality: int = 90,
@@ -114,7 +114,9 @@ def create_view_handler(
 
             if not isinstance(window, VtkRemoteControlledArea):
                 raise TypeError("Only VTK backends are supported by video decoder")
-            scheduler = RcaVideoRenderScheduler(window, target_fps=target_fps)
+            scheduler = RcaVideoRenderScheduler(
+                window, target_fps=target_fps, rca_encoder=encoder
+            )
 
         elif encoder:
             scheduler = RcaImageRenderScheduler(