Revert "Removed camera.gstreamer."

This reverts commit b4d714df8a.

docs/source/platypush/plugins/camera.gstreamer.rst

@@ -0,0 +1,5 @@
+``camera.gstreamer``
+======================================
+
+.. automodule:: platypush.plugins.camera.gstreamer
+    :members:

docs/source/plugins.rst

@@ -19,6 +19,7 @@ Plugins
     platypush/plugins/camera.android.ipcam.rst
     platypush/plugins/camera.cv.rst
     platypush/plugins/camera.ffmpeg.rst
+    platypush/plugins/camera.gstreamer.rst
     platypush/plugins/camera.ir.mlx90640.rst
     platypush/plugins/camera.pi.rst
     platypush/plugins/chat.irc.rst

platypush/plugins/camera/gstreamer/__init__.py

@@ -0,0 +1,94 @@
+from typing import Optional
+
+from PIL import Image
+from PIL.Image import Image as ImageType
+
+from platypush.plugins.camera import CameraPlugin
+from platypush.plugins.camera.gstreamer.model import GStreamerCamera
+from platypush.common.gstreamer import Pipeline
+
+
+class CameraGstreamerPlugin(CameraPlugin):
+    """
+    Plugin to interact with a camera over GStreamer.
+
+    Requires:
+
+        * **gst-python**
+        * **pygobject**
+
+    On Debian and derived systems:
+
+        * ``[sudo] apt-get install python3-gi python3-gst-1.0``
+
+    On Arch and derived systems:
+
+        * ``[sudo] pacman -S gst-python``
+
+    """
+
+    _camera_class = GStreamerCamera
+
+    def __init__(self, device: Optional[str] = '/dev/video0', **opts):
+        """
+        :param device: Path to the camera device (default ``/dev/video0``).
+        :param opts: Camera options - see constructor of :class:`platypush.plugins.camera.CameraPlugin`.
+        """
+        super().__init__(device=device, **opts)
+
+    def prepare_device(self, camera: GStreamerCamera) -> Pipeline:
+        pipeline = Pipeline()
+        src = pipeline.add_source('v4l2src', device=camera.info.device)
+        convert = pipeline.add('videoconvert')
+        assert camera.info and camera.info.resolution
+
+        video_filter = pipeline.add(
+            'capsfilter',
+            caps='video/x-raw,format=RGB,width={width},height={height},framerate={fps}/1'.format(
+                width=camera.info.resolution[0],
+                height=camera.info.resolution[1],
+                fps=camera.info.fps,
+            ),
+        )
+
+        sink = pipeline.add_sink('appsink', name='appsink', sync=False)
+        pipeline.link(src, convert, video_filter, sink)
+        return pipeline
+
+    def start_camera(
+        self, camera: GStreamerCamera, preview: bool = False, *args, **kwargs
+    ):
+        super().start_camera(*args, camera=camera, preview=preview, **kwargs)
+        if camera.object:
+            camera.object.play()
+
+    def release_device(self, camera: GStreamerCamera):
+        if camera.object:
+            camera.object.stop()
+
+    def capture_frame(self, camera: GStreamerCamera, *_, **__) -> Optional[ImageType]:
+        if not (camera.info and camera.info.fps and camera.info.resolution):
+            return None
+
+        timed_out = not camera.object.data_ready.wait(
+            timeout=5 + (1.0 / camera.info.fps)
+        )
+        if timed_out:
+            self.logger.warning('Frame capture timeout')
+            return None
+
+        data = camera.object.data
+        if data is None:
+            return None
+
+        camera.object.data_ready.clear()
+        if (
+            not data
+            and len(data) != camera.info.resolution[0] * camera.info.resolution[1] * 3
+        ):
+            return None
+
+        return Image.frombytes('RGB', camera.info.resolution, data)
+
+
+# vim:sw=4:ts=4:et:

platypush/plugins/camera/gstreamer/manifest.yaml

@@ -0,0 +1,16 @@
+manifest:
+  events: {}
+  install:
+    pip:
+      - numpy
+      - Pillow
+      - pygobject
+    apt:
+      - python3-gi
+      - python3-gst-1.0
+    pacman:
+      - gst-python
+      - python-gobject
+
+  package: platypush.plugins.camera.gstreamer
+  type: plugin

platypush/plugins/camera/gstreamer/model.py

@@ -0,0 +1,10 @@
+from platypush.common.gstreamer import Pipeline
+from platypush.plugins.camera import CameraInfo, Camera
+
+
+class GStreamerCamera(Camera):
+    info: CameraInfo
+    object: Pipeline
+
+
+# vim:sw=4:ts=4:et: