Added GStreamer camera plugin [relates to #151]

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

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

docs/source/plugins.rst

@@ -22,6 +22,7 @@ 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.telegram.rst

platypush/backend/http/static/css/source/webpanel/plugins/camera.gstreamer

@@ -0,0 +1 @@
+camera

platypush/backend/http/static/js/plugins/camera.gstreamer/index.js

@@ -0,0 +1,15 @@
+Vue.component('camera-gstreamer', {
+    template: '#tmpl-camera-gstreamer',
+    mixins: [cameraMixin],
+
+    methods: {
+        startStreaming: function() {
+            this._startStreaming('gstreamer');
+        },
+
+        capture: function() {
+            this._capture('gstreamer');
+        },
+    },
+});
+

platypush/backend/http/templates/nav.html

@@ -4,6 +4,7 @@
         'camera.android.ipcam': 'fab fa-android',
         'camera.cv': 'fas fa-camera',
         'camera.ffmpeg': 'fas fa-camera',
+        'camera.gstreamer': 'fas fa-camera',
         'camera.pi': 'fab fa-raspberry-pi',
         'camera.ir.mlx90640': 'fas fa-sun',
         'execute': 'fas fa-play',

platypush/backend/http/templates/plugins/camera.gstreamer/index.html

@@ -0,0 +1,6 @@
+<script type="text/javascript" src="{{ url_for('static', filename='js/plugins/camera/index.js') }}"></script>
+
+<script type="text/x-template" id="tmpl-camera-gstreamer">
+    {% include 'plugins/camera/index.html' %}
+</script>
+

platypush/plugins/camera/gstreamer/__init__.py

@@ -0,0 +1,64 @@
+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, Pipeline, Loop
+
+
+class CameraGstreamerPlugin(CameraPlugin):
+    """
+    Plugin to interact with a camera over GStreamer.
+
+    Requires:
+
+        * **gst-python** (``pip install 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('v4l2src', device=camera.info.device)
+        convert = pipeline.add('videoconvert')
+        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, *args, **kwargs) -> Optional[ImageType]:
+        timed_out = not camera.object.data_ready.wait(timeout=5 + (1. / camera.info.fps))
+        if timed_out:
+            self.logger.warning('Frame capture timeout')
+            return
+
+        data = camera.object.data
+        camera.object.data_ready.clear()
+        if not data and len(data) != camera.info.resolution[0] * camera.info.resolution[1] * 3:
+            return
+
+        return Image.frombytes('RGB', camera.info.resolution, data)
+
+
+# vim:sw=4:ts=4:et:

platypush/plugins/camera/gstreamer/model.py

@@ -0,0 +1,119 @@
+import logging
+import threading
+from dataclasses import dataclass
+
+from platypush.plugins.camera import CameraInfo, Camera
+
+# noinspection PyPackageRequirements
+import gi
+gi.require_version('Gst', '1.0')
+gi.require_version('GstApp', '1.0')
+
+# noinspection PyPackageRequirements,PyUnresolvedReferences
+from gi.repository import GLib, Gst, GstApp
+
+Gst.init(None)
+
+
+class Pipeline:
+    def __init__(self):
+        self.pipeline = Gst.Pipeline()
+        self.logger = logging.getLogger('gst-pipeline')
+        self.loop = Loop()
+        self.sink = None
+
+        self.bus = self.pipeline.get_bus()
+        self.bus.add_signal_watch()
+        self.bus.connect('message::eos', self.on_eos)
+        self.bus.connect('message::error', self.on_error)
+        self.data_ready = threading.Event()
+        self.data = None
+
+    def add(self, element_name: str, *args, **props):
+        el = Gst.ElementFactory.make(element_name, *args)
+        for k, v in props.items():
+            if k == 'caps':
+                v = Gst.caps_from_string(v)
+            el.set_property(k, v)
+
+        self.pipeline.add(el)
+        return el
+
+    def add_sink(self, element_name: str, *args, **props):
+        assert not self.sink, 'A sink element is already set for this pipeline'
+        sink = self.add(element_name, *args, **props)
+        sink.connect('new-sample', self.on_buffer)
+        sink.set_property('emit-signals', True)
+        self.sink = sink
+        return sink
+
+    @staticmethod
+    def link(*elements):
+        for i, el in enumerate(elements):
+            if i == len(elements)-1:
+                break
+            el.link(elements[i+1])
+
+    def emit(self, signal, *args, **kwargs):
+        return self.pipeline.emit(signal, *args, **kwargs)
+
+    def play(self):
+        assert self.sink, 'No sink element specified through add_sink()'
+        self.pipeline.set_state(Gst.State.PLAYING)
+        self.loop.start()
+
+    def pause(self):
+        self.pipeline.set_state(Gst.State.PAUSED)
+
+    def stop(self):
+        self.pipeline.set_state(Gst.State.NULL)
+        self.loop.stop()
+
+    def on_buffer(self, sink):
+        sample = GstApp.AppSink.pull_sample(sink)
+        buffer = sample.get_buffer()
+        size, offset, maxsize = buffer.get_sizes()
+        self.data = buffer.extract_dup(offset, size)
+        self.data_ready.set()
+        return False
+
+    def on_eos(self, *_, **__):
+        self.logger.info('End of stream event received')
+        self.stop()
+
+    # noinspection PyUnusedLocal
+    def on_error(self, bus, msg):
+        self.logger.warning('GStreamer pipeline error: {}'.format(msg.parse_error()))
+        self.stop()
+
+    def get_sink(self):
+        return self.sink
+
+
+class Loop(threading.Thread):
+    def __init__(self):
+        super().__init__()
+        self._loop = GLib.MainLoop()
+
+    def run(self):
+        self._loop.run()
+
+    def is_running(self) -> bool:
+        return self.is_alive() or self._loop is not None
+
+    def stop(self):
+        if not self.is_running():
+            return
+        if self._loop:
+            self._loop.quit()
+        if threading.get_ident() != self.ident:
+            self.join()
+        self._loop = None
+
+
+class GStreamerCamera(Camera):
+    info: CameraInfo
+    object: Pipeline
+
+
+# vim:sw=4:ts=4:et:

requirements.txt

@@ -300,8 +300,8 @@ croniter
 # Support for NextCloud integration
 # git+https://github.com/EnterpriseyIntranet/nextcloud-API.git
 
-# Support for FFmpeg integration
-# ffmpeg-python
+# Support for GStreamer integration
+# gst-python
 
 # Generic support for cameras
 # Pillow

setup.py

@@ -336,7 +336,7 @@ setup(
         'imap': ['imapclient'],
         # Support for NextCloud integration
         'nextcloud': ['nextcloud-API @ git+https://github.com/EnterpriseyIntranet/nextcloud-API.git'],
-        # Support for FFmpeg integration
-        'ffmpeg': ['ffmpeg-python'],
+        # Support for GStreamer integration
+        'gstreamer': ['gst-python'],
     },
 )