Source code for platypush.plugins.camera.cv
from typing import Optional, Union
from platypush.plugins.camera import CameraPlugin, Camera
from platypush.plugins.camera.model.writer.cv import CvFileWriter
[docs]
class CameraCvPlugin(CameraPlugin):
"""
Plugin to control generic cameras over OpenCV.
"""
[docs]
def __init__(
self,
color_transform: Optional[str] = 'COLOR_BGR2RGB',
video_type: str = 'XVID',
video_writer: str = 'ffmpeg',
**kwargs
):
"""
:param device: Device ID (0 for the first camera, 1 for the second etc.) or path (e.g. ``/dev/video0``).
:param video_type: Default video type to use when exporting captured frames to camera (default: 0, infers the
type from the video file extension). See
`here <https://docs.opencv.org/4.0.1/dd/d9e/classcv_1_1VideoWriter.html#afec93f94dc6c0b3e28f4dd153bc5a7f0>`_
for a reference on the supported types (e.g. 'MJPEG', 'XVID', 'H264', 'X264', 'AVC1' etc.)
:param color_transform: Color transformation to apply to the captured frames. See
https://docs.opencv.org/3.2.0/d7/d1b/group__imgproc__misc.html for a full list of supported color
transformations (default: "``COLOR_RGB2BGR``")
:param video_writer: Class to be used to write frames to a video file. Supported values:
- ``ffmpeg``: Use the FFmpeg writer (default, and usually more reliable - it requires ``ffmpeg``
installed).
- ``cv``: Use the native OpenCV writer.
The FFmpeg video writer requires ``scikit-video`` (``pip install scikit-video``) and ``ffmpeg``.
:param kwargs: Extra arguments to be passed up to :class:`platypush.plugins.camera.CameraPlugin`.
"""
super().__init__(
color_transform=color_transform, video_type=video_type, **kwargs
)
if video_writer == 'cv':
self._video_writer_class = CvFileWriter
[docs]
def prepare_device(self, device: Camera, **_):
import cv2
cam = cv2.VideoCapture(device.info.device)
if device.info.resolution and device.info.resolution[0]:
cam.set(cv2.CAP_PROP_FRAME_WIDTH, device.info.resolution[0])
cam.set(cv2.CAP_PROP_FRAME_HEIGHT, device.info.resolution[1])
return cam
[docs]
def release_device(self, device: Camera):
if device.object:
device.object.release()
device.object = None
[docs]
def capture_frame(self, camera: Camera, *args, **kwargs):
import cv2
from PIL import Image
ret, frame = camera.object.read()
assert ret, 'Cannot retrieve frame from {}'.format(camera.info.device)
color_transform = camera.info.color_transform
if isinstance(color_transform, str):
color_transform = getattr(
cv2, color_transform or self.camera_info.color_transform
)
if color_transform:
frame = cv2.cvtColor(frame, color_transform)
return Image.fromarray(frame)
# vim:sw=4:ts=4:et:
