import signal
import subprocess
from typing import Iterable, Optional
from PIL import Image
from PIL.Image import Image as ImageType
from platypush.plugins.camera import CameraPlugin
from platypush.plugins.camera.ffmpeg.model import FFmpegCamera, FFmpegCameraInfo
from platypush.plugins.camera.model.camera import Camera
[docs]
class CameraFfmpegPlugin(CameraPlugin):
"""
Plugin to interact with a camera over FFmpeg.
"""
_camera_class = FFmpegCamera
_camera_info_class = FFmpegCameraInfo
[docs]
def __init__(
self,
device: Optional[str] = '/dev/video0',
input_format: str = 'v4l2',
ffmpeg_args: Iterable[str] = (),
**opts,
):
"""
:param device: Path to the camera device (default: ``/dev/video0``).
:param input_format: FFmpeg input format for the camera device (default: ``v4l2``).
:param ffmpeg_args: Extra options to be passed to the FFmpeg executable.
:param opts: Camera options - see constructor of :class:`platypush.plugins.camera.CameraPlugin`.
"""
super().__init__(device=device, input_format=input_format, **opts)
self.camera_info.ffmpeg_args = ffmpeg_args or () # type: ignore
[docs]
def prepare_device(self, device: Camera, **_) -> subprocess.Popen:
if not (isinstance(device, FFmpegCamera)):
raise AssertionError
warmup_seconds = self._get_warmup_seconds(device)
ffmpeg = [
device.info.ffmpeg_bin,
'-y',
'-f',
device.info.input_format,
'-i',
device.info.device,
'-s',
*(
(f'{device.info.resolution[0]}x{device.info.resolution[1]}',)
if device.info.resolution
else ()
),
'-ss',
str(warmup_seconds),
*(('-r', str(device.info.fps)) if device.info.fps else ()),
'-pix_fmt',
'rgb24',
'-f',
'rawvideo',
*device.info.ffmpeg_args,
'-',
]
self.logger.info('Running FFmpeg command: "%s"', ' '.join(ffmpeg))
proc = subprocess.Popen(ffmpeg, stdout=subprocess.PIPE)
# Start in suspended mode
proc.send_signal(signal.SIGSTOP)
return proc
[docs]
def start_camera(self, camera: Camera, *args, preview: bool = False, **kwargs):
if not (isinstance(camera, FFmpegCamera)):
raise AssertionError
super().start_camera(*args, camera=camera, preview=preview, **kwargs)
if camera.object:
camera.object.send_signal(signal.SIGCONT)
[docs]
def release_device(self, device: Camera):
if not (isinstance(device, FFmpegCamera)):
raise AssertionError
if device.object:
device.object.terminate()
if device.object.stdout:
device.object.stdout.close()
device.object = None # type: ignore
[docs]
def wait_capture(self, camera: Camera):
if not (isinstance(camera, FFmpegCamera)):
raise AssertionError
if camera.object and camera.object.poll() is None:
try:
camera.object.wait(timeout=camera.info.capture_timeout)
except Exception as e:
self.logger.warning('Error on FFmpeg capture wait: %s', e)
[docs]
def capture_frame(self, device: Camera, *_, **__) -> Optional[ImageType]:
if not (isinstance(device, FFmpegCamera)):
raise AssertionError
if not (device.info.resolution):
raise AssertionError('Resolution not set')
if not (device.object.stdout):
raise AssertionError('Camera not started')
raw_size = device.info.resolution[0] * device.info.resolution[1] * 3
data = device.object.stdout.read(raw_size)
if len(data) < raw_size:
return
return Image.frombytes('RGB', device.info.resolution, data)
# vim:sw=4:ts=4:et:
