Using an io memory buffer to write the streamed images instead of a
physical file to improve streaming performance
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parent
60d5e7a0f6
commit
17af488b32
3 changed files with 81 additions and 15 deletions
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@ -2,9 +2,12 @@ import os
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import tempfile
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from flask import Response, Blueprint, send_from_directory
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from typing import Optional
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from platypush.backend.http.app import template_folder
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from platypush.backend.http.app.utils import authenticate, send_request
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from platypush.config import Config
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from platypush.plugins.camera.pi import CameraPiPlugin
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camera_pi = Blueprint('camera.pi', __name__, template_folder=template_folder)
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filename = os.path.join(tempfile.gettempdir(), 'camera_pi.jpg')
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@ -14,22 +17,34 @@ __routes__ = [
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camera_pi,
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]
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_camera: Optional[CameraPiPlugin] = None
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def get_frame_file(*args, **kwargs):
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response = send_request(*args, action='camera.pi.take_picture', image_file=filename, **kwargs)
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assert response.output and 'image_file' in response.output,\
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(response.errors[0] if response.errors else 'Unable to capture frame from the picamera')
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return response.output['image_file']
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def get_camera() -> CameraPiPlugin:
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global _camera
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# noinspection PyProtectedMember
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if _camera and _camera._camera and not _camera._camera.closed:
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return _camera
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camera_conf = Config.get('camera.pi') or {}
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_camera = CameraPiPlugin(**camera_conf)
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return _camera
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def get_frame():
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camera = get_camera()
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output = camera.get_output_stream()
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with output.ready:
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output.ready.wait()
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return output.frame
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def video_feed():
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try:
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while True:
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frame_file = get_frame_file(warmup_time=0, close=False)
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with open(frame_file, 'rb') as f:
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frame = f.read()
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frame = get_frame()
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yield (b'--frame\r\n'
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b'Content-Type: image/jpeg\r\n\r\n' + frame + b'\r\n')
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finally:
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@ -38,8 +53,11 @@ def video_feed():
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@camera_pi.route('/camera/pi/frame', methods=['GET'])
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@authenticate()
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def get_frame():
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frame_file = get_frame_file()
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def get_frame_img():
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response = send_request('camera.pi.take_picture', image_file=filename)
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frame_file = (response.output or {}).get('image_file')
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assert frame_file is not None
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return send_from_directory(os.path.dirname(frame_file),
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os.path.basename(frame_file))
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@ -47,8 +65,16 @@ def get_frame():
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@camera_pi.route('/camera/pi/stream', methods=['GET'])
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@authenticate()
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def get_stream_feed():
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return Response(video_feed(),
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mimetype='multipart/x-mixed-replace; boundary=frame')
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global _camera
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try:
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return Response(video_feed(),
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headers={'Cache-Control': 'no-cache, private', 'Pragma': 'no-cache', 'Age': 0},
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mimetype='multipart/x-mixed-replace; boundary=frame')
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finally:
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if _camera:
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_camera.close_output_stream()
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_camera = None
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# vim:sw=4:ts=4:et:
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@ -1,3 +1,4 @@
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import io
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import os
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import re
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import shutil
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@ -15,6 +16,24 @@ from platypush.message.event.camera import CameraRecordingStartedEvent, \
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from platypush.plugins import Plugin, action
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class StreamingOutput:
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def __init__(self):
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self.frame = None
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self.buffer = io.BytesIO()
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self.ready = threading.Condition()
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def write(self, buf):
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if buf.startswith(b'\xff\xd8'):
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# New frame, copy the existing buffer's content and notify all clients that it's available
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self.buffer.truncate()
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with self.ready:
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self.frame = self.buffer.getvalue()
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self.ready.notify_all()
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self.buffer.seek(0)
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return self.buffer.write(buf)
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class CameraPlugin(Plugin):
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"""
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Plugin to control generic cameras over OpenCV.
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@ -7,10 +7,10 @@ import socket
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import threading
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import time
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from typing import Optional
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from typing import Optional, Union
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from platypush.plugins import action
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from platypush.plugins.camera import CameraPlugin
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from platypush.plugins.camera import CameraPlugin, StreamingOutput
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class CameraPiPlugin(CameraPlugin):
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@ -67,6 +67,7 @@ class CameraPiPlugin(CameraPlugin):
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self._time_lapse_stop_condition = threading.Condition()
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self._recording_stop_condition = threading.Condition()
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self._streaming_stop_condition = threading.Condition()
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self._output: StreamingOutput = None
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# noinspection PyUnresolvedReferences,PyPackageRequirements
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def _get_camera(self, **opts):
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@ -173,6 +174,26 @@ class CameraPiPlugin(CameraPlugin):
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if camera and close:
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self.close()
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def get_output_stream(self, resize: Union[tuple, list] = None, **opts) -> StreamingOutput:
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camera = self._get_camera(**opts)
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if self._output and not camera.closed:
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return self._output
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capture_opts = {}
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if resize:
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capture_opts['resize'] = tuple(resize)
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self._output = StreamingOutput()
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camera.start_recording(self._output, format='mjpeg', **capture_opts)
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return self._output
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def close_output_stream(self):
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if self._camera and not self._camera.closed:
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self._camera.stop_recording()
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self._output = None
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@action
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def capture_sequence(self, n_images, directory, name_format='image_%04d.jpg', preview=False, warmup_time=2,
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resize=None, **opts):
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