Added FFmpeg camera plugin [relates to #150]

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

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

platypush/backend/http/static/css/source/webpanel/plugins/camera.cv/index.scss

@@ -1,116 +0,0 @@
-@import 'common/vars';
-
-.camera {
-    min-height: 90%;
-    margin-top: 4%;
-    overflow: auto;
-    display: flex;
-    flex-direction: column;
-    align-items: center;
-
-    .camera-container {
-        position: relative;
-        background: black;
-        margin-bottom: 1em;
-
-        .frame, .no-frame {
-            position: absolute;
-            top: 0;
-            width: 100%;
-            height: 100%;
-        }
-
-        .frame {
-            z-index: 1;
-        }
-
-        .no-frame {
-            display: flex;
-            background: rgba(0, 0, 0, 0.1);
-            color: white;
-            align-items: center;
-            justify-content: center;
-            z-index: 2;
-        }
-    }
-
-    .url {
-        width: 640px;
-        display: flex;
-        margin: 1em;
-
-        .row {
-            width: 100%;
-            display: flex;
-            align-items: center;
-        }
-
-        .name {
-            width: 140px;
-        }
-
-        input {
-            width: 500px;
-            font-weight: normal;
-        }
-    }
-
-    .params {
-        margin-top: 1em;
-        padding: 1em;
-        width: 640px;
-        display: flex;
-        flex-direction: column;
-        border: $default-border-3;
-        border-radius: 1em;
-
-        label {
-            font-weight: normal;
-        }
-
-        .head {
-            display: flex;
-            justify-content: center;
-
-            label {
-                width: 100%;
-                display: flex;
-                justify-content: right;
-
-                .name {
-                    margin-right: 1em;
-                }
-            }
-        }
-
-        .body {
-            display: flex;
-            flex-direction: column;
-            margin: 0 0 0 -1em;
-
-            .row {
-                width: 100%;
-                display: flex;
-                align-items: center;
-                padding: 0.5em;
-
-                .name {
-                    width: 30%;
-                }
-
-                input {
-                    width: 70%;
-                }
-
-                &:nth-child(even) {
-                    background: $default-bg-6;
-                }
-
-                &:hover {
-                    background: $hover-bg;
-                }
-            }
-        }
-    }
-}
-

platypush/plugins/camera/__init__.py

@@ -71,8 +71,10 @@ class CameraPlugin(Plugin, ABC):
                  capture_timeout: Optional[float] = 20.0, scale_x: Optional[float] = None,
                  scale_y: Optional[float] = None, rotate: Optional[float] = None, grayscale: Optional[bool] = None,
                  color_transform: Optional[Union[int, str]] = None, fps: float = 16, horizontal_flip: bool = False,
-                 vertical_flip: bool = False, video_type: Optional[str] = None, stream_format: str = 'mjpeg',
+                 vertical_flip: bool = False, input_format: Optional[str] = None, output_format: Optional[str] = None,
-                 listen_port: Optional[int] = 5000, bind_address: str = '0.0.0.0', **kwargs):
+                 stream_format: str = 'mjpeg', listen_port: Optional[int] = 5000, bind_address: str = '0.0.0.0',
+                 ffmpeg_bin: str = 'ffmpeg', input_codec: Optional[str] = None, output_codec: Optional[str] = None,
+                 **kwargs):
         """
         :param device: Identifier of the default capturing device.
         :param resolution: Default resolution, as a tuple of two integers.
@@ -96,9 +98,14 @@ class CameraPlugin(Plugin, ABC):
         :param fps: Frames per second (default: 25).
         :param horizontal_flip: If set, the images will be flipped on the horizontal axis.
         :param vertical_flip: If set, the images will be flipped on the vertical axis.
-        :param video_type: Plugin-specific format/type for the output videos.
         :param listen_port: Default port to be used for streaming over TCP (default: 5000).
         :param bind_address: Default bind address for TCP streaming (default: 0.0.0.0, accept any connections).
+        :param input_codec: Specify the ffmpeg video codec (``-vcodec``) used for the input.
+        :param output_codec: Specify the ffmpeg video codec (``-vcodec``) to be used for encoding the output. For some
+            ffmpeg output formats (e.g. ``h264`` and ``rtp``) this may default to ``libxvid``.
+        :param input_format: Plugin-specific format/type for the input stream.
+        :param output_format: Plugin-specific format/type for the output videos.
+        :param ffmpeg_bin: Path to the ffmpeg binary (default: ``ffmpeg``).
         :param stream_format: Default format for the output when streamed to a network device. Available:
 
             - ``MJPEG`` (default)
@@ -110,26 +117,29 @@ class CameraPlugin(Plugin, ABC):
         """
         super().__init__(**kwargs)
 
-        _default_frames_dir = os.path.join(Config.get('workdir'), get_plugin_name_by_class(self), 'frames')
+        self.workdir = os.path.join(Config.get('workdir'), get_plugin_name_by_class(self))
+        pathlib.Path(self.workdir).mkdir(mode=0o644, exist_ok=True, parents=True)
+
         # noinspection PyArgumentList
         self.camera_info = self._camera_info_class(device, color_transform=color_transform, warmup_frames=warmup_frames,
                                                    warmup_seconds=warmup_seconds, rotate=rotate, scale_x=scale_x,
-                                                   scale_y=scale_y, capture_timeout=capture_timeout,
+                                                   scale_y=scale_y, capture_timeout=capture_timeout, fps=fps,
-                                                   video_type=video_type, fps=fps, stream_format=stream_format,
+                                                   input_format=input_format, output_format=output_format,
-                                                   resolution=resolution, grayscale=grayscale, listen_port=listen_port,
+                                                   stream_format=stream_format, resolution=resolution,
+                                                   grayscale=grayscale, listen_port=listen_port,
                                                    horizontal_flip=horizontal_flip, vertical_flip=vertical_flip,
-                                                   bind_address=bind_address, frames_dir=os.path.abspath(
+                                                   ffmpeg_bin=ffmpeg_bin, input_codec=input_codec,
-                                                       os.path.expanduser(frames_dir or _default_frames_dir)))
+                                                   output_codec=output_codec, bind_address=bind_address,
+                                                   frames_dir=os.path.abspath(
+                                                       os.path.expanduser(frames_dir or
+                                                                          os.path.join(self.workdir, 'frames'))))
 
         self._devices: Dict[Union[int, str], Camera] = {}
         self._streams: Dict[Union[int, str], Camera] = {}
 
     def _merge_info(self, **info) -> CameraInfo:
         merged_info = self.camera_info.clone()
-        for k, v in info.items():
+        merged_info.set(**info)
-            if hasattr(merged_info, k):
-                setattr(merged_info, k, v)
-
         return merged_info
 
     def open_device(self, device: Optional[Union[int, str]] = None, stream: bool = False, **params) -> Camera:
@@ -179,12 +189,12 @@ class CameraPlugin(Plugin, ABC):
         """
         name = camera.info.device
         self.stop_preview(camera)
-        camera.start_event.clear()
+        self.release_device(camera)
 
+        camera.start_event.clear()
         if wait_capture:
             self.wait_capture(camera)
 
-        self.release_device(camera)
         if name in self._devices:
             del self._devices[name]
 
@@ -356,7 +366,7 @@ class CameraPlugin(Plugin, ABC):
         if duration and camera.info.warmup_seconds:
             duration = duration + camera.info.warmup_seconds
         if video_file:
-            camera.file_writer = self._video_writer_class(camera=camera, video_file=video_file, plugin=self)
+            camera.file_writer = self._video_writer_class(camera=camera, plugin=self, output_file=video_file)
 
         frame_queue = Queue()
         frame_processor = threading.Thread(target=self.frame_processor,
@@ -373,6 +383,10 @@ class CameraPlugin(Plugin, ABC):
                 frame_capture_start = time.time()
                 try:
                     frame = self.capture_frame(camera, **kwargs)
+                    if not frame:
+                        self.logger.warning('Invalid frame received, terminating the capture session')
+                        break
+
                     frame_queue.put(frame)
                 except AssertionError as e:
                     self.logger.warning(str(e))
@@ -478,12 +492,13 @@ class CameraPlugin(Plugin, ABC):
         return image_file
 
     @action
-    def take_picture(self, image_file: str, **camera) -> str:
+    def take_picture(self, image_file: str, preview: bool = False, **camera) -> str:
         """
         Alias for :meth:`.capture_image`.
 
         :param image_file: Path where the output image will be stored.
         :param camera: Camera parameters override - see constructors parameters.
+        :param preview: Show a preview of the camera frames.
         :return: The local path to the saved image.
         """
         return self.capture_image(image_file, **camera)
@@ -599,11 +614,11 @@ class CameraPlugin(Plugin, ABC):
         assert not camera.stream_event.is_set() and camera.info.device not in self._streams, \
             'A streaming session is already running for device {}'.format(camera.info.device)
 
+        self._streams[camera.info.device] = camera
+        camera.stream_event.set()
+
         camera.stream_thread = threading.Thread(target=self.streaming_thread, kwargs=dict(
             camera=camera, duration=duration, stream_format=stream_format))
-        self._streams[camera.info.device] = camera
-
-        camera.stream_event.set()
         camera.stream_thread.start()
         return self.status(camera.info.device)
 
@@ -624,7 +639,7 @@ class CameraPlugin(Plugin, ABC):
 
     def _stop_streaming(self, camera: Camera):
         camera.stream_event.clear()
-        if camera.stream_thread.is_alive():
+        if camera.stream_thread and camera.stream_thread.is_alive():
             camera.stream_thread.join(timeout=5.0)
 
         if camera.info.device in self._streams:

platypush/plugins/camera/ffmpeg/__init__.py

@@ -0,0 +1,83 @@
+import signal
+import subprocess
+from typing import Optional, Tuple
+
+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
+
+
+class CameraFfmpegPlugin(CameraPlugin):
+    """
+    Plugin to interact with a camera over FFmpeg.
+
+    Requires:
+
+        * **ffmpeg** package installed on the system.
+
+    """
+
+    _camera_class = FFmpegCamera
+    _camera_info_class = FFmpegCameraInfo
+
+    def __init__(self, device: Optional[str] = None, input_format: str = 'v4l2', ffmpeg_args: Tuple[str] = (), **opts):
+        """
+        :param device: Path to the camera device (e.g. ``/dev/video0``).
+        :param input_format: FFmpeg input format for the 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 ()
+
+    @staticmethod
+    def _get_warmup_seconds(camera: FFmpegCamera) -> float:
+        if camera.info.warmup_seconds:
+            return camera.info.warmup_seconds
+        if camera.info.warmup_frames and camera.info.fps:
+            return camera.info.warmup_frames / camera.info.fps
+        return 0
+
+    def prepare_device(self, camera: FFmpegCamera) -> subprocess.Popen:
+        warmup_seconds = self._get_warmup_seconds(camera)
+        ffmpeg = [camera.info.ffmpeg_bin, '-y', '-f', camera.info.input_format, '-i', camera.info.device, '-s',
+                  '{}x{}'.format(*camera.info.resolution), '-ss', str(warmup_seconds),
+                  *(('-r', str(camera.info.fps)) if camera.info.fps else ()),
+                  '-pix_fmt', 'rgb24', '-f', 'rawvideo', *camera.info.ffmpeg_args, '-']
+
+        self.logger.info('Running FFmpeg: {}'.format(' '.join(ffmpeg)))
+        proc = subprocess.Popen(ffmpeg, stdout=subprocess.PIPE)
+        # Start in suspended mode
+        proc.send_signal(signal.SIGSTOP)
+        return proc
+
+    def start_camera(self, camera: FFmpegCamera, preview: bool = False, *args, **kwargs):
+        super().start_camera(*args, camera=camera, preview=preview, **kwargs)
+        if camera.object:
+            camera.object.send_signal(signal.SIGCONT)
+
+    def release_device(self, camera: FFmpegCamera):
+        if camera.object:
+            camera.object.terminate()
+            if camera.object.stdout:
+                camera.object.stdout.close()
+            camera.object = None
+
+    def wait_capture(self, camera: FFmpegCamera) -> None:
+        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: {}'.format(str(e)))
+
+    def capture_frame(self, camera: FFmpegCamera, *args, **kwargs) -> Optional[ImageType]:
+        raw_size = camera.info.resolution[0] * camera.info.resolution[1] * 3
+        data = camera.object.stdout.read(raw_size)
+        if len(data) < raw_size:
+            return
+        return Image.frombytes('RGB', camera.info.resolution, data)
+
+
+# vim:sw=4:ts=4:et:

platypush/plugins/camera/ffmpeg/model.py

@@ -0,0 +1,24 @@
+from dataclasses import dataclass
+from subprocess import Popen
+from typing import Tuple
+
+from platypush.plugins.camera import CameraInfo, Camera
+
+
+@dataclass
+class FFmpegCameraInfo(CameraInfo):
+    ffmpeg_args: Tuple[str] = ()
+
+    def to_dict(self) -> dict:
+        return {
+            'ffmpeg_args': list(self.ffmpeg_args or ()),
+            **super().to_dict()
+        }
+
+
+class FFmpegCamera(Camera):
+    info: FFmpegCameraInfo
+    object: Popen
+
+
+# vim:sw=4:ts=4:et:

platypush/plugins/camera/model/camera.py

@@ -12,48 +12,57 @@ from platypush.plugins.camera.model.writer.preview import PreviewWriter
 @dataclass
 class CameraInfo:
     device: Optional[Union[int, str]]
-    resolution: Optional[Tuple[int, int]] = None
+    bind_address: Optional[str] = None
+    capture_timeout: float = 20.0
     color_transform: Optional[str] = None
+    ffmpeg_bin: Optional[str] = None
+    fps: Optional[float] = None
     frames_dir: Optional[str] = None
-    rotate: Optional[float] = None
+    grayscale: Optional[bool] = None
     horizontal_flip: bool = False
-    vertical_flip: bool = False
+    input_codec: Optional[str] = None
+    input_format: Optional[str] = None
+    listen_port: Optional[int] = None
+    output_codec: Optional[str] = None
+    output_format: Optional[str] = None
+    resolution: Optional[Tuple[int, int]] = None
+    rotate: Optional[float] = None
     scale_x: Optional[float] = None
     scale_y: Optional[float] = None
+    stream_format: Optional[str] = None
+    vertical_flip: bool = False
     warmup_frames: int = 0
     warmup_seconds: float = 0.
-    capture_timeout: float = 20.0
-    fps: Optional[float] = None
-    grayscale: Optional[bool] = None
-    video_type: Optional[str] = None
-    stream_format: str = 'mjpeg'
-    listen_port: Optional[int] = None
-    bind_address: Optional[str] = None
 
     def set(self, **kwargs):
         for k, v in kwargs.items():
-            setattr(self, k, v)
+            if hasattr(self, k):
+                setattr(self, k, v)
 
     def to_dict(self) -> dict:
         return {
-            'device': self.device,
+            'bind_address': self.bind_address,
+            'capture_timeout': self.capture_timeout,
             'color_transform': self.color_transform,
+            'device': self.device,
+            'ffmpeg_bin': self.ffmpeg_bin,
+            'fps': self.fps,
             'frames_dir': self.frames_dir,
-            'rotate': self.rotate,
+            'grayscale': self.grayscale,
             'horizontal_flip': self.horizontal_flip,
-            'vertical_flip': self.vertical_flip,
+            'input_codec': self.input_codec,
+            'input_format': self.input_format,
+            'listen_port': self.listen_port,
+            'output_codec': self.output_codec,
+            'output_format': self.output_format,
+            'resolution': list(self.resolution or ()),
+            'rotate': self.rotate,
             'scale_x': self.scale_x,
             'scale_y': self.scale_y,
+            'stream_format': self.stream_format,
+            'vertical_flip': self.vertical_flip,
             'warmup_frames': self.warmup_frames,
             'warmup_seconds': self.warmup_seconds,
-            'capture_timeout': self.capture_timeout,
-            'fps': self.fps,
-            'grayscale': self.grayscale,
-            'resolution': list(self.resolution or ()),
-            'video_type': self.video_type,
-            'stream_format': self.stream_format,
-            'listen_port': self.listen_port,
-            'bind_address': self.bind_address,
         }
 
     def clone(self):

platypush/plugins/camera/model/writer/__init__.py

@@ -9,8 +9,6 @@ from typing import Optional, IO
 
 from PIL.Image import Image
 
-logger = logging.getLogger('video-writer')
-
 
 class VideoWriter(ABC):
     """
@@ -21,6 +19,8 @@ class VideoWriter(ABC):
 
     def __init__(self, camera, plugin, *_, **__):
         from platypush.plugins.camera import Camera, CameraPlugin
+
+        self.logger = logging.getLogger(self.__class__.__name__)
         self.camera: Camera = camera
         self.plugin: CameraPlugin = plugin
         self.closed = False
@@ -60,9 +60,9 @@ class FileVideoWriter(VideoWriter, ABC):
     """
     Abstract class to handle frames-to-video file operations.
     """
-    def __init__(self, *args, video_file: str, **kwargs):
+    def __init__(self, *args, output_file: str, **kwargs):
         VideoWriter.__init__(self, *args, **kwargs)
-        self.video_file = os.path.abspath(os.path.expanduser(video_file))
+        self.output_file = os.path.abspath(os.path.expanduser(output_file))
 
 
 class StreamWriter(VideoWriter, ABC):
@@ -98,7 +98,7 @@ class StreamWriter(VideoWriter, ABC):
             try:
                 self.sock.write(data)
             except ConnectionError:
-                logger.warning('Client connection closed')
+                self.logger.info('Client connection closed')
                 self.close()
 
     @abstractmethod

platypush/plugins/camera/model/writer/cv.py

@@ -12,13 +12,13 @@ class CvFileWriter(FileVideoWriter):
         import cv2
         super(CvFileWriter, self).__init__(*args, **kwargs)
 
-        video_type = cv2.VideoWriter_fourcc(*(self.camera.info.video_type or 'xvid').upper())
+        video_type = cv2.VideoWriter_fourcc(*(self.camera.info.output_format or 'xvid').upper())
         resolution = (
             int(self.camera.info.resolution[0] * (self.camera.info.scale_x or 1.)),
             int(self.camera.info.resolution[1] * (self.camera.info.scale_y or 1.)),
         )
 
-        self.writer = cv2.VideoWriter(self.video_file, video_type, self.camera.info.fps, resolution, False)
+        self.writer = cv2.VideoWriter(self.output_file, video_type, self.camera.info.fps, resolution, False)
 
     def write(self, img):
         if not self.writer:

platypush/plugins/camera/model/writer/ffmpeg.py

@@ -1,54 +1,48 @@
-import logging
 import subprocess
 import threading
 import time
 
 from abc import ABC
-from typing import Optional, List
+from typing import Optional, Tuple
 
 from PIL.Image import Image
 
+from platypush.plugins.camera.model.camera import Camera
 from platypush.plugins.camera.model.writer import VideoWriter, FileVideoWriter, StreamWriter
 
 
-logger = logging.getLogger('ffmpeg-writer')
-
-
 class FFmpegWriter(VideoWriter, ABC):
     """
     Generic FFmpeg encoder for camera frames.
     """
 
-    def __init__(self, *args, input_file: str = '-', input_format: str = 'rawvideo', input_codec: Optional[str] = None,
+    def __init__(self, *args, input_file: str = '-', input_format: str = 'rawvideo', output_file: str = '-',
-                 output_file: str = '-', output_format: Optional[str] = None, output_codec: Optional[str] = None,
+                 output_format: Optional[str] = None, pix_fmt: Optional[str] = None,
-                 pix_fmt: Optional[str] = None, output_opts: Optional[List[str]] = None, **kwargs):
+                 output_opts: Optional[Tuple] = None, **kwargs):
         super().__init__(*args, **kwargs)
 
         self.input_file = input_file
         self.input_format = input_format
-        self.input_codec = input_codec
-        self.output_file = output_file
         self.output_format = output_format
-        self.output_codec = output_codec
+        self.output_file = output_file
         self.width, self.height = self.camera.effective_resolution()
         self.pix_fmt = pix_fmt
-        self.output_opts = output_opts or []
+        self.output_opts = output_opts or ()
 
-        logger.info('Starting FFmpeg. Command: {}'.format(' '.join(self.ffmpeg_args)))
+        self.logger.info('Starting FFmpeg. Command: {}'.format(' '.join(self.ffmpeg_args)))
         self.ffmpeg = subprocess.Popen(self.ffmpeg_args, stdin=subprocess.PIPE, stdout=subprocess.PIPE)
 
     @property
     def ffmpeg_args(self):
-        return ['ffmpeg', '-y',
+        return [self.camera.info.ffmpeg_bin, '-y',
                 '-f', self.input_format,
-                *(('-vcodec', self.input_codec) if self.input_codec else ()),
                 *(('-pix_fmt', self.pix_fmt) if self.pix_fmt else ()),
                 '-s', '{}x{}'.format(self.width, self.height),
                 '-r', str(self.camera.info.fps),
                 '-i', self.input_file,
                 *(('-f', self.output_format) if self.output_format else ()),
                 *self.output_opts,
-                *(('-vcodec', self.output_codec) if self.output_codec else ()),
+                *(('-vcodec', self.camera.info.output_codec) if self.camera.info.output_codec else ()),
                 self.output_file]
 
     def is_closed(self):
@@ -61,7 +55,7 @@ class FFmpegWriter(VideoWriter, ABC):
         try:
             self.ffmpeg.stdin.write(image.convert('RGB').tobytes())
         except Exception as e:
-            logger.warning('FFmpeg send error: {}'.format(str(e)))
+            self.logger.warning('FFmpeg send error: {}'.format(str(e)))
             self.close()
 
     def close(self):
@@ -77,7 +71,7 @@ class FFmpegWriter(VideoWriter, ABC):
                 try:
                     self.ffmpeg.wait(timeout=5.0)
                 except subprocess.TimeoutExpired:
-                    logger.warning('FFmpeg has not returned - killing it')
+                    self.logger.warning('FFmpeg has not returned - killing it')
                     self.ffmpeg.kill()
 
             if self.ffmpeg and self.ffmpeg.stdout:
@@ -95,9 +89,9 @@ class FFmpegFileWriter(FileVideoWriter, FFmpegWriter):
     Write camera frames to a file using FFmpeg.
     """
 
-    def __init__(self, *args, video_file: str, **kwargs):
+    def __init__(self, *args, output_file: str, **kwargs):
-        FileVideoWriter.__init__(self, *args, video_file=video_file, **kwargs)
+        FileVideoWriter.__init__(self, *args, output_file=output_file, **kwargs)
-        FFmpegWriter.__init__(self, *args, pix_fmt='rgb24', output_file=self.video_file, **kwargs)
+        FFmpegWriter.__init__(self, *args, pix_fmt='rgb24', output_file=self.output_file, **kwargs)
 
 
 class FFmpegStreamWriter(StreamWriter, FFmpegWriter, ABC):
@@ -105,12 +99,11 @@ class FFmpegStreamWriter(StreamWriter, FFmpegWriter, ABC):
     Stream camera frames using FFmpeg.
     """
 
-    def __init__(self, *args, output_format: str, **kwargs):
+    def __init__(self, *args, output_format: str, output_opts: Optional[Tuple] = None, **kwargs):
         StreamWriter.__init__(self, *args, **kwargs)
-        FFmpegWriter.__init__(self, *args, pix_fmt='rgb24', output_format=output_format,
+        FFmpegWriter.__init__(self, *args, pix_fmt='rgb24', output_format=output_format, output_opts=output_opts or (
-                              output_opts=[
+            '-tune', 'zerolatency', '-preset', 'superfast', '-trellis', '0',
-                                  '-tune', '-zerolatency', '-preset', 'superfast', '-trellis', '0',
+            '-fflags', 'nobuffer'), **kwargs)
-                                  '-fflags', 'nobuffer'], **kwargs)
         self._reader = threading.Thread(target=self._reader_thread)
         self._reader.start()
 
@@ -124,7 +117,7 @@ class FFmpegStreamWriter(StreamWriter, FFmpegWriter, ABC):
             try:
                 data = self.ffmpeg.stdout.read(1 << 15)
             except Exception as e:
-                logger.warning('FFmpeg reader error: {}'.format(str(e)))
+                self.logger.warning('FFmpeg reader error: {}'.format(str(e)))
                 break
 
             if not data:
@@ -132,7 +125,7 @@ class FFmpegStreamWriter(StreamWriter, FFmpegWriter, ABC):
 
             if self.frame is None:
                 latency = time.time() - start_time
-                logger.info('FFmpeg stream latency: {} secs'.format(latency))
+                self.logger.info('FFmpeg stream latency: {} secs'.format(latency))
 
             with self.ready:
                 self.frame = data
@@ -149,7 +142,7 @@ class FFmpegStreamWriter(StreamWriter, FFmpegWriter, ABC):
         try:
             self.ffmpeg.stdin.write(data)
         except Exception as e:
-            logger.warning('FFmpeg send error: {}'.format(str(e)))
+            self.logger.warning('FFmpeg send error: {}'.format(str(e)))
             self.close()
 
     def close(self):
@@ -169,8 +162,10 @@ class MKVStreamWriter(FFmpegStreamWriter):
 class H264StreamWriter(FFmpegStreamWriter):
     mimetype = 'video/h264'
 
-    def __init__(self, *args, **kwargs):
+    def __init__(self, camera: Camera, *args, **kwargs):
-        super().__init__(*args, output_format='h264', **kwargs)
+        if not camera.info.output_codec:
+            camera.info.output_codec = 'libxvid'
+        super().__init__(camera, *args, output_format='h264', **kwargs)
 
 
 class H265StreamWriter(FFmpegStreamWriter):

platypush/plugins/camera/model/writer/preview/__init__.py

@@ -4,7 +4,7 @@ from abc import ABC
 
 from platypush.plugins.camera.model.writer import VideoWriter
 
-logger = logging.getLogger('cam-preview')
+logger = logging.getLogger('platypush')
 
 
 class PreviewWriter(VideoWriter, ABC):

platypush/plugins/camera/model/writer/preview/ffplay.py

@@ -5,8 +5,6 @@ import threading
 from platypush.plugins.camera.model.writer.image import MJPEGStreamWriter
 from platypush.plugins.camera.model.writer.preview import PreviewWriter
 
-logger = logging.getLogger('cam-preview')
-
 
 class FFplayPreviewWriter(PreviewWriter, MJPEGStreamWriter):
     """
@@ -14,6 +12,7 @@ class FFplayPreviewWriter(PreviewWriter, MJPEGStreamWriter):
     """
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
+        self.logger = logging.getLogger(self.__class__.__name__)
         self.ffplay = subprocess.Popen(['ffplay', '-'], stdin=subprocess.PIPE)
         self._preview_thread = threading.Thread(target=self._ffplay_thread)
         self._preview_thread.start()
@@ -28,7 +27,7 @@ class FFplayPreviewWriter(PreviewWriter, MJPEGStreamWriter):
                 try:
                     self.ffplay.stdin.write(self.frame)
                 except Exception as e:
-                    logger.warning('ffplay write error: {}'.format(str(e)))
+                    self.logger.warning('ffplay write error: {}'.format(str(e)))
                     self.close()
                     break
 

platypush/plugins/camera/model/writer/preview/wx/__init__.py

@@ -1,11 +1,8 @@
-import logging
 from multiprocessing import Process, Queue, Event
 
 from platypush.plugins.camera.model.writer import VideoWriter
 from platypush.plugins.camera.model.writer.preview import PreviewWriter
 
-logger = logging.getLogger('cam-preview')
-
 
 class WxPreviewWriter(PreviewWriter, Process):
     """
@@ -47,7 +44,7 @@ class WxPreviewWriter(PreviewWriter, Process):
         try:
             self.bitmap_queue.put(image)
         except Exception as e:
-            logger.warning('Could not add an image to the preview queue: {}'.format(str(e)))
+            self.logger.warning('Could not add an image to the preview queue: {}'.format(str(e)))
 
 
 # vim:sw=4:ts=4:et:

platypush/plugins/ffmpeg.py

@@ -0,0 +1,148 @@
+import os
+import subprocess
+import threading
+from typing import Callable, Optional, List, Tuple
+
+from platypush.plugins import Plugin, action
+
+
+class FfmpegPlugin(Plugin):
+    """
+    Generic FFmpeg plugin to interact with media files and devices.
+
+    Requires:
+
+        * **ffmpeg-python** (``pip install ffmpeg-python``)
+        * The **ffmpeg** package installed on the system.
+
+    """
+
+    def __init__(self, ffmpeg_cmd: str = 'ffmpeg', ffprobe_cmd: str = 'ffprobe', **kwargs):
+        super().__init__(**kwargs)
+        self.ffmpeg_cmd = ffmpeg_cmd
+        self.ffprobe_cmd = ffprobe_cmd
+        self._threads = {}
+        self._next_thread_id = 1
+        self._thread_lock = threading.RLock()
+
+    @action
+    def info(self, filename: str, **kwargs) -> dict:
+        """
+        Get the information of a media file.
+
+        :param filename: Path to the media file.
+        :return: Media file information. Example:
+
+          .. code-block:: json
+
+              {
+                "streams": [
+                    {
+                        "index": 0,
+                        "codec_name": "h264",
+                        "codec_long_name": "H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10",
+                        "profile": "High 4:2:2",
+                        "codec_type": "video",
+                        "codec_time_base": "1/60",
+                        "codec_tag_string": "[0][0][0][0]",
+                        "codec_tag": "0x0000",
+                        "width": 640,
+                        "height": 480,
+                        "coded_width": 640,
+                        "coded_height": 480,
+                        "closed_captions": 0,
+                        "has_b_frames": 2,
+                        "pix_fmt": "yuv422p",
+                        "level": 30,
+                        "chroma_location": "left",
+                        "field_order": "progressive",
+                        "refs": 1,
+                        "is_avc": "true",
+                        "nal_length_size": "4",
+                        "r_frame_rate": "30/1",
+                        "avg_frame_rate": "30/1",
+                        "time_base": "1/1000",
+                        "start_pts": 0,
+                        "start_time": "0.000000",
+                        "bits_per_raw_sample": "8",
+                        "disposition": {
+                            "default": 1,
+                            "dub": 0,
+                            "original": 0,
+                            "comment": 0,
+                            "lyrics": 0,
+                            "karaoke": 0,
+                            "forced": 0,
+                            "hearing_impaired": 0,
+                            "visual_impaired": 0,
+                            "clean_effects": 0,
+                            "attached_pic": 0,
+                            "timed_thumbnails": 0
+                        },
+                        "tags": {
+                            "ENCODER": "Lavc58.91.100 libx264"
+                        }
+                    }
+                ],
+                "format": {
+                    "filename": "./output.mkv",
+                    "nb_streams": 1,
+                    "nb_programs": 0,
+                    "format_name": "matroska,webm",
+                    "format_long_name": "Matroska / WebM",
+                    "start_time": "0.000000",
+                    "size": "786432",
+                    "probe_score": 100,
+                    "tags": {
+                        "ENCODER": "Lavf58.45.100"
+                    }
+                }
+            }
+
+        """
+        # noinspection PyPackageRequirements
+        import ffmpeg
+        filename = os.path.abspath(os.path.expanduser(filename))
+        info = ffmpeg.probe(filename, cmd=self.ffprobe_cmd, **kwargs)
+        return info
+
+    @staticmethod
+    def _poll_thread(proc: subprocess.Popen, packet_size: int, on_packet: Callable[[bytes], None],
+                     on_open: Optional[Callable[[], None]] = None,
+                     on_close: Optional[Callable[[], None]] = None):
+        try:
+            if on_open:
+                on_open()
+
+            while proc.poll() is None:
+                data = proc.stdout.read(packet_size)
+                on_packet(data)
+        finally:
+            if on_close:
+                on_close()
+
+    @action
+    def start(self, pipeline: List[dict], pipe_stdin: bool = False, pipe_stdout: bool = False,
+              pipe_stderr: bool = False, quiet: bool = False, overwrite_output: bool = False,
+              on_packet: Callable[[bytes], None] = None, packet_size: int = 4096):
+        # noinspection PyPackageRequirements
+        import ffmpeg
+        stream = ffmpeg
+
+        for step in pipeline:
+            args = step.pop('args') if 'args' in step else []
+            stream = getattr(stream, step.pop('method'))(*args, **step)
+
+        self.logger.info('Executing {cmd} {args}'.format(cmd=self.ffmpeg_cmd, args=stream.get_args()))
+        proc = stream.run_async(cmd=self.ffmpeg_cmd, pipe_stdin=pipe_stdin, pipe_stdout=pipe_stdout,
+                                pipe_stderr=pipe_stderr, quiet=quiet, overwrite_output=overwrite_output)
+
+        if on_packet:
+            with self._thread_lock:
+                self._threads[self._next_thread_id] = threading.Thread(target=self._poll_thread, kwargs=dict(
+                    proc=proc, on_packet=on_packet, packet_size=packet_size))
+                self._threads[self._next_thread_id].start()
+                self._next_thread_id += 1
+
+
+# vim:sw=4:ts=4:et: