update video recorder to use ffmpeg-python for realtime video, expose depth image saving params

Author: mjd3

perception/image.py

@@ -1523,6 +1523,36 @@ def _image_data(self, normalize=False,
             return im_data.astype(np.uint16)
         return im_data.astype(np.uint8)
 
+    def save(self, filename, normalize=False, min_depth=MIN_DEPTH, max_depth=MAX_DEPTH, twobyte=False):
+        """Writes the image to a file.
+
+        Parameters
+        ----------
+        filename : :obj:`str`
+            The file to save the image to. Must be one of .png, .jpg,
+            .npy, or .npz.
+
+        Raises
+        ------
+        ValueError
+            If an unsupported file type is specified.
+        """
+        filename = str(filename)
+        file_root, file_ext = os.path.splitext(filename)
+        if file_ext in COLOR_IMAGE_EXTS:
+            im_data = self._image_data(normalize=normalize, min_depth=min_depth, max_depth=max_depth, twobyte=twobyte)
+            if im_data.dtype.type == np.uint8:
+                pil_image = PImage.fromarray(im_data.squeeze())
+                pil_image.save(filename)
+            else:
+                try:
+                    import png
+                except:
+                    raise ValueError('PyPNG not installed! Cannot save 16-bit images')
+                png.fromarray(im_data, 'L').save(filename)
+        else:
+            super().save(filename)
+
     def resize(self, size, interp='bilinear'):
         """Resize the image.
 

perception/video_recorder.py

@@ -1,79 +1,10 @@
 '''
-Class to record videos from webcams using opencv
-Author: Jacky Liang
+Class to record videos from webcams using ffmpeg-python
+Author: Mike Danielczuk
 '''
-import cv2
-import logging
-from multiprocessing import Process, Queue
-import numpy as np
-import os
-import skvideo.io as si
-import sys
+import ffmpeg
+import time
 
-class _Camera(Process):
-    """ Private class to manage a separate webcam data collection process.
-
-    Attributes
-    ----------
-    camera : :obj:`cv2.VideoCapture`
-        opencv video capturing object
-    cmd_q : :obj:`Queue`
-        queue for commands to the recording process
-    res : 2-tuple
-        height and width of the video stream
-    codec : :obj:`str`
-        string name of codec, e.g. XVID
-    fps : int
-        number of frames per second
-    rate : int
-        rate at which to read frames (e.g. 2 means skip every other frame)
-    """
-    def __init__(self, camera, cmd_q, res, codec, fps, rate=1):
-        Process.__init__(self)
-        
-        self.res = res
-        self.fps = fps
-        self.codec = codec
-
-        self.camera = camera
-        self.fourcc = cv2.VideoWriter_fourcc(*self.codec)
-        self.rate = rate
-        
-        self.cmd_q = cmd_q
-        self.recording = False
-        self.out = None
-        self.data_buf = None
-        self.count = 0
-        
-    def run(self):
-        """ Continually write images to the filename specified by a command queue. """
-        if not self.camera.is_running:
-            self.camera.start()
-        while True:
-            if not self.cmd_q.empty():
-                cmd = self.cmd_q.get()
-                if cmd[0] == 'stop':
-                    self.out.close()
-                    self.recording = False
-                elif cmd[0] == 'start':
-                    filename = cmd[1]
-                    self.out = si.FFmpegWriter(filename)
-                    self.recording = True
-                    self.count = 0
-
-            if self.recording:
-                if self.count == 0:
-                    image, _, _ = self.camera.frames()
-                    
-                    if self.data_buf is None:
-                        self.data_buf = np.zeros([1, image.height, image.width, image.channels])
-                    self.data_buf[0,...] = image.raw_data
-                    self.out.writeFrame(self.data_buf)
-
-                self.count += 1
-                if self.count == self.rate:
-                    self.count = 0
-                
 class VideoRecorder:
     """ Encapsulates video recording processes.
 
@@ -83,71 +14,55 @@ class VideoRecorder:
         USB index of device
     res : 2-tuple
         resolution of recording and saving. defaults to (640, 480)
-    codec : :obj:`str`
-        codec used for encoding video. default to XVID. 
+    video_format : :obj:`str`
+        format used for video. default to v4l2. 
     fps : int
         frames per second of video captures. defaults to 30
-    rate : int
-        rate at which to read frames (e.g. 2 means skip every other frame)
     """
-    def __init__(self, camera, device_id=0, res=(640, 480), codec='XVID', fps=30, rate=1):
+    def __init__(self, device_id=0, res=(640, 480), video_format='v4l2', fps=30):
+        self._device = device_id
         self._res = res
-        self._codec = codec
+        self._format = video_format
         self._fps = fps
-        self._rate = rate
-        
-        self._cmd_q = Queue()
-        
-        self._actual_camera = camera
 
         self._recording = False
-        self._started = False
 
     @property
     def is_recording(self):
         return self._recording
-
+    
     @property
     def is_started(self):
-        return self._started
+        return True
 
     def start(self):
-        """ Starts the camera recording process. """
-        self._started = True
-        self._camera = _Camera(self._actual_camera, self._cmd_q, self._res, self._codec, self._fps, self._rate)
-        self._camera.start()
+        pass
 
-    def start_recording(self, output_file):
+    def start_recording(self, output_file, overwrite=True):
         """ Starts recording to a given output video file.
 
         Parameters
         ----------
         output_file : :obj:`str`
             filename to write video to
         """
-        if not self._started:
-            raise Exception("Must start the video recorder first by calling .start()!")
         if self._recording:
             raise Exception("Cannot record a video while one is already recording!")
         self._recording = True
-        self._cmd_q.put(('start', output_file))
+        self._video = (
+            ffmpeg
+            .input('/dev/video{}'.format(self._device), f=self._format, s='{}x{}'.format(*self._res), framerate=self._fps)
+            .output(output_file)
+            .run_async(quiet=True, overwrite_output=overwrite)
+        )
+        time.sleep(2) # Pause until video starts
 
     def stop_recording(self):
         """ Stops writing video to file. """
         if not self._recording:
             raise Exception("Cannot stop a video recording when it's not recording!")
-        self._cmd_q.put(('stop',))
+        self._video.terminate()
         self._recording = False
-        
+
     def stop(self):
-        """ Stop the camera process. """
-        if not self._started:
-            raise Exception("Cannot stop a video recorder before starting it!")
-        self._started = False
-        if self._actual_camera.is_running:
-            self._actual_camera.stop()
-        if self._camera is not None:
-            try:
-                self._camera.terminate()
-            except:
-                pass
+        pass

setup.py

@@ -18,7 +18,8 @@
     'ipython==5.5.0',
     'scikit-image',
     'scikit-learn',
-    'scikit-video'
+    'scikit-video',
+    'ffmpeg-python'
 ]
 
 exec(open('perception/version.py').read())