__init__.py 文件源码

def video(self, tensor=None, videofile=None, win=None, env=None, opts=None):
        """
        This function plays a video. It takes as input the filename of the video
        or a `LxHxWxC` tensor containing all the frames of the video. The function
        does not support any plot-specific `options`.
        """
        opts = {} if opts is None else opts
        opts['fps'] = opts.get('fps', 25)
        _assert_opts(opts)
        assert tensor is not None or videofile is not None, \
            'should specify video tensor or file'

        if tensor is not None:
            import cv2
            import tempfile
            assert tensor.ndim == 4, 'video should be in 4D tensor'
            videofile = '/tmp/%s.ogv' % next(tempfile._get_candidate_names())
            if cv2.__version__.startswith('2'):  # OpenCV 2
                fourcc = cv2.cv.CV_FOURCC(
                    chr(ord('T')),
                    chr(ord('H')),
                    chr(ord('E')),
                    chr(ord('O'))
                )
            elif cv2.__version__.startswith('3'):  # OpenCV 3
                fourcc = cv2.VideoWriter_fourcc(
                    chr(ord('T')),
                    chr(ord('H')),
                    chr(ord('E')),
                    chr(ord('O'))
                )
            writer = cv2.VideoWriter(
                videofile,
                fourcc,
                opts.get('fps'),
                (tensor.shape[1], tensor.shape[2])
            )
            assert writer.isOpened(), 'video writer could not be opened'
            for i in range(tensor.shape[0]):
                writer.write(tensor[i, :, :, :])
            writer.release()
            writer = None

        extension = videofile.split(".")[-1].lower()
        mimetypes = dict(mp4='mp4', ogv='ogg', avi='avi', webm='webm')
        mimetype = mimetypes.get(extension)
        assert mimetype is not None, 'unknown video type: %s' % extension

        bytestr = loadfile(videofile)
        videodata = """
            <video controls>
                <source type="video/%s" src="data:video/%s;base64,%s">
                Your browser does not support the video tag.
            </video>
        """ % (mimetype, mimetype, base64.b64encode(bytestr).decode('utf-8'))
        return self.text(text=videodata, win=win, env=env, opts=opts)