from __future__ import absolute_import
import os
import sys
import fcntl
import timeit
import sys
import numpy as np
import pyfakewebcam.v4l2 as _v4l2
cv2_imported = False
try:
import cv2
cv2_imported = True
except:
sys.stderr.write(
"Warning! opencv could not be imported; performace will be degraded!\n"
)
class FakeWebcam:
# TODO: add support for more pixfmts
# TODO: add support for grayscale
def __init__(self, video_device, width, height, channels=3, input_pixfmt="RGB"):
if channels != 3:
raise NotImplementedError(
"Code only supports inputs with 3 channels right now. You tried to intialize with {} channels".format(
channels
)
)
if input_pixfmt != "RGB":
raise NotImplementedError(
"Code only supports RGB pixfmt. You tried to intialize with {}".format(
input_pixfmt
)
)
if not os.path.exists(video_device):
sys.stderr.write(
"\n--- Make sure the v4l2loopback kernel module is loaded ---\n"
)
sys.stderr.write("sudo modprobe v4l2loopback devices=1\n\n")
raise FileNotFoundError("device does not exist: {}".format(video_device))
self._channels = channels
self._video_device = os.open(video_device, os.O_WRONLY | os.O_SYNC)
self._settings = _v4l2.v4l2_format()
self._settings.type = _v4l2.V4L2_BUF_TYPE_VIDEO_OUTPUT
self._settings.fmt.pix.pixelformat = _v4l2.V4L2_PIX_FMT_YUYV
self._settings.fmt.pix.width = width
self._settings.fmt.pix.height = height
self._settings.fmt.pix.field = _v4l2.V4L2_FIELD_NONE
self._settings.fmt.pix.bytesperline = width * 2
self._settings.fmt.pix.sizeimage = width * height * 2
self._settings.fmt.pix.colorspace = _v4l2.V4L2_COLORSPACE_JPEG
self._buffer = np.zeros(
(self._settings.fmt.pix.height, 2 * self._settings.fmt.pix.width),
dtype=np.uint8,
)
self._yuv = np.zeros(
(self._settings.fmt.pix.height, self._settings.fmt.pix.width, 3),
dtype=np.uint8,
)
self._ones = np.ones(
(self._settings.fmt.pix.height, self._settings.fmt.pix.width, 1),
dtype=np.uint8,
)
self._rgb2yuv = np.array(
[
[0.299, 0.587, 0.114, 0],
[-0.168736, -0.331264, 0.5, 128],
[0.5, -0.418688, -0.081312, 128],
]
)
fcntl.ioctl(self._video_device, _v4l2.VIDIOC_S_FMT, self._settings)
def print_capabilities(self):
capability = _v4l2.v4l2_capability()
print(
(
"get capabilities result",
(fcntl.ioctl(self._video_device, _v4l2.VIDIOC_QUERYCAP, capability)),
)
)
print(("capabilities", hex(capability.capabilities)))
print(("v4l2 driver: {}".format(capability.driver)))
# TODO: improve the conversion from RGB to YUV using cython when opencv is not available
def schedule_frame(self, frame):
if frame.shape[0] != self._settings.fmt.pix.height:
raise Exception(
"frame height does not match the height of webcam device: {}!={}\n".format(
self._settings.fmt.pix.height, frame.shape[0]
)
)
if frame.shape[1] != self._settings.fmt.pix.width:
raise Exception(
"frame width does not match the width of webcam device: {}!={}\n".format(
self._settings.fmt.pix.width, frame.shape[1]
)
)
if frame.shape[2] != self._channels:
raise Exception(
"num frame channels does not match the num channels of webcam device: {}!={}\n".format(
self._channels, frame.shape[2]
)
)
if cv2_imported:
# t1 = timeit.default_timer()
self._yuv = cv2.cvtColor(frame, cv2.COLOR_RGB2YUV)
# t2 = timeit.default_timer()
# sys.stderr.write('conversion time: {}\n'.format(t2-t1))
else:
# t1 = timeit.default_timer()
frame = np.concatenate((frame, self._ones), axis=2)
frame = np.dot(frame, self._rgb2yuv.T)
self._yuv[:, :, :] = np.clip(frame, 0, 255)
# t2 = timeit.default_timer()
# sys.stderr.write('conversion time: {}\n'.format(t2-t1))
# t1 = timeit.default_timer()
for i in range(self._settings.fmt.pix.height):
self._buffer[i, ::2] = self._yuv[i, :, 0]
self._buffer[i, 1::4] = self._yuv[i, ::2, 1]
self._buffer[i, 3::4] = self._yuv[i, ::2, 2]
# t2 = timeit.default_timer()
# sys.stderr.write('pack time: {}\n'.format(t2-t1))
os.write(self._video_device, self._buffer.tostring())
