def set_controls(fd, input_or_output):
# first we get the controls through enumeration
queryctrls = list(get_device_controls_by_class(fd, class_))
control_array = (v4l2.v4l2_ext_control * len(queryctrls))()
for index, queryctrl in enumerate(queryctrls):
control_array[index].id = queryctrl.id
ext_controls = v4l2.v4l2_ext_controls(class_, len(queryctrls))
ext_controls.controls = control_array
# we store the original values so we can set them back later
try:
ioctl(fd, v4l2.VIDIOC_G_EXT_CTRLS, ext_controls)
except IOError, e:
assert e.errno == errno.EINVAL
assert not queryctrls
return
def get_controls(fd, input_or_output):
# first we get the controls through enumeration
# note, currently not distinguishing by disabled flag.
queryctrls = list(get_device_controls_by_class(fd, class_))
control_array = (v4l2.v4l2_ext_control * len(queryctrls))()
for index, queryctrl in enumerate(queryctrls):
control_array[index].id = queryctrl.id
ext_controls = v4l2.v4l2_ext_controls(class_, len(queryctrls))
ext_controls.controls = control_array
try:
ioctl(fd, v4l2.VIDIOC_G_EXT_CTRLS, ext_controls)
except IOError, e:
assert e.errno == errno.EINVAL
assert not queryctrls
return
def try_controls(fd, input_or_output):
# first we get the controls through enumeration
queryctrls = list(get_device_controls_by_class(fd, class_))
# try sane values
control_array = (v4l2.v4l2_ext_control * len(queryctrls))()
for index, queryctrl in enumerate(queryctrls):
control_array[index].id = queryctrl.id
control_array[index].value = queryctrl.default
ext_controls = v4l2.v4l2_ext_controls(class_, len(queryctrls))
ext_controls.controls = control_array
try:
ioctl(fd, v4l2.VIDIOC_TRY_EXT_CTRLS, ext_controls)
except IOError, e:
# driver may raise EINVAL if the control array has a
# length of zero
assert e.errno == errno.EINVAL
assert not queryctrls
return
def set_controls(fd, input_or_output):
# first we get the controls through enumeration
queryctrls = list(get_device_controls_by_class(fd, class_))
control_array = (v4l2.v4l2_ext_control * len(queryctrls))()
for index, queryctrl in enumerate(queryctrls):
control_array[index].id = queryctrl.id
ext_controls = v4l2.v4l2_ext_controls(class_, len(queryctrls))
ext_controls.controls = control_array
# we store the original values so we can set them back later
try:
ioctl(fd, v4l2.VIDIOC_G_EXT_CTRLS, ext_controls)
except IOError as e:
assert e.errno == errno.EINVAL
assert not queryctrls
return
original_values = [(c.value, c.value64) for c in control_array]
# set to minimum value
for index, control in enumerate(control_array):
control.value = queryctrls[index].minimum
control.value64 = queryctrls[index].minimum
ioctl(fd, v4l2.VIDIOC_S_EXT_CTRLS, ext_controls)
# test invalid control
if queryctrls:
control_array[-1].value = 1 << 31
control_array[-1].value64 = 1 << 32
try:
ioctl(fd, v4l2.VIDIOC_S_EXT_CTRLS, ext_controls)
except IOError as e:
# the driver may either prune the value or raise
# ERANGE if control value is out of bounds
assert e.errno == errno.ERANGE
assert ext_controls.error_idx == len(control_array) - 1
# set back original values
for index, control in enumerate(control_array):
control.value = original_values[index][0]
control.value64 = original_values[index][1]
ioctl(fd, v4l2.VIDIOC_S_EXT_CTRLS, ext_controls)
def get_controls(fd, input_or_output):
# first we get the controls through enumeration
# note, currently not distinguishing by disabled flag.
queryctrls = list(get_device_controls_by_class(fd, class_))
control_array = (v4l2.v4l2_ext_control * len(queryctrls))()
for index, queryctrl in enumerate(queryctrls):
control_array[index].id = queryctrl.id
ext_controls = v4l2.v4l2_ext_controls(class_, len(queryctrls))
ext_controls.controls = control_array
try:
ioctl(fd, v4l2.VIDIOC_G_EXT_CTRLS, ext_controls)
except IOError as e:
assert e.errno == errno.EINVAL
assert not queryctrls
return
assert ext_controls.error_idx == 0
assert ext_controls.reserved[0] == 0
assert ext_controls.reserved[1] == 0
for index, control in enumerate(control_array):
assert control.value >= queryctrls[index].minimum
assert control.value <= queryctrls[index].maximum
