7.61. ioctl VIDIOC_SUBDEV_G_ROUTING, VIDIOC_SUBDEV_S_ROUTING¶
7.61.1. Name¶
VIDIOC_SUBDEV_G_ROUTING - VIDIOC_SUBDEV_S_ROUTING - Get or set routing between streams of media pads in a media entity.
7.61.2. Synopsis¶
-
VIDIOC_SUBDEV_G_ROUTING¶
int ioctl(int fd, VIDIOC_SUBDEV_G_ROUTING, struct v4l2_subdev_routing *argp)
-
VIDIOC_SUBDEV_S_ROUTING¶
int ioctl(int fd, VIDIOC_SUBDEV_S_ROUTING, struct v4l2_subdev_routing *argp)
7.61.3. Arguments¶
fd
File descriptor returned by open().
argp
Pointer to struct
v4l2_subdev_routing
.
7.61.4. Description¶
These ioctls are used to get and set the routing in a media entity. The routing configuration determines the flows of data inside an entity.
Drivers report their current routing tables using the
VIDIOC_SUBDEV_G_ROUTING
ioctl and application may enable or disable routes
with the VIDIOC_SUBDEV_S_ROUTING
ioctl, by adding or removing routes and
setting or clearing flags of the flags
field of a
struct v4l2_subdev_route
.
All stream configurations are reset when VIDIOC_SUBDEV_S_ROUTING
is called. This
means that the userspace must reconfigure all streams after calling the ioctl
with e.g. VIDIOC_SUBDEV_S_FMT
.
Only subdevices which have both sink and source pads can support routing.
When inspecting routes through VIDIOC_SUBDEV_G_ROUTING
and the application
provided num_routes
is not big enough to contain all the available routes
the subdevice exposes, drivers return the ENOSPC error code and adjust the
value of the num_routes
field. Application should then reserve enough memory
for all the route entries and call VIDIOC_SUBDEV_G_ROUTING
again.
-
type v4l2_subdev_routing¶
__u32 |
|
Format to modified, from enum v4l2_subdev_format_whence. |
struct |
|
Array of struct |
__u32 |
|
Number of entries of the routes array |
__u32 |
|
Reserved for future extensions. Applications and drivers must set the array to zero. |
-
type v4l2_subdev_route¶
__u32 |
|
Sink pad number. |
__u32 |
|
Sink pad stream number. |
__u32 |
|
Source pad number. |
__u32 |
|
Source pad stream number. |
__u32 |
|
Route enable/disable flags v4l2_subdev_routing_flags. |
__u32 |
|
Reserved for future extensions. Applications and drivers must set the array to zero. |
V4L2_SUBDEV_ROUTE_FL_ACTIVE |
0 |
The route is enabled. Set by applications. |
7.61.5. Return Value¶
On success 0 is returned, on error -1 and the errno
variable is set
appropriately. The generic error codes are described at the
Generic Error Codes chapter.
- ENOSPC
The application provided
num_routes
is not big enough to contain all the available routes the subdevice exposes.- EINVAL
The sink or source pad identifiers reference a non-existing pad, or reference pads of different types (ie. the sink_pad identifiers refers to a source pad) or the sink or source stream identifiers reference a non-existing stream on the sink or source pad.
- E2BIG
The application provided
num_routes
forVIDIOC_SUBDEV_S_ROUTING
is larger than the number of routes the driver can handle.