Enumerating and Configuring Sensor Modes

The driver exports a number of sensor modes to the Tegra camera framework.

These modes are used to configure the output resolution and other general aspects of sensor operation, such as pixel format or PWL (piecewise linear) compression.

Mode information can be queried using V4L2 controls.

When using nvarguscamerasrc, the mode is selected using the sensor-mode parameter:

gst-launch-1.0 nvarguscamerasrc sensor-mode=1 ! nv3dsink

When using V4L2, the mode is selected through a V4L2 control.

Mode-Related Controls

Control	Identifier	Type	Remarks
sensor_mode	TEGRA_CAMERA_CID_SENSOR_MODE_ID	integer64
frame_rate	TEGRA_CAMERA_CID_FRAME_RATE	integer64
bypass_mode	TEGRA_CAMERA_CID_VI_BYPASS_MODE	intmenu
sensor_image_properties	TEGRA_CAMERA_CID_SENSOR_IMAGE_PROPERTIES	integer[][]	Array of struct sensor_image_properties
sensor_control_properties	TEGRA_CAMERA_CID_SENSOR_CONTROL_PROPERTIES	integer[][]	Array of struct sensor_control_properties
preferred_stride	TEGRA_CAMERA_CID_VI_PREFERRED_STRIDE	integer
mode_raw_fourcc	TIS_SENSOR_CID_MODE_RAW_FOURCC	integer[]

Note

TEGRA_CAMERA_CID_-constants and related structures are defined in tegra-v4l2-camera.h, which is installed in /usr/src on JetPack images.

Tegra Camera Mode Controls

Mode enumeration and configuration is essentially bypassing the V4L2 format configuration process.

To get information about the available video modes, query sensor_image_properties.

To configure resolution and frame rate, set sensor_mode and frame_rate accordingly. Then, call V4L2’s VIDIOC_S_FMT, specifying the correct image size and pixel format. Make sure that bypass_mode is 0. preferred_stride can be used to influence the physical organization of the received image data.

Mode Raw FourCC

The mode_raw_fourcc control gives information about the actual pixel format of a sensor mode.

The normal way to query this information would be to use the pixel_format member of the sensor_image_properties structure. However, since the Tegra camera framework restricts the available pixel formats to a whitelist, some pixel formats are not supported this way.

This data provided control is an array with an entry for each mode.

Control	Mode Raw FourCC
Name	mode_raw_fourcc
Identifier	TIS_SENSOR_CID_MODE_RAW_FOURCC
Type	V4L2_CTRL_TYPE_INTEGER[]