Timestamp zero when publish only compressed image

LynX19

On V2 with depthai_ros_driver, when I publish only compressed image for rgb, timestamp become zero, not happen with left or right.
On V3, can not publish rgb image when turn on set true both parameter, left and right topic still can publish
V2:

rgb:
      i_publish_compressed: true
      i_publish_topic: true

$ ros2 topic echo /oak_front/rgb/camera_info --once
header:
  stamp:
    sec: 0
    nanosec: 0
  frame_id: ''

V3:

rgb:
      i_publish_compressed: true
      i_publish_topic: true

[component_container-1] [INFO] [1777544653.427218601] [oak]: Pipeline type: RGBD
[component_container-1] [INFO] [1777544654.016779772] [oak]: Finished setting up pipeline.
[component_container-1] [INFO] [1777544654.157485248] [oak]: Published URDF
[component_container-1] [WARN] [1777544654.304199866] [oak]: If you detect any issues with Kilted release, please report issues to GH: https://github.com/luxonis/depthai-ros/issues/719
[component_container-1] [INFO] [1777544654.306106287] [oak]: Driver ready!
[component_container-1] [INFO] [1777544654.313595867] [oak_state_publisher]: got segment oak
[component_container-1] [INFO] [1777544654.313611774] [oak_state_publisher]: got segment oak_model_origin
[component_container-1] [INFO] [1777544654.313615545] [oak_state_publisher]: got segment oak_parent_frame
[component_container-1] [2026-04-30 17:24:14.394] [depthai] [error] Communication exception - possible device error/misconfiguration. Original message 'failed to publish message: ros_message argument is null, at ./src/rcl/publisher.c:247'

OskarSonc

LynX19 - Thanks for reporting this. I checked the driver code and this looks like a real driver-side issue, not a config mistake.

On V2, rgb.i_publish_compressed: true can cause camera_info to be published with a zero timestamp/header.

On V3/Kilted, rgb.i_publish_compressed: true currently also depends on rgb.i_low_bandwidth: true; without low-bandwidth enabled, the RGB compressed publish path can fail and produce the ros_message argument is null error you saw.

As a temporary workaround on V3, please also set:

rgb:
  i_low_bandwidth: true

Will sent this to the dev team.

Thanks,
Oskar

LynX19

On V3:
With this config, all 3 raw image topics of rgb, left, right have really lagging, like 2 FPS, better if remove low banwidth
All compressed smoothly. Timestamp have value

left:
  i_low_bandwidth: true
  i_publish_compressed: false
  i_publish_topic: true
rgb:
  i_low_bandwidth: true
  i_publish_compressed: false
  i_publish_topic: true
right:
  i_low_bandwidth: true
  i_publish_compressed: false
  i_publish_topic: true

With this config, everything seems ok, only publish compressed, timestamp still have value

left:
  i_low_bandwidth: true
  i_publish_compressed: true
  i_publish_topic: true
rgb:
  i_low_bandwidth: true
  i_publish_compressed: true
  i_publish_topic: true
right:
  i_low_bandwidth: true
  i_publish_compressed: true
  i_publish_topic: true

My camera is OAK-D-PRO-W USB
OS: Ubuntu 22.04
ROS Distro: Humble

OskarSonc

LynX19 - thanks, that helps. This looks consistent with the current V3 low-bandwidth path.

When i_low_bandwidth: true is enabled but i_publish_compressed: false, the driver still goes through the encoded low-bandwidth path and then converts back to raw on the host, which can cause the heavy lag you’re seeing. That also explains why the fully compressed setup is smooth and why timestamps still look correct there.

For now, if you need raw image topics, it’s better to keep i_low_bandwidth: false. If you want low-bandwidth streaming, i_publish_compressed: true seems to be the safer setup at the moment.

I’ve already passed this to the dev team, and they’ve added it to their TODO list.