Realsense D435 Missing frames

[PhilSc20]

Hi there,
I am trying to run rtabmap on Ubuntu 18.04 with a Realsense D435 camera. When I open the Intel realsense viewer, everything works fine and I can see the camera stream. However, if I press the start button in rtabmap, an error occurs as follows:
[ERROR] (2020-01-14 13:29:18.877) CameraRealSense2.cpp:1209::captureImage() Missing frames (received 1)

Also, a window pops up, saying: The camera has reached the end of the stream.

Thanks for any help!

[PhilSc20]

Now it seems that the camera stream in rtabmap will work if I just start and stop it for a random amount of times. Sometimes it starts after the third try and sometimes it needs to be started and stopped for over 20 times. I have no idea why that is, as I didn't change anything else.

[matlabbe]

Which realsense sdk version are you using? Which rtabmap version?

[PhilSc20]

I am using
realsense sdk version: 2.31.0
rtabmap version: 0.19.6

[matlabbe]

I reproduced your problem. It seems to happen randomly. I even reproduced the problem seen in this post in realsense-viewer where the image stamps are going backward! I am also using a D435i, I got a lot of warnings about imu cannot be interpolated when starting realsense in rtabmap, and sometimes it causes latencies (like 2-3 frames per second). I reproduced also the timestamp not synced between image and imu data of the original issue in realsense-ewer. Some people seem to say that it may be related to ubuntu kernel version. I'll try with older kernel versions.

Versions I tested:

• Linux 5.0.0-37-generic -40~18.04.1-Ubuntu SMP x86_64 GNU/Linux
• rtabmap from source 0.19.6 (latest)
• realsense binaries 2.31.0
• firmware D400: 05.12.01.00

[matlabbe]

Update: I don't have issues with kernel 4.15, see also this comment: IntelRealSense/librealsense#4505 (comment)