MartyG-RealSense
commented
2 weeks ago Hi @RDVision-mchedefaux Thanks very much for your questions.
- Each RealSense camera that is attached to a computer consumes a portion of the computer's resources. The more cameras that are attached and active simultaneously, the more resources that are consumed. Though only two of your four cameras are RealSense, I would imagine that the same resource consumption applies too to the non-RealSense cameras if they are all active at the same time.
For four cameras or more that are capturing simultaneously, a computer with an Intel Core i7 or i9, or a CPU with equivalent processing power to that specification, is recommendable.
If the problem is not caused by your computing hardware then the described problem that occurs after 2 to 3 hours could also be caused by your program if it is experiencing a memory leak (where the computer's available memory capacity is progressively consumed over a period of time until the program becomes unstable or freezes). You can check for the possibility of a memory leak over time using an Ubuntu system monitoring tool such as htop.
The problem only being cleared by a full shutdown instead of a reboot could be further evidence of a memory leak, as a shutdown should give the computer's memory an opportunity to fully clear and reset to its normal state.
- Please try inserting a 'for int' instruction before your poll_for_frames() line to make the SDK skip some initial frames before beginning capture. This helps to avoid 'bad' frames that may occur during camera start-up if auto-exposure is enabled. Does doing so make a difference to your lost frame problem, please?
rs2::frameset frames;
for (int i = 0; i < 10; i++)
if (pipe->poll_for_frames(&frames))
{
RDVision-mchedefaux
Issue Description
I am currently writing a program to record synchronized frame from different cameras : 2 RGB GenICam cameras and 2 realsense. I have two different problems (one minor and one major) that I need to solve. For general introducing, I need to record at 10Hz from all four cameras, every cameras as its own USB controller, no hub used. Each RGB cameras trigger one realsense and one RGB camera is called the master as its trigger the other RGB Camera. The saving is made on a nvme drive (no drive bottleneck). No apparent CPU bottleneck either as we are at 20-30% CPU usage. I am using the Hardware synchronisation mode 4 (external synchronisation).
1. Important frame loss after long recording (Major) :
After 2 to 3 hours of recording (never more but no apparent periods), the 2 realsense start to drop frames significantly (99%) and synchronized drops (when 1 realsense lose 15 frames in a row, the other too). When this happen, it will never recover and will need a full switch off of the Jetson : if I only reboot it, the frameloss will still be happening. In addition, when the frame loss begin, it is also visible on the realsense viewer showing 0.5 to 1 fps. It appeared to be a SDK issue as its synchronized between the two cameras but not much more idea. In addition, I tried to separate the 2 realsense with a 2ms delay between the two RGB Camera (and so between the two realsense) but It didn't change anything.
2. Continuous synchronized frame loss during normal recording (Minor) :
During a recording, I encounter continuous frame loss directly at the beginning of the recording (1% to 2% of frame lost) and this lost are also synchronized between the two realsense cameras (when one lose a frame, the other one too). I also tried to add a delay between the two cameras and got little better results (but still there) but I don't know if it's real improvement or if it's due to randomness.
Code sneek peak
For information, a sneek peak at my recording code for realsense :
This is working in a thread and getting single camera frames (Depth, and IR if needed) and there's one other thread that is emptying the ImageQueue thread safe queue to save the frames. Each cameras has its own record thread and saving thread so a total of 4 for the two realsense.
Thank you very much in advance