8 Replies Latest reply on Oct 7, 2017 4:23 PM by MartyG

    SR300 only able to get 14.99 fps color image

    ntm

      Hello,

       

      I am trying to use an SR300 on Ubuntu with librealsense to retrieve depth and color images.

      Unfortunately, I am having a lot of trouble so far.

      Currently I am using librealsense 2.0 (RC1) and the new pipeline API to get the data from the camera,

      but the framerate seems to be limited at 14,99 fps for the color image, no matter what resolution or fps

      setting I try to use. The problem also occurs in the provided examples and tools (i.e. the realsense-viewer),

      so it's probably not my fault.

      I am aware that this is not a final version, but the previous librealsense versions are even worse (with

      version 1.x I only got green noise as the color stream).

       

      I hope someone is able to help me.

      Thanks!

        • 1. Re: SR300 only able to get 14.99 fps color image
          MartyG

          The 'stuck at 15 FPS no matter what' issue occurred a couple of times in the past with the SR300's direct predecessor the F200.  It was shown to be caused by low light conditions.  Someone did an experiment to verify it.

           

          Re: F200 lightining conditions vs FPS

           

          RealSense expert Samontab speculated in another case that the camera's auto exposure was coming on in low light conditions.

           

          F200 stuck 15fps in colour stream

          • 2. Re: SR300 only able to get 14.99 fps color image
            ntm

            Well, I already tried turning auto exposure off, setting exposure time to the minimum and adding more light to the scene, but nothing seems to work. I am also guessing, that the auto exposure is not somehow turning itself back on since the image stays essentially completely black (due to the low exposure time).

            • 3. Re: SR300 only able to get 14.99 fps color image
              MartyG

              The SR300 statistically has more issues with Librealsense than the R200 does.  For example, it is recommended for SR300 users that the patch script is run once Librealsense is installed, even if it is a brand new installation.  I believe the ideal config for SR300 is also Ubuntu 16.04 LTS and at least Kernel 4.4.

              • 4. Re: SR300 only able to get 14.99 fps color image
                ntm

                I ran the patch script and I am using the recommended kernel and OS.

                • 5. Re: SR300 only able to get 14.99 fps color image
                  MartyG

                  One of the leaders of Librealsense, ddiakopoulos, said in another case where FPS was being limited, "USB bandwidth could be another factor.  Although I think the primary reason is that the SR300 will aggressively grow exposure values in low-light conditions, lowering the the FPS of the color stream."

                  • 6. Re: SR300 only able to get 14.99 fps color image
                    ntm

                    I have read that too, but I think that that is not the issue here since I am able to get color at 30 fps with either VLC accessing the video4linux stream directly, or with the old SDK 1.x if I modify the CMakeLists.txt to use libuvc, which is the intended backend when running on a mac OS, as a backend instead of video4linux. I do not want to use either of those hacks because I can not access the depth at the same time when I use VLC and when I use librealsense 1.x with the libuvc backend it just keeps crashing a lot (basically every time you close and reopen any application using the camera you have to plug it out and back in or it will crash, and sometimes it just keeps crashing multiple times before finally working for no good reason).

                    • 7. Re: SR300 only able to get 14.99 fps color image
                      ntm

                      I also tried using the low-level sensor API of the new SDK instead of the high-level pipeline API, but when I call .start(...) on the sensor I get an exception stating that the method call failed, because the UVC device was not opened (although I called .open(...) on that same sensor before that). I am not sure if I missed something and I could not find any thorough documentation on that nor any example code.

                      • 8. Re: SR300 only able to get 14.99 fps color image
                        MartyG

                        I am not a RealSense stream programming expert unfortunately, so can be of limited help with such in-depth coding questions.

                         

                        I could not find any further documentation on the Low Level API mode of SDK 2.0 yet either, so we may have to wait for the full documentation to be released.  That should occur at the same time as the new D415 and D435 cameras go on sale in the Intel Click online store this month.

                         

                        I apologize that I could not be of more help in this case, and hope that somebody else can contribute useful leads in the investigation into your problem.  Good luck!