Why does nvarguscamerasrc report a framerate of 30/1 rather than the actual framerate?

Robotics & Edge Computing Jetson & Embedded Systems Jetson Nano
1

I’m using a Jetson Nano with a Raspberry Pi camera module. If I don’t explicitly specify a framerate then nvarguscamerasrc reports a framerate of 30/1 rather than the actual framerate:

$ gst-launch-1.0 -v nvarguscamerasrc num-buffers=60 \
    ! 'video/x-raw(memory:NVMM), width=3280, height=2464' \
    ! fakesink
...
/GstPipeline:pipeline0/GstNvArgusCameraSrc:nvarguscamerasrc0.GstPad:src: caps =
    video/x-raw(memory:NVMM),
    width=(int)3280, height=(int)2464,
    format=(string)NV12,
    framerate=(fraction)30/1
...
GST_ARGUS: Running with following settings:
   ...
   Output Stream W = 3280 H = 2464 
   ...
   Frame Rate = 21.000000
...

So above we can see that it knows that Frame Rate = 21 however it fills in framerate=(fraction)30/1 and this is what’s seen by everything downstream in the pipeline.

If I specify an incorrect framerate then this is neither corrected nor does it result in an error:

$ gst-launch-1.0 -v nvarguscamerasrc num-buffers=60 \
    ! 'video/x-raw(memory:NVMM), width=3280, height=2464, framerate=120/1' \
    ! fakesink
...
/GstPipeline:pipeline0/GstNvArgusCameraSrc:nvarguscamerasrc0.GstPad:src: caps =
    video/x-raw(memory:NVMM),
    width=(int)3280, height=(int)2464,
    format=(string)NV12,
    framerate=(fraction)120/1
...
GST_ARGUS: Running with following settings:
   ...
   Output Stream W = 3280 H = 2464 
   ...
   Frame Rate = 21.000000

Here I specified 120/1 and even though it can only capture at 21/1 at this width and height it doesn’t complain - it captures at 21/1 but reports 120/1 downstream in the pipeline.

This is a little frustrating - I don’t want to worry about the framerate and I’m happy to let the camera chose the rate, e.g. 21/1 above, but I want the actual rate reported in the pipeline rather than an incorrect default of 30/1 (if I don’t specify a framerate) or an incorrect rate if I specify an invalid framerate and the camera chooses a different one.

I can confirm that the incorrect framerate makes it all the way down the pipeline and is stored in any resulting video file:

$ gst-launch-1.0 -v nvarguscamerasrc \
    ! 'video/x-raw(memory:NVMM), width=3280, height=2464' \
    ! nvjpegenc \
    ! matroskamux \
    ! filesink location=out.mkv
...
Frame Rate = 21.000000
...
$ ffprobe -loglevel panic -show_streams out.mkv | fgrep r_frame_rate
r_frame_rate=30/1

Here Frame Rate = 21 but r_frame_rate=30/1 is reported for the resulting MKV file.

Is there any way to tell nvarguscamerasrc to report the actual framerate to the pipeline?

2

Hi,
We can reproduce it on r32.2. Checking and will update.

3

It has been half a year, what is the status on this issue?

4

Hi,
The issue is fixed in r32.3.1. Please upgrade and give it a try.