Display second screen using mmapi ex. 8

Robotics & Edge Computing Jetson Systems Jetson AGX Orin
,
1

I am trying to display second display using mmapi example 08 using without video

How do i do that?

3

Hi,
Would like to get more information, do you use Jetson Nano developer kit with Jetpack 4.6.6(r32.7.6)?

4

We use orin agx with customized carrier board fron Connectec that have two displays

7

Hi Eamo,

Currently, our mmapi example 8 does not support rendering to dual displays simultaneously. However, you can use modetest to render on two displays at the same time. Please see the example below:

modetest -M nvidia-drm -s 74:#0@XB24 -s 71:#0@XB24 -P 39@46:1920x1080 -P 52@59:1920x1080

I have a few questions to confirm your setup:

  • Do you want to display content on both screens simultaneously, or just render to the second display?
  • Could you share the command you used and the corresponding fail log?
  • Just to confirm again, are you using mmapi example 8 or gstreamer?

Thanks,
David

8

We want to display 2 diffrent frames on 2 diffrent screens

We run the example with flag –disable-video and it run on first display

BUT the same flag not working on second display using flag -crtc 1

How to display using mmapi ex. 8 on second display?

9

Hi,

The mmapi example 8 is currently not supported.
We will provide a patch once it is completed.

Thank you for your understanding.

10

Do you support drm atomic api?

jetpack version is 6.1

11

HI,

Yes.

Please run below commands to enable

sudo modprobe nvidia-drm modeset=1

Thanks

12

Can you tell me if the ex. 8 upadted?

13

Hi,

Yes.
We will provide a patch once it is completed.

Thanks

15

We get the patch

  1. We see that sometimes the sample run and sometimes we get black screens
  2. The second screen use dmabuf does the first screen can also use dmabuf? Does the second screen must use dmabuf?
  3. The second screen get only nv12 format can it support another formats? When i am trying another format (for example yuyv) i get green screen
16

Hi,

  1. We don’t observe the issue in our side.
    • To investigate, we need more information:
    • Which screen goes black (first / second / both)?
    • When it happens (at startup, after some time)?
    • Please provide the video for us to review.
  2. Both screens use dmabuf since we allocate NvBufSurface.
  3. Please make sure your input yuyv file is yuyv format.
    • For example, please use ffmpeg to make yuyv format video and run the process again
    ffmpeg -i /usr/src/jetson_multimedia_api/data/Video/sample_outdoor_car_1080p_10fps.h264 \
-pix_fmt yuyv422 ~/car.yuv

Thanks

17
  1. We saw both screens black sometimes after we run the command systemctl stop gdm. We watch the dmesg and did not see any change between good run and black screens. Which information do you need to know?
18

Hi,

This is the expected behavior.

To run DRM samples, you must stop gdm to gain ‘DRM Master’ privileges. The black screen is the gap between gdm releasing the GPU and ex.8 sample code taking it over.

Thanks

19

We get black screen that does not show the video i add

out.txt (20.6 KB)

dmesg output when it work ok and when it does not

I also attach screen when systemctl stop gdm work well

capt8.zip (23.1 KB)

20

From the log alone we don’t see any errors, so we’ll try to reproduce in our side. Could you please share the detailed steps or commands you run?

Please try sudo systemctl isolate multi-user.target instead of systemctl stop gdm to change to the command line mode and run steps again.

Thanks

21

We tried the systemctl command and get sometimes two black screens

22

Hi,

Do you mean that after running sudo systemctl isolate multi-user.target , the both screen went black?

Could you please share the steps so that we can try to reproduce the issue on our side?
It would also be very helpful if you could provide a recorded video for our review.

Thank you!

23

Yes.

I call this command systemctl isolate multi-user.target from ssh (putty) and sometmes get black screens

24

Hi,

After the monitor goes black, could you run video_dec_drm and see the video output via SSH?

Thanks