Error Using nvjpegdec with USB Camera on Nvidia Jetson Orin Nano

Issue Overview

Users of the Nvidia Jetson Orin Nano Developer Kit are experiencing issues when attempting to use the nvjpegdec hardware decoder with a USB camera. The specific symptoms include receiving an error message that states "Empty caps" when executing a GStreamer command designed to process MJPEG video streams. This issue occurs during the setup phase, specifically when trying to decode video from a USB camera using the following GStreamer pipeline:

gst-launch-1.0 v4l2src device=/dev/video1 ! image/jpeg, width=1920, height=1080, framerate=30/1 ! nvjpegdec ! videoconvert ! xvimagesink

The error log indicates that the nvjpegdec is unable to negotiate the video format correctly, leading to a failure in processing the stream. In contrast, using the software decoder (jpegdec) does not result in this error, suggesting that the problem is specifically related to the hardware acceleration provided by nvjpegdec.

The developer kit is running Jetpack 5.1.1 (L4T 35.3.1) with Ubuntu 20.04 and Linux kernel version 5.10.104-tegra. The camera formats supported by the USB camera include MJPG and YUYV, with various resolutions available.

Possible Causes

• Hardware Incompatibility: The nvjpegdec may not fully support certain formats or configurations of the USB camera being used.

• Software Bugs: There may be unresolved bugs in Jetpack versions 5.1.1 and 5.1.2 affecting the functionality of nvjpegdec with live video streams.

• Configuration Errors: Incorrect GStreamer pipeline configurations could lead to negotiation failures between elements.

• Driver Issues: Outdated or incompatible drivers for the USB camera or Jetson Orin Nano may cause issues with video decoding.

• Environmental Factors: Power supply issues or overheating could potentially affect hardware performance.

• User Errors: Misconfigurations in command syntax or parameters could lead to the observed problems.

Troubleshooting Steps, Solutions & Fixes

1. Verify Camera Compatibility:

   • Ensure that your USB camera is compatible with the Jetson Orin Nano and supports MJPEG output.

2. Test Alternative Decoders:

   • As a workaround, use the nvv4l2decoder plugin instead of nvjpegdec. Modify your GStreamer command as follows:

     gst-launch-1.0 v4l2src device=/dev/video1 ! image/jpeg, width=1920, height=1080 ! nvv4l2decoder mjpeg=1 ! videoconvert ! xvimagesink
     

   • Note that some users have reported latency issues with this method.

3. Adjust GStreamer Pipeline:

   • If using nvv4l2decoder, consider adding parameters to reduce latency:

     gst-launch-1.0 v4l2src device=/dev/video1 io-mode=2 ! image/jpeg,width=1920,height=1080 ! nvv4l2decoder mjpeg=1 ! nvvidconv ! video/x-raw,format=BGRx ! videoconvert ! xvimagesink
     

4. Use Software Decoder as Temporary Solution:

   • If hardware decoding fails, you can use the software decoder as a temporary solution:

     gst-launch-1.0 v4l2src device=/dev/video1 ! image/jpeg,width=1920,height=1080 ! jpegdec ! videoconvert ! xvimagesink
     

5. Check for Software Updates:

   • Keep an eye out for updates to Jetpack that may resolve known issues with nvjpegdec. Users have indicated that improvements are expected in Jetpack 5.1.3.

6. Set Additional Parameters:

   • Some users have found success by setting additional parameters such as mjpegdecode=1 in their pipeline:

     gst-launch-1.0 v4l2src device=/dev/video1 ! image/jpeg,width=1920,height=1080 ! nvjpegdec mjpegdecode=1 ! videoconvert ! xvimagesink
     

7. Monitor System Performance:

   • Ensure that your system is not experiencing performance bottlenecks due to high CPU usage or insufficient power supply.

8. Community Engagement:

   • Engage with community forums or Nvidia support for further insights and potential fixes based on collective experiences.

By following these troubleshooting steps and solutions, users should be able to address the issues related to using nvjpegdec with their USB cameras on the Nvidia Jetson Orin Nano Developer Kit effectively.