Cannot build gstreamer pipeline with tee, appsink and file sink

Issue Overview

Users are experiencing difficulties when attempting to build a GStreamer pipeline on the Nvidia Jetson Orin Nano Developer Kit. The specific error encountered is queue_dataflow gstqueue.c:1516:gst_queue_loop: queue is empty, which occurs when trying to connect both an appsink and a filesink to a tee element in the pipeline. The issue arises during the execution of the command:

gst-launch-1.0 videotestsrc ! tee name=t ! \
queue ! nvvidconv ! 'video/x-raw, format=(string)RGBA' ! nvvidconv ! 'video/x-raw, format=(string)NV12' ! x264enc speed-preset=fast ! h264parse ! qtmux ! filesink location=demoVideos/videotestsrc.mov t. ! \
queue ! nvvidconv ! 'video/x-raw, format=(string)RGBA' ! appsink -e

The user reports that simpler pipelines work correctly when only one sink is attached, indicating that the problem lies specifically with the configuration involving multiple sinks. The user is operating with JetPack 5.1.2, L4T 35.4.1, and Ubuntu 20.04.

Possible Causes

1. Hardware Incompatibilities: The Jetson Orin Nano may have limitations or specific requirements for handling multiple streams in GStreamer.
2. Software Bugs: There may be unresolved bugs in the GStreamer version included with JetPack 5.1.2 that affect multi-sink configurations.
3. Configuration Errors: Incorrectly configured elements in the GStreamer pipeline could lead to data flow issues.
4. Driver Issues: Outdated or incompatible drivers for the GStreamer plugins may cause failures in data processing.
5. Environmental Factors: Insufficient power supply or overheating could impact performance and lead to unexpected behavior.
6. User Errors: Misconfigurations or incorrect command usage by the user could lead to the observed problems.

Troubleshooting Steps, Solutions & Fixes

1. Basic Diagnostics:

   • Verify that all components are properly connected and powered.
   • Check for any hardware error messages in system logs using:

     dmesg | grep -i error
     

2. Testing Pipeline Components:

   • Test each component of the pipeline separately to ensure they work independently:

     gst-launch-1.0 videotestsrc ! filesink location=test.mov
     gst-launch-1.0 videotestsrc ! appsink
     

3. Modify Pipeline Configuration:

   • Replace nvvidconv with videoconvert if NVMM buffers are not necessary, as suggested by forum users:

     gst-launch-1.0 videotestsrc ! tee name=t ! \
     queue ! videoconvert ! 'video/x-raw, format=(string)RGBA' ! videoconvert ! 'video/x-raw, format=(string)NV12' ! x264enc speed-preset=fast ! h264parse ! qtmux ! filesink location=test/videotestsrc.mov t. ! \
     queue ! videoconvert ! 'video/x-raw, format=(string)RGBA' ! appsink -e
     

4. Adjust Queue Settings:

   • Increase the maximum size of buffers in queues to handle more data flow:

     gst-launch-1.0 videotestsrc ! tee name=t ! \
     queue max-size-buffers=10 max-size-bytes=0 max-size-time=0 ...
     

5. Use Alternative Sinks:

   • If appsink continues to fail, try using fakesink for testing purposes to isolate issues related to data handling:

     gst-launch-1.0 videotestsrc ! tee name=t ! \
     queue ... t. ! queue ... fakesink
     

6. Debugging Output:

   • Use GStreamer debugging flags to gather more information about where the pipeline fails:

     GST_DEBUG=3 gst-launch-1.0 ...
     

7. Check for Updates:

   • Ensure that all software packages are up-to-date, including JetPack and GStreamer plugins.

8. Consult Documentation and Community:

   • Refer to the Jetson Orin Nano Developer Kit User Guide for additional troubleshooting tips and best practices.
   • Engage with community forums for shared experiences and solutions.

9. Unresolved Issues:

   • If issues persist after trying all recommended steps, consider opening a new support thread on relevant forums detailing steps taken and errors encountered.

By following these troubleshooting steps, users should be able to diagnose and potentially resolve issues related to building a GStreamer pipeline with multiple sinks on the Nvidia Jetson Orin Nano Developer Kit.