Play Failed via SSH
Problem
In the Debian Operating System (OS), playing some audio or video sources may fail via SSH but succeed on the UART terminal.
Solution
After log in through the SSH terminal each time, you can try to check if the DISPLAY environment variable are properly configured to specify the display device.
The following code block provides an example.
export DISPLAY=:0 gst-play-1.0 1080p_h264_aac.mp4