v4l2src "lost frames detected: count = 18446744073709551615" in gst-launch-1.0
Hi there - I am attempting to capture video using a USB device on Linux with gst-launch-1.0. I'm encountering an issue where there's a continuous stream of debug messages indicated lost frames as below:
0:00:00.652740786 2325 0x17ce830 INFO v4l2src gstv4l2src.c:957:gst_v4l2src_create: sync to 0:00:00.533866656 out ts 0:00:00.561163631 0:00:00.652990860 2325 0x17ce830 WARN v4l2src gstv4l2src.c:976:gst_v4l2src_create: lost frames detected: count = 18446744073709551615 - ts: 0:00:00.561163631
I get watchable video out of it but it seems like there is some frame loss.
Originally I was capturing to huffyuv and thought perhaps the encoding was causing the issue. But the same number of lost frames still show up when I eliminate the encoding step and use the fakesink with the command below:
gst-launch-1.0 -qe v4l2src device=/dev/video0
do-timestamp=true norm=NTSC pixel-aspect-ratio=1
! "video/x-raw,format=YUY2,interlace-mode=interleaved,width=720,height=480"
! queue max-size-buffers=0 max-size-time=0 max-size-bytes=0
! fakesink
There does not seem to be any issue with CPU load because the output of top doesn't show CPU consumption of more than 30% (when using the more strenuous encoding command)
I thought it was curious that the number of lost frames is always 18446744073709551615
Here's the full debug output - https://pastebin.com/j7CPDuuz
That output shows that I am using GStreamer Core Library version 1.14.4 - this is the version that was installed via apt on the Raspberry Pi 4 that I am using.
Thanks for your help!