I'm debugging an occasional problem in retrieving MJPEG stream from a USB camera. After a seemingly random amount of time, turbojpeg reports the JPEG header couldn't be found in the stream data. Now I'm wondering if this is a dropped frame or something like that. I found this: https://www.linuxtv.org/wiki/index.php/V4L_capturing#Video_framerates which has some ideas on how I could analyze the
framerate of my sensor, but I'm not sure what to feed to gst-launch
I run: gst-launch v4l2src device=/dev/video1 ! image/jpeg, width=1280, height=720, interlaced=false, framerate=30/1 ! fpsdisplaysink fps-update-interval=100000 which produces the error: ERROR: from element /GstPipeline:pipeline0/GstV4l2Src:v4l2src0: Could not negotiate format
gst-launch --gst-debug=v4l2src:5 v4l2src device=/dev/video1 ! fakesink 2>&1 | sed -une '/caps of src/ s/[:;] /\n/gp'
This gives me the details that match my parameters
Mostly I'm trying to see if it's possible to either avoid that single frame being lost (if it is frame loss), and if that cannot happen, somehow notice that
using this properly shows the stream: mplayer tv:// -tv device=/dev/video1:width=1280:height=720:fps=30
And I think that's MJPEG as this is printed: Selected video codec: MJPEG (Motion JPEG) [libavcodec
sailus: if you see this today, can you point me to a git repo containing your v7 fwnode series?
Then I'll try to review this tomorrow morning when my brain is fresh :-)
'this' == patch 12/18.
hverkuil: Thanks for the reviews.
I'll update them.
I found a bunch of issues today I didn't realise existed when sending the set.
It's not entirely trivial.
hverkuil: Still around?
asquare :-)