v4l2src launches inconsistently with camera

[Marianna Smidth Buschle]

You should simplify your pipeline to narrow the source of the problem.

gst-launch-1.0 v4l2src device=/dev/video2 ! fakesink

And build from there, try fx adding identify and dump the data to see if 
it is coming through.


Also, from the later discussions I agree with Nicolas that it seems more 
like a driver or HW issue.

So try using the standard v4l2 tools for debugging: v4l2-ctl, yavta, 
qv4l2...

See if the streaming works consistently there.


Best Regards

Marianna

On 15/09/2023 19.26, gstreamer-devel-request at lists.freedesktop.org wrote:
> Message: 3
> Date: Fri, 15 Sep 2023 13:26:43 -0400
> From: Dwight Kulkarni<dwight at realtime-7.com>
> To: Discussion of the development of and with GStreamer
> 	<gstreamer-devel at lists.freedesktop.org>
> Subject: v4l2src launches inconsistently with camera
> Message-ID:
> 	<CAKW2B8h+J_Sh0Gcy8qBDcPgmLmGK+gGP5OQBermOpf0a9-4qng at mail.gmail.com>
> Content-Type: text/plain; charset="utf-8"
>
> Hi all,
>
> We have a camera board and are trying to use Gstreamer with it.
>
> Two different units of the exact same camera board are giving different
> behaviour when launching with gstreamer.
>
> One of the boards is always launching. Other boards are launching with some
> frequency like 8/10 or 9/10 times. And one of the boards is never launching.
>
> When we measure the MIPI output on the camera board, we can measure data
> there when pipeline launches. This means the board is sending data.
>
> However, for whatever reason Gstreamer some of the time doesn't start up.
>
> We think it might be some sort of timing issue, but it is very
> inconsistent. I am attaching a sample log which includes dmesg output for
> the two cases. In one case, gstreamer was successful and other case not, in
> starting up.
>
> In both instances, we don't see any error message but no stream appears. It
> even says v4l2src was set to PLAYING successfully in both cases.
>
> If anyone has any insight into this, would really appreciate it. We have
> tried everything even remaking the board twice, but it seems to be some
> timing or initialization or sequencing issue.
>
> -- Sincerely, Dwight Kulkarni -------------- next part -------------- 
> An HTML attachment was scrubbed... URL: 
> <https://lists.freedesktop.org/archives/gstreamer-devel/attachments/20230915/58f435ad/attachment.htm> 
> -------------- next part -------------- root at viperimx8mp:~# 
> GST_DEBUG=4 gst-launch-1.0 v4l2src device=/dev/video2 ! 
> imxvideoconvert_g2d ! "video/x-raw, width=1920, height=1080, 
> framerate=15/1" ! vpuenc_h264 bitrate=4096 ! h264parse ! rtph264pay ! 
> udpsink host=10.0.0.79 port=5000 sync=false

-- 
Best regards / Med venlig hilsen
“Marianna Smidth Buschle”