topic mxc_v4l2_capture driver with gstreamer mfw_gst_v4lsrc fails at startup in i.MX Processors

mxc_v4l2_capture driver with gstreamer mfw_gst_v4lsrc fails at startup

normancheung — Thu, 06 Mar 2014 06:52:19 GMT

I am using Linux 3.0.35 FSL sdk 4.0.0 on iMX6-solo. My pipeline is an audio and video capture and mux to a MKV container and then write to filesink.

When starting the pipeline, both gst-launch or my program, will fail (fails intermittently 50/50) with timeout on this ioctl call to mxc_v4l2_capture

-- ioctl (v4l_src->fd_v4l, VIDIOC_QUERYBUF, buf)

in function mfw_gst_v4lsrc_start_capturing ()

console also log a timeout error.

Once it started the pipeline works well, no issue.

I wonder what might be the problem with the mxc_v4l2_capture device driver? Is this timing related?

Thanks,

Norman

Re: mxc_v4l2_capture driver with gstreamer mfw_gst_v4lsrc fails at startup

normancheung — Thu, 06 Mar 2014 06:56:27 GMT

Just to add more info on this post, last week I posted this:

https://community.freescale.com/message/382547#382547

but there was no reply. But now I have traced down to mxc_v4l2_capture driver. Some background on this issue.

Thanks

Re: mxc_v4l2_capture driver with gstreamer mfw_gst_v4lsrc fails at startup

joanxie — Fri, 14 Mar 2014 09:16:49 GMT

did you use v4lsink or isink? as I konwn, isink has delay issue.

Re: mxc_v4l2_capture driver with gstreamer mfw_gst_v4lsrc fails at startup

normancheung — Mon, 28 Apr 2014 01:17:45 GMT

This issue seems to be fixed in the latest yocto master tree.

I merged the code in, and after running a few days, I have not seen any failure at startup yet. I looked at the code, it seems that a mutex lock is put in the Frame Buffer acquisition. That make sense, implying that the behavior I saweaking the timing was a deadlock situation.

Thanks