v4l2src does not support progressive interlacing

[Nicolas Dufresne]

Le ven. 19 oct. 2018 19 h 12, Tim Harvey <tharvey at gateworks.com> a écrit :

> On Fri, Oct 19, 2018 at 1:31 PM Tim Harvey <tharvey at gateworks.com> wrote:
> >
> > On Fri, Oct 19, 2018 at 11:57 AM Nicolas Dufresne <nicolas at ndufresne.ca>
> wrote:
> > >
> > > Le vendredi 19 octobre 2018 à 11:27 -0700, Tim Harvey a écrit :
> > > > On Thu, Oct 18, 2018 at 7:32 PM Nicolas Dufresne <
> > > > nicolas at ndufresne.ca> wrote:
> > > > >
> > > > > Hi Tim,
> > > > >
> > > > > this felt familiar, this issue was fixed for colorimetry recently.
> > > > > I
> > > > > have filed this issue and attached a patch. If you could give this
> > > > > patch a try to confirm it would be nice.
> > > > >
> > > > > https://bugzilla.gnome.org/show_bug.cgi?id=797306
> > > > >
> > > >
> > > > Nicolas,
> > > >
> > > > Thanks - I'm working on testing this but building gstreamer on my
> > > > target board is proving to be challenging. I gave up trying to
> > > > understand the gst-build option and am now trying to gst-uninstalled
> > > > option and stuck trying to figure out how to disable gl from
> > > > gst-plugins-base as that's failing to build. Hopefully I will have
> > > > some feedback after banging my head against the wall a bit more.
> > >
> > > Thanks, let me know, and don't harm yourself please ;-D
> > >
> >
> > Nicolas,
> >
> > Indeed your patch does resolve this issue of v4l2src failing to
> > negotiate my interlaced pipeline. Let me know if you need me to act on
> > the bug directly or anything else that is needed to get this upstream.
> >
>
> Nicolas,
>
> Sorry, I was mistaken. The patch didn't resolve the situation... I had
> an invalid build environment.
>
> With your patch:
> # media-ctl --get-v4l2 '"adv7180 2-0020":0'
>                 [fmt:UYVY8_2X8/720x240 at 1001/30000 field:alternate
> colorspace:smpte170m]
> # gst-launch-1.0 v4l2src device=/dev/video7 !
> video/x-raw,format=UYVY,interlace-mode=interleaved ! jpegenc !
> rtpjpegpay ! udpsink host=$SERVER port=5000
> Setting pipeline to PAUSED ...
> Pipeline is live and does not need PREROLL ...
> Setting pipeline to PLAYING ...
> New clock: GstSystemClock
> 0:00:00.644954667  7467  0x1ae3cc0 ERROR                   v4l2
> gstv4l2object.c:1942:gst_v4l2_object_get_interlace_mode: Unknown enum
> v4l2_field 6
> 0:00:00.645201000  7467  0x1ae3cc0 ERROR                   v4l2
> gstv4l2object.c:1942:gst_v4l2_object_get_interlace_mode: Unknown enum
> v4l2_field 6
> 0:00:00.645341334  7467  0x1ae3cc0 ERROR                   v4l2
> gstv4l2object.c:1942:gst_v4l2_object_get_interlace_mode: Unknown enum
> v4l2_field 6
> 0:00:00.645476667  7467  0x1ae3cc0 ERROR                   v4l2
> gstv4l2object.c:1942:gst_v4l2_object_get_interlace_mode: Unknown enum
> v4l2_field 6
>

V4l2 field 6 is V4L2_FIELD_SEQ_BT, which we never supported in GStreamer
V4L2. Though we used to let it stream. The following trace was misleading,
since the device does not really wants interleaved and you didn't request
progressive. Can you attach a trace when ran with environment
GST_DEBUG="v4l2*:7". That will give me more data to verify. I'll try and
improve the error, though I might not have enough time to enable
interlace-mode=field, as it's a bit complicated the way it's defined in
GStreamer (requires two video meta !). There is pending patches for
interlace-mode=alternate which is equally complex.

ERROR: from element /GstPipeline:pipeline0/GstV4l2Src:v4l2src0: Device
> '/dev/video7' does not support progressive interlacing
> Additional debug info:
> gstv4l2object.c(3838): gst_v4l2_object_set_format_full ():
> /GstPipeline:pipeline0/GstV4l2Src:v4l2src0:
> Device wants interleaved interlacing
> Execution ended after 0:00:00.004613334
> Setting pipeline to PAUSED ...
> Setting pipeline to READY ...
> Setting pipeline to NULL ...
> Freeing pipeline ...
>
> enabling gst-debug creates a massive slew of debug. Can you tell
> what's happening from the above?
>
> Tim
>
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