AW: Displaying camera not working

Iñigo Huguet inigohuguet at fanamoel.com
Wed Apr 25 09:43:06 UTC 2018


Hi Dimitrios.

Sorry but I don't know how to do what you say, this is my first time 
with video processing and with gstreamer too.

What do you mean with the sprite data dump? How must I use 
rawvideoparse, can you tell me the pipeline command? How do I set the 
chromacities?

Thanks!


El 24/04/18 a las 16:41, Dimitrios Katsaros escribió:
> Another "easy" check is to use v4l2src num-buffers=1 ! fakesink dump=1 
> and check that the byte dump is equal to the sprite data dump
>
> On Tue, Apr 24, 2018 at 4:40 PM, Dimitrios Katsaros 
> <patcherwork at gmail.com <mailto:patcherwork at gmail.com>> wrote:
>
>     Just my 2 cents, if you are sure that you know that the data is
>     being read correctly you can use "rawvideoparse" to set the
>     correct caps of the buffers. It will also merge partial buffers,
>     so make sure you include the correct strides for the buffers and
>     also make sure the chromaticities for the buffers are set
>     correctly, otherwise you will get discoloration on the output.
>
>     On Tue, Apr 24, 2018 at 3:23 PM, Iñigo Huguet
>     <inigohuguet at fanamoel.com <mailto:inigohuguet at fanamoel.com>> wrote:
>
>         I don't have playbin2, but I do have playbin.
>
>         It doesn't work right now, I think it is because the driver
>         doesn't report correctly its available framesizes (width X
>         height). That's why I had to specify them with video/x-raw
>         width=720,height=576
>
>         There is any way to specify the framesize with playbin? If
>         not, I will try to fix the driver.
>
>
>         El 24/04/18 a las 12:45, Bernhard Graaf escribió:
>
>             Have you try to use playbin2 instead?
>             Something like 'gst-launch-1.0 playbin2
>             uri=v4l2:///dev/video1'.
>             If its works, have a look into the log and see what
>             playbin2 had done.
>
>             Bernhard
>
>             -----Ursprüngliche Nachricht-----
>             Von: gstreamer-devel
>             [mailto:gstreamer-devel-bounces at lists.freedesktop.org
>             <mailto:gstreamer-devel-bounces at lists.freedesktop.org>]
>             Im Auftrag von Iñigo Huguet
>             Gesendet: Dienstag, 24. April 2018 11:13
>             An: Antonio Ospite; gstreamer-devel at lists.freedesktop.org
>             <mailto:gstreamer-devel at lists.freedesktop.org>
>             Betreff: Re: Displaying camera not working
>
>             Hi.
>
>             I have gotten one frame as you told me
>
>             gst-launch-1.0 v4l2src num-buffers=1 device=/dev/video1 !
>             video/x-raw,format=NV12,width=720,height=576 ! filesink
>             location=raw_frame.bin
>
>             Then, in my computer, I converted it to png:
>
>             gst-launch-1.0 -v filesrc location=raw_frame.bin !
>             videoparse width=720
>             height=576 format=GST_VIDEO_FORMAT_NV12 ! videoconvert !
>             pngenc !
>             filesink location=raw_frame.png
>
>             I can see the .png image correctly, so it seems that the
>             driver outputs
>             NV12. What can I try now? Maybe I need any additional
>             plugin? (I'm using
>             a custom build using Buildroot so I don't have all plugins
>             installed)
>
>             El 23/04/18 a las 17:09, Antonio Ospite escribió:
>
>                 On Mon, 23 Apr 2018 16:26:42 +0200
>                 Iñigo Huguet <inigohuguet at fanamoel.com
>                 <mailto:inigohuguet at fanamoel.com>> wrote:
>
>                     I have managed to solve a problem: it seems that
>                     the sprite was not well
>                     reported by the driver (it said it was 1080
>                     instead of 720). Now I think
>                     it gives the correct values for a 720x576px NV12
>                     frame: sprite 720, size
>                     622080
>
>                     However, I still doesn't have a good output, and I
>                     don't know what to do
>                     to find what's wrong (I have no previous
>                     experience with video nor
>                     gstreamer).
>
>                     With this pipeline: gst-launch-1.0 v4l2src
>                     device=/dev/video1 !
>                     video/x-raw,format=NV12,width=720,
>                     height=576 ! videoconvert ! xvimagesink sync=false
>
>                     I only get an output with very colorful lines
>                     (almost horizontal lines).
>
>                     I attach the output of the driver and gstreamer with
>                     GST_DEBUG=*videosink*:6,*imagesink*:6,*v4l2*:6
>
>                     Any hint? Thanks!
>
>                 If you cannot trust the driver to report the correct
>                 data format (I am
>                 thinking to the pixelformat in particular), then
>                 GStreamer videoconvert
>                 won't be able to use the caps in any meaningful way.
>
>                 You could analyze a raw frame to confirm that it's
>                 actually NV12.
>
>                 A sample pipeline which (hopefully) dumps one frame is:
>
>                     gst-launch-1.0 v4l2src num-buffers=1
>                 device=/dev/video1 ! filesink
>
>             location=raw_frame.bin
>
>                 Upload the raw data somewhere and maybe someone will
>                 take a look
>                 if they have time.
>
>                 Ciao,
>                      Antonio
>
>             _______________________________________________
>             gstreamer-devel mailing list
>             gstreamer-devel at lists.freedesktop.org
>             <mailto:gstreamer-devel at lists.freedesktop.org>
>             https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel
>             <https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel>
>
>             _______________________________________________
>             gstreamer-devel mailing list
>             gstreamer-devel at lists.freedesktop.org
>             <mailto:gstreamer-devel at lists.freedesktop.org>
>             https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel
>             <https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel>
>
>
>         _______________________________________________
>         gstreamer-devel mailing list
>         gstreamer-devel at lists.freedesktop.org
>         <mailto:gstreamer-devel at lists.freedesktop.org>
>         https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel
>         <https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel>
>
>
>
>
>
> _______________________________________________
> gstreamer-devel mailing list
> gstreamer-devel at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/gstreamer-devel/attachments/20180425/74e0061d/attachment.html>


More information about the gstreamer-devel mailing list