need help to understand the pipeline

[Peter Maersk-Moller]

Well I can't see how you full system is put together, but I can see than
one of the link you send is using CSI used to take in a camera feed
somewhat raw. And the other link lists it supports the following formats:

   -

   support for output formats: *RAW RGB, RGB565/555/444, CCIR656,
   YUV422/420, YCbCr422*, and compression


Plenty of support for raw formats. Furthermore your output from GStreamer
suggests your output (source of v4l2src) outputs YUY2. So the v4l2src
modules gets data and outputs raw video in the format YUY2. This is similar
in quality to a Y422 og Y42B. This is better than I420 as it has twice as
many bytes for colour information. While I420 is often for consumer
products, your format is what is usually used for Prosumer. A compromise
between  cosumer and professionel level. This is good so what is the
problem? Why do you think you have a problem?

That said, apparently the video encoder wants a nv12  comparable to I420
(consumer level). Videoconvert converts and encodes the result. If you want
better result, check if the encoder can support higher quality inputs. But
that's outside the scope of your question. Fact is, you are not using
JPEG/MJPEG and that is often a good thing depending oin what you want. So
what is the problem?

Best regardd

Peter


On Fri, Jul 16, 2021 at 4:14 PM niXman via gstreamer-devel <
gstreamer-devel at lists.freedesktop.org> wrote:

>
> hello!
>
>
> > Assuming your pipeline actually runs, I can assure you that your
> > videoconvert does not take jpeg as input and you have specified
> > video/x-raw
> > as format (a family of raw formats). So v4l2src does output raw video
> > and
> > not JPEG.
>
> if this is the case, should I receive frames of size W * H *
> BITS_FOR_PIXEL bytes?
>
> > Now I don't know your platform and maybe your v4l2src
> > implementation has the ability to read JPEG/MJPEG from the camera and
> > convert it to raw video on your specific hardware platform, but as
> > such,
> > you have no JPEG in your pipeline. And I am assuming your pipeline is
> > running. Is it?
>
> link for the cam:
>
> https://eu.mouser.com/ProductDetail/SMART-Wireless-Computing/ACC-1H10-00-P3?qs=%2Fha2pyFaduhBYc1JrwWqtHuacCzXw%2FJje6%2FvUrFj3%252BPWtt5afRW%2Fbw%3D%3D
>
> and link for the chip it uses (page 80):
>
> https://cdn.sparkfun.com/datasheets/Sensors/LightImaging/OV5640_datasheet.pdf
>
> I don’t understand who to believe?
> and how to understand what exactly the camera gives?
>
> if the camera actually sends uncompressed YUV, then each frame must be
> 5MP * 12 = 60Mbit per frame? really?
>
>
> > Now run your pipeline again with the '-v' flag set for gst-launch-1.0
> > pipeline and post ALL the output here. We can then identify what each
> > module take as input and what they output.
>
> sure:
>
> /GstPipeline:pipeline0/GstV4l2Src:v4l2src0.GstPad:src: caps =
> video/x-raw, width=(int)1280, height=(int)800, framerate=(fraction)10/1,
> interlace-mode=(string)progressive, format=(string)YUY2,
> pixel-aspect-ratio=(fraction)1/1, colorimetry=(string)bt709
>
> /GstPipeline:pipeline0/GstCapsFilter:capsfilter0.GstPad:src: caps =
> video/x-raw, width=(int)1280, height=(int)800, framerate=(fraction)10/1,
> interlace-mode=(string)progressive, format=(string)YUY2,
> pixel-aspect-ratio=(fraction)1/1, colorimetry=(string)bt709
>
> /GstPipeline:pipeline0/GstVideoConvert:videoconvert0.GstPad:src: caps =
> video/x-raw, width=(int)1280, height=(int)800, framerate=(fraction)10/1,
> interlace-mode=(string)progressive, pixel-aspect-ratio=(fraction)1/1,
> format=(string)NV12, colorimetry=(string)bt601
>
> /GstPipeline:pipeline0/v4l2h264enc:v4l2h264enc0.GstPad:src: caps =
> video/x-h264, stream-format=(string)byte-stream, alignment=(string)au,
> profile=(string)high, level=(string)1, width=(int)1280, height=(int)800,
> pixel-aspect-ratio=(fraction)1/1, framerate=(fraction)10/1,
> interlace-mode=(string)progressive, colorimetry=(string)bt601
>
> /GstPipeline:pipeline0/GstH264Parse:h264parse0.GstPad:sink: caps =
> video/x-h264, stream-format=(string)byte-stream, alignment=(string)au,
> profile=(string)high, level=(string)1, width=(int)1280, height=(int)800,
> pixel-aspect-ratio=(fraction)1/1, framerate=(fraction)10/1,
> interlace-mode=(string)progressive, colorimetry=(string)bt601
>
>
> thanks!
>
> best!
> _______________________________________________
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> gstreamer-devel at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/gstreamer-devel
>
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