[libcamera-devel] [PATCH v6 0/1] Provide multiple colorimetry for libcamerasrc.

[Rishikesh Donadkar]

Hello Umang,
> The test number results #2 and #3 have same initial colorimetry members
> (sRGB, bt601,...) , so should be parsed in the same way, how come one
> fails at bt601 and other one doesn't at bt601 ?

bt601  translates to 2:4:5:4 after conversion to colorspace,
validation and conversion back to colorimetry at the time of exposing
caps. Gstreamer checks if the colorimetry that we are exposing is
among the ones present in the colorimetry list, In case#3 Since
2:4:5:4 is present in the colorimetry list, negotiation is a success.

> As mentioned earlier. bt601 doesn't have 1:1 mapping to the kernel
> colorspace[1], hence we need to look at it separately. I would avoid
> using that as the same for testing it, until we assess the scope of that
> work.

Noted.

Regards,
Rishikesh Donadkar


On Mon, Sep 19, 2022 at 11:15 AM Umang Jain <umang.jain at ideasonboard.com> wrote:
>
> Hi Rishi,
>
> Thank you for the test results
>
> On 9/19/22 8:27 AM, Rishikesh Donadkar wrote:
> > GStreamer pipeline supports passing multiple colorimetry as a comma
> > separated list.
> >
> > For Example :
> >
> > gst-launch-1.0 libcamerasrc ! "video/x-raw,colorimetry={bt2020,bt709,sRGB}" ! glimagesink
> >
> > In this case, if supported by the camera one of bt2020, bt709, sRGB
> > should be applied.
> >
> > This series aims to adds multiple colorimetry support to the libcamera
> > gstreamer element.
> >
> > ---
> > changes from v1 to v2:
> > - Moved the function colorspace_from_colorimetry() from PATCH 1/2 to
> >    PATCH 2/2.
> >
> > changes from v2 to v3:
> > - Rebase on top of [v3 PATCH 4/4] gstreamer: Provide colorimetry <> ColorSpace mappings.
> > - Use the comparator utility function gst_video_colorimetry_is_equal()
> >    to cut down code.
> > - Rename dup_stream_cfg to pristine_stream_cfg.
> > - Log the colorimetry that is selected from the list.
> > - Change the API for the function gst_libcamera_configure_stream_from_caps()
> >    to pass pass state->config_ here instead of taking it in a holder
> >    variable reference.
> >
> > changes from v3 to v4:
> > - Discard the approach form expanding the colorimetry list through caps
> >    normalization. Instead enumerate the colorimetry list and try out the
> >    colorimetry.
> > - Add error checking for invalid colorimetry.
> >
> > changes for v4 to v5:
> > - Use gboolean instead of int. Return true/false.
> > - Add else if for the mutually exclusive conditions.
> > - Add final else to trace if anything other than a string or a list is
> >    passed in the colorimetry field by the user.
> >
> > changes from v5 to v6:
> > - Compare colorspace instead of colorimetry, this will reduce the
> >    colorimetry<->colorspace conversion.
> > - Compare the colorspace applied directly with the colorimetry requested
> >    in the caps.
> > ---
> >
> > ----
> > Test results(on RPi 4 + OV5647):
> > gst-launch-1.0 libcamerasrc ! "video/x-raw,colorimetry={bt2020,bt709,sRGB}" ! glimagesink
> > Selected colorimetry bt709
> >
> > gst-launch-1.0 libcamerasrc ! "video/x-raw,colorimetry={sRGB,bt601,bt2020,bt709}" ! glimagesink
> > Negotiation fails on bt601.
> >
> > gst-launch-1.0 libcamerasrc ! "video/x-raw,colorimetry={sRGB,bt601,bt2020,bt709,2:4:5:4}" ! glimagesink
> > Selected colorimetry bt601.
>
> This is confusing, are you sure this isn't a typo?
>
> The test number results #2 and #3 have same initial colorimetry members
> (sRGB, bt601,...) , so should be parsed in the same way, how come one
> fails at bt601 and other one doesn't at bt601 ?
>
> As mentioned earlier. bt601 doesn't have 1:1 mapping to the kernel
> colorspace[1], hence we need to look at it separately. I would avoid
> using that as the same for testing it, until we assess the scope of that
> work.
>
> [1]
> https://gitlab.freedesktop.org/gstreamer/gst-plugins-base/-/merge_requests/724/diffs
> >
> > gst-launch-1.0 libcamerasrc ! "video/x-raw,colorimetry={sRGB,bt709,bt2020,bt601}" ! glimagesink
> > Selected colorimetry bt709
> > ----
> >
> > Rishikesh Donadkar (1):
> >    gstreamer: Provide multiple colorimetry support for libcamerasrc
> >
> >   src/gstreamer/gstlibcamera-utils.cpp | 49 +++++++++++++++++++++++-----
> >   src/gstreamer/gstlibcamera-utils.h   |  4 ++-
> >   src/gstreamer/gstlibcamerasrc.cpp    |  2 +-
> >   3 files changed, 44 insertions(+), 11 deletions(-)
> >
>