On Tue, Oct 13, 2020 at 11:03 AM Stanimir Varbanov <stanimir.varba...@linaro.org> wrote: > > Hi, > > On 7/2/20 2:52 PM, Stanimir Varbanov wrote: > > Hi, > > > > Once we have this event there is still open question how the client will > > know the data buffer on which the new colorspace is valid/applied. > > > > The options could be: > > * a new buffer flag and > > * some information in the v4l2_event structure. > > > > Thoughts? > > Kindly ping. >
The event itself sounds good to me, but how do we know which buffer is the first to have the new colorimetry? Best regards, Tomasz > > > > On 7/2/20 1:00 PM, Stanimir Varbanov wrote: > >> This event indicate that the source colorspace is changed > >> during run-time. The client has to retrieve the new colorspace > >> identifiers by getting the format (G_FMT). > >> > >> Signed-off-by: Stanimir Varbanov <stanimir.varba...@linaro.org> > >> --- > >> .../userspace-api/media/v4l/vidioc-dqevent.rst | 11 ++++++++++- > >> .../userspace-api/media/videodev2.h.rst.exceptions | 1 + > >> include/uapi/linux/videodev2.h | 1 + > >> 3 files changed, 12 insertions(+), 1 deletion(-) > >> > >> diff --git a/Documentation/userspace-api/media/v4l/vidioc-dqevent.rst > >> b/Documentation/userspace-api/media/v4l/vidioc-dqevent.rst > >> index a9a176d5256d..3f69c753db58 100644 > >> --- a/Documentation/userspace-api/media/v4l/vidioc-dqevent.rst > >> +++ b/Documentation/userspace-api/media/v4l/vidioc-dqevent.rst > >> @@ -381,7 +381,16 @@ call. > >> that many Video Capture devices are not able to recover from a > >> temporary > >> loss of signal and so restarting streaming I/O is required in order > >> for > >> the hardware to synchronize to the video signal. > >> - > >> + * - ``V4L2_EVENT_SRC_CH_COLORIMETRY`` > >> + - 0x0002 > >> + - This event gets triggered when a colorspace change is detected at > >> + an input. By colorspace change here we include also changes in the > >> + colorspace specifiers (transfer function, Y'CbCr encoding and > >> + quantization). This event can come from an input or from video > >> decoder. > >> + Once the event has been send to the client the driver has to update > >> + the colorspace specifiers internally so that they could be retrieved > >> by > >> + client. In that case queue re-negotiation is not needed as this change > >> + only reflects on the interpretation of the data. > >> > >> Return Value > >> ============ > >> diff --git a/Documentation/userspace-api/media/videodev2.h.rst.exceptions > >> b/Documentation/userspace-api/media/videodev2.h.rst.exceptions > >> index ca05e4e126b2..54fc21af852d 100644 > >> --- a/Documentation/userspace-api/media/videodev2.h.rst.exceptions > >> +++ b/Documentation/userspace-api/media/videodev2.h.rst.exceptions > >> @@ -492,6 +492,7 @@ replace define V4L2_EVENT_CTRL_CH_FLAGS > >> ctrl-changes-flags > >> replace define V4L2_EVENT_CTRL_CH_RANGE ctrl-changes-flags > >> > >> replace define V4L2_EVENT_SRC_CH_RESOLUTION src-changes-flags > >> +replace define V4L2_EVENT_SRC_CH_COLORIMETRY src-changes-flags > >> > >> replace define V4L2_EVENT_MD_FL_HAVE_FRAME_SEQ > >> :c:type:`v4l2_event_motion_det` > >> > >> diff --git a/include/uapi/linux/videodev2.h > >> b/include/uapi/linux/videodev2.h > >> index 303805438814..b5838bc4e3a3 100644 > >> --- a/include/uapi/linux/videodev2.h > >> +++ b/include/uapi/linux/videodev2.h > >> @@ -2351,6 +2351,7 @@ struct v4l2_event_frame_sync { > >> }; > >> > >> #define V4L2_EVENT_SRC_CH_RESOLUTION (1 << 0) > >> +#define V4L2_EVENT_SRC_CH_COLORIMETRY (1 << 1) > >> > >> struct v4l2_event_src_change { > >> __u32 changes; > >> > > > > -- > regards, > Stan