Re: [PATCH v4 04/12] v4l: Add source event change for bit-depth
From: Hans Verkuil <hidden>
Date: 2020-01-08 16:09:41
Also in:
linux-arm-msm, linux-media, lkml
On 1/6/20 4:49 PM, Stanimir Varbanov wrote:
quoted hunk ↗ jump to hunk
This event indicate that the source color bit-depth is changed during run-time. The client must get the new format and re-allocate buffers for it. This can usually happens with video decoder (encoders) when the bit-stream color bit-depth is changed from 8 to 10bits or vice versa. Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by: Stanimir Varbanov <redacted> --- Documentation/media/uapi/v4l/vidioc-dqevent.rst | 8 +++++++- Documentation/media/videodev2.h.rst.exceptions | 1 + include/uapi/linux/videodev2.h | 1 + 3 files changed, 9 insertions(+), 1 deletion(-)diff --git a/Documentation/media/uapi/v4l/vidioc-dqevent.rst b/Documentation/media/uapi/v4l/vidioc-dqevent.rst index 42659a3d1705..fad853d440cf 100644 --- a/Documentation/media/uapi/v4l/vidioc-dqevent.rst +++ b/Documentation/media/uapi/v4l/vidioc-dqevent.rst@@ -402,7 +402,13 @@ 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_COLOR_DEPTH`` + - 0x0002 + - This event gets triggered when color bit-depth change is detected + from a video decoder. Applications will have to query the new pixel + format and re-negotiate the queue. In most cases the streaming must be + stopped and restarted (:ref:`VIDIOC_STREAMOFF <VIDIOC_STREAMON>` + followed by :ref:`VIDIOC_STREAMON <VIDIOC_STREAMON>`).
I think this is too specific for decoders. Something similar to the
CH_RESOLUTION description would be more appropriate:
- This event gets triggered when a color bit-depth change (but not a
resolution change!) is detected at an input. This can come from an
input connector or from a video decoder. Applications will have to query
the new pixel format and re-negotiate the queue.
For stateful decoders follow the guidelines in :ref:`decoder`.
Video capture devices will in most cases have to stop and restart
streaming (:ref:`VIDIOC_STREAMOFF <VIDIOC_STREAMON>` followed by
:ref:`VIDIOC_STREAMON <VIDIOC_STREAMON>`).
And update dev-decoder.rst where needed with this new event flag.
As to your question on irc: once I've acked this patch it can be merged
via a venus PR.
Regards,
Hans
quoted hunk ↗ jump to hunk
Return Value ============diff --git a/Documentation/media/videodev2.h.rst.exceptions b/Documentation/media/videodev2.h.rst.exceptions index cb6ccf91776e..209709114378 100644 --- a/Documentation/media/videodev2.h.rst.exceptions +++ b/Documentation/media/videodev2.h.rst.exceptions@@ -490,6 +490,7 @@ 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_COLOR_DEPTH 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 5f9357dcb060..1d349c9d57a7 100644 --- a/include/uapi/linux/videodev2.h +++ b/include/uapi/linux/videodev2.h@@ -2332,6 +2332,7 @@ struct v4l2_event_frame_sync { }; #define V4L2_EVENT_SRC_CH_RESOLUTION (1 << 0) +#define V4L2_EVENT_SRC_CH_COLOR_DEPTH (1 << 1) struct v4l2_event_src_change { __u32 changes;