On Tue, 15 Feb 2022 12:01:02 +0100, you wrote:
>The number of 'entry point offset' could be very variable.
>Rather than use a large static array define a v4l2 dynamic array
>of integer control.
>The number of entry point offsets is reported by the elems field.
If we are going to support multiple slice headers in a single control
then we are going to need to know how to split these entries between
them as I assume that the entry point offset entries for all slice
headers would just be catenated here. You could add extra elements here
or generate a completely new control but I think it would be easier to
reinstate the num_entry_point_offsets field in the slice_params
structure (its a field that userpace has in its hand anyway so its no
effort for it to fill in). num_entry_point_offsets is a field that RPi
wants (without needing the entry points themselves) so that would help
me.
Regards
John Cox
>Signed-off-by: Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxxxxx>
>---
>version 2:
>- Define a new CID for entry point offsets parameters
> .../userspace-api/media/v4l/ext-ctrls-codec.rst | 9 +++++++++
> include/uapi/linux/v4l2-controls.h | 1 +
> 2 files changed, 10 insertions(+)
>
>diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
>index c3ae97657fa7..679595e94643 100644
>--- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
>+++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
>@@ -3101,6 +3101,15 @@ enum v4l2_mpeg_video_hevc_size_of_length_field -
>
> \normalsize
>
>+``V4L2_CID_STATELESS_HEVC_ENTRY_POINT_OFFSETS (integer)``
>+ Specifies the i-th entry point offset in bytes and is represented by
>+ offset_len_minus1 plus 1 bits.
>+ This control is a dynamically sized array. The number of entry point
>+ offsets is reported by the ``elems`` field.
>+ This bitstream parameter is defined according to :ref:`hevc`.
>+ They are described in section 7.4.7.1 "General slice segment header
>+ semantics" of the specification.
>+
> ``V4L2_CID_STATELESS_HEVC_SCALING_MATRIX (struct)``
> Specifies the HEVC scaling matrix parameters used for the scaling process
> for transform coefficients.
>diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
>index 27f5d272dc43..700e6cce958c 100644
>--- a/include/uapi/linux/v4l2-controls.h
>+++ b/include/uapi/linux/v4l2-controls.h
>@@ -2314,6 +2314,7 @@ struct v4l2_ctrl_vp9_compressed_hdr {
> #define V4L2_CID_STATELESS_HEVC_DECODE_PARAMS (V4L2_CID_CODEC_STATELESS_BASE + 404)
> #define V4L2_CID_STATELESS_HEVC_DECODE_MODE (V4L2_CID_CODEC_STATELESS_BASE + 405)
> #define V4L2_CID_STATELESS_HEVC_START_CODE (V4L2_CID_CODEC_STATELESS_BASE + 406)
>+#define V4L2_CID_STATELESS_HEVC_ENTRY_POINT_OFFSET (V4L2_CID_CODEC_STATELESS_BASE + 407)
>
> enum v4l2_stateless_hevc_decode_mode {
> V4L2_STATELESS_HEVC_DECODE_MODE_SLICE_BASED,
