Messages in this thread | | | Date | Wed, 16 Feb 2022 18:19:10 +0100 | Subject | Re: [RFC v2 7/8] media: uapi: Add V4L2_CID_STATELESS_HEVC_ENTRY_POINT_OFFSET control | From | Benjamin Gaignard <> |
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Le 16/02/2022 à 11:54, John Cox a écrit : > 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.
Would that means num_entry_point_offsets field in slice parameter control + one control for the entry points themselves ? or the both on slice parameter control (like now) ?
Regards Benjamin
> > Regards > > John Cox > >> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com> >> --- >> 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,
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