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@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,
