[PATCH v13 11/17] media: uapi: Add V4L2_CID_STATELESS_HEVC_ENTRY_POINT_OFFSETS control

Benjamin Gaignard
2022-07-08T16:27:39Z

The number of 'entry point offset' can be very variable.
Instead of using a large static array define a v4l2 dynamic array
of U32 (V4L2_CTRL_TYPE_U32).
The number of entry point offsets is reported by the elems field
and in struct v4l2_ctrl_hevc_slice_params.num_entry_point_offsets
field.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
Acked-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Tested-by: Jernej Skrabec <jernej.skrabec@gmail.com>
---
version 13:
- Reword num_entry_point_offsets field and control usage (yes, again)

.../userspace-api/media/v4l/ext-ctrls-codec.rst | 16 ++++++++++++++++
drivers/media/v4l2-core/v4l2-ctrls-defs.c | 5 +++++
include/media/hevc-ctrls.h | 5 ++++-
3 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
index c2e0adece613..c05c5553f0e3 100644
--- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
+++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
@@ -3010,6 +3010,11 @@ enum v4l2_mpeg_video_hevc_size_of_length_field -
* - __u32
- ``data_bit_offset``
- Offset (in bits) to the video data in the current slice data.
+ * - __u32
+ - ``num_entry_point_offsets``
+ - Specifies the number of entry point offset syntax elements in the slice header.
+ When the driver supports it, the ``V4L2_CID_STATELESS_HEVC_ENTRY_POINT_OFFSETS``
+ must be set.
* - __u8
- ``nal_unit_type``
- Specifies the coding type of the slice (B, P or I).
@@ -3150,6 +3155,17 @@ enum v4l2_mpeg_video_hevc_size_of_length_field -

\normalsize

+``V4L2_CID_STATELESS_HEVC_ENTRY_POINT_OFFSETS (integer)``
+ Specifies entry point offsets in bytes.
+ 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.
+ When multiple slices are submitted in a request, the length of
+ this array must be the sum of num_entry_point_offsets of all the
+ slices in the request.
+
``V4L2_CID_STATELESS_HEVC_SCALING_MATRIX (struct)``
Specifies the HEVC scaling matrix parameters used for the scaling process
for transform coefficients.
diff --git a/drivers/media/v4l2-core/v4l2-ctrls-defs.c b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
index d594efbcbb93..e22921e7ea61 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls-defs.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
@@ -1188,6 +1188,7 @@ const char *v4l2_ctrl_get_name(u32 id)
case V4L2_CID_STATELESS_HEVC_DECODE_PARAMS: return "HEVC Decode Parameters";
case V4L2_CID_STATELESS_HEVC_DECODE_MODE: return "HEVC Decode Mode";
case V4L2_CID_STATELESS_HEVC_START_CODE: return "HEVC Start Code";
+ case V4L2_CID_STATELESS_HEVC_ENTRY_POINT_OFFSETS: return "HEVC Entry Point Offsets";

/* Colorimetry controls */
/* Keep the order of the 'case's the same as in v4l2-controls.h! */
@@ -1518,6 +1519,10 @@ void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
case V4L2_CID_STATELESS_HEVC_DECODE_PARAMS:
*type = V4L2_CTRL_TYPE_HEVC_DECODE_PARAMS;
break;
+ case V4L2_CID_STATELESS_HEVC_ENTRY_POINT_OFFSETS:
+ *type = V4L2_CTRL_TYPE_U32;
+ *flags |= V4L2_CTRL_FLAG_DYNAMIC_ARRAY;
+ break;
case V4L2_CID_STATELESS_VP9_COMPRESSED_HDR:
*type = V4L2_CTRL_TYPE_VP9_COMPRESSED_HDR;
break;
diff --git a/include/media/hevc-ctrls.h b/include/media/hevc-ctrls.h
index a372c184689e..3a6601a46ced 100644
--- a/include/media/hevc-ctrls.h
+++ b/include/media/hevc-ctrls.h
@@ -20,6 +20,7 @@
#define V4L2_CID_STATELESS_HEVC_DECODE_PARAMS (V4L2_CID_CODEC_BASE + 1012)
#define V4L2_CID_STATELESS_HEVC_DECODE_MODE (V4L2_CID_CODEC_BASE + 1015)
#define V4L2_CID_STATELESS_HEVC_START_CODE (V4L2_CID_CODEC_BASE + 1016)
+#define V4L2_CID_STATELESS_HEVC_ENTRY_POINT_OFFSETS (V4L2_CID_CODEC_BASE + 1017)

/* enum v4l2_ctrl_type type values */
#define V4L2_CTRL_TYPE_HEVC_SPS 0x0120
@@ -316,6 +317,8 @@ struct v4l2_hevc_pred_weight_table {
*
* @bit_size: size (in bits) of the current slice data
* @data_bit_offset: offset (in bits) to the video data in the current slice data
+ * @num_entry_point_offsets: specifies the number of entry point offset syntax
+ * elements in the slice header.
* @nal_unit_type: specifies the coding type of the slice (B, P or I)
* @nuh_temporal_id_plus1: minus 1 specifies a temporal identifier for the NAL unit
* @slice_type: see V4L2_HEVC_SLICE_TYPE_{}
@@ -358,7 +361,7 @@ struct v4l2_hevc_pred_weight_table {
struct v4l2_ctrl_hevc_slice_params {
__u32 bit_size;
__u32 data_bit_offset;
-
+ __u32 num_entry_point_offsets;
/* ISO/IEC 23008-2, ITU-T Rec. H.265: NAL unit header */
__u8 nal_unit_type;
__u8 nuh_temporal_id_plus1;