[PATCH v11 11/17] media: uapi: Add V4L2_CID_STATELESS_HEVC_ENTRY_POINT_OFFSETS control

[Benjamin Gaignard]

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 at collabora.com>
Acked-by: Nicolas Dufresne <nicolas.dufresne at collabora.com>
Tested-by: Jernej Skrabec <jernej.skrabec at gmail.com>
---
version 11:
- Be more verbose about num_entry_point_offsets field usage.

 .../userspace-api/media/v4l/ext-ctrls-codec.rst   | 15 +++++++++++++++
 drivers/media/v4l2-core/v4l2-ctrls-defs.c         |  5 +++++
 include/media/hevc-ctrls.h                        |  5 ++++-
 3 files changed, 24 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..59e751c38d06 100644
--- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
+++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
@@ -3010,6 +3010,13 @@ 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.
+        This field must be set even if V4L2_CID_STATELESS_HEVC_ENTRY_POINT_OFFSETS
+        control isn't used. Additionally, if entry point offsets control is needed
+        and if submitting multiple slices at once, length of entry point offsets
+        array must be sum of num_entry_point_offsets of all slices in that job.
     * - __u8
       - ``nal_unit_type``
       - Specifies the coding type of the slice (B, P or I).
@@ -3150,6 +3157,14 @@ 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.
+
 ``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;
-- 
2.32.0