Re: Re: [PATCH v12 11/17] media: uapi: Add V4L2_CID_STATELESS_HEVC_ENTRY_POINT_OFFSETS control

[Jernej Škrabec]

Dne petek, 08. julij 2022 ob 18:00:24 CEST je Benjamin Gaignard napisal(a):
> Le 08/07/2022 à 16:02, Jernej Škrabec a écrit :
> > Hi Benjamin!
> > 
> > Dne petek, 08. julij 2022 ob 14:05:48 CEST je Benjamin Gaignard 
napisal(a):
> >> 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@xxxxxxxxxxxxx>
> >> Acked-by: Nicolas Dufresne <nicolas.dufresne@xxxxxxxxxxxxx>
> >> Tested-by: Jernej Skrabec <jernej.skrabec@xxxxxxxxx>
> >> ---
> >> version 12:
> >> - Reword num_entry_point_offsets documentation
> >> 
> >>   .../userspace-api/media/v4l/ext-ctrls-codec.rst     | 13 +++++++++++++
> >>   drivers/media/v4l2-core/v4l2-ctrls-defs.c           |  5 +++++
> >>   include/media/hevc-ctrls.h                          |  5 ++++-
> >>   3 files changed, 22 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..0cd967126fdf 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 +3155,14 @@ 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.
> > 
> > You forgot to update above description per Ezequiel comment.
> 
> No it was num_entry_point_offsets which was needed to be updated
> not this control.

Both needs to be updated. Ezequiel said:

"I would add Jernej's clarification about the length of the control
here, where the control is documented."

""
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.
""

Best regards,
Jernej

> 
> Regards,
> Benjamin
> 
> > Best regards,
> > Jernej
> > 
> >> +
> >> 
> >>   ``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;