[PATCH v6 09/17] media: uapi: HEVC: Define V4L2_CID_STATELESS_HEVC_SLICE_PARAMS as a dynamic array

[Jernej Škrabec]

Dne nedelja, 29. maj 2022 ob 11:19:12 CEST je Jernej Škrabec napisal(a):
> Dne petek, 27. maj 2022 ob 16:31:26 CEST je Benjamin Gaignard napisal(a):
> > Make explicit that V4L2_CID_STATELESS_HEVC_SLICE_PARAMS control is
> > a dynamic array control type.
> > Some drivers may be able to receive multiple slices in one control
> > to improve decoding performance.
> > 
> > Define the max size of the dynamic that can driver can set in .dims = {}.
> > 
> > Signed-off-by: Benjamin Gaignard <benjamin.gaignard at collabora.com>
> > ---
> > version 6:
> > - Set V4L2_CTRL_FLAG_DYNAMIC_ARRAY flag automatically when using
> >   V4L2_CID_STATELESS_HEVC_SLICE_PARAMS control.
> > - Add a define for max slices count
> > 
> >  Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst | 2 ++
> >  drivers/media/v4l2-core/v4l2-ctrls-defs.c                 | 1 +
> >  include/media/hevc-ctrls.h                                | 5 +++++
> >  3 files changed, 8 insertions(+)
> > 
> > diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst b/
> Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
> > index 06b967de140c..0796b1563daa 100644
> > --- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
> > +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
> > @@ -2986,6 +2986,8 @@ enum v4l2_mpeg_video_hevc_size_of_length_field -
> >      These bitstream parameters are defined according to :ref:`hevc`.
> >      They are described in section 7.4.7 "General slice segment header
> >      semantics" of the specification.
> > +    This control is a dynamically sized 1-dimensional array,
> > +    V4L2_CTRL_FLAG_DYNAMIC_ARRAY flag must be set when using it.
> >  
> >  .. c:type:: v4l2_ctrl_hevc_slice_params
> >  
> > diff --git a/drivers/media/v4l2-core/v4l2-ctrls-defs.c b/drivers/media/
v4l2-
> core/v4l2-ctrls-defs.c
> > index 9f55503cd3d6..d594efbcbb93 100644
> > --- a/drivers/media/v4l2-core/v4l2-ctrls-defs.c
> > +++ b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
> > @@ -1510,6 +1510,7 @@ void v4l2_ctrl_fill(u32 id, const char **name, enum 
> v4l2_ctrl_type *type,
> >  		break;
> >  	case V4L2_CID_STATELESS_HEVC_SLICE_PARAMS:
> >  		*type = V4L2_CTRL_TYPE_HEVC_SLICE_PARAMS;
> > +		*flags |= V4L2_CTRL_FLAG_DYNAMIC_ARRAY;
> 
> This change breaks Cedrus. I'll check what needs to be changed.

Please include the change bellow to keep Cedrus working. I'll expand support 
for more slices later.

 Best regards,
 Jernej

--- a/drivers/staging/media/sunxi/cedrus/cedrus.c
+++ b/drivers/staging/media/sunxi/cedrus/cedrus.c
@@ -178,6 +178,7 @@ static const struct cedrus_control cedrus_controls[] = {
        {
                .cfg = {
                        .id     = V4L2_CID_STATELESS_HEVC_SLICE_PARAMS,
+                       .dims   = { 1 },
                },
                .codec          = CEDRUS_CODEC_H265,
        },
 
> >  		break;
> >  	case V4L2_CID_STATELESS_HEVC_SCALING_MATRIX:
> >  		*type = V4L2_CTRL_TYPE_HEVC_SCALING_MATRIX;
> > diff --git a/include/media/hevc-ctrls.h b/include/media/hevc-ctrls.h
> > index 0dbd5d681c28..140151609c96 100644
> > --- a/include/media/hevc-ctrls.h
> > +++ b/include/media/hevc-ctrls.h
> > @@ -311,9 +311,14 @@ struct v4l2_hevc_pred_weight_table {
> >  #define 
V4L2_HEVC_SLICE_PARAMS_FLAG_SLICE_LOOP_FILTER_ACROSS_SLICES_ENABLED 
> (1ULL << 8)
> >  #define V4L2_HEVC_SLICE_PARAMS_FLAG_DEPENDENT_SLICE_SEGMENT	(1ULL << 
> 9)
> >  
> > +#define V4L2_HEVC_SLICE_MAX_COUNT	600
> > +
> >  /**
> >   * v4l2_ctrl_hevc_slice_params - HEVC slice parameters
> >   *
> > + * This control is a dynamically sized 1-dimensional array,
> > + * V4L2_CTRL_FLAG_DYNAMIC_ARRAY flag must be set when using it.
> > + *
> >   * @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
> >   * @nal_unit_type: specifies the coding type of the slice (B, P or I)
> > -- 
> > 2.32.0
> > 
> > 
> 
> 
>