Re: [PATCH v2 4/9] media: uapi: Add a control for HANTRO driver

[Benjamin Gaignard]

Le 22/02/2021 à 17:16, John Cox a écrit :
> > The HEVC HANTRO driver needs to know the number of bits to skip at
> > the beginning of the slice header.
> > That is a hardware specific requirement so create a dedicated control
> > that this purpose.
> >
> > Signed-off-by: Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxxxxx>
> > ---
> > include/uapi/linux/hantro-v4l2-controls.h | 20 ++++++++++++++++++++
> > include/uapi/linux/v4l2-controls.h        |  5 +++++
> > 2 files changed, 25 insertions(+)
> > create mode 100644 include/uapi/linux/hantro-v4l2-controls.h
> >
> > diff --git a/include/uapi/linux/hantro-v4l2-controls.h b/include/uapi/linux/hantro-v4l2-controls.h
> > new file mode 100644
> > index 000000000000..30b1999b7af3
> > --- /dev/null
> > +++ b/include/uapi/linux/hantro-v4l2-controls.h
> > @@ -0,0 +1,20 @@
> > +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
> > +
> > +#ifndef __UAPI_HANTRO_V4L2_CONYTROLS_H__
> > +#define __UAPI_HANTRO_V4L2_CONYTROLS_H__
> > +
> > +#include <linux/v4l2-controls.h>
> > +#include <media/hevc-ctrls.h>
> > +
> > +#define V4L2_CID_HANTRO_HEVC_EXTRA_DECODE_PARAMS	(V4L2_CID_USER_HANTRO_BASE + 0)
> > +
> > +/**
> > + * struct hantro_hevc_extra_decode_params - extra decode parameters for hantro driver
> > + * @hevc_hdr_skip_lenght:	header first bits offset
> > + */
> > +struct hantro_hevc_extra_decode_params {
> > +	__u32	hevc_hdr_skip_lenght;
> > +	__u8	padding[4];
> > +};
> Can you clarify how hevc_hdr_skip_length differs from
> v4l2_ctrl_hevc_slice_params.data_bit_offset?  At first sight they would
> appear to be very similar.

hevc_hdr_skip_length is the difference between the start positions of 2 nals.
v4l2_ctrl_hevc_slice_params.data_bit_offset is the offset of the data in the nal.


Benjamin

> Regards
>
> John Cox
>
> > +#endif
> > diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
> > index 039c0d7add1b..ced7486c7f46 100644
> > --- a/include/uapi/linux/v4l2-controls.h
> > +++ b/include/uapi/linux/v4l2-controls.h
> > @@ -209,6 +209,11 @@ enum v4l2_colorfx {
> >   * We reserve 128 controls for this driver.
> >   */
> > #define V4L2_CID_USER_CCS_BASE			(V4L2_CID_USER_BASE + 0x10f0)
> > +/*
> > + * The base for HANTRO driver controls.
> > + * We reserve 32 controls for this driver.
> > + */
> > +#define V4L2_CID_USER_HANTRO_BASE		(V4L2_CID_USER_BASE + 0x1170)
> >
> > /* MPEG-class control IDs */
> > /* The MPEG controls are applicable to all codec controls