From: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
To: Jernej Skrabec <jernej.skrabec@siol.net>
Cc: devel@driverdev.osuosl.org, hverkuil@xs4all.nl,
gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
mripard@kernel.org, paul.kocialkowski@bootlin.com, wens@csie.org,
linux-arm-kernel@lists.infradead.org,
linux-media@vger.kernel.org
Subject: Re: [PATCH v2 1/4] media: uapi: hevc: Add scaling matrix control
Date: Wed, 8 Jan 2020 15:11:57 +0100 [thread overview]
Message-ID: <20200108151157.17cf9774@kernel.org> (raw)
In-Reply-To: <20191213160428.54303-2-jernej.skrabec@siol.net>
Em Fri, 13 Dec 2019 17:04:25 +0100
Jernej Skrabec <jernej.skrabec@siol.net> escreveu:
> HEVC has a scaling matrix concept. Add support for it.
> +struct v4l2_ctrl_hevc_scaling_matrix {
> + __u8 scaling_list_4x4[6][16];
> + __u8 scaling_list_8x8[6][64];
> + __u8 scaling_list_16x16[6][64];
> + __u8 scaling_list_32x32[2][64];
> + __u8 scaling_list_dc_coef_16x16[6];
> + __u8 scaling_list_dc_coef_32x32[2];
> +};
I never looked at HEVC spec, but the above seems really weird.
Please correct me if I am wrong, but each of the above matrixes
is independent, and the driver will use just one of the above on
any specific time (for a given video output node), right?
If so, why would userspace be forced to update lots of matrixes, if would
likely use just one at a given time?
IMO, the proper way would be, instead, to use an uAPI like:
/*
* Actually, as this is uAPI, we will use a fixed size integer type, like
* unsigned int
*/
enum hevc_scaling_matrix_type {
HEVC_SCALING_MATRIX_4x4,
HEVC_SCALING_MATRIX_8x8,
...
HEVC_SCALING_MATRIX_DC_COEF_32x32,
};
struct v4l2_ctrl_hevc_scaling_matrix {
__u32 scaling_type /* as defined by enum hevc_scaling_matrix_type */
union {
__u8 scaling_list_4x4[6][16];
__u8 scaling_list_8x8[6][64];
__u8 scaling_list_16x16[6][64];
__u8 scaling_list_32x32[2][64];
__u8 scaling_list_dc_coef_16x16[6];
__u8 scaling_list_dc_coef_32x32[2];
};
};
And let the core use a default for each scaling matrix, if userspace doesn't
set it.
Cheers,
Mauro
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next prev parent reply other threads:[~2020-01-08 14:12 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-13 16:04 [PATCH v2 0/4] media: cedrus: hevc: Add support for scaling matrix and multi-slice frames Jernej Skrabec
2019-12-13 16:04 ` [PATCH v2 1/4] media: uapi: hevc: Add scaling matrix control Jernej Skrabec
2020-01-08 14:11 ` Mauro Carvalho Chehab [this message]
2020-01-08 14:43 ` Paul Kocialkowski
2020-01-09 15:17 ` Jernej Škrabec
2020-01-09 15:19 ` Hans Verkuil
2019-12-13 16:04 ` [PATCH v2 2/4] media: cedrus: hevc: Add support for scaling matrix Jernej Skrabec
2020-01-07 15:01 ` Hans Verkuil
2020-01-07 17:10 ` Jernej Škrabec
2020-01-08 7:48 ` Hans Verkuil
2020-01-08 14:46 ` Hans Verkuil
2020-01-16 19:49 ` Jernej Škrabec
2019-12-13 16:04 ` [PATCH v2 3/4] media: uapi: hevc: Add segment address field Jernej Skrabec
2020-01-08 14:31 ` Mauro Carvalho Chehab
2020-01-09 14:46 ` Jernej Škrabec
2019-12-13 16:04 ` [PATCH v2 4/4] media: cedrus: hevc: Add support for multiple slices Jernej Skrabec
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