From: Simon Ser <contact@emersion.fr>
To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: dri-devel@lists.freedesktop.org,
Pekka Paalanen <ppaalanen@gmail.com>,
Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>,
Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
Maxime Ripard <mripard@kernel.org>,
Thomas Zimmermann <tzimmermann@suse.de>,
David Airlie <airlied@gmail.com>, Simona Vetter <simona@ffwll.ch>,
Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>,
Daniel Stone <daniel@fooishbar.org>
Subject: Re: [PATCH] drm/fourcc: document format naming scheme
Date: Sun, 26 Apr 2026 16:59:19 +0000 [thread overview]
Message-ID: <XUz08zbEN3acyjqze6qP6M8Mx2WdKet8WU6eVe9vF2XMr7vlYxEXNAy7qfbmi6V3STr5sLeU0Ew6_9MCm7VQFxHZg8zznLQ8etKUVbi-dLI=@emersion.fr> (raw)
In-Reply-To: <20260426164739.GE2964234@killaraus.ideasonboard.com>
On Sunday, April 26th, 2026 at 18:47, Laurent Pinchart <laurent.pinchart@ideasonboard.com> wrote:
> > + * Memory layout is always described in little-endian order.
>
> This sentence may be a bit vague, especially given that we have the
> DRM_FORMAT_BIG_ENDIAN() macro.
Right, that macro is almost never used… I see it only used for
XRGB1555 and RGB565. Someone recommended against using it, I don't
remember who.
See also:
* Note that the DRM_FORMAT_BIG_ENDIAN flag should only be used in
* case the format can't be specified otherwise, so we don't end up
* with two values describing the same format.
> > + * - The first digit indicates chroma sub-sampling: 0 for 2x2, 2 for 2x1, 4 for
> > + * none.
>
> We also have 4x4 and 4x1 sub-sampled formats, it would be good to
> document them.
Yeah, but these use a completely different scheme, like the NV family.
And then there's single-plane YUV formats, which are just the wild west.
Not sure how to document all of that…
next prev parent reply other threads:[~2026-04-26 16:59 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-26 15:16 [PATCH] drm/fourcc: document format naming scheme Simon Ser
2026-04-26 16:47 ` Laurent Pinchart
2026-04-26 16:59 ` Simon Ser [this message]
2026-04-28 5:16 ` Claude review: " Claude Code Review Bot
2026-04-28 5:16 ` Claude Code Review Bot
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='XUz08zbEN3acyjqze6qP6M8Mx2WdKet8WU6eVe9vF2XMr7vlYxEXNAy7qfbmi6V3STr5sLeU0Ew6_9MCm7VQFxHZg8zznLQ8etKUVbi-dLI=@emersion.fr' \
--to=contact@emersion.fr \
--cc=airlied@gmail.com \
--cc=daniel@fooishbar.org \
--cc=dmitry.baryshkov@oss.qualcomm.com \
--cc=dri-devel@lists.freedesktop.org \
--cc=laurent.pinchart@ideasonboard.com \
--cc=maarten.lankhorst@linux.intel.com \
--cc=mripard@kernel.org \
--cc=ppaalanen@gmail.com \
--cc=simona@ffwll.ch \
--cc=tomi.valkeinen@ideasonboard.com \
--cc=tzimmermann@suse.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox