From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laurent Pinchart Subject: Re: [PATCH 1/2] media: media.h: Add a pad flag MEDIA_PAD_FL_METADATA Date: Thu, 26 Mar 2020 00:26:21 +0200 Message-ID: <20200325222621.GX19171@pendragon.ideasonboard.com> References: <20200325212704.29862-1-dafna.hirschfeld@collabora.com> <20200325212704.29862-2-dafna.hirschfeld@collabora.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Return-path: Content-Disposition: inline In-Reply-To: <20200325212704.29862-2-dafna.hirschfeld@collabora.com> Sender: linux-media-owner@vger.kernel.org To: Dafna Hirschfeld Cc: linux-media@vger.kernel.org, helen.koike@collabora.com, ezequiel@collabora.com, hverkuil@xs4all.nl, kernel@collabora.com, dafna3@gmail.com, sakari.ailus@linux.intel.com, linux-rockchip@lists.infradead.org, mchehab@kernel.org List-Id: linux-rockchip.vger.kernel.org Hi Dafna, Thank you for the patch. On Wed, Mar 25, 2020 at 10:27:03PM +0100, Dafna Hirschfeld wrote: > Add a flag to the flags field of 'struct media_pad_desc' > that indicates that the data transmitted by the pad is > metadata. > > Signed-off-by: Dafna Hirschfeld > --- > Documentation/media/uapi/mediactl/media-types.rst | 4 ++++ > include/uapi/linux/media.h | 1 + > 2 files changed, 5 insertions(+) > > diff --git a/Documentation/media/uapi/mediactl/media-types.rst b/Documentation/media/uapi/mediactl/media-types.rst > index 3af6a414b501..4ca902478971 100644 > --- a/Documentation/media/uapi/mediactl/media-types.rst > +++ b/Documentation/media/uapi/mediactl/media-types.rst > @@ -361,6 +361,7 @@ Types and flags used to represent the media graph elements > .. _MEDIA-PAD-FL-SINK: > .. _MEDIA-PAD-FL-SOURCE: > .. _MEDIA-PAD-FL-MUST-CONNECT: > +.. _MEDIA-PAD-FL-METADATA: > > .. flat-table:: Media pad flags > :header-rows: 0 > @@ -381,6 +382,9 @@ Types and flags used to represent the media graph elements > configuration dependent) for the pad to need enabled links even > when this flag isn't set; the absence of the flag doesn't imply > there is none. > + * - ``MEDIA_PAD_FL_METADATA`` > + - This flag indicates that the data transmitted by the pad is of > + type metadata. > > > One and only one of ``MEDIA_PAD_FL_SINK`` and ``MEDIA_PAD_FL_SOURCE`` > diff --git a/include/uapi/linux/media.h b/include/uapi/linux/media.h > index 383ac7b7d8f0..ae37226eb5c9 100644 > --- a/include/uapi/linux/media.h > +++ b/include/uapi/linux/media.h > @@ -210,6 +210,7 @@ struct media_entity_desc { > #define MEDIA_PAD_FL_SINK (1 << 0) > #define MEDIA_PAD_FL_SOURCE (1 << 1) > #define MEDIA_PAD_FL_MUST_CONNECT (1 << 2) > +#define MEDIA_PAD_FL_METADATA (1 << 3) I think we need to reserve a few bits here. We'll have more than metadata. Audio comes to mind, there will likely be more. Having independent flags would not only waste a bit of space in the bitfield (not that we're about to run out of bits, but still), but would make it possible to specify invalid configurations such as MEDIA_PAD_FL_METADATA | MEDIA_PAD_FL_AUDIO. And now that I've written this, I realize that audio metadata could be a thing, so maybe a metadata flag is actually the best option :-) There are pros and cons for both options, so I won't recommend one. > struct media_pad_desc { > __u32 entity; /* entity ID */ -- Regards, Laurent Pinchart