From patchwork Tue Apr 3 21:15:43 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luca Ceresoli X-Patchwork-Id: 48361 X-Patchwork-Delegate: hverkuil@xs4all.nl Received: from vger.kernel.org ([209.132.180.67]) by www.linuxtv.org with esmtp (Exim 4.84_2) (envelope-from ) id 1f3TIK-00075D-TT; Tue, 03 Apr 2018 21:16:45 +0000 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753499AbeDCVQC (ORCPT + 1 other); Tue, 3 Apr 2018 17:16:02 -0400 Received: from srv-hp10-72.netsons.net ([94.141.22.72]:45253 "EHLO srv-hp10-72.netsons.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752525AbeDCVQA (ORCPT ); Tue, 3 Apr 2018 17:16:00 -0400 Received: from [146.241.135.18] (port=564 helo=yard.fritz.box) by srv-hp10.netsons.net with esmtpa (Exim 4.89_1) (envelope-from ) id 1f3THY-0029LL-53; Tue, 03 Apr 2018 23:15:56 +0200 From: Luca Ceresoli To: linux-media@vger.kernel.org Cc: Mauro Carvalho Chehab , linux-kernel@vger.kernel.org, Luca Ceresoli , Hans Verkuil Subject: [PATCH 2/5] media: docs: clarify relationship between crop and selection APIs Date: Tue, 3 Apr 2018 23:15:43 +0200 Message-Id: <1522790146-16061-2-git-send-email-luca@lucaceresoli.net> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1522790146-16061-1-git-send-email-luca@lucaceresoli.net> References: <1522790146-16061-1-git-send-email-luca@lucaceresoli.net> X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - srv-hp10.netsons.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - lucaceresoli.net X-Get-Message-Sender-Via: srv-hp10.netsons.net: authenticated_id: luca+lucaceresoli.net/only user confirmed/virtual account not confirmed X-Authenticated-Sender: srv-hp10.netsons.net: luca@lucaceresoli.net X-Source: X-Source-Args: X-Source-Dir: Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Having two somewhat similar and largely overlapping APIs is confusing, especially since the older one appears in the docs before the newer and most featureful counterpart. Clarify all of this in several ways: - swap the two sections - give a name to the two APIs in the section names - add a note at the beginning of the CROP API section Also remove a note that is incorrect (correct wording is in vidioc-cropcap.rst). Signed-off-by: Luca Ceresoli Based on info from: Hans Verkuil Cc: Hans Verkuil --- Documentation/media/uapi/v4l/common.rst | 2 +- Documentation/media/uapi/v4l/crop.rst | 21 ++++++++++++--------- Documentation/media/uapi/v4l/selection-api-005.rst | 2 ++ Documentation/media/uapi/v4l/selection-api.rst | 4 ++-- 4 files changed, 17 insertions(+), 12 deletions(-) diff --git a/Documentation/media/uapi/v4l/common.rst b/Documentation/media/uapi/v4l/common.rst index 13f2ed3fc5a6..5f93e71122ef 100644 --- a/Documentation/media/uapi/v4l/common.rst +++ b/Documentation/media/uapi/v4l/common.rst @@ -41,6 +41,6 @@ applicable to all devices. extended-controls format planar-apis - crop selection-api + crop streaming-par diff --git a/Documentation/media/uapi/v4l/crop.rst b/Documentation/media/uapi/v4l/crop.rst index 182565b9ace4..83fa16eb347e 100644 --- a/Documentation/media/uapi/v4l/crop.rst +++ b/Documentation/media/uapi/v4l/crop.rst @@ -2,9 +2,18 @@ .. _crop: -************************************* -Image Cropping, Insertion and Scaling -************************************* +***************************************************** +Image Cropping, Insertion and Scaling -- the CROP API +***************************************************** + +.. note:: + + The CROP API is mostly superseded by the newer :ref:`SELECTION API + `. The new API should be preferred in most cases, + with the exception of pixel aspect ratio detection, which is + implemented by :ref:`VIDIOC_CROPCAP ` and has no + equivalent in the SELECTION API. See :ref:`selection-vs-crop` for a + comparison of the two APIs. Some video capture devices can sample a subsection of the picture and shrink or enlarge it to an image of arbitrary size. We call these @@ -40,12 +49,6 @@ support scaling or the :ref:`VIDIOC_G_CROP ` and :ref:`VIDIOC_S_CROP ` ioctls. Their size (and position where applicable) will be fixed in this case. -.. note:: - - All capture and output devices must support the - :ref:`VIDIOC_CROPCAP ` ioctl such that applications - can determine if scaling takes place. - Cropping Structures =================== diff --git a/Documentation/media/uapi/v4l/selection-api-005.rst b/Documentation/media/uapi/v4l/selection-api-005.rst index 5b47a28ac6d7..2ad30a49184f 100644 --- a/Documentation/media/uapi/v4l/selection-api-005.rst +++ b/Documentation/media/uapi/v4l/selection-api-005.rst @@ -1,5 +1,7 @@ .. -*- coding: utf-8; mode: rst -*- +.. _selection-vs-crop: + ******************************** Comparison with old cropping API ******************************** diff --git a/Documentation/media/uapi/v4l/selection-api.rst b/Documentation/media/uapi/v4l/selection-api.rst index 81ea52d785b9..e4e623824b30 100644 --- a/Documentation/media/uapi/v4l/selection-api.rst +++ b/Documentation/media/uapi/v4l/selection-api.rst @@ -2,8 +2,8 @@ .. _selection-api: -API for cropping, composing and scaling -======================================= +Cropping, composing and scaling -- the SELECTION API +==================================================== .. toctree::