From patchwork Sat Mar 1 13:17:07 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sakari Ailus X-Patchwork-Id: 3746951 Return-Path: X-Original-To: patchwork-linux-media@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 216C99F2ED for ; Sat, 1 Mar 2014 13:14:34 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 5796E202F0 for ; Sat, 1 Mar 2014 13:14:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7D508202F2 for ; Sat, 1 Mar 2014 13:14:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752781AbaCANOW (ORCPT ); Sat, 1 Mar 2014 08:14:22 -0500 Received: from nblzone-211-213.nblnetworks.fi ([83.145.211.213]:45722 "EHLO hillosipuli.retiisi.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752676AbaCANOA (ORCPT ); Sat, 1 Mar 2014 08:14:00 -0500 Received: from lanttu.localdomain (salottisipuli.retiisi.org.uk [IPv6:2001:1bc8:102:7fc9::83:2]) by hillosipuli.retiisi.org.uk (Postfix) with ESMTP id 0B164600A3; Sat, 1 Mar 2014 15:13:57 +0200 (EET) From: Sakari Ailus To: linux-media@vger.kernel.org Cc: hverkuil@xs4all.nl, k.debski@samsung.com, laurent.pinchart@ideasonboard.com Subject: [PATH v6 10/10] v4l: Document timestamp buffer flag behaviour Date: Sat, 1 Mar 2014 15:17:07 +0200 Message-Id: <1393679828-25878-11-git-send-email-sakari.ailus@iki.fi> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1393679828-25878-1-git-send-email-sakari.ailus@iki.fi> References: <1393679828-25878-1-git-send-email-sakari.ailus@iki.fi> Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Timestamp buffer flags are constant at the moment. Document them so that 1) they're always valid and 2) not changed by the drivers. This leaves room to extend the functionality later on if needed. Signed-off-by: Sakari Ailus Acked-by: Hans Verkuil --- Documentation/DocBook/media/v4l/io.xml | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/Documentation/DocBook/media/v4l/io.xml b/Documentation/DocBook/media/v4l/io.xml index d44401c..1bffb1c 100644 --- a/Documentation/DocBook/media/v4l/io.xml +++ b/Documentation/DocBook/media/v4l/io.xml @@ -653,6 +653,20 @@ plane, are stored in struct v4l2_plane instead. In that case, struct v4l2_buffer contains an array of plane structures. + Dequeued video buffers come with timestamps. The driver + decides at which part of the frame and with which clock the + timestamp is taken. Please see flags in the masks + V4L2_BUF_FLAG_TIMESTAMP_MASK and + V4L2_BUF_FLAG_TSTAMP_SRC_MASK in . These flags are always valid and constant + across all buffers during the whole video stream. Changes in these + flags may take place as a side effect of &VIDIOC-S-INPUT; or + &VIDIOC-S-OUTPUT; however. The + V4L2_BUF_FLAG_TIMESTAMP_COPY timestamp type + which is used by e.g. on mem-to-mem devices is an exception to the + rule: the timestamp source flags are copied from the OUTPUT video + buffer to the CAPTURE video buffer. + struct <structname>v4l2_buffer</structname>