From patchwork Thu Oct 14 08:54:05 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kieran Bingham X-Patchwork-Id: 14133 Return-Path: X-Original-To: parsemail@patchwork.libcamera.org Delivered-To: parsemail@patchwork.libcamera.org Received: from lancelot.ideasonboard.com (lancelot.ideasonboard.com [92.243.16.209]) by patchwork.libcamera.org (Postfix) with ESMTPS id 8DA96BDC71 for ; Thu, 14 Oct 2021 08:54:13 +0000 (UTC) Received: from lancelot.ideasonboard.com (localhost [IPv6:::1]) by lancelot.ideasonboard.com (Postfix) with ESMTP id D4CAA68F4F; Thu, 14 Oct 2021 10:54:12 +0200 (CEST) Authentication-Results: lancelot.ideasonboard.com; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="hC9Blztf"; dkim-atps=neutral Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lancelot.ideasonboard.com (Postfix) with ESMTPS id 2539268F4A for ; Thu, 14 Oct 2021 10:54:11 +0200 (CEST) Received: from Monstersaurus.ksquared.org.uk.beta.tailscale.net (cpc89244-aztw30-2-0-cust3082.18-1.cable.virginm.net [86.31.172.11]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id A3FB62F3; Thu, 14 Oct 2021 10:54:10 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1634201650; bh=s/DOZzV76+3i2lS9/fxtMqv9SFBa1sxZIIohC3noL3s=; h=From:To:Cc:Subject:Date:From; b=hC9BlztfHg+xR2uLpZOw0DyF1CMlA1oleil8O4Oh0LuQpBen5bMGa24ikRycdDlQo btAbcqkpgaEldo9p2MU7q6d032obN21dQZyIVI7JUQz4qFm1kEfUf1izzscW3/mel1 X0DKWGpFujQuf0bbLeHpYUgFXt5kDAxvkfmrT3zU= From: Kieran Bingham To: libcamera devel Date: Thu, 14 Oct 2021 09:54:05 +0100 Message-Id: <20211014085405.3795243-1-kieran.bingham@ideasonboard.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Subject: [libcamera-devel] [PATCH] libcamera: v4l2_videodevice: Explain multiplanar bytesused reasoning X-BeenThere: libcamera-devel@lists.libcamera.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: libcamera-devel-bounces@lists.libcamera.org Sender: "libcamera-devel" The ternary operation used to get the total bytesused of a V4L2 single planar format which is stored in a multiplanar buffer can easily be mis-read to think it's a bug, and appears to be reading the value of the first of N planes as the total. Directly explain the reasoning for why it looks like the condition is inverted, as it is correct that the total bytes used is stored in only the first plane of the multiplanar buffer. Signed-off-by: Kieran Bingham Reviewed-by: Laurent Pinchart --- src/libcamera/v4l2_videodevice.cpp | 1 + 1 file changed, 1 insertion(+) diff --git a/src/libcamera/v4l2_videodevice.cpp b/src/libcamera/v4l2_videodevice.cpp index ba5f88cd41ed..f4752f8bb23f 100644 --- a/src/libcamera/v4l2_videodevice.cpp +++ b/src/libcamera/v4l2_videodevice.cpp @@ -1711,6 +1711,7 @@ FrameBuffer *V4L2VideoDevice::dequeueBuffer() return buffer; } + /* Single planar format stored in a multiplanar buffer */ unsigned int bytesused = multiPlanar ? planes[0].bytesused : buf.bytesused;