From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 25059C433DB for ; Tue, 26 Jan 2021 06:30:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DDACB22B3F for ; Tue, 26 Jan 2021 06:30:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729182AbhAZGaP (ORCPT ); Tue, 26 Jan 2021 01:30:15 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39070 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729232AbhAYODO (ORCPT ); Mon, 25 Jan 2021 09:03:14 -0500 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D7FEDC061574; Mon, 25 Jan 2021 06:02:13 -0800 (PST) Received: from [IPv6:2804:214:81d7:a6cc:f83c:66c3:4225:e59d] (unknown [IPv6:2804:214:81d7:a6cc:f83c:66c3:4225:e59d]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: koike) by bhuna.collabora.co.uk (Postfix) with ESMTPSA id 211021F452BD; Mon, 25 Jan 2021 14:02:09 +0000 (GMT) Subject: Re: [PATCH] media: doc: pixfmt-yuv: Fix 4:4:4 subsampling info From: Helen Koike To: Laurent Pinchart Cc: linux-media@vger.kernel.org, hverkuil@xs4all.nl, hans.verkuil@cisco.com, kernel@collabora.com, linux-kernel@vger.kernel.org References: <20210122182723.327438-1-helen.koike@collabora.com> <7f650d51-d419-53cc-0ad1-b241a10ab801@collabora.com> Message-ID: <9468d3e1-ac8b-8de7-5632-1da9119c992e@collabora.com> Date: Mon, 25 Jan 2021 11:02:01 -0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.6.1 MIME-Version: 1.0 In-Reply-To: <7f650d51-d419-53cc-0ad1-b241a10ab801@collabora.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/25/21 10:57 AM, Helen Koike wrote: > > > On 1/23/21 6:56 AM, Laurent Pinchart wrote: >> Hi Helen, >> >> Thank you for the patch. >> >> On Fri, Jan 22, 2021 at 03:27:23PM -0300, Helen Koike wrote: >>> YUV 4:4:4 is not subsampled, fix this in the docs. >>> >>> Fixes: da785536e007 ("media: doc: pixfmt-yuv: Move all semi-planar YUV formats to common file") >>> Signed-off-by: Helen Koike >>> --- >>> Documentation/userspace-api/media/v4l/pixfmt-yuv-planar.rst | 4 ++-- >>> 1 file changed, 2 insertions(+), 2 deletions(-) >>> >>> diff --git a/Documentation/userspace-api/media/v4l/pixfmt-yuv-planar.rst b/Documentation/userspace-api/media/v4l/pixfmt-yuv-planar.rst >>> index 7d4d39201a3f..bcb4ef24c334 100644 >>> --- a/Documentation/userspace-api/media/v4l/pixfmt-yuv-planar.rst >>> +++ b/Documentation/userspace-api/media/v4l/pixfmt-yuv-planar.rst >>> @@ -396,8 +396,8 @@ number of lines as the luma plane. >>> NV24 and NV42 >>> ------------- >>> >>> -Semi-planar YUV 4:4:4 formats. The chroma plane is subsampled by 2 in the >>> -horizontal direction. Chroma lines contain half the number of pixels and the >>> +Semi-planar YUV 4:4:4 formats. No sub-sampling. >> >> "The chroma plane is not subsampled." ? > > Ack. > >> >>> +Chroma lines contain the same number of pixels and the >>> same number of bytes as luma lines, and the chroma plane contains the same >>> number of lines as the luma plane. >> >> That's not quite right, the chroma lines contain twice the number of >> pixels and bytes, as there's one Cb and one Cr value in the chroma line >> for each Y value in the luma line. Actually, it is the same number o pixels, but twice the number o bytes. Since a trio (YCbCr) compose a pixel. At least this is how I understand comparing the logic of the text description of NV16 YUV4:2:2. Regards, Helen >> >> >> Maybe the text could be reflowed ? >> > > Ack. > > I'll submit v2 updating the text. > > Thanks, > Helen >