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[23.128.96.18]) by mx.google.com with ESMTP id i1si1455798edy.450.2021.01.12.07.00.35; Tue, 12 Jan 2021 07:00:59 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389499AbhALO7M convert rfc822-to-8bit (ORCPT + 99 others); Tue, 12 Jan 2021 09:59:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43220 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732459AbhALO7M (ORCPT ); Tue, 12 Jan 2021 09:59:12 -0500 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C544BC061794 for ; Tue, 12 Jan 2021 06:58:31 -0800 (PST) Received: from lupine.hi.pengutronix.de ([2001:67c:670:100:3ad5:47ff:feaf:1a17] helo=lupine) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1kzL7j-00020s-4W; Tue, 12 Jan 2021 15:58:19 +0100 Received: from pza by lupine with local (Exim 4.92) (envelope-from ) id 1kzL7h-0007qp-JE; Tue, 12 Jan 2021 15:58:17 +0100 Message-ID: Subject: Re: [PATCH v7 6/9] media: Add parsing for APP14 data segment in jpeg helpers From: Philipp Zabel To: Mirela Rabulea , mchehab@kernel.org, hverkuil-cisco@xs4all.nl, shawnguo@kernel.org, robh+dt@kernel.org Cc: paul.kocialkowski@bootlin.com, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, linux-imx@nxp.com, s.hauer@pengutronix.de, aisheng.dong@nxp.com, daniel.baluta@nxp.com, robert.chiras@nxp.com, laurentiu.palcu@nxp.com, mark.rutland@arm.com, devicetree@vger.kernel.org, ezequiel@collabora.com, laurent.pinchart+renesas@ideasonboard.com, niklas.soderlund+renesas@ragnatech.se, dafna.hirschfeld@collabora.com Date: Tue, 12 Jan 2021 15:58:17 +0100 In-Reply-To: <20210111192822.12178-7-mirela.rabulea@oss.nxp.com> References: <20210111192822.12178-1-mirela.rabulea@oss.nxp.com> <20210111192822.12178-7-mirela.rabulea@oss.nxp.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT User-Agent: Evolution 3.30.5-1.1 MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:100:3ad5:47ff:feaf:1a17 X-SA-Exim-Mail-From: p.zabel@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2021-01-11 at 21:28 +0200, Mirela Rabulea wrote: > From: Mirela Rabulea > > According to Rec. ITU-T T.872 (06/2012) 6.5.3 > APP14 segment is for color encoding, it contains a transform flag, which > may have values of 0, 1 and 2 and are interpreted as follows: > 0 - CMYK for images that are encoded with four components > - RGB for images that are encoded with three components > 1 - An image encoded with three components using YCbCr colour encoding. > 2 - An image encoded with four components using YCCK colour encoding. > > This is used in imx-jpeg decoder, to distinguish between > YUV444 and RGB24. > > Signed-off-by: Mirela Rabulea > --- > Changes in v7: > Check there are 6 bytes available in the stream before checking for "Adobe\0" > Change jpeg_parse_app14_data function to differentiate between the 3 scenarios: app14 missing, or app14 present but with/without parsing errors: > App14 missing => Added V4L2_JPEG_APP14_TF_UNKNOWN to the enum v4l2_jpeg_app14_tf, use it to indicate app14 & TF is missing > App14 present without parsing errors => Return the transform flag value as enum v4l2_jpeg_app14_tf (new paramater of jpeg_parse_app14_data function) > App14 present with parsing errors => Return -EINVAL from jpeg_parse_app14_data, also return from calling function (v4l2_jpeg_parse_header) when this error is met. > > drivers/media/v4l2-core/v4l2-jpeg.c | 47 +++++++++++++++++++++++++++-- > include/media/v4l2-jpeg.h | 20 ++++++++++++ > 2 files changed, 65 insertions(+), 2 deletions(-) > > diff --git a/drivers/media/v4l2-core/v4l2-jpeg.c b/drivers/media/v4l2-core/v4l2-jpeg.c > index 8947fd95c6f1..8d5fedb136dd 100644 > --- a/drivers/media/v4l2-core/v4l2-jpeg.c > +++ b/drivers/media/v4l2-core/v4l2-jpeg.c > @@ -45,6 +45,7 @@ MODULE_LICENSE("GPL"); > #define DHP 0xffde /* hierarchical progression */ > #define EXP 0xffdf /* expand reference */ > #define APP0 0xffe0 /* application data */ > +#define APP14 0xffee /* application data for colour encoding */ > #define APP15 0xffef > #define JPG0 0xfff0 /* extensions */ > #define JPG13 0xfffd > @@ -444,8 +445,44 @@ static int jpeg_skip_segment(struct jpeg_stream *stream) > return jpeg_skip(stream, len - 2); > } > > +/* Rec. ITU-T T.872 (06/2012) 6.5.3 */ > +static int jpeg_parse_app14_data(struct jpeg_stream *stream, > + enum v4l2_jpeg_app14_tf *tf) > +{ > + int ret; > + int lp; > + int skip; > + > + lp = jpeg_get_word_be(stream); > + if (lp < 0) > + return lp; > + > + /* Check for "Adobe\0" in Ap1..6 */ > + if (stream->curr + 6 > stream->end || > + strncmp(stream->curr, "Adobe\0", 6)) > + return -EINVAL; > + > + /* get to Ap12 */ > + ret = jpeg_skip(stream, 11); > + if (ret < 0) > + return ret; > + > + ret = jpeg_get_byte(stream); > + if (ret < 0) > + return ret; > + > + *tf = ret; > + > + skip = lp - 2 - 11; > + ret = jpeg_skip(stream, skip); > + if (ret < 0) > + return ret; > + > + return 0; This could be simplified to return jpeg_skip(stream, skip); although it would be better style to move the *tf = ... assignment down past the last error return instead. Either way, Reviewed-by: Philipp Zabel regards Philipp