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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 D1244C433E9 for ; Mon, 4 Jan 2021 17:01:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A96D9224DF for ; Mon, 4 Jan 2021 17:01:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728076AbhADRBD convert rfc822-to-8bit (ORCPT ); Mon, 4 Jan 2021 12:01:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55204 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728070AbhADRA7 (ORCPT ); Mon, 4 Jan 2021 12:00:59 -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 49D20C061794 for ; Mon, 4 Jan 2021 09:00:19 -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 1kwTDF-0002Ic-Sc; Mon, 04 Jan 2021 18:00:09 +0100 Received: from pza by lupine with local (Exim 4.92) (envelope-from ) id 1kwTD7-00075O-Sl; Mon, 04 Jan 2021 18:00:01 +0100 Message-ID: Subject: Re: [PATCH v6 6/9] media: Add parsing for APP14 data segment in jpeg helpers From: Philipp Zabel To: "Mirela Rabulea (OSS)" , 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, Mirela Rabulea Date: Mon, 04 Jan 2021 18:00:01 +0100 In-Reply-To: <20201215111843.30269-7-mirela.rabulea@oss.nxp.com> References: <20201215111843.30269-1-mirela.rabulea@oss.nxp.com> <20201215111843.30269-7-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: devicetree@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Hi Mirela, thank you for the update. Just two issues below: On Tue, 2020-12-15 at 13:18 +0200, Mirela Rabulea (OSS) 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 v6: > Switch variable to lowercase Lp->lp > Check for "Adobe\0" in Ap1..6 > Make the transform flag an enum > Removed a change in comment section, a leftover from a previous version > Thanks Philipp for feedback. > > drivers/media/v4l2-core/v4l2-jpeg.c | 43 +++++++++++++++++++++++++++-- > include/media/v4l2-jpeg.h | 18 ++++++++++++ > 2 files changed, 59 insertions(+), 2 deletions(-) > > diff --git a/drivers/media/v4l2-core/v4l2-jpeg.c b/drivers/media/v4l2-core/v4l2-jpeg.c > index 8947fd95c6f1..d1483e7a775c 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 +445,41 @@ 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) > +{ > + int ret; > + int lp; > + int skip; > + int tf; > + > + lp = jpeg_get_word_be(stream); > + if (lp < 0) > + return lp; Here we should check that there are still 6 bytes available to compare: if (stream->curr + 6 > stream->end) return -EINVAL; > + /* Check for "Adobe\0" in Ap1..6 */ > + if (strncmp(stream->curr, "Adobe\0", 6)) > + return -EINVAL; > + > + /* get to Ap12 */ > + ret = jpeg_skip(stream, 11); > + if (ret < 0) > + return -EINVAL; > + > + tf = jpeg_get_byte(stream); > + if (tf < 0) > + return tf; > + > + skip = lp - 2 - 11; > + ret = jpeg_skip(stream, skip); > + if (ret < 0) > + return -EINVAL; > + else > + return tf; > +} > + > /** > - * jpeg_parse_header - locate marker segments and optionally parse headers > + * v4l2_jpeg_parse_header - locate marker segments and optionally parse headers > * @buf: address of the JPEG buffer, should start with a SOI marker > * @len: length of the JPEG buffer > * @out: returns marker segment positions and optionally parsed headers > @@ -476,6 +510,9 @@ int v4l2_jpeg_parse_header(void *buf, size_t len, struct v4l2_jpeg_header *out) > if (marker != SOI) > return -EINVAL; > > + /* init value to signal if this marker is not present */ > + out->app14_tf = -EINVAL; > + Here we set app14_tf to a value that is not part of the enum. You could define a value V4L2_JPEG_APP14_TF_UNKNOWN for the uninitialized / error state. > /* loop through marker segments */ > while ((marker = jpeg_next_marker(&stream)) >= 0) { > switch (marker) { > @@ -519,7 +556,9 @@ int v4l2_jpeg_parse_header(void *buf, size_t len, struct v4l2_jpeg_header *out) > ret = jpeg_parse_restart_interval(&stream, > &out->restart_interval); > break; > - > + case APP14: > + out->app14_tf = jpeg_parse_app14_data(&stream); Same as above in case of -EINVAL return. Apart from this, Reviewed-by: Philipp Zabel regards Philipp