[{"id":13314,"web_url":"https://patchwork.libcamera.org/comment/13314/","msgid":"","date":"2020-10-21T08:27:05","subject":"Re: [libcamera-devel] [RFC PATCH 1/2] android: jpeg:\n\tencoder_libjpeg Allow encoding raw frame bytes","submitter":{"id":4,"url":"https://patchwork.libcamera.org/api/people/4/","name":"Kieran Bingham","email":"kieran.bingham@ideasonboard.com"},"content":"Hi Umang,\n\nOn 21/10/2020 09:08, Umang Jain wrote:\n> Allow encoding frame which are directly handed over to the encoder\n> via a span or vector i.e. a raw frame bytes. Introduce an overloaded\n> EncoderLibJpeg::encode() with libcamera::Span source parameter to\n> achieve this functionality. This makes the libjpeg-encoder a bit\n> flexible for use case such as compressing a thumbnail generated for\n> Exif.\n> \n\nThis looks good to me, It changes the internals of this to support only\nsingle-plane formats, but we only support single-plane formats so I'm\nnot worried by that.\n\nIt also gives the compressRGB, compressNV12 better input parameters in\nmy opinion, as it's clear what data they are operating on. In other\nwords, I like that they deal with span internally, rather than operating\non a MappedBuffer type. Particularly as the MappedBuffer topics will\nlikely need more thought later.\n\n> Signed-off-by: Umang Jain \n> ---\n> src/android/jpeg/encoder_libjpeg.cpp | 37 +++++++++++++++++-----------\n> src/android/jpeg/encoder_libjpeg.h | 7 ++++--\n> 2 files changed, 28 insertions(+), 16 deletions(-)\n> \n> diff --git a/src/android/jpeg/encoder_libjpeg.cpp b/src/android/jpeg/encoder_libjpeg.cpp\n> index f11e004..bfaf9d5 100644\n> --- a/src/android/jpeg/encoder_libjpeg.cpp\n> +++ b/src/android/jpeg/encoder_libjpeg.cpp\n> @@ -104,9 +104,9 @@ int EncoderLibJpeg::configure(const StreamConfiguration &cfg)\n> \treturn 0;\n> }\n> \n> -void EncoderLibJpeg::compressRGB(const libcamera::MappedBuffer *frame)\n> +void EncoderLibJpeg::compressRGB(const libcamera::Span &frame)\n> {\n> -\tunsigned char *src = static_cast(frame->maps()[0].data());\n> +\tunsigned char *src = static_cast(frame.data());\n> \t/* \\todo Stride information should come from buffer configuration. */\n> \tunsigned int stride = pixelFormatInfo_->stride(compress_.image_width, 0);\n> \n> @@ -122,7 +122,7 @@ void EncoderLibJpeg::compressRGB(const libcamera::MappedBuffer *frame)\n> * Compress the incoming buffer from a supported NV format.\n> * This naively unpacks the semi-planar NV12 to a YUV888 format for libjpeg.\n> */\n> -void EncoderLibJpeg::compressNV(const libcamera::MappedBuffer *frame)\n> +void EncoderLibJpeg::compressNV(const libcamera::Span &frame)\n> {\n> \tuint8_t tmprowbuf[compress_.image_width * 3];\n> \n> @@ -144,7 +144,7 @@ void EncoderLibJpeg::compressNV(const libcamera::MappedBuffer *frame)\n> \tunsigned int cb_pos = nvSwap_ ? 1 : 0;\n> \tunsigned int cr_pos = nvSwap_ ? 0 : 1;\n> \n> -\tconst unsigned char *src = static_cast(frame->maps()[0].data());\n> +\tconst unsigned char *src = static_cast(frame.data());\n> \tconst unsigned char *src_c = src + y_stride * compress_.image_height;\n> \n> \tJSAMPROW row_pointer[1];\n> @@ -179,17 +179,10 @@ void EncoderLibJpeg::compressNV(const libcamera::MappedBuffer *frame)\n> \t}\n> }\n> \n> -int EncoderLibJpeg::encode(const FrameBuffer *source,\n> +int EncoderLibJpeg::encode(const libcamera::Span &frame,\n> \t\t\t const libcamera::Span &dest,\n> \t\t\t const libcamera::Span &exifData)\n> {\n> -\tMappedFrameBuffer frame(source, PROT_READ);\n> -\tif (!frame.isValid()) {\n> -\t\tLOG(JPEG, Error) << \"Failed to map FrameBuffer : \"\n> -\t\t\t\t << strerror(frame.error());\n> -\t\treturn frame.error();\n> -\t}\n> -\n> \tunsigned char *destination = dest.data();\n> \tunsigned long size = dest.size();\n> \n> @@ -215,11 +208,27 @@ int EncoderLibJpeg::encode(const FrameBuffer *source,\n> \t\t\t << \"x\" << compress_.image_height;\n> \n> \tif (nv_)\n> -\t\tcompressNV(&frame);\n> +\t\tcompressNV(frame);\n> \telse\n> -\t\tcompressRGB(&frame);\n> +\t\tcompressRGB(frame);\n> \n> \tjpeg_finish_compress(&compress_);\n> \n> \treturn size;\n> }\n> +\n> +int EncoderLibJpeg::encode(const FrameBuffer *source,\n> +\t\t\t const libcamera::Span &dest,\n> +\t\t\t const libcamera::Span &exifData)\n> +{\n> +\tMappedFrameBuffer frame(source, PROT_READ);\n> +\tif (!frame.isValid()) {\n> +\t\tLOG(JPEG, Error) << \"Failed to map FrameBuffer : \"\n> +\t\t\t\t << strerror(frame.error());\n> +\t\treturn frame.error();\n> +\t}\n> +\n> +\tlibcamera::Span src = frame.maps()[0];\n> +\n> +\treturn encode(src, dest, exifData);\n\nThis could also be:\n\treturn encode(frame.maps()[0], dest, exifData);\n\nI don't think there's a need to declare a new span for this, but it's\nfine if you prefer it / find it more readable.\n\nReviewed-by: Kieran Bingham \n\n> +}\n> diff --git a/src/android/jpeg/encoder_libjpeg.h b/src/android/jpeg/encoder_libjpeg.h\n> index 934caef..bf2e512 100644\n> --- a/src/android/jpeg/encoder_libjpeg.h\n> +++ b/src/android/jpeg/encoder_libjpeg.h\n> @@ -21,13 +21,16 @@ public:\n> \t~EncoderLibJpeg();\n> \n> \tint configure(const libcamera::StreamConfiguration &cfg) override;\n> +\tint encode(const libcamera::Span &frames,\n> +\t\t const libcamera::Span &destination,\n> +\t\t const libcamera::Span &exifData);\n> \tint encode(const libcamera::FrameBuffer *source,\n> \t\t const libcamera::Span &destination,\n> \t\t const libcamera::Span &exifData) override;\n> \n> private:\n> -\tvoid compressRGB(const libcamera::MappedBuffer *frame);\n> -\tvoid compressNV(const libcamera::MappedBuffer *frame);\n> +\tvoid compressRGB(const libcamera::Span &frame);\n> +\tvoid compressNV(const libcamera::Span &frame);\n> \n> \tstruct jpeg_compress_struct compress_;\n> \tstruct jpeg_error_mgr jerr_;\n>","headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id E76D6C3D3C\n\tfor ;\n\tWed, 21 Oct 2020 08:27:09 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 8080E61D98;\n\tWed, 21 Oct 2020 10:27:09 +0200 (CEST)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[213.167.242.64])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id E8A7760352\n\tfor ;\n\tWed, 21 Oct 2020 10:27:08 +0200 (CEST)","from [192.168.0.20]\n\t(cpc89244-aztw30-2-0-cust3082.18-1.cable.virginm.net [86.31.172.11])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 5EEAC92;\n\tWed, 21 Oct 2020 10:27:08 +0200 (CEST)"],"Authentication-Results":"lancelot.ideasonboard.com;\n\tdkim=fail reason=\"signature verification failed\" (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"jMbX3ioz\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1603268828;\n\tbh=CrLYxYwTI8AE8uCWClxmjCoiCCieBBBRkj+spxScQXE=;\n\th=Reply-To:Subject:To:References:From:Date:In-Reply-To:From;\n\tb=jMbX3iozbzBiLFjqq6Hm7IteYnfjR955ujZaTjgNY6re84ESMjeOsaVTGbNP7+bs7\n\tKMXOpwE6RVAmuIUc94mOmu/8cCtxM731c7z7z4yvjnopdMabbxFXpIbhiJwvR5NGK5\n\t49Q2qjGaomcqbu4gcrskoezAZF9zN3vfzx9d/2Rg=","To":"Umang Jain , libcamera-devel@lists.libcamera.org","References":"<20201021080806.46636-1-email@uajain.com>\n\t<20201021080806.46636-2-email@uajain.com>","From":"Kieran Bingham ","Autocrypt":"addr=kieran.bingham@ideasonboard.com; keydata=\n\tmQINBFYE/WYBEACs1PwjMD9rgCu1hlIiUA1AXR4rv2v+BCLUq//vrX5S5bjzxKAryRf0uHat\n\tV/zwz6hiDrZuHUACDB7X8OaQcwhLaVlq6byfoBr25+hbZG7G3+5EUl9cQ7dQEdvNj6V6y/SC\n\trRanWfelwQThCHckbobWiQJfK9n7rYNcPMq9B8e9F020LFH7Kj6YmO95ewJGgLm+idg1Kb3C\n\tpotzWkXc1xmPzcQ1fvQMOfMwdS+4SNw4rY9f07Xb2K99rjMwZVDgESKIzhsDB5GY465sCsiQ\n\tcSAZRxqE49RTBq2+EQsbrQpIc8XiffAB8qexh5/QPzCmR4kJgCGeHIXBtgRj+nIkCJPZvZtf\n\tKr2EAbc6tgg6DkAEHJb+1okosV09+0+TXywYvtEop/WUOWQ+zo+Y/OBd+8Ptgt1pDRyOBzL8\n\tRXa8ZqRf0Mwg75D+dKntZeJHzPRJyrlfQokngAAs4PaFt6UfS+ypMAF37T6CeDArQC41V3ko\n\tlPn1yMsVD0p+6i3DPvA/GPIksDC4owjnzVX9kM8Zc5Cx+XoAN0w5Eqo4t6qEVbuettxx55gq\n\t8K8FieAjgjMSxngo/HST8TpFeqI5nVeq0/lqtBRQKumuIqDg+Bkr4L1V/PSB6XgQcOdhtd36\n\tOe9X9dXB8YSNt7VjOcO7BTmFn/Z8r92mSAfHXpb07YJWJosQOQARAQABtDBLaWVyYW4gQmlu\n\tZ2hhbSA8a2llcmFuLmJpbmdoYW1AaWRlYXNvbmJvYXJkLmNvbT6JAlcEEwEKAEECGwMFCwkI\n\tBwIGFQgJCgsCBBYCAwECHgECF4ACGQEWIQSQLdeYP70o/eNy1HqhHkZyEKRh/QUCXWTtygUJ\n\tCyJXZAAKCRChHkZyEKRh/f8dEACTDsbLN2nioNZMwyLuQRUAFcXNolDX48xcUXsWS2QjxaPm\n\tVsJx8Uy8aYkS85mdPBh0C83OovQR/OVbr8AxhGvYqBs3nQvbWuTl/+4od7DfK2VZOoKBAu5S\n\tQK2FYuUcikDqYcFWJ8DQnubxfE8dvzojHEkXw0sA4igINHDDFX3HJGZtLio+WpEFQtCbfTAG\n\tYZslasz1YZRbwEdSsmO3/kqy5eMnczlm8a21A3fKUo3g8oAZEFM+f4DUNzqIltg31OAB/kZS\n\tenKZQ/SWC8PmLg/ZXBrReYakxXtkP6w3FwMlzOlhGxqhIRNiAJfXJBaRhuUWzPOpEDE9q5YJ\n\tBmqQL2WJm1VSNNVxbXJHpaWMH1sA2R00vmvRrPXGwyIO0IPYeUYQa3gsy6k+En/aMQJd27dp\n\taScf9am9PFICPY5T4ppneeJLif2lyLojo0mcHOV+uyrds9XkLpp14GfTkeKPdPMrLLTsHRfH\n\tfA4I4OBpRrEPiGIZB/0im98MkGY/Mu6qxeZmYLCcgD6qz4idOvfgVOrNh+aA8HzIVR+RMW8H\n\tQGBN9f0E3kfwxuhl3omo6V7lDw8XOdmuWZNC9zPq1UfryVHANYbLGz9KJ4Aw6M+OgBC2JpkD\n\thXMdHUkC+d20dwXrwHTlrJi1YNp6rBc+xald3wsUPOZ5z8moTHUX/uPA/qhGsbkCDQRWBP1m\n\tARAAzijkb+Sau4hAncr1JjOY+KyFEdUNxRy+hqTJdJfaYihxyaj0Ee0P0zEi35CbE6lgU0Uz\n\ttih9fiUbSV3wfsWqg1Ut3/5rTKu7kLFp15kF7eqvV4uezXRD3Qu4yjv/rMmEJbbD4cTvGCYI\n\td6MDC417f7vK3hCbCVIZSp3GXxyC1LU+UQr3fFcOyCwmP9vDUR9JV0BSqHHxRDdpUXE26Dk6\n\tmhf0V1YkspE5St814ETXpEus2urZE5yJIUROlWPIL+hm3NEWfAP06vsQUyLvr/GtbOT79vXl\n\tEn1aulcYyu20dRRxhkQ6iILaURcxIAVJJKPi8dsoMnS8pB0QW12AHWuirPF0g6DiuUfPmrA5\n\tPKe56IGlpkjc8cO51lIxHkWTpCMWigRdPDexKX+Sb+W9QWK/0JjIc4t3KBaiG8O4yRX8ml2R\n\t+rxfAVKM6V769P/hWoRGdgUMgYHFpHGSgEt80OKK5HeUPy2cngDUXzwrqiM5Sz6Od0qw5pCk\n\tNlXqI0W/who0iSVM+8+RmyY0OEkxEcci7rRLsGnM15B5PjLJjh1f2ULYkv8s4SnDwMZ/kE04\n\t/UqCMK/KnX8pwXEMCjz0h6qWNpGwJ0/tYIgQJZh6bqkvBrDogAvuhf60Sogw+mH8b+PBlx1L\n\toeTK396wc+4c3BfiC6pNtUS5GpsPMMjYMk7kVvEAEQEAAYkCPAQYAQoAJgIbDBYhBJAt15g/\n\tvSj943LUeqEeRnIQpGH9BQJdizzIBQkLSKZiAAoJEKEeRnIQpGH9eYgQAJpjaWNgqNOnMTmD\n\tMJggbwjIotypzIXfhHNCeTkG7+qCDlSaBPclcPGYrTwCt0YWPU2TgGgJrVhYT20ierN8LUvj\n\t6qOPTd+Uk7NFzL65qkh80ZKNBFddx1AabQpSVQKbdcLb8OFs85kuSvFdgqZwgxA1vl4TFhNz\n\tPZ79NAmXLackAx3sOVFhk4WQaKRshCB7cSl+RIng5S/ThOBlwNlcKG7j7W2MC06BlTbdEkUp\n\tECzuuRBv8wX4OQl+hbWbB/VKIx5HKlLu1eypen/5lNVzSqMMIYkkZcjV2SWQyUGxSwq0O/sx\n\tS0A8/atCHUXOboUsn54qdxrVDaK+6jIAuo8JiRWctP16KjzUM7MO0/+4zllM8EY57rXrj48j\n\tsbEYX0YQnzaj+jO6kJtoZsIaYR7rMMq9aUAjyiaEZpmP1qF/2sYenDx0Fg2BSlLvLvXM0vU8\n\tpQk3kgDu7kb/7PRYrZvBsr21EIQoIjXbZxDz/o7z95frkP71EaICttZ6k9q5oxxA5WC6sTXc\n\tMW8zs8avFNuA9VpXt0YupJd2ijtZy2mpZNG02fFVXhIn4G807G7+9mhuC4XG5rKlBBUXTvPU\n\tAfYnB4JBDLmLzBFavQfvonSfbitgXwCG3vS+9HEwAjU30Bar1PEOmIbiAoMzuKeRm2LVpmq4\n\tWZw01QYHU/GUV/zHJSFk","Organization":"Ideas on Board","Message-ID":"","Date":"Wed, 21 Oct 2020 09:27:05 +0100","User-Agent":"Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101\n\tThunderbird/68.10.0","MIME-Version":"1.0","In-Reply-To":"<20201021080806.46636-2-email@uajain.com>","Content-Language":"en-GB","Subject":"Re: [libcamera-devel] [RFC PATCH 1/2] android: jpeg:\n\tencoder_libjpeg Allow encoding raw frame bytes","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Reply-To":"kieran.bingham@ideasonboard.com","Content-Type":"text/plain; charset=\"us-ascii\"","Content-Transfer-Encoding":"7bit","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}},{"id":13394,"web_url":"https://patchwork.libcamera.org/comment/13394/","msgid":"<20201022043053.GH3942@pendragon.ideasonboard.com>","date":"2020-10-22T04:30:53","subject":"Re: [libcamera-devel] [RFC PATCH 1/2] android: jpeg:\n\tencoder_libjpeg Allow encoding raw frame bytes","submitter":{"id":2,"url":"https://patchwork.libcamera.org/api/people/2/","name":"Laurent Pinchart","email":"laurent.pinchart@ideasonboard.com"},"content":"Hello Umang,\n\nThank you for the patch.\n\nOn Wed, Oct 21, 2020 at 09:27:05AM +0100, Kieran Bingham wrote:\n> On 21/10/2020 09:08, Umang Jain wrote:\n> > Allow encoding frame which are directly handed over to the encoder\n\ns/frame/frames/\n\n> > via a span or vector i.e. a raw frame bytes. Introduce an overloaded\n> > EncoderLibJpeg::encode() with libcamera::Span source parameter to\n> > achieve this functionality. This makes the libjpeg-encoder a bit\n> > flexible for use case such as compressing a thumbnail generated for\n> > Exif.\n> \n> This looks good to me, It changes the internals of this to support only\n> single-plane formats, but we only support single-plane formats so I'm\n> not worried by that.\n\nFine with me as well, we can address this later if/when needed.\n\n> It also gives the compressRGB, compressNV12 better input parameters in\n> my opinion, as it's clear what data they are operating on. In other\n> words, I like that they deal with span internally, rather than operating\n> on a MappedBuffer type. Particularly as the MappedBuffer topics will\n> likely need more thought later.\n> \n> > Signed-off-by: Umang Jain \n> > ---\n> > src/android/jpeg/encoder_libjpeg.cpp | 37 +++++++++++++++++-----------\n> > src/android/jpeg/encoder_libjpeg.h | 7 ++++--\n> > 2 files changed, 28 insertions(+), 16 deletions(-)\n> > \n> > diff --git a/src/android/jpeg/encoder_libjpeg.cpp b/src/android/jpeg/encoder_libjpeg.cpp\n> > index f11e004..bfaf9d5 100644\n> > --- a/src/android/jpeg/encoder_libjpeg.cpp\n> > +++ b/src/android/jpeg/encoder_libjpeg.cpp\n> > @@ -104,9 +104,9 @@ int EncoderLibJpeg::configure(const StreamConfiguration &cfg)\n> > \treturn 0;\n> > }\n> > \n> > -void EncoderLibJpeg::compressRGB(const libcamera::MappedBuffer *frame)\n> > +void EncoderLibJpeg::compressRGB(const libcamera::Span &frame)\n> > {\n> > -\tunsigned char *src = static_cast(frame->maps()[0].data());\n> > +\tunsigned char *src = static_cast(frame.data());\n\nI think you can drop the static_cast<>. Same in compressNV().\n\nIt would be nice to turn the argument to the function into a const\nlibcamera::Span &frame. However, src will likely need to\nremain mutable, as the libjpeg API doesn't take a const pointer :-( You\nwill thus need a const_cast<>().\n\n> > \t/* \\todo Stride information should come from buffer configuration. */\n> > \tunsigned int stride = pixelFormatInfo_->stride(compress_.image_width, 0);\n> > \n> > @@ -122,7 +122,7 @@ void EncoderLibJpeg::compressRGB(const libcamera::MappedBuffer *frame)\n> > * Compress the incoming buffer from a supported NV format.\n> > * This naively unpacks the semi-planar NV12 to a YUV888 format for libjpeg.\n> > */\n> > -void EncoderLibJpeg::compressNV(const libcamera::MappedBuffer *frame)\n> > +void EncoderLibJpeg::compressNV(const libcamera::Span &frame)\n> > {\n> > \tuint8_t tmprowbuf[compress_.image_width * 3];\n> > \n> > @@ -144,7 +144,7 @@ void EncoderLibJpeg::compressNV(const libcamera::MappedBuffer *frame)\n> > \tunsigned int cb_pos = nvSwap_ ? 1 : 0;\n> > \tunsigned int cr_pos = nvSwap_ ? 0 : 1;\n> > \n> > -\tconst unsigned char *src = static_cast(frame->maps()[0].data());\n> > +\tconst unsigned char *src = static_cast(frame.data());\n> > \tconst unsigned char *src_c = src + y_stride * compress_.image_height;\n> > \n> > \tJSAMPROW row_pointer[1];\n> > @@ -179,17 +179,10 @@ void EncoderLibJpeg::compressNV(const libcamera::MappedBuffer *frame)\n> > \t}\n> > }\n> > \n> > -int EncoderLibJpeg::encode(const FrameBuffer *source,\n> > +int EncoderLibJpeg::encode(const libcamera::Span &frame,\n> > \t\t\t const libcamera::Span &dest,\n> > \t\t\t const libcamera::Span &exifData)\n> > {\n> > -\tMappedFrameBuffer frame(source, PROT_READ);\n> > -\tif (!frame.isValid()) {\n> > -\t\tLOG(JPEG, Error) << \"Failed to map FrameBuffer : \"\n> > -\t\t\t\t << strerror(frame.error());\n> > -\t\treturn frame.error();\n> > -\t}\n> > -\n> > \tunsigned char *destination = dest.data();\n> > \tunsigned long size = dest.size();\n> > \n> > @@ -215,11 +208,27 @@ int EncoderLibJpeg::encode(const FrameBuffer *source,\n> > \t\t\t << \"x\" << compress_.image_height;\n> > \n> > \tif (nv_)\n> > -\t\tcompressNV(&frame);\n> > +\t\tcompressNV(frame);\n> > \telse\n> > -\t\tcompressRGB(&frame);\n> > +\t\tcompressRGB(frame);\n> > \n> > \tjpeg_finish_compress(&compress_);\n> > \n> > \treturn size;\n> > }\n> > +\n> > +int EncoderLibJpeg::encode(const FrameBuffer *source,\n> > +\t\t\t const libcamera::Span &dest,\n> > +\t\t\t const libcamera::Span &exifData)\n> > +{\n> > +\tMappedFrameBuffer frame(source, PROT_READ);\n> > +\tif (!frame.isValid()) {\n> > +\t\tLOG(JPEG, Error) << \"Failed to map FrameBuffer : \"\n> > +\t\t\t\t << strerror(frame.error());\n> > +\t\treturn frame.error();\n> > +\t}\n> > +\n> > +\tlibcamera::Span src = frame.maps()[0];\n> > +\n> > +\treturn encode(src, dest, exifData);\n> \n> This could also be:\n> \treturn encode(frame.maps()[0], dest, exifData);\n> \n> I don't think there's a need to declare a new span for this, but it's\n> fine if you prefer it / find it more readable.\n\nI like Kieran's suggestion.\n\n> Reviewed-by: Kieran Bingham \n> \n> > +}\n> > diff --git a/src/android/jpeg/encoder_libjpeg.h b/src/android/jpeg/encoder_libjpeg.h\n> > index 934caef..bf2e512 100644\n> > --- a/src/android/jpeg/encoder_libjpeg.h\n> > +++ b/src/android/jpeg/encoder_libjpeg.h\n> > @@ -21,13 +21,16 @@ public:\n> > \t~EncoderLibJpeg();\n> > \n> > \tint configure(const libcamera::StreamConfiguration &cfg) override;\n> > +\tint encode(const libcamera::Span &frames,\n\ns/frames/frame/\n\nReviewed-by: Laurent Pinchart \n\n> > +\t\t const libcamera::Span &destination,\n> > +\t\t const libcamera::Span &exifData);\n> > \tint encode(const libcamera::FrameBuffer *source,\n> > \t\t const libcamera::Span &destination,\n> > \t\t const libcamera::Span &exifData) override;\n> > \n> > private:\n> > -\tvoid compressRGB(const libcamera::MappedBuffer *frame);\n> > -\tvoid compressNV(const libcamera::MappedBuffer *frame);\n> > +\tvoid compressRGB(const libcamera::Span &frame);\n> > +\tvoid compressNV(const libcamera::Span &frame);\n> > \n> > \tstruct jpeg_compress_struct compress_;\n> > \tstruct jpeg_error_mgr jerr_;","headers":{"Return-Path":"","X-Original-To":"parsemail@patchwork.libcamera.org","Delivered-To":"parsemail@patchwork.libcamera.org","Received":["from lancelot.ideasonboard.com (lancelot.ideasonboard.com\n\t[92.243.16.209])\n\tby patchwork.libcamera.org (Postfix) with ESMTPS id DEA42BDB13\n\tfor ;\n\tThu, 22 Oct 2020 04:31:41 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id 571E66112D;\n\tThu, 22 Oct 2020 06:31:41 +0200 (CEST)","from perceval.ideasonboard.com (perceval.ideasonboard.com\n\t[IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id E86486034F\n\tfor ;\n\tThu, 22 Oct 2020 06:31:39 +0200 (CEST)","from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi\n\t[62.78.145.57])\n\tby perceval.ideasonboard.com (Postfix) with ESMTPSA id 4793B53;\n\tThu, 22 Oct 2020 06:31:39 +0200 (CEST)"],"Authentication-Results":"lancelot.ideasonboard.com;\n\tdkim=fail reason=\"signature verification failed\" (1024-bit key;\n\tunprotected) header.d=ideasonboard.com header.i=@ideasonboard.com\n\theader.b=\"t9qwbieh\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1603341099;\n\tbh=c8Y3x/8x560tTfTJyIjPiACXcnvQneHDgOd0z1FiK2s=;\n\th=Date:From:To:Cc:Subject:References:In-Reply-To:From;\n\tb=t9qwbiehOeSqQgAzn54O8NTFSNcCisNK1T1bA1/jKncOgOm9uiVMxQgq0zyfcbe0O\n\tCQREY7RnGcvWvX5GdlfxJMTgaKSQU8OH86T65S4T1Q+G+Gm+JfVFsSSL6ASEa+v1js\n\troewv7+B//EdaQaoWlTogM5Qd1jnEmUNzt5ZlIuE=","Date":"Thu, 22 Oct 2020 07:30:53 +0300","From":"Laurent Pinchart ","To":"Umang Jain ","Message-ID":"<20201022043053.GH3942@pendragon.ideasonboard.com>","References":"<20201021080806.46636-1-email@uajain.com>\n\t<20201021080806.46636-2-email@uajain.com>\n\t","MIME-Version":"1.0","Content-Disposition":"inline","In-Reply-To":"","Subject":"Re: [libcamera-devel] [RFC PATCH 1/2] android: jpeg:\n\tencoder_libjpeg Allow encoding raw frame bytes","X-BeenThere":"libcamera-devel@lists.libcamera.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"","List-Unsubscribe":",\n\t","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n\t","Cc":"libcamera-devel@lists.libcamera.org","Content-Type":"text/plain; charset=\"us-ascii\"","Content-Transfer-Encoding":"7bit","Errors-To":"libcamera-devel-bounces@lists.libcamera.org","Sender":"\"libcamera-devel\" "}}]