[{"id":13539,"web_url":"https://patchwork.libcamera.org/comment/13539/","msgid":"<6f5f8ee2-83b6-6da1-8610-58dc6c016a07@ideasonboard.com>","date":"2020-10-28T14:43:05","subject":"Re: [libcamera-devel] [PATCH v2 0/3] android: jpeg: exif: Embed a\n\tJPEG-encoded thumbnail","submitter":{"id":4,"url":"https://patchwork.libcamera.org/api/people/4/","name":"Kieran Bingham","email":"kieran.bingham@ideasonboard.com"},"content":"Hi Umang,\n\nOn 27/10/2020 21:24, Umang Jain wrote:\n> Changes in v2:\n> - Drop patch 1/3 from v1.\n> - Use pointers instead of reference if the function is making change to\n> the parameter.\n> - Split Thumbnailer class and its usage into 2 patches.\n> - More rigorous const correct-ness in patch 1/3\n> \n> There are two major open-ended topics I would like further commenta on:\n> \n> 1. Whether to keep thumbnailEncoder_ inside PostProcessorJpeg or move it\n> to Thumbnailer class itself? Hiroh suggests that it might be useful\n> to keep it in the latter, so let's discuss it widely of what makes\n> sense.\n\nI still think encoding the thumbnail is separate to rescaling it. Your\nthumbnail class is really just a simple, fixed-output-size scaler class.\n\nI think I saw Laurent say somewhere that as thumbnails can also be\nstored as uncompressed, we could also choose to do that at some point,\nwhich would keep it separate.\n\n> 2. Fate of EncoderLibJpeg::encode() introduced in patch 1/3. This is\n> basically allowing us to encode from raw bytes, but is still internal\n> to EncoderLibJpeg(and uses the same naming as Encoder::encode()\n> virtual function). Should I rename it to something else, while\n> keeping it internal to EncoderLibJpeg? Also, I wonder if this is a\n> potential candidate for Encoder interface too? In the sense that\n> Encoder(s) have a way to encode stuff directly handed to them as\n> bytes. \n\n\nThere's going to be more churn to these interfaces as we extend the\nPostProcessors, and we don't yet know what we need, or how that will\nplay out.\n\nParticularly in regards to the fact that we'll also likely need to make\nupdates to the FrameBuffer / MappedFrameBuffer type interfaces - so I\nthink we should stick with what we have for now, and we can update if\nneeded when those issues get resolved.\n\n--\nKieran\n\n\n> \n> Thanks for the reviews all of you!\n> \n> Umang Jain (3):\n> android: jpeg: encoder_libjpeg: Allow encoding raw frame bytes\n> android: jpeg: Introduce a simple image thumbnailer\n> android: jpeg: post_processor_jpeg: Embed thumbnail into Exif metadata\n> \n> src/android/jpeg/encoder_libjpeg.cpp | 18 ++--\n> src/android/jpeg/encoder_libjpeg.h | 7 +-\n> src/android/jpeg/exif.cpp | 24 ++++-\n> src/android/jpeg/exif.h | 2 +\n> src/android/jpeg/post_processor_jpeg.cpp | 34 +++++++\n> src/android/jpeg/post_processor_jpeg.h | 8 +-\n> src/android/jpeg/thumbnailer.cpp | 113 +++++++++++++++++++++++\n> src/android/jpeg/thumbnailer.h | 36 ++++++++\n> src/android/meson.build | 1 +\n> 9 files changed, 233 insertions(+), 10 deletions(-)\n> create mode 100644 src/android/jpeg/thumbnailer.cpp\n> create mode 100644 src/android/jpeg/thumbnailer.h\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 6D6FAC3B5C\n\tfor ;\n\tWed, 28 Oct 2020 14:43:10 +0000 (UTC)","from lancelot.ideasonboard.com (localhost [IPv6:::1])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTP id DFAC5626E7;\n\tWed, 28 Oct 2020 15:43:09 +0100 (CET)","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 3EE7762679\n\tfor ;\n\tWed, 28 Oct 2020 15:43:09 +0100 (CET)","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 16B0C99A;\n\tWed, 28 Oct 2020 15:43:07 +0100 (CET)"],"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=\"D+kHl2AT\"; dkim-atps=neutral","DKIM-Signature":"v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com;\n\ts=mail; t=1603896188;\n\tbh=nqcEJ5Uforej8xPvlcJYHTx3luCr+KP12NoTugNlByY=;\n\th=Reply-To:Subject:To:Cc:References:From:Date:In-Reply-To:From;\n\tb=D+kHl2ATaGGe3dGAE83ILmUzGAR4EXFEDoJIC0VPNKvmJxClcHezyBEXRYZ+a71zC\n\tUOyuSMguzTxQxw9Kx1mjr2DX9e4d8/FZKahfJB6e5EP3jwPiyJ/Lf1lqa5YLAkIEj9\n\thKwPILYW72bSwyByMdjreMNUMVqnfuaOY87r9kGk=","To":"Umang Jain , libcamera-devel@lists.libcamera.org","References":"<20201027212447.131431-1-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":"<6f5f8ee2-83b6-6da1-8610-58dc6c016a07@ideasonboard.com>","Date":"Wed, 28 Oct 2020 14:43:05 +0000","User-Agent":"Mozilla/5.0 (X11; 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