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    "msgid": "<20230915-libyuv-convert-v1-0-1e5bcf68adac@baylibre.com>",
    "date": "2023-09-15T07:57:24",
    "name": "[libcamera-devel,RFC,0/7] android: add YUYV->NV12 conversion via libyuv",
    "submitter": {
        "id": 153,
        "url": "https://patchwork.libcamera.org/api/people/153/?format=api",
        "name": "Mattijs Korpershoek",
        "email": "mkorpershoek@baylibre.com"
    },
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            "date": "2023-09-15T07:57:24",
            "name": "android: add YUYV->NV12 conversion via libyuv",
            "version": 1,
            "mbox": "https://patchwork.libcamera.org/series/4023/mbox/"
        }
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        "Date": "Fri, 15 Sep 2023 09:57:24 +0200",
        "Message-Id": "<20230915-libyuv-convert-v1-0-1e5bcf68adac@baylibre.com>",
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        "To": "libcamera-devel@lists.libcamera.org",
        "X-Mailer": "b4 0.12.4-dev-6aa5d",
        "Subject": "[libcamera-devel] [PATCH RFC 0/7] android: add YUYV->NV12\n\tconversion via libyuv",
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        "From": "Mattijs Korpershoek via libcamera-devel\n\t<libcamera-devel@lists.libcamera.org>",
        "Reply-To": "Mattijs Korpershoek <mkorpershoek@baylibre.com>",
        "Cc": "Guillaume La Roque <glaroque@baylibre.com>",
        "Errors-To": "libcamera-devel-bounces@lists.libcamera.org",
        "Sender": "\"libcamera-devel\" <libcamera-devel-bounces@lists.libcamera.org>"
    },
    "content": "On some platforms, it's possible that the gralloc implementation\nand the CSI receiver cannot agree on a pixel format.\nWhen that happens, there is usually a m2m converter in the pipeline\nwhich handles pixel format conversion.\n\nOn platforms without pixel format converters, such as the AM62x,\nwe need to do software conversion.\n\nThe AM62x platform:\n* uses a CSI receiver (j721e-csi2rx), that only supports\n  packed YUV422 formats such as YUYV, YVYU, UYVY and VYUY.\n* Has a gralloc implementation that only supports of semi-planar\n  YUV420 formats such as NV12.\n\nThis series add support for software conversion using libyuv.\nRight now, only YUYV->NV12 is supported.\n\nThis has been send as an RFC because:\n\n1. I don't have much media knowledge, nor C++ knowledge so this is\n   probably not good enough for libcamera's high quality codebase.\n\n2. I'm not sure that transforming the \"main Type::Direct\" stream into\n   an Internal stream has no side effects.\n\n3. I'm unsure what to do with the gralloc size in case of conversion.\n   Right now, we always allocate HAL_PIXEL_FORMAT_YCBCR_420_888 in\n   CameraStream::getBuffer(). This should be adapted both on:\n   - the gralloc capabilities of the platform\n   - the conversion (if any)\n\nThis has been tested on a AM62x SK EVM board with an Alinx\nAN5641 (ov5640) sensor. In Android 13.\nIt might work on BeaglePlay with the same sensor, but I have not\ntested that.\n\nBoth preview and still capture are functional with the\ndefault com.android.camera2 app.\nNote that video recording is not supported, because that would require\na similar conversion from YUYV->MJPEG which I did not investigate yet.\n\nI would appreciate some feedback. Thanks a lot in advance if you\nhave a look!\n\nDepends on:\n- https://patchwork.libcamera.org/cover/18995/\n\nSigned-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>\n---\nMattijs Korpershoek (7):\n      android: yuv: separate source destination in length check\n      android: yuv: loop over each plane for size check\n      android: yuv: prepare support for other pixel formats\n      android: camera_device: support when no Direct stream is found\n      android: camera_stream: add add explicit input configuration\n      android: yuv: add YUYV -> NV12 conversion\n      WIP: android: add YUYV->NV12 format conversion via libyuv\n\n src/android/camera_capabilities.cpp    |  90 ++++++++++++++++++-\n src/android/camera_capabilities.h      |   4 +\n src/android/camera_device.cpp          |   9 +-\n src/android/camera_stream.cpp          |  57 +++++++++++-\n src/android/camera_stream.h            |   5 ++\n src/android/yuv/post_processor_yuv.cpp | 156 ++++++++++++++++++++++-----------\n src/android/yuv/post_processor_yuv.h   |  12 ++-\n 7 files changed, 270 insertions(+), 63 deletions(-)\n---\nbase-commit: 58e501c71c47e57f02afde1bd296a037038cd6d5\nchange-id: 20230914-libyuv-convert-fec7082343e4\n\nCheers,"
}