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Diffstat (limited to 'Documentation/media/uapi/v4l/pixfmt-meta-intel-ipu3.rst')
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1 files changed, 35 insertions, 109 deletions
diff --git a/Documentation/media/uapi/v4l/pixfmt-meta-intel-ipu3.rst b/Documentation/media/uapi/v4l/pixfmt-meta-intel-ipu3.rst index dc871006b41a..7fb54339f4a7 100644 --- a/Documentation/media/uapi/v4l/pixfmt-meta-intel-ipu3.rst +++ b/Documentation/media/uapi/v4l/pixfmt-meta-intel-ipu3.rst @@ -1,4 +1,27 @@ -.. -*- coding: utf-8; mode: rst -*- +.. This file is dual-licensed: you can use it either under the terms +.. of the GPL 2.0 or the GFDL 1.1+ license, at your option. Note that this +.. dual licensing only applies to this file, and not this project as a +.. whole. +.. +.. a) This file is free software; you can redistribute it and/or +.. modify it under the terms of the GNU General Public License version +.. 2.0 as published by the Free Software Foundation. +.. +.. This file is distributed in the hope that it will be useful, +.. but WITHOUT ANY WARRANTY; without even the implied warranty of +.. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +.. GNU General Public License version 2.0 for more details. +.. +.. Or, alternatively, +.. +.. b) Permission is granted to copy, distribute and/or modify this +.. document under the terms of the GNU Free Documentation License, +.. Version 1.1 or any later version published by the Free Software +.. Foundation, with no Invariant Sections, no Front-Cover Texts +.. and no Back-Cover Texts. A copy of the license is included at +.. Documentation/media/uapi/fdl-appendix.rst. +.. +.. TODO: replace it to GPL-2.0 OR GFDL-1.1-or-later WITH no-invariant-sections .. _v4l2-meta-fmt-params: .. _v4l2-meta-fmt-stat-3a: @@ -7,21 +30,22 @@ V4L2_META_FMT_IPU3_PARAMS ('ip3p'), V4L2_META_FMT_IPU3_3A ('ip3s') ****************************************************************** -.. c:type:: ipu3_uapi_stats_3a +.. ipu3_uapi_stats_3a 3A statistics ============= -For IPU3 ImgU, the 3A statistics accelerators collect different statistics over -an input bayer frame. Those statistics, defined in data struct :c:type:`ipu3_uapi_stats_3a`, -are obtained from "ipu3-imgu 3a stat" metadata capture video node, which are then -passed to user space for statistics analysis using :c:type:`v4l2_meta_format` interface. +The IPU3 ImgU 3A statistics accelerators collect different statistics over +an input Bayer frame. Those statistics are obtained from the "ipu3-imgu [01] 3a +stat" metadata capture video nodes, using the :c:type:`v4l2_meta_format` +interface. They are formatted as described by the :c:type:`ipu3_uapi_stats_3a` +structure. The statistics collected are AWB (Auto-white balance) RGBS (Red, Green, Blue and Saturation measure) cells, AWB filter response, AF (Auto-focus) filter response, and AE (Auto-exposure) histogram. -struct :c:type:`ipu3_uapi_4a_config` saves configurable parameters for all above. +The struct :c:type:`ipu3_uapi_4a_config` saves all configurable parameters. .. code-block:: c @@ -37,105 +61,14 @@ struct :c:type:`ipu3_uapi_4a_config` saves configurable parameters for all above struct ipu3_uapi_ff_status stats_3a_status; }; -.. c:type:: ipu3_uapi_params +.. ipu3_uapi_params Pipeline parameters =================== -IPU3 pipeline has a number of image processing stages, each of which takes a -set of parameters as input. The major stages of pipelines are shown here: - -Raw pixels -> Bayer Downscaling -> Optical Black Correction -> - -Linearization -> Lens Shading Correction -> White Balance / Exposure / - -Focus Apply -> Bayer Noise Reduction -> ANR -> Demosaicing -> Color - -Correction Matrix -> Gamma correction -> Color Space Conversion -> - -Chroma Down Scaling -> Chromatic Noise Reduction -> Total Color - -Correction -> XNR3 -> TNR -> DDR - -The table below presents a description of the above algorithms. - -======================== ======================================================= -Name Description -======================== ======================================================= -Optical Black Correction Optical Black Correction block subtracts a pre-defined - value from the respective pixel values to obtain better - image quality. - Defined in :c:type:`ipu3_uapi_obgrid_param`. -Linearization This algo block uses linearization parameters to - address non-linearity sensor effects. The Lookup table - table is defined in - :c:type:`ipu3_uapi_isp_lin_vmem_params`. -SHD Lens shading correction is used to correct spatial - non-uniformity of the pixel response due to optical - lens shading. This is done by applying a different gain - for each pixel. The gain, black level etc are - configured in :c:type:`ipu3_uapi_shd_config_static`. -BNR Bayer noise reduction block removes image noise by - applying a bilateral filter. - See :c:type:`ipu3_uapi_bnr_static_config` for details. -ANR Advanced Noise Reduction is a block based algorithm - that performs noise reduction in the Bayer domain. The - convolution matrix etc can be found in - :c:type:`ipu3_uapi_anr_config`. -Demosaicing Demosaicing converts raw sensor data in Bayer format - into RGB (Red, Green, Blue) presentation. Then add - outputs of estimation of Y channel for following stream - processing by Firmware. The struct is defined as - :c:type:`ipu3_uapi_dm_config`. (TODO) -Color Correction Color Correction algo transforms sensor specific color - space to the standard "sRGB" color space. This is done - by applying 3x3 matrix defined in - :c:type:`ipu3_uapi_ccm_mat_config`. -Gamma correction Gamma correction :c:type:`ipu3_uapi_gamma_config` is a - basic non-linear tone mapping correction that is - applied per pixel for each pixel component. -CSC Color space conversion transforms each pixel from the - RGB primary presentation to YUV (Y: brightness, - UV: Luminance) presentation. This is done by applying - a 3x3 matrix defined in - :c:type:`ipu3_uapi_csc_mat_config` -CDS Chroma down sampling - After the CSC is performed, the Chroma Down Sampling - is applied for a UV plane down sampling by a factor - of 2 in each direction for YUV 4:2:0 using a 4x2 - configurable filter :c:type:`ipu3_uapi_cds_params`. -CHNR Chroma noise reduction - This block processes only the chrominance pixels and - performs noise reduction by cleaning the high - frequency noise. - See struct :c:type:`ipu3_uapi_yuvp1_chnr_config`. -TCC Total color correction as defined in struct - :c:type:`ipu3_uapi_yuvp2_tcc_static_config`. -XNR3 eXtreme Noise Reduction V3 is the third revision of - noise reduction algorithm used to improve image - quality. This removes the low frequency noise in the - captured image. Two related structs are being defined, - :c:type:`ipu3_uapi_isp_xnr3_params` for ISP data memory - and :c:type:`ipu3_uapi_isp_xnr3_vmem_params` for vector - memory. -TNR Temporal Noise Reduction block compares successive - frames in time to remove anomalies / noise in pixel - values. :c:type:`ipu3_uapi_isp_tnr3_vmem_params` and - :c:type:`ipu3_uapi_isp_tnr3_params` are defined for ISP - vector and data memory respectively. -======================== ======================================================= - -A few stages of the pipeline will be executed by firmware running on the ISP -processor, while many others will use a set of fixed hardware blocks also -called accelerator cluster (ACC) to crunch pixel data and produce statistics. - -ACC parameters of individual algorithms, as defined by -:c:type:`ipu3_uapi_acc_param`, can be chosen to be applied by the user -space through struct :c:type:`ipu3_uapi_flags` embedded in -:c:type:`ipu3_uapi_params` structure. For parameters that are configured as -not enabled by the user space, the corresponding structs are ignored by the -driver, in which case the existing configuration of the algorithm will be -preserved. +The pipeline parameters are passed to the "ipu3-imgu [01] parameters" metadata +output video nodes, using the :c:type:`v4l2_meta_format` interface. They are +formatted as described by the :c:type:`ipu3_uapi_params` structure. Both 3A statistics and pipeline parameters described here are closely tied to the underlying camera sub-system (CSS) APIs. They are usually consumed and @@ -143,13 +76,6 @@ produced by dedicated user space libraries that comprise the important tuning tools, thus freeing the developers from being bothered with the low level hardware and algorithm details. -It should be noted that IPU3 DMA operations require the addresses of all data -structures (that includes both input and output) to be aligned on 32 byte -boundaries. - -The meta data :c:type:`ipu3_uapi_params` will be sent to "ipu3-imgu parameters" -video node in ``V4L2_BUF_TYPE_META_CAPTURE`` format. - .. code-block:: c struct ipu3_uapi_params { |