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ffmpeg / libavcore / imgutils.h @ a6ddf8bf

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/*
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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#ifndef AVCORE_IMGUTILS_H
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#define AVCORE_IMGUTILS_H
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/**
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 * @file
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 * misc image utilities
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 */
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#include "libavutil/pixdesc.h"
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#include "avcore.h"
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/**
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 * Compute the max pixel step for each plane of an image with a
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 * format described by pixdesc
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 *
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 * The pixel step is the distance in bytes between the first byte of
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 * the group of bytes which describe a pixel component and the first
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 * byte of the successive group in the same plane for the same
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 * component.
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 *
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 * @param max_pixstep an array which is filled with the max pixel step
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 * for each plane. Since a plane may contain different pixel
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 * components, the computed max_pixstep[plane] is relative to the
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 * component in the plane with the max pixel step.
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 * @param max_pixstep_comp an array which is filled with the component
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 * for each plane which has the max pixel step. May be NULL.
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 */
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static inline void av_fill_image_max_pixstep(int max_pixstep[4], int max_pixstep_comp[4],
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                                             const AVPixFmtDescriptor *pixdesc)
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{
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    int i;
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    memset(max_pixstep, 0, 4*sizeof(max_pixstep[0]));
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    if (max_pixstep_comp)
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        memset(max_pixstep_comp, 0, 4*sizeof(max_pixstep_comp[0]));
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    for (i = 0; i < 4; i++) {
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        const AVComponentDescriptor *comp = &(pixdesc->comp[i]);
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        if ((comp->step_minus1+1) > max_pixstep[comp->plane]) {
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            max_pixstep[comp->plane] = comp->step_minus1+1;
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            if (max_pixstep_comp)
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                max_pixstep_comp[comp->plane] = i;
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        }
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    }
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}
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/**
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 * Compute the size of an image line with format pix_fmt and width
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 * width for the plane plane.
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 *
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 * @return the computed size in bytes
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 */
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int av_get_image_linesize(enum PixelFormat pix_fmt, int width, int plane);
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/**
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 * Fill plane linesizes for an image with pixel format pix_fmt and
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 * width width.
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 *
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 * @param linesizes array to be filled with the linesize for each plane
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 * @return >= 0 in case of success, a negative error code otherwise
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 */
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int av_fill_image_linesizes(int linesizes[4], enum PixelFormat pix_fmt, int width);
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/**
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 * Fill plane data pointers for an image with pixel format pix_fmt and
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 * height height.
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 *
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 * @param data pointers array to be filled with the pointer for each image plane
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 * @param ptr the pointer to a buffer which will contain the image
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 * @param linesizes[4] the array containing the linesize for each
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 * plane, should be filled by av_fill_image_linesizes()
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 * @return the size in bytes required for the image buffer, a negative
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 * error code in case of failure
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 */
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int av_fill_image_pointers(uint8_t *data[4], enum PixelFormat pix_fmt, int height,
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                           uint8_t *ptr, const int linesizes[4]);
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/**
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 * Check if the given dimension of an image is valid, meaning that all
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 * bytes of the image can be addressed with a signed int.
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 *
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 * @param w the width of the picture
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 * @param h the height of the picture
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 * @param log_offset the offset to sum to the log level for logging with log_ctx
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 * @param log_ctx the parent logging context, it may be NULL
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 * @return >= 0 if valid, a negative error code otherwise
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 */
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int av_check_image_size(unsigned int w, unsigned int h, int log_offset, void *log_ctx);
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#endif /* AVCORE_IMGUTILS_H */