/* * pixel format descriptor * Copyright (c) 2009 Michael Niedermayer <michaelni@gmx.at> * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #ifndef AVUTIL_PIXDESC_H #define AVUTIL_PIXDESC_H #include <inttypes.h> typedef struct AVComponentDescriptor{ uint16_t plane :2; ///< which of the 4 planes contains the component /** * Number of elements between 2 horizontally consecutive pixels minus 1. * Elements are bits for bitstream formats, bytes otherwise. */ uint16_t step_minus1 :3; /** * Number of elements before the component of the first pixel plus 1. * Elements are bits for bitstream formats, bytes otherwise. */ uint16_t offset_plus1 :3; uint16_t shift :3; ///< number of least significant bits that must be shifted away to get the value uint16_t depth_minus1 :4; ///< number of bits in the component minus 1 }AVComponentDescriptor; /** * Descriptor that unambiguously describes how the bits of a pixel are * stored in the up to 4 data planes of an image. It also stores the * subsampling factors and number of components. * * @note This is separate of the colorspace (RGB, YCbCr, YPbPr, JPEG-style YUV * and all the YUV variants) AVPixFmtDescriptor just stores how values * are stored not what these values represent. */ typedef struct AVPixFmtDescriptor{ const char *name; uint8_t nb_components; ///< The number of components each pixel has, (1-4) /** * Amount to shift the luma width right to find the chroma width. * For YV12 this is 1 for example. * chroma_width = -((-luma_width) >> log2_chroma_w) * The note above is needed to ensure rounding up. * This value only refers to the chroma components. */ uint8_t log2_chroma_w; ///< chroma_width = -((-luma_width )>>log2_chroma_w) /** * Amount to shift the luma height right to find the chroma height. * For YV12 this is 1 for example. * chroma_height= -((-luma_height) >> log2_chroma_h) * The note above is needed to ensure rounding up. * This value only refers to the chroma components. */ uint8_t log2_chroma_h; uint8_t flags; /** * Parameters that describe how pixels are packed. If the format * has chroma components, they must be stored in comp[1] and * comp[2]. */ AVComponentDescriptor comp[4]; }AVPixFmtDescriptor; #define PIX_FMT_BE 1 ///< Pixel format is big-endian. #define PIX_FMT_PAL 2 ///< Pixel format has a palette in data[1], values are indexes in this palette. #define PIX_FMT_BITSTREAM 4 ///< All values of a component are bit-wise packed end to end. #define PIX_FMT_HWACCEL 8 ///< Pixel format is an HW accelerated format. /** * The array of all the pixel format descriptors. */ extern const AVPixFmtDescriptor av_pix_fmt_descriptors[]; /** * Read a line from an image, and write the values of the * pixel format component c to dst. * * @param data the array containing the pointers to the planes of the image * @param linesize the array containing the linesizes of the image * @param desc the pixel format descriptor for the image * @param x the horizontal coordinate of the first pixel to read * @param y the vertical coordinate of the first pixel to read * @param w the width of the line to read, that is the number of * values to write to dst * @param read_pal_component if not zero and the format is a paletted * format writes the values corresponding to the palette * component c in data[1] to dst, rather than the palette indexes in * data[0]. The behavior is undefined if the format is not paletted. */ void av_read_image_line(uint16_t *dst, const uint8_t *data[4], const int linesize[4], const AVPixFmtDescriptor *desc, int x, int y, int c, int w, int read_pal_component); /** * Write the values from src to the pixel format component c of an * image line. * * @param src array containing the values to write * @param data the array containing the pointers to the planes of the * image to write into. It is supposed to be zeroed. * @param linesize the array containing the linesizes of the image * @param desc the pixel format descriptor for the image * @param x the horizontal coordinate of the first pixel to write * @param y the vertical coordinate of the first pixel to write * @param w the width of the line to write, that is the number of * values to write to the image line */ void av_write_image_line(const uint16_t *src, uint8_t *data[4], const int linesize[4], const AVPixFmtDescriptor *desc, int x, int y, int c, int w); /** * Return the pixel format corresponding to name. * * If there is no pixel format with name name, then looks for a * pixel format with the name corresponding to the native endian * format of name. * For example in a little-endian system, first looks for "gray16", * then for "gray16le". * * Finally if no pixel format has been found, returns PIX_FMT_NONE. */ enum PixelFormat av_get_pix_fmt(const char *name); /** * Print in buf the string corresponding to the pixel format with * number pix_fmt, or an header if pix_fmt is negative. * * @param buf the buffer where to write the string * @param buf_size the size of buf * @param pix_fmt the number of the pixel format to print the * corresponding info string, or a negative value to print the * corresponding header. */ char *av_get_pix_fmt_string (char *buf, int buf_size, enum PixelFormat pix_fmt); /** * Return the number of bits per pixel used by the pixel format * described by pixdesc. * * The returned number of bits refers to the number of bits actually * used for storing the pixel information, that is padding bits are * not counted. */ int av_get_bits_per_pixel(const AVPixFmtDescriptor *pixdesc); #endif /* AVUTIL_PIXDESC_H */