/* * pixel format descriptor * Copyright (c) 2009 Michael Niedermayer * * This file is part of Libav. * * Libav 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. * * Libav 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 Libav; 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 #include "attributes.h" #include "pixfmt.h" typedef struct AVComponentDescriptor { /** * Which of the 4 planes contains the component. */ int plane; /** * Number of elements between 2 horizontally consecutive pixels. * Elements are bits for bitstream formats, bytes otherwise. */ int step; /** * Number of elements before the component of the first pixel. * Elements are bits for bitstream formats, bytes otherwise. */ int offset; /** * Number of least significant bits that must be shifted away * to get the value. */ int shift; /** * Number of bits in the component. */ int depth; #if FF_API_PLUS1_MINUS1 /** deprecated, use step instead */ attribute_deprecated int step_minus1; /** deprecated, use depth instead */ attribute_deprecated int depth_minus1; /** deprecated, use offset instead */ attribute_deprecated int offset_plus1; #endif } 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 = AV_CEIL_RSHIFT(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; /** * Amount to shift the luma height right to find the chroma height. * For YV12 this is 1 for example. * chroma_height= AV_CEIL_RSHIFT(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; /** * Combination of AV_PIX_FMT_FLAG_... flags. */ uint64_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]. * If the format is RGB-like, the first component is R, followed * by G and B. * * If the format is YUV-like, the first component is Y, followed * by U and V. * * If present, the Alpha channel is always the last component. */ AVComponentDescriptor comp[4]; /** * Alternative comma-separated names. */ const char *alias; } AVPixFmtDescriptor; /** * Pixel format is big-endian. */ #define AV_PIX_FMT_FLAG_BE (1 << 0) /** * Pixel format has a palette in data[1], values are indexes in this palette. */ #define AV_PIX_FMT_FLAG_PAL (1 << 1) /** * All values of a component are bit-wise packed end to end. */ #define AV_PIX_FMT_FLAG_BITSTREAM (1 << 2) /** * Pixel format is an HW accelerated format. */ #define AV_PIX_FMT_FLAG_HWACCEL (1 << 3) /** * At least one pixel component is not in the first data plane. */ #define AV_PIX_FMT_FLAG_PLANAR (1 << 4) /** * The pixel format contains RGB-like data (as opposed to YUV/grayscale). */ #define AV_PIX_FMT_FLAG_RGB (1 << 5) /** * The pixel format is "pseudo-paletted". This means that Libav treats it as * paletted internally, but the palette is generated by the decoder and is not * stored in the file. */ #define AV_PIX_FMT_FLAG_PSEUDOPAL (1 << 6) /** * The pixel format has an alpha channel. */ #define AV_PIX_FMT_FLAG_ALPHA (1 << 7) /** * 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 AVPixelFormat av_get_pix_fmt(const char *name); /** * Return the short name for a pixel format, NULL in case pix_fmt is * unknown. * * @see av_get_pix_fmt(), av_get_pix_fmt_string() */ const char *av_get_pix_fmt_name(enum AVPixelFormat pix_fmt); /** * 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 AVPixelFormat pix_fmt); /** * Return the number of bits per pixel used by the pixel format * described by pixdesc. Note that this is not the same as the number * of bits per sample. * * 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); /** * @return a pixel format descriptor for provided pixel format or NULL if * this pixel format is unknown. */ const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt); /** * Iterate over all pixel format descriptors known to libavutil. * * @param prev previous descriptor. NULL to get the first descriptor. * * @return next descriptor or NULL after the last descriptor */ const AVPixFmtDescriptor *av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev); /** * @return an AVPixelFormat id described by desc, or AV_PIX_FMT_NONE if desc * is not a valid pointer to a pixel format descriptor. */ enum AVPixelFormat av_pix_fmt_desc_get_id(const AVPixFmtDescriptor *desc); /** * Utility function to access log2_chroma_w log2_chroma_h from * the pixel format AVPixFmtDescriptor. * * @param[in] pix_fmt the pixel format * @param[out] h_shift store log2_chroma_w (horizontal/width shift) * @param[out] v_shift store log2_chroma_h (vertical/height shift) * * @return 0 on success, AVERROR(ENOSYS) on invalid or unknown pixel format */ int av_pix_fmt_get_chroma_sub_sample(enum AVPixelFormat pix_fmt, int *h_shift, int *v_shift); /** * @return number of planes in pix_fmt, a negative AVERROR if pix_fmt is not a * valid pixel format. */ int av_pix_fmt_count_planes(enum AVPixelFormat pix_fmt); /** * Utility function to swap the endianness of a pixel format. * * @param[in] pix_fmt the pixel format * * @return pixel format with swapped endianness if it exists, * otherwise AV_PIX_FMT_NONE */ enum AVPixelFormat av_pix_fmt_swap_endianness(enum AVPixelFormat pix_fmt); /** * @return the name for provided color range or NULL if unknown. */ const char *av_color_range_name(enum AVColorRange range); /** * @return the name for provided color primaries or NULL if unknown. */ const char *av_color_primaries_name(enum AVColorPrimaries primaries); /** * @return the name for provided color transfer or NULL if unknown. */ const char *av_color_transfer_name(enum AVColorTransferCharacteristic transfer); /** * @return the name for provided color space or NULL if unknown. */ const char *av_color_space_name(enum AVColorSpace space); /** * @return the name for provided chroma location or NULL if unknown. */ const char *av_chroma_location_name(enum AVChromaLocation location); #endif /* AVUTIL_PIXDESC_H */