Mercurial > mm7
diff lib/libavutil/pixdesc.h @ 2134:992d2e6f907d
preparation for libavcodec
author | zipi |
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date | Tue, 31 Dec 2013 14:52:14 +0000 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/lib/libavutil/pixdesc.h Tue Dec 31 14:52:14 2013 +0000 @@ -0,0 +1,289 @@ +/* + * 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 <stdint.h> +#include "pixfmt.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 2 or 4 components, then alpha is last. + * If the format has 1 or 2 components, then luma is 0. + * If the format has 3 or 4 components, + * if the RGB flag is set then 0 is red, 1 is green and 2 is blue; + * otherwise 0 is luma, 1 is chroma-U and 2 is chroma-V. + */ + AVComponentDescriptor comp[4]; +}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 FFmpeg 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) + +#if FF_API_PIX_FMT +/** + * @deprecate use the AV_PIX_FMT_FLAG_* flags + */ +#define PIX_FMT_BE AV_PIX_FMT_FLAG_BE +#define PIX_FMT_PAL AV_PIX_FMT_FLAG_PAL +#define PIX_FMT_BITSTREAM AV_PIX_FMT_FLAG_BITSTREAM +#define PIX_FMT_HWACCEL AV_PIX_FMT_FLAG_HWACCEL +#define PIX_FMT_PLANAR AV_PIX_FMT_FLAG_PLANAR +#define PIX_FMT_RGB AV_PIX_FMT_FLAG_RGB +#define PIX_FMT_PSEUDOPAL AV_PIX_FMT_FLAG_PSEUDOPAL +#define PIX_FMT_ALPHA AV_PIX_FMT_FLAG_ALPHA +#endif + +#if FF_API_PIX_FMT_DESC +/** + * The array of all the pixel format descriptors. + */ +extern const AVPixFmtDescriptor av_pix_fmt_descriptors[]; +#endif + +/** + * 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 AV_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 the number of bits per pixel for the pixel format + * described by pixdesc, including any padding or unused bits. + */ +int av_get_padded_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. + * + * See avcodec_get_chroma_sub_sample() for a function that asserts a + * valid pixel format instead of returning an error code. + * Its recommanded that you use avcodec_get_chroma_sub_sample unless + * you do check the return code! + * + * @param[in] pix_fmt the pixel format + * @param[out] h_shift store log2_chroma_w + * @param[out] v_shift store log2_chroma_h + * + * @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); + +void ff_check_pixfmt_descriptors(void); + +/** + * 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); + + +#endif /* AVUTIL_PIXDESC_H */