221 lines
8.2 KiB
C
221 lines
8.2 KiB
C
/*
|
|
* pixel format descriptor
|
|
* Copyright (c) 2009 Michael Niedermayer <michaelni@gmx.at>
|
|
*
|
|
* 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 <inttypes.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 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.
|
|
#define PIX_FMT_PLANAR 16 ///< At least one pixel component is not in the first data plane
|
|
#define PIX_FMT_RGB 32 ///< The pixel format contains RGB-like data (as opposed to YUV/grayscale)
|
|
/**
|
|
* 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 PIX_FMT_PSEUDOPAL 64
|
|
|
|
#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 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.
|
|
*
|
|
* 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_h
|
|
* @param[out] v_shift store log2_chroma_w
|
|
*
|
|
* @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);
|
|
|
|
|
|
#endif /* AVUTIL_PIXDESC_H */
|