Subversion Repositories Kolibri OS

/*

 * pixel format descriptor

 * Copyright (c) 2009 Michael Niedermayer 

 *

 * 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 

#include "attributes.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

/**

 * @deprecated 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 attribute_deprecated 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 a 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 */