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Mike Fleming3933d922018-04-02 10:53:08 -07001/*
2 * This file is part of Libav.
3 *
4 * Libav is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * Libav is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with Libav; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19#ifndef AVUTIL_IMGUTILS_H
20#define AVUTIL_IMGUTILS_H
21
22/**
23 * @file
24 * misc image utilities
25 *
26 * @addtogroup lavu_picture
27 * @{
28 */
29
30#include "avutil.h"
31#include "pixdesc.h"
32#include "rational.h"
33
34/**
35 * Compute the max pixel step for each plane of an image with a
36 * format described by pixdesc.
37 *
38 * The pixel step is the distance in bytes between the first byte of
39 * the group of bytes which describe a pixel component and the first
40 * byte of the successive group in the same plane for the same
41 * component.
42 *
43 * @param max_pixsteps an array which is filled with the max pixel step
44 * for each plane. Since a plane may contain different pixel
45 * components, the computed max_pixsteps[plane] is relative to the
46 * component in the plane with the max pixel step.
47 * @param max_pixstep_comps an array which is filled with the component
48 * for each plane which has the max pixel step. May be NULL.
49 */
50void av_image_fill_max_pixsteps(int max_pixsteps[4], int max_pixstep_comps[4],
51 const AVPixFmtDescriptor *pixdesc);
52
53/**
54 * Compute the size of an image line with format pix_fmt and width
55 * width for the plane plane.
56 *
57 * @return the computed size in bytes
58 */
59int av_image_get_linesize(enum AVPixelFormat pix_fmt, int width, int plane);
60
61/**
62 * Fill plane linesizes for an image with pixel format pix_fmt and
63 * width width.
64 *
65 * @param linesizes array to be filled with the linesize for each plane
66 * @return >= 0 in case of success, a negative error code otherwise
67 */
68int av_image_fill_linesizes(int linesizes[4], enum AVPixelFormat pix_fmt, int width);
69
70/**
71 * Fill plane data pointers for an image with pixel format pix_fmt and
72 * height height.
73 *
74 * @param data pointers array to be filled with the pointer for each image plane
75 * @param ptr the pointer to a buffer which will contain the image
76 * @param linesizes the array containing the linesize for each
77 * plane, should be filled by av_image_fill_linesizes()
78 * @return the size in bytes required for the image buffer, a negative
79 * error code in case of failure
80 */
81int av_image_fill_pointers(uint8_t *data[4], enum AVPixelFormat pix_fmt, int height,
82 uint8_t *ptr, const int linesizes[4]);
83
84/**
85 * Allocate an image with size w and h and pixel format pix_fmt, and
86 * fill pointers and linesizes accordingly.
87 * The allocated image buffer has to be freed by using
88 * av_freep(&pointers[0]).
89 *
90 * @param align the value to use for buffer size alignment
91 * @return the size in bytes required for the image buffer, a negative
92 * error code in case of failure
93 */
94int av_image_alloc(uint8_t *pointers[4], int linesizes[4],
95 int w, int h, enum AVPixelFormat pix_fmt, int align);
96
97/**
98 * Copy image plane from src to dst.
99 * That is, copy "height" number of lines of "bytewidth" bytes each.
100 * The first byte of each successive line is separated by *_linesize
101 * bytes.
102 *
103 * @param dst_linesize linesize for the image plane in dst
104 * @param src_linesize linesize for the image plane in src
105 */
106void av_image_copy_plane(uint8_t *dst, int dst_linesize,
107 const uint8_t *src, int src_linesize,
108 int bytewidth, int height);
109
110/**
111 * Copy image in src_data to dst_data.
112 *
113 * @param dst_linesizes linesizes for the image in dst_data
114 * @param src_linesizes linesizes for the image in src_data
115 */
116void av_image_copy(uint8_t *dst_data[4], int dst_linesizes[4],
117 const uint8_t *src_data[4], const int src_linesizes[4],
118 enum AVPixelFormat pix_fmt, int width, int height);
119
120/**
121 * Check if the given dimension of an image is valid, meaning that all
122 * bytes of the image can be addressed with a signed int.
123 *
124 * @param w the width of the picture
125 * @param h the height of the picture
126 * @param log_offset the offset to sum to the log level for logging with log_ctx
127 * @param log_ctx the parent logging context, it may be NULL
128 * @return >= 0 if valid, a negative error code otherwise
129 */
130int av_image_check_size(unsigned int w, unsigned int h, int log_offset, void *log_ctx);
131
132/**
133 * Check if the given sample aspect ratio of an image is valid.
134 *
135 * It is considered invalid if the denominator is 0 or if applying the ratio
136 * to the image size would make the smaller dimension less than 1. If the
137 * sar numerator is 0, it is considered unknown and will return as valid.
138 *
139 * @param w width of the image
140 * @param h height of the image
141 * @param sar sample aspect ratio of the image
142 * @return 0 if valid, a negative AVERROR code otherwise
143 */
144int av_image_check_sar(unsigned int w, unsigned int h, AVRational sar);
145
146/**
147 * @}
148 */
149
150
151#endif /* AVUTIL_IMGUTILS_H */