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imgutils.h
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1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg 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  * FFmpeg 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 FFmpeg; 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  */
50 void 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  */
59 int 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  */
68 int 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  */
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  */
94 int 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  * bytewidth must be contained by both absolute values of dst_linesize
104  * and src_linesize, otherwise the function behavior is undefined.
105  *
106  * @param dst_linesize linesize for the image plane in dst
107  * @param src_linesize linesize for the image plane in src
108  */
109 void av_image_copy_plane(uint8_t *dst, int dst_linesize,
110  const uint8_t *src, int src_linesize,
111  int bytewidth, int height);
112 
113 /**
114  * Copy image in src_data to dst_data.
115  *
116  * @param dst_linesizes linesizes for the image in dst_data
117  * @param src_linesizes linesizes for the image in src_data
118  */
119 void av_image_copy(uint8_t *dst_data[4], int dst_linesizes[4],
120  const uint8_t *src_data[4], const int src_linesizes[4],
121  enum AVPixelFormat pix_fmt, int width, int height);
122 
123 /**
124  * Setup the data pointers and linesizes based on the specified image
125  * parameters and the provided array.
126  *
127  * The fields of the given image are filled in by using the src
128  * address which points to the image data buffer. Depending on the
129  * specified pixel format, one or multiple image data pointers and
130  * line sizes will be set. If a planar format is specified, several
131  * pointers will be set pointing to the different picture planes and
132  * the line sizes of the different planes will be stored in the
133  * lines_sizes array. Call with !src to get the required
134  * size for the src buffer.
135  *
136  * To allocate the buffer and fill in the dst_data and dst_linesize in
137  * one call, use av_image_alloc().
138  *
139  * @param dst_data data pointers to be filled in
140  * @param dst_linesizes linesizes for the image in dst_data to be filled in
141  * @param src buffer which will contain or contains the actual image data, can be NULL
142  * @param pix_fmt the pixel format of the image
143  * @param width the width of the image in pixels
144  * @param height the height of the image in pixels
145  * @param align the value used in src for linesize alignment
146  * @return the size in bytes required for src, a negative error code
147  * in case of failure
148  */
149 int av_image_fill_arrays(uint8_t *dst_data[4], int dst_linesize[4],
150  const uint8_t *src,
151  enum AVPixelFormat pix_fmt, int width, int height, int align);
152 
153 /**
154  * Return the size in bytes of the amount of data required to store an
155  * image with the given parameters.
156  *
157  * @param[in] align the assumed linesize alignment
158  */
160 
161 /**
162  * Copy image data from an image into a buffer.
163  *
164  * av_image_get_buffer_size() can be used to compute the required size
165  * for the buffer to fill.
166  *
167  * @param dst a buffer into which picture data will be copied
168  * @param dst_size the size in bytes of dst
169  * @param src_data pointers containing the source image data
170  * @param src_linesizes linesizes for the image in src_data
171  * @param pix_fmt the pixel format of the source image
172  * @param width the width of the source image in pixels
173  * @param height the height of the source image in pixels
174  * @param align the assumed linesize alignment for dst
175  * @return the number of bytes written to dst, or a negative value
176  * (error code) on error
177  */
178 int av_image_copy_to_buffer(uint8_t *dst, int dst_size,
179  const uint8_t * const src_data[4], const int src_linesize[4],
180  enum AVPixelFormat pix_fmt, int width, int height, int align);
181 
182 /**
183  * Check if the given dimension of an image is valid, meaning that all
184  * bytes of the image can be addressed with a signed int.
185  *
186  * @param w the width of the picture
187  * @param h the height of the picture
188  * @param log_offset the offset to sum to the log level for logging with log_ctx
189  * @param log_ctx the parent logging context, it may be NULL
190  * @return >= 0 if valid, a negative error code otherwise
191  */
192 int av_image_check_size(unsigned int w, unsigned int h, int log_offset, void *log_ctx);
193 
194 /**
195  * Check if the given sample aspect ratio of an image is valid.
196  *
197  * It is considered invalid if the denominator is 0 or if applying the ratio
198  * to the image size would make the smaller dimension less than 1. If the
199  * sar numerator is 0, it is considered unknown and will return as valid.
200  *
201  * @param w width of the image
202  * @param h height of the image
203  * @param sar sample aspect ratio of the image
204  * @return 0 if valid, a negative AVERROR code otherwise
205  */
206 int av_image_check_sar(unsigned int w, unsigned int h, AVRational sar);
207 
208 /**
209  * @}
210  */
211 
212 
213 #endif /* AVUTIL_IMGUTILS_H */