libavutil/imgutils.h

   1 /*
   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  */
  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  */
  81 int 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  */
  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  * @param dst_linesize linesize for the image plane in dst
 104  * @param src_linesize linesize for the image plane in src
 105  */
 106 void 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  */
 116 void 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  * Copy image data located in uncacheable (e.g. GPU mapped) memory. Where
 122  * available, this function will use special functionality for reading from such
 123  * memory, which may result in greatly improved performance compared to plain
 124  * av_image_copy().
 125  *
 126  * The data pointers and the linesizes must be aligned to the maximum required
 127  * by the CPU architecture.
 128  *
 129  * @note The linesize parameters have the type ptrdiff_t here, while they are
 130  *       int for av_image_copy().
 131  * @note On x86, the linesizes currently need to be aligned to the cacheline
 132  *       size (i.e. 64) to get improved performance.
 133  */
 134 void av_image_copy_uc_from(uint8_t *dst_data[4],       const ptrdiff_t dst_linesizes[4],
 135                            const uint8_t *src_data[4], const ptrdiff_t src_linesizes[4],
 136                            enum AVPixelFormat pix_fmt, int width, int height);
 137
 138 /**
 139  * Setup the data pointers and linesizes based on the specified image
 140  * parameters and the provided array.
 141  *
 142  * The fields of the given image are filled in by using the src
 143  * address which points to the image data buffer. Depending on the
 144  * specified pixel format, one or multiple image data pointers and
 145  * line sizes will be set.  If a planar format is specified, several
 146  * pointers will be set pointing to the different picture planes and
 147  * the line sizes of the different planes will be stored in the
 148  * lines_sizes array. Call with src == NULL to get the required
 149  * size for the src buffer.
 150  *
 151  * To allocate the buffer and fill in the dst_data and dst_linesize in
 152  * one call, use av_image_alloc().
 153  *
 154  * @param dst_data      data pointers to be filled in
 155  * @param dst_linesize  linesizes for the image in dst_data to be filled in
 156  * @param src           buffer which will contain or contains the actual image data, can be NULL
 157  * @param pix_fmt       the pixel format of the image
 158  * @param width         the width of the image in pixels
 159  * @param height        the height of the image in pixels
 160  * @param align         the value used in src for linesize alignment
 161  * @return the size in bytes required for src, a negative error code
 162  * in case of failure
 163  */
 164 int av_image_fill_arrays(uint8_t *dst_data[4], int dst_linesize[4],
 165                          const uint8_t *src,
 166                          enum AVPixelFormat pix_fmt, int width, int height, int align);
 167
 168 /**
 169  * Return the size in bytes of the amount of data required to store an
 170  * image with the given parameters.
 171  *
 172  * @param pix_fmt  the pixel format of the image
 173  * @param width    the width of the image in pixels
 174  * @param height   the height of the image in pixels
 175  * @param align    the assumed linesize alignment
 176  * @return the buffer size in bytes, a negative error code in case of failure
 177  */
 178 int av_image_get_buffer_size(enum AVPixelFormat pix_fmt, int width, int height, int align);
 179
 180 /**
 181  * Copy image data from an image into a buffer.
 182  *
 183  * av_image_get_buffer_size() can be used to compute the required size
 184  * for the buffer to fill.
 185  *
 186  * @param dst           a buffer into which picture data will be copied
 187  * @param dst_size      the size in bytes of dst
 188  * @param src_data      pointers containing the source image data
 189  * @param src_linesize  linesizes for the image in src_data
 190  * @param pix_fmt       the pixel format of the source image
 191  * @param width         the width of the source image in pixels
 192  * @param height        the height of the source image in pixels
 193  * @param align         the assumed linesize alignment for dst
 194  * @return the number of bytes written to dst, or a negative value
 195  * (error code) on error
 196  */
 197 int av_image_copy_to_buffer(uint8_t *dst, int dst_size,
 198                             const uint8_t * const src_data[4], const int src_linesize[4],
 199                             enum AVPixelFormat pix_fmt, int width, int height, int align);
 200
 201 /**
 202  * Check if the given dimension of an image is valid, meaning that all
 203  * bytes of the image can be addressed with a signed int.
 204  *
 205  * @param w the width of the picture
 206  * @param h the height of the picture
 207  * @param log_offset the offset to sum to the log level for logging with log_ctx
 208  * @param log_ctx the parent logging context, it may be NULL
 209  * @return >= 0 if valid, a negative error code otherwise
 210  */
 211 int av_image_check_size(unsigned int w, unsigned int h, int log_offset, void *log_ctx);
 212
 213 /**
 214  * Check if the given sample aspect ratio of an image is valid.
 215  *
 216  * It is considered invalid if the denominator is 0 or if applying the ratio
 217  * to the image size would make the smaller dimension less than 1. If the
 218  * sar numerator is 0, it is considered unknown and will return as valid.
 219  *
 220  * @param w width of the image
 221  * @param h height of the image
 222  * @param sar sample aspect ratio of the image
 223  * @return 0 if valid, a negative AVERROR code otherwise
 224  */
 225 int av_image_check_sar(unsigned int w, unsigned int h, AVRational sar);
 226
 227 /**
 228  * Overwrite the image data with black. This is suitable for filling a
 229  * sub-rectangle of an image, meaning the padding between the right most pixel
 230  * and the left most pixel on the next line will not be overwritten. For some
 231  * formats, the image size might be rounded up due to inherent alignment.
 232  *
 233  * If the pixel format has alpha, the alpha is cleared to opaque.
 234  *
 235  * This can return an error if the pixel format is not supported. Normally, all
 236  * non-hwaccel pixel formats should be supported.
 237  *
 238  * Passing NULL for dst_data is allowed. Then the function returns whether the
 239  * operation would have succeeded. (It can return an error if the pix_fmt is
 240  * not supported.)
 241  *
 242  * @param dst_data      data pointers to destination image
 243  * @param dst_linesize  linesizes for the destination image
 244  * @param pix_fmt       the pixel format of the image
 245  * @param range         the color range of the image (important for colorspaces such as YUV)
 246  * @param width         the width of the image in pixels
 247  * @param height        the height of the image in pixels
 248  * @return 0 if the image data was cleared, a negative AVERROR code otherwise
 249  */
 250 int av_image_fill_black(uint8_t *dst_data[4], const ptrdiff_t dst_linesize[4],
 251                         enum AVPixelFormat pix_fmt, enum AVColorRange range,
 252                         int width, int height);
 253
 254 /**
 255  * @}
 256  */
 257
 258
 259 #endif /* AVUTIL_IMGUTILS_H */