1 /* 2 * pixel format descriptor 3 * Copyright (c) 2009 Michael Niedermayer <michaelni@gmx.at> 4 * 5 * This file is part of FFmpeg. 6 * 7 * FFmpeg is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License as published by the Free Software Foundation; either 10 * version 2.1 of the License, or (at your option) any later version. 11 * 12 * FFmpeg is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with FFmpeg; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22 #ifndef AVUTIL_PIXDESC_H 23 #define AVUTIL_PIXDESC_H 24 25 #include <inttypes.h> 26 27 #include "attributes.h" 28 #include "pixfmt.h" 29 #include "version.h" 30 31 typedef struct AVComponentDescriptor { 32 /** 33 * Which of the 4 planes contains the component. 34 */ 35 int plane; 36 37 /** 38 * Number of elements between 2 horizontally consecutive pixels. 39 * Elements are bits for bitstream formats, bytes otherwise. 40 */ 41 int step; 42 43 /** 44 * Number of elements before the component of the first pixel. 45 * Elements are bits for bitstream formats, bytes otherwise. 46 */ 47 int offset; 48 49 /** 50 * Number of least significant bits that must be shifted away 51 * to get the value. 52 */ 53 int shift; 54 55 /** 56 * Number of bits in the component. 57 */ 58 int depth; 59 60 #if FF_API_PLUS1_MINUS1 61 /** deprecated, use step instead */ 62 attribute_deprecated int step_minus1; 63 64 /** deprecated, use depth instead */ 65 attribute_deprecated int depth_minus1; 66 67 /** deprecated, use offset instead */ 68 attribute_deprecated int offset_plus1; 69 #endif 70 } AVComponentDescriptor; 71 72 /** 73 * Descriptor that unambiguously describes how the bits of a pixel are 74 * stored in the up to 4 data planes of an image. It also stores the 75 * subsampling factors and number of components. 76 * 77 * @note This is separate of the colorspace (RGB, YCbCr, YPbPr, JPEG-style YUV 78 * and all the YUV variants) AVPixFmtDescriptor just stores how values 79 * are stored not what these values represent. 80 */ 81 typedef struct AVPixFmtDescriptor { 82 const char *name; 83 uint8_t nb_components; ///< The number of components each pixel has, (1-4) 84 85 /** 86 * Amount to shift the luma width right to find the chroma width. 87 * For YV12 this is 1 for example. 88 * chroma_width = AV_CEIL_RSHIFT(luma_width, log2_chroma_w) 89 * The note above is needed to ensure rounding up. 90 * This value only refers to the chroma components. 91 */ 92 uint8_t log2_chroma_w; 93 94 /** 95 * Amount to shift the luma height right to find the chroma height. 96 * For YV12 this is 1 for example. 97 * chroma_height= AV_CEIL_RSHIFT(luma_height, log2_chroma_h) 98 * The note above is needed to ensure rounding up. 99 * This value only refers to the chroma components. 100 */ 101 uint8_t log2_chroma_h; 102 103 /** 104 * Combination of AV_PIX_FMT_FLAG_... flags. 105 */ 106 uint64_t flags; 107 108 /** 109 * Parameters that describe how pixels are packed. 110 * If the format has 1 or 2 components, then luma is 0. 111 * If the format has 3 or 4 components: 112 * if the RGB flag is set then 0 is red, 1 is green and 2 is blue; 113 * otherwise 0 is luma, 1 is chroma-U and 2 is chroma-V. 114 * 115 * If present, the Alpha channel is always the last component. 116 */ 117 AVComponentDescriptor comp[4]; 118 119 /** 120 * Alternative comma-separated names. 121 */ 122 const char *alias; 123 } AVPixFmtDescriptor; 124 125 /** 126 * Pixel format is big-endian. 127 */ 128 #define AV_PIX_FMT_FLAG_BE (1 << 0) 129 /** 130 * Pixel format has a palette in data[1], values are indexes in this palette. 131 */ 132 #define AV_PIX_FMT_FLAG_PAL (1 << 1) 133 /** 134 * All values of a component are bit-wise packed end to end. 135 */ 136 #define AV_PIX_FMT_FLAG_BITSTREAM (1 << 2) 137 /** 138 * Pixel format is an HW accelerated format. 139 */ 140 #define AV_PIX_FMT_FLAG_HWACCEL (1 << 3) 141 /** 142 * At least one pixel component is not in the first data plane. 143 */ 144 #define AV_PIX_FMT_FLAG_PLANAR (1 << 4) 145 /** 146 * The pixel format contains RGB-like data (as opposed to YUV/grayscale). 147 */ 148 #define AV_PIX_FMT_FLAG_RGB (1 << 5) 149 150 #if FF_API_PSEUDOPAL 151 /** 152 * The pixel format is "pseudo-paletted". This means that it contains a 153 * fixed palette in the 2nd plane but the palette is fixed/constant for each 154 * PIX_FMT. This allows interpreting the data as if it was PAL8, which can 155 * in some cases be simpler. Or the data can be interpreted purely based on 156 * the pixel format without using the palette. 157 * An example of a pseudo-paletted format is AV_PIX_FMT_GRAY8 158 * 159 * @deprecated This flag is deprecated, and will be removed. When it is removed, 160 * the extra palette allocation in AVFrame.data[1] is removed as well. Only 161 * actual paletted formats (as indicated by AV_PIX_FMT_FLAG_PAL) will have a 162 * palette. Starting with FFmpeg versions which have this flag deprecated, the 163 * extra "pseudo" palette is already ignored, and API users are not required to 164 * allocate a palette for AV_PIX_FMT_FLAG_PSEUDOPAL formats (it was required 165 * before the deprecation, though). 166 */ 167 #define AV_PIX_FMT_FLAG_PSEUDOPAL (1 << 6) 168 #endif 169 170 /** 171 * The pixel format has an alpha channel. This is set on all formats that 172 * support alpha in some way, including AV_PIX_FMT_PAL8. The alpha is always 173 * straight, never pre-multiplied. 174 * 175 * If a codec or a filter does not support alpha, it should set all alpha to 176 * opaque, or use the equivalent pixel formats without alpha component, e.g. 177 * AV_PIX_FMT_RGB0 (or AV_PIX_FMT_RGB24 etc.) instead of AV_PIX_FMT_RGBA. 178 */ 179 #define AV_PIX_FMT_FLAG_ALPHA (1 << 7) 180 181 /** 182 * The pixel format is following a Bayer pattern 183 */ 184 #define AV_PIX_FMT_FLAG_BAYER (1 << 8) 185 186 /** 187 * The pixel format contains IEEE-754 floating point values. Precision (double, 188 * single, or half) should be determined by the pixel size (64, 32, or 16 bits). 189 */ 190 #define AV_PIX_FMT_FLAG_FLOAT (1 << 9) 191 192 /** 193 * Return the number of bits per pixel used by the pixel format 194 * described by pixdesc. Note that this is not the same as the number 195 * of bits per sample. 196 * 197 * The returned number of bits refers to the number of bits actually 198 * used for storing the pixel information, that is padding bits are 199 * not counted. 200 */ 201 int av_get_bits_per_pixel(const AVPixFmtDescriptor *pixdesc); 202 203 /** 204 * Return the number of bits per pixel for the pixel format 205 * described by pixdesc, including any padding or unused bits. 206 */ 207 int av_get_padded_bits_per_pixel(const AVPixFmtDescriptor *pixdesc); 208 209 /** 210 * @return a pixel format descriptor for provided pixel format or NULL if 211 * this pixel format is unknown. 212 */ 213 const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt); 214 215 /** 216 * Iterate over all pixel format descriptors known to libavutil. 217 * 218 * @param prev previous descriptor. NULL to get the first descriptor. 219 * 220 * @return next descriptor or NULL after the last descriptor 221 */ 222 const AVPixFmtDescriptor *av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev); 223 224 /** 225 * @return an AVPixelFormat id described by desc, or AV_PIX_FMT_NONE if desc 226 * is not a valid pointer to a pixel format descriptor. 227 */ 228 enum AVPixelFormat av_pix_fmt_desc_get_id(const AVPixFmtDescriptor *desc); 229 230 /** 231 * Utility function to access log2_chroma_w log2_chroma_h from 232 * the pixel format AVPixFmtDescriptor. 233 * 234 * @param[in] pix_fmt the pixel format 235 * @param[out] h_shift store log2_chroma_w (horizontal/width shift) 236 * @param[out] v_shift store log2_chroma_h (vertical/height shift) 237 * 238 * @return 0 on success, AVERROR(ENOSYS) on invalid or unknown pixel format 239 */ 240 int av_pix_fmt_get_chroma_sub_sample(enum AVPixelFormat pix_fmt, 241 int *h_shift, int *v_shift); 242 243 /** 244 * @return number of planes in pix_fmt, a negative AVERROR if pix_fmt is not a 245 * valid pixel format. 246 */ 247 int av_pix_fmt_count_planes(enum AVPixelFormat pix_fmt); 248 249 /** 250 * @return the name for provided color range or NULL if unknown. 251 */ 252 const char *av_color_range_name(enum AVColorRange range); 253 254 /** 255 * @return the AVColorRange value for name or an AVError if not found. 256 */ 257 int av_color_range_from_name(const char *name); 258 259 /** 260 * @return the name for provided color primaries or NULL if unknown. 261 */ 262 const char *av_color_primaries_name(enum AVColorPrimaries primaries); 263 264 /** 265 * @return the AVColorPrimaries value for name or an AVError if not found. 266 */ 267 int av_color_primaries_from_name(const char *name); 268 269 /** 270 * @return the name for provided color transfer or NULL if unknown. 271 */ 272 const char *av_color_transfer_name(enum AVColorTransferCharacteristic transfer); 273 274 /** 275 * @return the AVColorTransferCharacteristic value for name or an AVError if not found. 276 */ 277 int av_color_transfer_from_name(const char *name); 278 279 /** 280 * @return the name for provided color space or NULL if unknown. 281 */ 282 const char *av_color_space_name(enum AVColorSpace space); 283 284 /** 285 * @return the AVColorSpace value for name or an AVError if not found. 286 */ 287 int av_color_space_from_name(const char *name); 288 289 /** 290 * @return the name for provided chroma location or NULL if unknown. 291 */ 292 const char *av_chroma_location_name(enum AVChromaLocation location); 293 294 /** 295 * @return the AVChromaLocation value for name or an AVError if not found. 296 */ 297 int av_chroma_location_from_name(const char *name); 298 299 /** 300 * Return the pixel format corresponding to name. 301 * 302 * If there is no pixel format with name name, then looks for a 303 * pixel format with the name corresponding to the native endian 304 * format of name. 305 * For example in a little-endian system, first looks for "gray16", 306 * then for "gray16le". 307 * 308 * Finally if no pixel format has been found, returns AV_PIX_FMT_NONE. 309 */ 310 enum AVPixelFormat av_get_pix_fmt(const char *name); 311 312 /** 313 * Return the short name for a pixel format, NULL in case pix_fmt is 314 * unknown. 315 * 316 * @see av_get_pix_fmt(), av_get_pix_fmt_string() 317 */ 318 const char *av_get_pix_fmt_name(enum AVPixelFormat pix_fmt); 319 320 /** 321 * Print in buf the string corresponding to the pixel format with 322 * number pix_fmt, or a header if pix_fmt is negative. 323 * 324 * @param buf the buffer where to write the string 325 * @param buf_size the size of buf 326 * @param pix_fmt the number of the pixel format to print the 327 * corresponding info string, or a negative value to print the 328 * corresponding header. 329 */ 330 char *av_get_pix_fmt_string(char *buf, int buf_size, 331 enum AVPixelFormat pix_fmt); 332 333 /** 334 * Read a line from an image, and write the values of the 335 * pixel format component c to dst. 336 * 337 * @param data the array containing the pointers to the planes of the image 338 * @param linesize the array containing the linesizes of the image 339 * @param desc the pixel format descriptor for the image 340 * @param x the horizontal coordinate of the first pixel to read 341 * @param y the vertical coordinate of the first pixel to read 342 * @param w the width of the line to read, that is the number of 343 * values to write to dst 344 * @param read_pal_component if not zero and the format is a paletted 345 * format writes the values corresponding to the palette 346 * component c in data[1] to dst, rather than the palette indexes in 347 * data[0]. The behavior is undefined if the format is not paletted. 348 * @param dst_element_size size of elements in dst array (2 or 4 byte) 349 */ 350 void av_read_image_line2(void *dst, const uint8_t *data[4], 351 const int linesize[4], const AVPixFmtDescriptor *desc, 352 int x, int y, int c, int w, int read_pal_component, 353 int dst_element_size); 354 355 void av_read_image_line(uint16_t *dst, const uint8_t *data[4], 356 const int linesize[4], const AVPixFmtDescriptor *desc, 357 int x, int y, int c, int w, int read_pal_component); 358 359 /** 360 * Write the values from src to the pixel format component c of an 361 * image line. 362 * 363 * @param src array containing the values to write 364 * @param data the array containing the pointers to the planes of the 365 * image to write into. It is supposed to be zeroed. 366 * @param linesize the array containing the linesizes of the image 367 * @param desc the pixel format descriptor for the image 368 * @param x the horizontal coordinate of the first pixel to write 369 * @param y the vertical coordinate of the first pixel to write 370 * @param w the width of the line to write, that is the number of 371 * values to write to the image line 372 * @param src_element_size size of elements in src array (2 or 4 byte) 373 */ 374 void av_write_image_line2(const void *src, uint8_t *data[4], 375 const int linesize[4], const AVPixFmtDescriptor *desc, 376 int x, int y, int c, int w, int src_element_size); 377 378 void av_write_image_line(const uint16_t *src, uint8_t *data[4], 379 const int linesize[4], const AVPixFmtDescriptor *desc, 380 int x, int y, int c, int w); 381 382 /** 383 * Utility function to swap the endianness of a pixel format. 384 * 385 * @param[in] pix_fmt the pixel format 386 * 387 * @return pixel format with swapped endianness if it exists, 388 * otherwise AV_PIX_FMT_NONE 389 */ 390 enum AVPixelFormat av_pix_fmt_swap_endianness(enum AVPixelFormat pix_fmt); 391 392 #define FF_LOSS_RESOLUTION 0x0001 /**< loss due to resolution change */ 393 #define FF_LOSS_DEPTH 0x0002 /**< loss due to color depth change */ 394 #define FF_LOSS_COLORSPACE 0x0004 /**< loss due to color space conversion */ 395 #define FF_LOSS_ALPHA 0x0008 /**< loss of alpha bits */ 396 #define FF_LOSS_COLORQUANT 0x0010 /**< loss due to color quantization */ 397 #define FF_LOSS_CHROMA 0x0020 /**< loss of chroma (e.g. RGB to gray conversion) */ 398 399 /** 400 * Compute what kind of losses will occur when converting from one specific 401 * pixel format to another. 402 * When converting from one pixel format to another, information loss may occur. 403 * For example, when converting from RGB24 to GRAY, the color information will 404 * be lost. Similarly, other losses occur when converting from some formats to 405 * other formats. These losses can involve loss of chroma, but also loss of 406 * resolution, loss of color depth, loss due to the color space conversion, loss 407 * of the alpha bits or loss due to color quantization. 408 * av_get_fix_fmt_loss() informs you about the various types of losses 409 * which will occur when converting from one pixel format to another. 410 * 411 * @param[in] dst_pix_fmt destination pixel format 412 * @param[in] src_pix_fmt source pixel format 413 * @param[in] has_alpha Whether the source pixel format alpha channel is used. 414 * @return Combination of flags informing you what kind of losses will occur 415 * (maximum loss for an invalid dst_pix_fmt). 416 */ 417 int av_get_pix_fmt_loss(enum AVPixelFormat dst_pix_fmt, 418 enum AVPixelFormat src_pix_fmt, 419 int has_alpha); 420 421 /** 422 * Compute what kind of losses will occur when converting from one specific 423 * pixel format to another. 424 * When converting from one pixel format to another, information loss may occur. 425 * For example, when converting from RGB24 to GRAY, the color information will 426 * be lost. Similarly, other losses occur when converting from some formats to 427 * other formats. These losses can involve loss of chroma, but also loss of 428 * resolution, loss of color depth, loss due to the color space conversion, loss 429 * of the alpha bits or loss due to color quantization. 430 * av_get_fix_fmt_loss() informs you about the various types of losses 431 * which will occur when converting from one pixel format to another. 432 * 433 * @param[in] dst_pix_fmt destination pixel format 434 * @param[in] src_pix_fmt source pixel format 435 * @param[in] has_alpha Whether the source pixel format alpha channel is used. 436 * @return Combination of flags informing you what kind of losses will occur 437 * (maximum loss for an invalid dst_pix_fmt). 438 */ 439 enum AVPixelFormat av_find_best_pix_fmt_of_2(enum AVPixelFormat dst_pix_fmt1, enum AVPixelFormat dst_pix_fmt2, 440 enum AVPixelFormat src_pix_fmt, int has_alpha, int *loss_ptr); 441 442 #endif /* AVUTIL_PIXDESC_H */ 443