pixdesc.h 14 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394
  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. #ifndef AVUTIL_PIXDESC_H
  22. #define AVUTIL_PIXDESC_H
  23. #include <inttypes.h>
  24. #include "attributes.h"
  25. #include "pixfmt.h"
  26. #include "version.h"
  27. typedef struct AVComponentDescriptor {
  28. /**
  29. * Which of the 4 planes contains the component.
  30. */
  31. int plane;
  32. /**
  33. * Number of elements between 2 horizontally consecutive pixels.
  34. * Elements are bits for bitstream formats, bytes otherwise.
  35. */
  36. int step;
  37. /**
  38. * Number of elements before the component of the first pixel.
  39. * Elements are bits for bitstream formats, bytes otherwise.
  40. */
  41. int offset;
  42. /**
  43. * Number of least significant bits that must be shifted away
  44. * to get the value.
  45. */
  46. int shift;
  47. /**
  48. * Number of bits in the component.
  49. */
  50. int depth;
  51. #if FF_API_PLUS1_MINUS1
  52. /** deprecated, use step instead */
  53. attribute_deprecated int step_minus1;
  54. /** deprecated, use depth instead */
  55. attribute_deprecated int depth_minus1;
  56. /** deprecated, use offset instead */
  57. attribute_deprecated int offset_plus1;
  58. #endif
  59. } AVComponentDescriptor;
  60. /**
  61. * Descriptor that unambiguously describes how the bits of a pixel are
  62. * stored in the up to 4 data planes of an image. It also stores the
  63. * subsampling factors and number of components.
  64. *
  65. * @note This is separate of the colorspace (RGB, YCbCr, YPbPr, JPEG-style YUV
  66. * and all the YUV variants) AVPixFmtDescriptor just stores how values
  67. * are stored not what these values represent.
  68. */
  69. typedef struct AVPixFmtDescriptor {
  70. const char *name;
  71. uint8_t nb_components; ///< The number of components each pixel has, (1-4)
  72. /**
  73. * Amount to shift the luma width right to find the chroma width.
  74. * For YV12 this is 1 for example.
  75. * chroma_width = AV_CEIL_RSHIFT(luma_width, log2_chroma_w)
  76. * The note above is needed to ensure rounding up.
  77. * This value only refers to the chroma components.
  78. */
  79. uint8_t log2_chroma_w;
  80. /**
  81. * Amount to shift the luma height right to find the chroma height.
  82. * For YV12 this is 1 for example.
  83. * chroma_height= AV_CEIL_RSHIFT(luma_height, log2_chroma_h)
  84. * The note above is needed to ensure rounding up.
  85. * This value only refers to the chroma components.
  86. */
  87. uint8_t log2_chroma_h;
  88. /**
  89. * Combination of AV_PIX_FMT_FLAG_... flags.
  90. */
  91. uint64_t flags;
  92. /**
  93. * Parameters that describe how pixels are packed.
  94. * If the format has 1 or 2 components, then luma is 0.
  95. * If the format has 3 or 4 components:
  96. * if the RGB flag is set then 0 is red, 1 is green and 2 is blue;
  97. * otherwise 0 is luma, 1 is chroma-U and 2 is chroma-V.
  98. *
  99. * If present, the Alpha channel is always the last component.
  100. */
  101. AVComponentDescriptor comp[4];
  102. /**
  103. * Alternative comma-separated names.
  104. */
  105. const char *alias;
  106. } AVPixFmtDescriptor;
  107. /**
  108. * Pixel format is big-endian.
  109. */
  110. #define AV_PIX_FMT_FLAG_BE (1 << 0)
  111. /**
  112. * Pixel format has a palette in data[1], values are indexes in this palette.
  113. */
  114. #define AV_PIX_FMT_FLAG_PAL (1 << 1)
  115. /**
  116. * All values of a component are bit-wise packed end to end.
  117. */
  118. #define AV_PIX_FMT_FLAG_BITSTREAM (1 << 2)
  119. /**
  120. * Pixel format is an HW accelerated format.
  121. */
  122. #define AV_PIX_FMT_FLAG_HWACCEL (1 << 3)
  123. /**
  124. * At least one pixel component is not in the first data plane.
  125. */
  126. #define AV_PIX_FMT_FLAG_PLANAR (1 << 4)
  127. /**
  128. * The pixel format contains RGB-like data (as opposed to YUV/grayscale).
  129. */
  130. #define AV_PIX_FMT_FLAG_RGB (1 << 5)
  131. /**
  132. * The pixel format is "pseudo-paletted". This means that it contains a
  133. * fixed palette in the 2nd plane but the palette is fixed/constant for each
  134. * PIX_FMT. This allows interpreting the data as if it was PAL8, which can
  135. * in some cases be simpler. Or the data can be interpreted purely based on
  136. * the pixel format without using the palette.
  137. * An example of a pseudo-paletted format is AV_PIX_FMT_GRAY8
  138. */
  139. #define AV_PIX_FMT_FLAG_PSEUDOPAL (1 << 6)
  140. /**
  141. * The pixel format has an alpha channel. This is set on all formats that
  142. * support alpha in some way. The exception is AV_PIX_FMT_PAL8, which can
  143. * carry alpha as part of the palette. Details are explained in the
  144. * AVPixelFormat enum, and are also encoded in the corresponding
  145. * AVPixFmtDescriptor.
  146. *
  147. * The alpha is always straight, never pre-multiplied.
  148. *
  149. * If a codec or a filter does not support alpha, it should set all alpha to
  150. * opaque, or use the equivalent pixel formats without alpha component, e.g.
  151. * AV_PIX_FMT_RGB0 (or AV_PIX_FMT_RGB24 etc.) instead of AV_PIX_FMT_RGBA.
  152. */
  153. #define AV_PIX_FMT_FLAG_ALPHA (1 << 7)
  154. /**
  155. * Return the number of bits per pixel used by the pixel format
  156. * described by pixdesc. Note that this is not the same as the number
  157. * of bits per sample.
  158. *
  159. * The returned number of bits refers to the number of bits actually
  160. * used for storing the pixel information, that is padding bits are
  161. * not counted.
  162. */
  163. int av_get_bits_per_pixel(const AVPixFmtDescriptor *pixdesc);
  164. /**
  165. * Return the number of bits per pixel for the pixel format
  166. * described by pixdesc, including any padding or unused bits.
  167. */
  168. int av_get_padded_bits_per_pixel(const AVPixFmtDescriptor *pixdesc);
  169. /**
  170. * @return a pixel format descriptor for provided pixel format or NULL if
  171. * this pixel format is unknown.
  172. */
  173. const AVPixFmtDescriptor *av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt);
  174. /**
  175. * Iterate over all pixel format descriptors known to libavutil.
  176. *
  177. * @param prev previous descriptor. NULL to get the first descriptor.
  178. *
  179. * @return next descriptor or NULL after the last descriptor
  180. */
  181. const AVPixFmtDescriptor *av_pix_fmt_desc_next(const AVPixFmtDescriptor *prev);
  182. /**
  183. * @return an AVPixelFormat id described by desc, or AV_PIX_FMT_NONE if desc
  184. * is not a valid pointer to a pixel format descriptor.
  185. */
  186. enum AVPixelFormat av_pix_fmt_desc_get_id(const AVPixFmtDescriptor *desc);
  187. /**
  188. * Utility function to access log2_chroma_w log2_chroma_h from
  189. * the pixel format AVPixFmtDescriptor.
  190. *
  191. * See av_get_chroma_sub_sample() for a function that asserts a
  192. * valid pixel format instead of returning an error code.
  193. * Its recommended that you use avcodec_get_chroma_sub_sample unless
  194. * you do check the return code!
  195. *
  196. * @param[in] pix_fmt the pixel format
  197. * @param[out] h_shift store log2_chroma_w (horizontal/width shift)
  198. * @param[out] v_shift store log2_chroma_h (vertical/height shift)
  199. *
  200. * @return 0 on success, AVERROR(ENOSYS) on invalid or unknown pixel format
  201. */
  202. int av_pix_fmt_get_chroma_sub_sample(enum AVPixelFormat pix_fmt,
  203. int *h_shift, int *v_shift);
  204. /**
  205. * @return number of planes in pix_fmt, a negative AVERROR if pix_fmt is not a
  206. * valid pixel format.
  207. */
  208. int av_pix_fmt_count_planes(enum AVPixelFormat pix_fmt);
  209. /**
  210. * @return the name for provided color range or NULL if unknown.
  211. */
  212. const char *av_color_range_name(enum AVColorRange range);
  213. /**
  214. * @return the name for provided color primaries or NULL if unknown.
  215. */
  216. const char *av_color_primaries_name(enum AVColorPrimaries primaries);
  217. /**
  218. * @return the name for provided color transfer or NULL if unknown.
  219. */
  220. const char *av_color_transfer_name(enum AVColorTransferCharacteristic transfer);
  221. /**
  222. * @return the name for provided color space or NULL if unknown.
  223. */
  224. const char *av_color_space_name(enum AVColorSpace space);
  225. /**
  226. * @return the name for provided chroma location or NULL if unknown.
  227. */
  228. const char *av_chroma_location_name(enum AVChromaLocation location);
  229. /**
  230. * Return the pixel format corresponding to name.
  231. *
  232. * If there is no pixel format with name name, then looks for a
  233. * pixel format with the name corresponding to the native endian
  234. * format of name.
  235. * For example in a little-endian system, first looks for "gray16",
  236. * then for "gray16le".
  237. *
  238. * Finally if no pixel format has been found, returns AV_PIX_FMT_NONE.
  239. */
  240. enum AVPixelFormat av_get_pix_fmt(const char *name);
  241. /**
  242. * Return the short name for a pixel format, NULL in case pix_fmt is
  243. * unknown.
  244. *
  245. * @see av_get_pix_fmt(), av_get_pix_fmt_string()
  246. */
  247. const char *av_get_pix_fmt_name(enum AVPixelFormat pix_fmt);
  248. /**
  249. * Print in buf the string corresponding to the pixel format with
  250. * number pix_fmt, or a header if pix_fmt is negative.
  251. *
  252. * @param buf the buffer where to write the string
  253. * @param buf_size the size of buf
  254. * @param pix_fmt the number of the pixel format to print the
  255. * corresponding info string, or a negative value to print the
  256. * corresponding header.
  257. */
  258. char *av_get_pix_fmt_string(char *buf, int buf_size,
  259. enum AVPixelFormat pix_fmt);
  260. /**
  261. * Read a line from an image, and write the values of the
  262. * pixel format component c to dst.
  263. *
  264. * @param data the array containing the pointers to the planes of the image
  265. * @param linesize the array containing the linesizes of the image
  266. * @param desc the pixel format descriptor for the image
  267. * @param x the horizontal coordinate of the first pixel to read
  268. * @param y the vertical coordinate of the first pixel to read
  269. * @param w the width of the line to read, that is the number of
  270. * values to write to dst
  271. * @param read_pal_component if not zero and the format is a paletted
  272. * format writes the values corresponding to the palette
  273. * component c in data[1] to dst, rather than the palette indexes in
  274. * data[0]. The behavior is undefined if the format is not paletted.
  275. */
  276. void av_read_image_line(uint16_t *dst, const uint8_t *data[4],
  277. const int linesize[4], const AVPixFmtDescriptor *desc,
  278. int x, int y, int c, int w, int read_pal_component);
  279. /**
  280. * Write the values from src to the pixel format component c of an
  281. * image line.
  282. *
  283. * @param src array containing the values to write
  284. * @param data the array containing the pointers to the planes of the
  285. * image to write into. It is supposed to be zeroed.
  286. * @param linesize the array containing the linesizes of the image
  287. * @param desc the pixel format descriptor for the image
  288. * @param x the horizontal coordinate of the first pixel to write
  289. * @param y the vertical coordinate of the first pixel to write
  290. * @param w the width of the line to write, that is the number of
  291. * values to write to the image line
  292. */
  293. void av_write_image_line(const uint16_t *src, uint8_t *data[4],
  294. const int linesize[4], const AVPixFmtDescriptor *desc,
  295. int x, int y, int c, int w);
  296. /**
  297. * Utility function to swap the endianness of a pixel format.
  298. *
  299. * @param[in] pix_fmt the pixel format
  300. *
  301. * @return pixel format with swapped endianness if it exists,
  302. * otherwise AV_PIX_FMT_NONE
  303. */
  304. enum AVPixelFormat av_pix_fmt_swap_endianness(enum AVPixelFormat pix_fmt);
  305. #define FF_LOSS_RESOLUTION 0x0001 /**< loss due to resolution change */
  306. #define FF_LOSS_DEPTH 0x0002 /**< loss due to color depth change */
  307. #define FF_LOSS_COLORSPACE 0x0004 /**< loss due to color space conversion */
  308. #define FF_LOSS_ALPHA 0x0008 /**< loss of alpha bits */
  309. #define FF_LOSS_COLORQUANT 0x0010 /**< loss due to color quantization */
  310. #define FF_LOSS_CHROMA 0x0020 /**< loss of chroma (e.g. RGB to gray conversion) */
  311. /**
  312. * Compute what kind of losses will occur when converting from one specific
  313. * pixel format to another.
  314. * When converting from one pixel format to another, information loss may occur.
  315. * For example, when converting from RGB24 to GRAY, the color information will
  316. * be lost. Similarly, other losses occur when converting from some formats to
  317. * other formats. These losses can involve loss of chroma, but also loss of
  318. * resolution, loss of color depth, loss due to the color space conversion, loss
  319. * of the alpha bits or loss due to color quantization.
  320. * av_get_fix_fmt_loss() informs you about the various types of losses
  321. * which will occur when converting from one pixel format to another.
  322. *
  323. * @param[in] dst_pix_fmt destination pixel format
  324. * @param[in] src_pix_fmt source pixel format
  325. * @param[in] has_alpha Whether the source pixel format alpha channel is used.
  326. * @return Combination of flags informing you what kind of losses will occur
  327. * (maximum loss for an invalid dst_pix_fmt).
  328. */
  329. int av_get_pix_fmt_loss(enum AVPixelFormat dst_pix_fmt,
  330. enum AVPixelFormat src_pix_fmt,
  331. int has_alpha);
  332. /**
  333. * Compute what kind of losses will occur when converting from one specific
  334. * pixel format to another.
  335. * When converting from one pixel format to another, information loss may occur.
  336. * For example, when converting from RGB24 to GRAY, the color information will
  337. * be lost. Similarly, other losses occur when converting from some formats to
  338. * other formats. These losses can involve loss of chroma, but also loss of
  339. * resolution, loss of color depth, loss due to the color space conversion, loss
  340. * of the alpha bits or loss due to color quantization.
  341. * av_get_fix_fmt_loss() informs you about the various types of losses
  342. * which will occur when converting from one pixel format to another.
  343. *
  344. * @param[in] dst_pix_fmt destination pixel format
  345. * @param[in] src_pix_fmt source pixel format
  346. * @param[in] has_alpha Whether the source pixel format alpha channel is used.
  347. * @return Combination of flags informing you what kind of losses will occur
  348. * (maximum loss for an invalid dst_pix_fmt).
  349. */
  350. enum AVPixelFormat av_find_best_pix_fmt_of_2(enum AVPixelFormat dst_pix_fmt1, enum AVPixelFormat dst_pix_fmt2,
  351. enum AVPixelFormat src_pix_fmt, int has_alpha, int *loss_ptr);
  352. #endif /* AVUTIL_PIXDESC_H */