swscale.h 15 KB

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  1. /*
  2. * Copyright (C) 2001-2011 Michael Niedermayer <michaelni@gmx.at>
  3. *
  4. * This file is part of FFmpeg.
  5. *
  6. * FFmpeg is free software; you can redistribute it and/or
  7. * modify it under the terms of the GNU Lesser General Public
  8. * License as published by the Free Software Foundation; either
  9. * version 2.1 of the License, or (at your option) any later version.
  10. *
  11. * FFmpeg is distributed in the hope that it will be useful,
  12. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14. * Lesser General Public License for more details.
  15. *
  16. * You should have received a copy of the GNU Lesser General Public
  17. * License along with FFmpeg; if not, write to the Free Software
  18. * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19. */
  20. #ifndef SWSCALE_SWSCALE_H
  21. #define SWSCALE_SWSCALE_H
  22. /**
  23. * @file
  24. * @ingroup libsws
  25. * external API header
  26. */
  27. #include <stdint.h>
  28. #include "libavutil/avutil.h"
  29. #include "libavutil/frame.h"
  30. #include "libavutil/log.h"
  31. #include "libavutil/pixfmt.h"
  32. #include "version.h"
  33. /**
  34. * @defgroup libsws libswscale
  35. * Color conversion and scaling library.
  36. *
  37. * @{
  38. *
  39. * Return the LIBSWSCALE_VERSION_INT constant.
  40. */
  41. unsigned swscale_version(void);
  42. /**
  43. * Return the libswscale build-time configuration.
  44. */
  45. const char *swscale_configuration(void);
  46. /**
  47. * Return the libswscale license.
  48. */
  49. const char *swscale_license(void);
  50. /* values for the flags, the stuff on the command line is different */
  51. #define SWS_FAST_BILINEAR 1
  52. #define SWS_BILINEAR 2
  53. #define SWS_BICUBIC 4
  54. #define SWS_X 8
  55. #define SWS_POINT 0x10
  56. #define SWS_AREA 0x20
  57. #define SWS_BICUBLIN 0x40
  58. #define SWS_GAUSS 0x80
  59. #define SWS_SINC 0x100
  60. #define SWS_LANCZOS 0x200
  61. #define SWS_SPLINE 0x400
  62. #define SWS_SRC_V_CHR_DROP_MASK 0x30000
  63. #define SWS_SRC_V_CHR_DROP_SHIFT 16
  64. #define SWS_PARAM_DEFAULT 123456
  65. #define SWS_PRINT_INFO 0x1000
  66. //the following 3 flags are not completely implemented
  67. //internal chrominance subsampling info
  68. #define SWS_FULL_CHR_H_INT 0x2000
  69. //input subsampling info
  70. #define SWS_FULL_CHR_H_INP 0x4000
  71. #define SWS_DIRECT_BGR 0x8000
  72. #define SWS_ACCURATE_RND 0x40000
  73. #define SWS_BITEXACT 0x80000
  74. #define SWS_ERROR_DIFFUSION 0x800000
  75. #define SWS_MAX_REDUCE_CUTOFF 0.002
  76. #define SWS_CS_ITU709 1
  77. #define SWS_CS_FCC 4
  78. #define SWS_CS_ITU601 5
  79. #define SWS_CS_ITU624 5
  80. #define SWS_CS_SMPTE170M 5
  81. #define SWS_CS_SMPTE240M 7
  82. #define SWS_CS_DEFAULT 5
  83. #define SWS_CS_BT2020 9
  84. /**
  85. * Return a pointer to yuv<->rgb coefficients for the given colorspace
  86. * suitable for sws_setColorspaceDetails().
  87. *
  88. * @param colorspace One of the SWS_CS_* macros. If invalid,
  89. * SWS_CS_DEFAULT is used.
  90. */
  91. const int *sws_getCoefficients(int colorspace);
  92. // when used for filters they must have an odd number of elements
  93. // coeffs cannot be shared between vectors
  94. typedef struct SwsVector {
  95. double *coeff; ///< pointer to the list of coefficients
  96. int length; ///< number of coefficients in the vector
  97. } SwsVector;
  98. // vectors can be shared
  99. typedef struct SwsFilter {
  100. SwsVector *lumH;
  101. SwsVector *lumV;
  102. SwsVector *chrH;
  103. SwsVector *chrV;
  104. } SwsFilter;
  105. struct SwsContext;
  106. /**
  107. * Return a positive value if pix_fmt is a supported input format, 0
  108. * otherwise.
  109. */
  110. int sws_isSupportedInput(enum AVPixelFormat pix_fmt);
  111. /**
  112. * Return a positive value if pix_fmt is a supported output format, 0
  113. * otherwise.
  114. */
  115. int sws_isSupportedOutput(enum AVPixelFormat pix_fmt);
  116. /**
  117. * @param[in] pix_fmt the pixel format
  118. * @return a positive value if an endianness conversion for pix_fmt is
  119. * supported, 0 otherwise.
  120. */
  121. int sws_isSupportedEndiannessConversion(enum AVPixelFormat pix_fmt);
  122. /**
  123. * Allocate an empty SwsContext. This must be filled and passed to
  124. * sws_init_context(). For filling see AVOptions, options.c and
  125. * sws_setColorspaceDetails().
  126. */
  127. struct SwsContext *sws_alloc_context(void);
  128. /**
  129. * Initialize the swscaler context sws_context.
  130. *
  131. * @return zero or positive value on success, a negative value on
  132. * error
  133. */
  134. av_warn_unused_result
  135. int sws_init_context(struct SwsContext *sws_context, SwsFilter *srcFilter, SwsFilter *dstFilter);
  136. /**
  137. * Free the swscaler context swsContext.
  138. * If swsContext is NULL, then does nothing.
  139. */
  140. void sws_freeContext(struct SwsContext *swsContext);
  141. /**
  142. * Allocate and return an SwsContext. You need it to perform
  143. * scaling/conversion operations using sws_scale().
  144. *
  145. * @param srcW the width of the source image
  146. * @param srcH the height of the source image
  147. * @param srcFormat the source image format
  148. * @param dstW the width of the destination image
  149. * @param dstH the height of the destination image
  150. * @param dstFormat the destination image format
  151. * @param flags specify which algorithm and options to use for rescaling
  152. * @param param extra parameters to tune the used scaler
  153. * For SWS_BICUBIC param[0] and [1] tune the shape of the basis
  154. * function, param[0] tunes f(1) and param[1] f´(1)
  155. * For SWS_GAUSS param[0] tunes the exponent and thus cutoff
  156. * frequency
  157. * For SWS_LANCZOS param[0] tunes the width of the window function
  158. * @return a pointer to an allocated context, or NULL in case of error
  159. * @note this function is to be removed after a saner alternative is
  160. * written
  161. */
  162. struct SwsContext *sws_getContext(int srcW, int srcH, enum AVPixelFormat srcFormat,
  163. int dstW, int dstH, enum AVPixelFormat dstFormat,
  164. int flags, SwsFilter *srcFilter,
  165. SwsFilter *dstFilter, const double *param);
  166. /**
  167. * Scale the image slice in srcSlice and put the resulting scaled
  168. * slice in the image in dst. A slice is a sequence of consecutive
  169. * rows in an image.
  170. *
  171. * Slices have to be provided in sequential order, either in
  172. * top-bottom or bottom-top order. If slices are provided in
  173. * non-sequential order the behavior of the function is undefined.
  174. *
  175. * @param c the scaling context previously created with
  176. * sws_getContext()
  177. * @param srcSlice the array containing the pointers to the planes of
  178. * the source slice
  179. * @param srcStride the array containing the strides for each plane of
  180. * the source image
  181. * @param srcSliceY the position in the source image of the slice to
  182. * process, that is the number (counted starting from
  183. * zero) in the image of the first row of the slice
  184. * @param srcSliceH the height of the source slice, that is the number
  185. * of rows in the slice
  186. * @param dst the array containing the pointers to the planes of
  187. * the destination image
  188. * @param dstStride the array containing the strides for each plane of
  189. * the destination image
  190. * @return the height of the output slice
  191. */
  192. int sws_scale(struct SwsContext *c, const uint8_t *const srcSlice[],
  193. const int srcStride[], int srcSliceY, int srcSliceH,
  194. uint8_t *const dst[], const int dstStride[]);
  195. /**
  196. * Scale source data from src and write the output to dst.
  197. *
  198. * This is merely a convenience wrapper around
  199. * - sws_frame_start()
  200. * - sws_send_slice(0, src->height)
  201. * - sws_receive_slice(0, dst->height)
  202. * - sws_frame_end()
  203. *
  204. * @param dst The destination frame. See documentation for sws_frame_start() for
  205. * more details.
  206. * @param src The source frame.
  207. *
  208. * @return 0 on success, a negative AVERROR code on failure
  209. */
  210. int sws_scale_frame(struct SwsContext *c, AVFrame *dst, const AVFrame *src);
  211. /**
  212. * Initialize the scaling process for a given pair of source/destination frames.
  213. * Must be called before any calls to sws_send_slice() and sws_receive_slice().
  214. *
  215. * This function will retain references to src and dst, so they must both use
  216. * refcounted buffers (if allocated by the caller, in case of dst).
  217. *
  218. * @param dst The destination frame.
  219. *
  220. * The data buffers may either be already allocated by the caller or
  221. * left clear, in which case they will be allocated by the scaler.
  222. * The latter may have performance advantages - e.g. in certain cases
  223. * some output planes may be references to input planes, rather than
  224. * copies.
  225. *
  226. * Output data will be written into this frame in successful
  227. * sws_receive_slice() calls.
  228. * @param src The source frame. The data buffers must be allocated, but the
  229. * frame data does not have to be ready at this point. Data
  230. * availability is then signalled by sws_send_slice().
  231. * @return 0 on success, a negative AVERROR code on failure
  232. *
  233. * @see sws_frame_end()
  234. */
  235. int sws_frame_start(struct SwsContext *c, AVFrame *dst, const AVFrame *src);
  236. /**
  237. * Finish the scaling process for a pair of source/destination frames previously
  238. * submitted with sws_frame_start(). Must be called after all sws_send_slice()
  239. * and sws_receive_slice() calls are done, before any new sws_frame_start()
  240. * calls.
  241. */
  242. void sws_frame_end(struct SwsContext *c);
  243. /**
  244. * Indicate that a horizontal slice of input data is available in the source
  245. * frame previously provided to sws_frame_start(). The slices may be provided in
  246. * any order, but may not overlap. For vertically subsampled pixel formats, the
  247. * slices must be aligned according to subsampling.
  248. *
  249. * @param slice_start first row of the slice
  250. * @param slice_height number of rows in the slice
  251. *
  252. * @return a non-negative number on success, a negative AVERROR code on failure.
  253. */
  254. int sws_send_slice(struct SwsContext *c, unsigned int slice_start,
  255. unsigned int slice_height);
  256. /**
  257. * Request a horizontal slice of the output data to be written into the frame
  258. * previously provided to sws_frame_start().
  259. *
  260. * @param slice_start first row of the slice; must be a multiple of
  261. * sws_receive_slice_alignment()
  262. * @param slice_height number of rows in the slice; must be a multiple of
  263. * sws_receive_slice_alignment(), except for the last slice
  264. * (i.e. when slice_start+slice_height is equal to output
  265. * frame height)
  266. *
  267. * @return a non-negative number if the data was successfully written into the output
  268. * AVERROR(EAGAIN) if more input data needs to be provided before the
  269. * output can be produced
  270. * another negative AVERROR code on other kinds of scaling failure
  271. */
  272. int sws_receive_slice(struct SwsContext *c, unsigned int slice_start,
  273. unsigned int slice_height);
  274. /**
  275. * @return alignment required for output slices requested with sws_receive_slice().
  276. * Slice offsets and sizes passed to sws_receive_slice() must be
  277. * multiples of the value returned from this function.
  278. */
  279. unsigned int sws_receive_slice_alignment(const struct SwsContext *c);
  280. /**
  281. * @param dstRange flag indicating the while-black range of the output (1=jpeg / 0=mpeg)
  282. * @param srcRange flag indicating the while-black range of the input (1=jpeg / 0=mpeg)
  283. * @param table the yuv2rgb coefficients describing the output yuv space, normally ff_yuv2rgb_coeffs[x]
  284. * @param inv_table the yuv2rgb coefficients describing the input yuv space, normally ff_yuv2rgb_coeffs[x]
  285. * @param brightness 16.16 fixed point brightness correction
  286. * @param contrast 16.16 fixed point contrast correction
  287. * @param saturation 16.16 fixed point saturation correction
  288. #if LIBSWSCALE_VERSION_MAJOR > 6
  289. * @return negative error code on error, non negative otherwise
  290. #else
  291. * @return -1 if not supported
  292. #endif
  293. */
  294. int sws_setColorspaceDetails(struct SwsContext *c, const int inv_table[4],
  295. int srcRange, const int table[4], int dstRange,
  296. int brightness, int contrast, int saturation);
  297. /**
  298. #if LIBSWSCALE_VERSION_MAJOR > 6
  299. * @return negative error code on error, non negative otherwise
  300. #else
  301. * @return -1 if not supported
  302. #endif
  303. */
  304. int sws_getColorspaceDetails(struct SwsContext *c, int **inv_table,
  305. int *srcRange, int **table, int *dstRange,
  306. int *brightness, int *contrast, int *saturation);
  307. /**
  308. * Allocate and return an uninitialized vector with length coefficients.
  309. */
  310. SwsVector *sws_allocVec(int length);
  311. /**
  312. * Return a normalized Gaussian curve used to filter stuff
  313. * quality = 3 is high quality, lower is lower quality.
  314. */
  315. SwsVector *sws_getGaussianVec(double variance, double quality);
  316. /**
  317. * Scale all the coefficients of a by the scalar value.
  318. */
  319. void sws_scaleVec(SwsVector *a, double scalar);
  320. /**
  321. * Scale all the coefficients of a so that their sum equals height.
  322. */
  323. void sws_normalizeVec(SwsVector *a, double height);
  324. void sws_freeVec(SwsVector *a);
  325. SwsFilter *sws_getDefaultFilter(float lumaGBlur, float chromaGBlur,
  326. float lumaSharpen, float chromaSharpen,
  327. float chromaHShift, float chromaVShift,
  328. int verbose);
  329. void sws_freeFilter(SwsFilter *filter);
  330. /**
  331. * Check if context can be reused, otherwise reallocate a new one.
  332. *
  333. * If context is NULL, just calls sws_getContext() to get a new
  334. * context. Otherwise, checks if the parameters are the ones already
  335. * saved in context. If that is the case, returns the current
  336. * context. Otherwise, frees context and gets a new context with
  337. * the new parameters.
  338. *
  339. * Be warned that srcFilter and dstFilter are not checked, they
  340. * are assumed to remain the same.
  341. */
  342. struct SwsContext *sws_getCachedContext(struct SwsContext *context,
  343. int srcW, int srcH, enum AVPixelFormat srcFormat,
  344. int dstW, int dstH, enum AVPixelFormat dstFormat,
  345. int flags, SwsFilter *srcFilter,
  346. SwsFilter *dstFilter, const double *param);
  347. /**
  348. * Convert an 8-bit paletted frame into a frame with a color depth of 32 bits.
  349. *
  350. * The output frame will have the same packed format as the palette.
  351. *
  352. * @param src source frame buffer
  353. * @param dst destination frame buffer
  354. * @param num_pixels number of pixels to convert
  355. * @param palette array with [256] entries, which must match color arrangement (RGB or BGR) of src
  356. */
  357. void sws_convertPalette8ToPacked32(const uint8_t *src, uint8_t *dst, int num_pixels, const uint8_t *palette);
  358. /**
  359. * Convert an 8-bit paletted frame into a frame with a color depth of 24 bits.
  360. *
  361. * With the palette format "ABCD", the destination frame ends up with the format "ABC".
  362. *
  363. * @param src source frame buffer
  364. * @param dst destination frame buffer
  365. * @param num_pixels number of pixels to convert
  366. * @param palette array with [256] entries, which must match color arrangement (RGB or BGR) of src
  367. */
  368. void sws_convertPalette8ToPacked24(const uint8_t *src, uint8_t *dst, int num_pixels, const uint8_t *palette);
  369. /**
  370. * Get the AVClass for swsContext. It can be used in combination with
  371. * AV_OPT_SEARCH_FAKE_OBJ for examining options.
  372. *
  373. * @see av_opt_find().
  374. */
  375. const AVClass *sws_get_class(void);
  376. /**
  377. * @}
  378. */
  379. #endif /* SWSCALE_SWSCALE_H */