libswscale/swscale.h

   1 /*
   2  * Copyright (C) 2001-2003 Michael Niedermayer <michaelni@gmx.at>
   3  *
   4  * This file is part of Libav.
   5  *
   6  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #ifndef SWSCALE_SWSCALE_H
  22 #define SWSCALE_SWSCALE_H
  23
  24 /**
  25  * @file
  26  * @ingroup libsws
  27  * @brief
  28  *     external api for the swscale stuff
  29  */
  30
  31 #include <stdint.h>
  32
  33 #include "libavutil/avutil.h"
  34 #include "libavutil/log.h"
  35 #include "libavutil/pixfmt.h"
  36 #include "version.h"
  37
  38 /**
  39  * @defgroup libsws Color conversion and scaling
  40  * @{
  41  *
  42  * Return the LIBSWSCALE_VERSION_INT constant.
  43  */
  44 unsigned swscale_version(void);
  45
  46 /**
  47  * Return the libswscale build-time configuration.
  48  */
  49 const char *swscale_configuration(void);
  50
  51 /**
  52  * Return the libswscale license.
  53  */
  54 const char *swscale_license(void);
  55
  56 /* values for the flags, the stuff on the command line is different */
  57 #define SWS_FAST_BILINEAR     1
  58 #define SWS_BILINEAR          2
  59 #define SWS_BICUBIC           4
  60 #define SWS_X                 8
  61 #define SWS_POINT          0x10
  62 #define SWS_AREA           0x20
  63 #define SWS_BICUBLIN       0x40
  64 #define SWS_GAUSS          0x80
  65 #define SWS_SINC          0x100
  66 #define SWS_LANCZOS       0x200
  67 #define SWS_SPLINE        0x400
  68
  69 #define SWS_SRC_V_CHR_DROP_MASK     0x30000
  70 #define SWS_SRC_V_CHR_DROP_SHIFT    16
  71
  72 #define SWS_PARAM_DEFAULT           123456
  73
  74 #define SWS_PRINT_INFO              0x1000
  75
  76 //the following 3 flags are not completely implemented
  77 //internal chrominace subsampling info
  78 #define SWS_FULL_CHR_H_INT    0x2000
  79 //input subsampling info
  80 #define SWS_FULL_CHR_H_INP    0x4000
  81 #define SWS_DIRECT_BGR        0x8000
  82 #define SWS_ACCURATE_RND      0x40000
  83 #define SWS_BITEXACT          0x80000
  84
  85 #if FF_API_SWS_CPU_CAPS
  86 /**
  87  * CPU caps are autodetected now, those flags
  88  * are only provided for API compatibility.
  89  */
  90 #define SWS_CPU_CAPS_MMX      0x80000000
  91 #define SWS_CPU_CAPS_MMXEXT   0x20000000
  92 #define SWS_CPU_CAPS_MMX2     0x20000000
  93 #define SWS_CPU_CAPS_3DNOW    0x40000000
  94 #define SWS_CPU_CAPS_ALTIVEC  0x10000000
  95 #if FF_API_ARCH_BFIN
  96 #define SWS_CPU_CAPS_BFIN     0x01000000
  97 #endif
  98 #define SWS_CPU_CAPS_SSE2     0x02000000
  99 #endif
 100
 101 #define SWS_MAX_REDUCE_CUTOFF 0.002
 102
 103 #define SWS_CS_ITU709         1
 104 #define SWS_CS_FCC            4
 105 #define SWS_CS_ITU601         5
 106 #define SWS_CS_ITU624         5
 107 #define SWS_CS_SMPTE170M      5
 108 #define SWS_CS_SMPTE240M      7
 109 #define SWS_CS_DEFAULT        5
 110
 111 /**
 112  * Return a pointer to yuv<->rgb coefficients for the given colorspace
 113  * suitable for sws_setColorspaceDetails().
 114  *
 115  * @param colorspace One of the SWS_CS_* macros. If invalid,
 116  * SWS_CS_DEFAULT is used.
 117  */
 118 const int *sws_getCoefficients(int colorspace);
 119
 120 // when used for filters they must have an odd number of elements
 121 // coeffs cannot be shared between vectors
 122 typedef struct SwsVector {
 123     double *coeff;              ///< pointer to the list of coefficients
 124     int length;                 ///< number of coefficients in the vector
 125 } SwsVector;
 126
 127 // vectors can be shared
 128 typedef struct SwsFilter {
 129     SwsVector *lumH;
 130     SwsVector *lumV;
 131     SwsVector *chrH;
 132     SwsVector *chrV;
 133 } SwsFilter;
 134
 135 struct SwsContext;
 136
 137 /**
 138  * Return a positive value if pix_fmt is a supported input format, 0
 139  * otherwise.
 140  */
 141 int sws_isSupportedInput(enum AVPixelFormat pix_fmt);
 142
 143 /**
 144  * Return a positive value if pix_fmt is a supported output format, 0
 145  * otherwise.
 146  */
 147 int sws_isSupportedOutput(enum AVPixelFormat pix_fmt);
 148
 149 /**
 150  * @param[in]  pix_fmt the pixel format
 151  * @return a positive value if an endianness conversion for pix_fmt is
 152  * supported, 0 otherwise.
 153  */
 154 int sws_isSupportedEndiannessConversion(enum AVPixelFormat pix_fmt);
 155
 156 /**
 157  * Allocate an empty SwsContext. This must be filled and passed to
 158  * sws_init_context(). For filling see AVOptions, options.c and
 159  * sws_setColorspaceDetails().
 160  */
 161 struct SwsContext *sws_alloc_context(void);
 162
 163 /**
 164  * Initialize the swscaler context sws_context.
 165  *
 166  * @return zero or positive value on success, a negative value on
 167  * error
 168  */
 169 int sws_init_context(struct SwsContext *sws_context, SwsFilter *srcFilter, SwsFilter *dstFilter);
 170
 171 /**
 172  * Free the swscaler context swsContext.
 173  * If swsContext is NULL, then does nothing.
 174  */
 175 void sws_freeContext(struct SwsContext *swsContext);
 176
 177 /**
 178  * Allocate and return an SwsContext. You need it to perform
 179  * scaling/conversion operations using sws_scale().
 180  *
 181  * @param srcW the width of the source image
 182  * @param srcH the height of the source image
 183  * @param srcFormat the source image format
 184  * @param dstW the width of the destination image
 185  * @param dstH the height of the destination image
 186  * @param dstFormat the destination image format
 187  * @param flags specify which algorithm and options to use for rescaling
 188  * @return a pointer to an allocated context, or NULL in case of error
 189  * @note this function is to be removed after a saner alternative is
 190  *       written
 191  */
 192 struct SwsContext *sws_getContext(int srcW, int srcH, enum AVPixelFormat srcFormat,
 193                                   int dstW, int dstH, enum AVPixelFormat dstFormat,
 194                                   int flags, SwsFilter *srcFilter,
 195                                   SwsFilter *dstFilter, const double *param);
 196
 197 /**
 198  * Scale the image slice in srcSlice and put the resulting scaled
 199  * slice in the image in dst. A slice is a sequence of consecutive
 200  * rows in an image.
 201  *
 202  * Slices have to be provided in sequential order, either in
 203  * top-bottom or bottom-top order. If slices are provided in
 204  * non-sequential order the behavior of the function is undefined.
 205  *
 206  * @param c         the scaling context previously created with
 207  *                  sws_getContext()
 208  * @param srcSlice  the array containing the pointers to the planes of
 209  *                  the source slice
 210  * @param srcStride the array containing the strides for each plane of
 211  *                  the source image
 212  * @param srcSliceY the position in the source image of the slice to
 213  *                  process, that is the number (counted starting from
 214  *                  zero) in the image of the first row of the slice
 215  * @param srcSliceH the height of the source slice, that is the number
 216  *                  of rows in the slice
 217  * @param dst       the array containing the pointers to the planes of
 218  *                  the destination image
 219  * @param dstStride the array containing the strides for each plane of
 220  *                  the destination image
 221  * @return          the height of the output slice
 222  */
 223 int sws_scale(struct SwsContext *c, const uint8_t *const srcSlice[],
 224               const int srcStride[], int srcSliceY, int srcSliceH,
 225               uint8_t *const dst[], const int dstStride[]);
 226
 227 /**
 228  * @param inv_table the yuv2rgb coefficients, normally ff_yuv2rgb_coeffs[x]
 229  * @return -1 if not supported
 230  */
 231 int sws_setColorspaceDetails(struct SwsContext *c, const int inv_table[4],
 232                              int srcRange, const int table[4], int dstRange,
 233                              int brightness, int contrast, int saturation);
 234
 235 /**
 236  * @return -1 if not supported
 237  */
 238 int sws_getColorspaceDetails(struct SwsContext *c, int **inv_table,
 239                              int *srcRange, int **table, int *dstRange,
 240                              int *brightness, int *contrast, int *saturation);
 241
 242 /**
 243  * Allocate and return an uninitialized vector with length coefficients.
 244  */
 245 SwsVector *sws_allocVec(int length);
 246
 247 /**
 248  * Return a normalized Gaussian curve used to filter stuff
 249  * quality = 3 is high quality, lower is lower quality.
 250  */
 251 SwsVector *sws_getGaussianVec(double variance, double quality);
 252
 253 /**
 254  * Allocate and return a vector with length coefficients, all
 255  * with the same value c.
 256  */
 257 SwsVector *sws_getConstVec(double c, int length);
 258
 259 /**
 260  * Allocate and return a vector with just one coefficient, with
 261  * value 1.0.
 262  */
 263 SwsVector *sws_getIdentityVec(void);
 264
 265 /**
 266  * Scale all the coefficients of a by the scalar value.
 267  */
 268 void sws_scaleVec(SwsVector *a, double scalar);
 269
 270 /**
 271  * Scale all the coefficients of a so that their sum equals height.
 272  */
 273 void sws_normalizeVec(SwsVector *a, double height);
 274 void sws_convVec(SwsVector *a, SwsVector *b);
 275 void sws_addVec(SwsVector *a, SwsVector *b);
 276 void sws_subVec(SwsVector *a, SwsVector *b);
 277 void sws_shiftVec(SwsVector *a, int shift);
 278
 279 /**
 280  * Allocate and return a clone of the vector a, that is a vector
 281  * with the same coefficients as a.
 282  */
 283 SwsVector *sws_cloneVec(SwsVector *a);
 284
 285 /**
 286  * Print with av_log() a textual representation of the vector a
 287  * if log_level <= av_log_level.
 288  */
 289 void sws_printVec2(SwsVector *a, AVClass *log_ctx, int log_level);
 290
 291 void sws_freeVec(SwsVector *a);
 292
 293 SwsFilter *sws_getDefaultFilter(float lumaGBlur, float chromaGBlur,
 294                                 float lumaSharpen, float chromaSharpen,
 295                                 float chromaHShift, float chromaVShift,
 296                                 int verbose);
 297 void sws_freeFilter(SwsFilter *filter);
 298
 299 /**
 300  * Check if context can be reused, otherwise reallocate a new one.
 301  *
 302  * If context is NULL, just calls sws_getContext() to get a new
 303  * context. Otherwise, checks if the parameters are the ones already
 304  * saved in context. If that is the case, returns the current
 305  * context. Otherwise, frees context and gets a new context with
 306  * the new parameters.
 307  *
 308  * Be warned that srcFilter and dstFilter are not checked, they
 309  * are assumed to remain the same.
 310  */
 311 struct SwsContext *sws_getCachedContext(struct SwsContext *context,
 312                                         int srcW, int srcH, enum AVPixelFormat srcFormat,
 313                                         int dstW, int dstH, enum AVPixelFormat dstFormat,
 314                                         int flags, SwsFilter *srcFilter,
 315                                         SwsFilter *dstFilter, const double *param);
 316
 317 /**
 318  * Convert an 8-bit paletted frame into a frame with a color depth of 32 bits.
 319  *
 320  * The output frame will have the same packed format as the palette.
 321  *
 322  * @param src        source frame buffer
 323  * @param dst        destination frame buffer
 324  * @param num_pixels number of pixels to convert
 325  * @param palette    array with [256] entries, which must match color arrangement (RGB or BGR) of src
 326  */
 327 void sws_convertPalette8ToPacked32(const uint8_t *src, uint8_t *dst, int num_pixels, const uint8_t *palette);
 328
 329 /**
 330  * Convert an 8-bit paletted frame into a frame with a color depth of 24 bits.
 331  *
 332  * With the palette format "ABCD", the destination frame ends up with the format "ABC".
 333  *
 334  * @param src        source frame buffer
 335  * @param dst        destination frame buffer
 336  * @param num_pixels number of pixels to convert
 337  * @param palette    array with [256] entries, which must match color arrangement (RGB or BGR) of src
 338  */
 339 void sws_convertPalette8ToPacked24(const uint8_t *src, uint8_t *dst, int num_pixels, const uint8_t *palette);
 340
 341 /**
 342  * Get the AVClass for swsContext. It can be used in combination with
 343  * AV_OPT_SEARCH_FAKE_OBJ for examining options.
 344  *
 345  * @see av_opt_find().
 346  */
 347 const AVClass *sws_get_class(void);
 348
 349 /**
 350  * @}
 351  */
 352
 353 #endif /* SWSCALE_SWSCALE_H */