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