libswscale/swscale_internal.h

   1 /*
   2  * Copyright (C) 2001-2003 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
  21 #ifndef SWSCALE_SWSCALE_INTERNAL_H
  22 #define SWSCALE_SWSCALE_INTERNAL_H
  23
  24 #include "config.h"
  25
  26 #if HAVE_ALTIVEC_H
  27 #include <altivec.h>
  28 #endif
  29
  30 #include "libavutil/avutil.h"
  31
  32 #define STR(s)         AV_TOSTRING(s) //AV_STRINGIFY is too long
  33
  34 #define MAX_FILTER_SIZE 256
  35
  36 #if ARCH_X86
  37 #define VOFW 5120
  38 #else
  39 #define VOFW 2048 // faster on PPC and not tested on others
  40 #endif
  41
  42 #define VOF  (VOFW*2)
  43
  44 #if HAVE_BIGENDIAN
  45 #define ALT32_CORR (-1)
  46 #else
  47 #define ALT32_CORR   1
  48 #endif
  49
  50 #if ARCH_X86_64
  51 #   define APCK_PTR2 8
  52 #   define APCK_COEF 16
  53 #   define APCK_SIZE 24
  54 #else
  55 #   define APCK_PTR2 4
  56 #   define APCK_COEF 8
  57 #   define APCK_SIZE 16
  58 #endif
  59
  60 struct SwsContext;
  61
  62 typedef int (*SwsFunc)(struct SwsContext *context, const uint8_t* src[],
  63                        int srcStride[], int srcSliceY, int srcSliceH,
  64                        uint8_t* dst[], int dstStride[]);
  65
  66 /* This struct should be aligned on at least a 32-byte boundary. */
  67 typedef struct SwsContext {
  68     /**
  69      * info on struct for av_log
  70      */
  71     const AVClass *av_class;
  72
  73     /**
  74      * Note that src, dst, srcStride, dstStride will be copied in the
  75      * sws_scale() wrapper so they can be freely modified here.
  76      */
  77     SwsFunc swScale;
  78     int srcW;                     ///< Width  of source      luma/alpha planes.
  79     int srcH;                     ///< Height of source      luma/alpha planes.
  80     int dstH;                     ///< Height of destination luma/alpha planes.
  81     int chrSrcW;                  ///< Width  of source      chroma     planes.
  82     int chrSrcH;                  ///< Height of source      chroma     planes.
  83     int chrDstW;                  ///< Width  of destination chroma     planes.
  84     int chrDstH;                  ///< Height of destination chroma     planes.
  85     int lumXInc, chrXInc;
  86     int lumYInc, chrYInc;
  87     enum PixelFormat dstFormat;   ///< Destination pixel format.
  88     enum PixelFormat srcFormat;   ///< Source      pixel format.
  89     int chrSrcHSubSample;         ///< Binary logarithm of horizontal subsampling factor between luma/alpha and chroma planes in source      image.
  90     int chrSrcVSubSample;         ///< Binary logarithm of vertical   subsampling factor between luma/alpha and chroma planes in source      image.
  91     int chrDstHSubSample;         ///< Binary logarithm of horizontal subsampling factor between luma/alpha and chroma planes in destination image.
  92     int chrDstVSubSample;         ///< Binary logarithm of vertical   subsampling factor between luma/alpha and chroma planes in destination image.
  93     int vChrDrop;                 ///< Binary logarithm of extra vertical subsampling factor in source image chroma planes specified by user.
  94     int sliceDir;                 ///< Direction that slices are fed to the scaler (1 = top-to-bottom, -1 = bottom-to-top).
  95     double param[2];              ///< Input parameters for scaling algorithms that need them.
  96
  97     uint32_t pal_yuv[256];
  98     uint32_t pal_rgb[256];
  99
 100     /**
 101      * @name Scaled horizontal lines ring buffer.
 102      * The horizontal scaler keeps just enough scaled lines in a ring buffer
 103      * so they may be passed to the vertical scaler. The pointers to the
 104      * allocated buffers for each line are duplicated in sequence in the ring
 105      * buffer to simplify indexing and avoid wrapping around between lines
 106      * inside the vertical scaler code. The wrapping is done before the
 107      * vertical scaler is called.
 108      */
 109     //@{
 110     int16_t **lumPixBuf;          ///< Ring buffer for scaled horizontal luma   plane lines to be fed to the vertical scaler.
 111     int16_t **chrPixBuf;          ///< Ring buffer for scaled horizontal chroma plane lines to be fed to the vertical scaler.
 112     int16_t **alpPixBuf;          ///< Ring buffer for scaled horizontal alpha  plane lines to be fed to the vertical scaler.
 113     int       vLumBufSize;        ///< Number of vertical luma/alpha lines allocated in the ring buffer.
 114     int       vChrBufSize;        ///< Number of vertical chroma     lines allocated in the ring buffer.
 115     int       lastInLumBuf;       ///< Last scaled horizontal luma/alpha line from source in the ring buffer.
 116     int       lastInChrBuf;       ///< Last scaled horizontal chroma     line from source in the ring buffer.
 117     int       lumBufIndex;        ///< Index in ring buffer of the last scaled horizontal luma/alpha line from source.
 118     int       chrBufIndex;        ///< Index in ring buffer of the last scaled horizontal chroma     line from source.
 119     //@}
 120
 121     uint8_t formatConvBuffer[VOF]; //FIXME dynamic allocation, but we have to change a lot of code for this to be useful
 122
 123     /**
 124      * @name Horizontal and vertical filters.
 125      * To better understand the following fields, here is a pseudo-code of
 126      * their usage in filtering a horizontal line:
 127      * @code
 128      * for (i = 0; i < width; i++) {
 129      *     dst[i] = 0;
 130      *     for (j = 0; j < filterSize; j++)
 131      *         dst[i] += src[ filterPos[i] + j ] * filter[ filterSize * i + j ];
 132      *     dst[i] >>= FRAC_BITS; // The actual implementation is fixed-point.
 133      * }
 134      * @endcode
 135      */
 136     //@{
 137     int16_t *hLumFilter;          ///< Array of horizontal filter coefficients for luma/alpha planes.
 138     int16_t *hChrFilter;          ///< Array of horizontal filter coefficients for chroma     planes.
 139     int16_t *vLumFilter;          ///< Array of vertical   filter coefficients for luma/alpha planes.
 140     int16_t *vChrFilter;          ///< Array of vertical   filter coefficients for chroma     planes.
 141     int16_t *hLumFilterPos;       ///< Array of horizontal filter starting positions for each dst[i] for luma/alpha planes.
 142     int16_t *hChrFilterPos;       ///< Array of horizontal filter starting positions for each dst[i] for chroma     planes.
 143     int16_t *vLumFilterPos;       ///< Array of vertical   filter starting positions for each dst[i] for luma/alpha planes.
 144     int16_t *vChrFilterPos;       ///< Array of vertical   filter starting positions for each dst[i] for chroma     planes.
 145     int      hLumFilterSize;      ///< Horizontal filter size for luma/alpha pixels.
 146     int      hChrFilterSize;      ///< Horizontal filter size for chroma     pixels.
 147     int      vLumFilterSize;      ///< Vertical   filter size for luma/alpha pixels.
 148     int      vChrFilterSize;      ///< Vertical   filter size for chroma     pixels.
 149     //@}
 150
 151     int lumMmx2FilterCodeSize;    ///< Runtime-generated MMX2 horizontal fast bilinear scaler code size for luma/alpha planes.
 152     int chrMmx2FilterCodeSize;    ///< Runtime-generated MMX2 horizontal fast bilinear scaler code size for chroma     planes.
 153     uint8_t *lumMmx2FilterCode;   ///< Runtime-generated MMX2 horizontal fast bilinear scaler code for luma/alpha planes.
 154     uint8_t *chrMmx2FilterCode;   ///< Runtime-generated MMX2 horizontal fast bilinear scaler code for chroma     planes.
 155
 156     int canMMX2BeUsed;
 157
 158     int dstY;                     ///< Last destination vertical line output from last slice.
 159     int flags;                    ///< Flags passed by the user to select scaler algorithm, optimizations, subsampling, etc...
 160     void * yuvTable;            // pointer to the yuv->rgb table start so it can be freed()
 161     uint8_t * table_rV[256];
 162     uint8_t * table_gU[256];
 163     int    table_gV[256];
 164     uint8_t * table_bU[256];
 165
 166     //Colorspace stuff
 167     int contrast, brightness, saturation;    // for sws_getColorspaceDetails
 168     int srcColorspaceTable[4];
 169     int dstColorspaceTable[4];
 170     int srcRange;                 ///< 0 = MPG YUV range, 1 = JPG YUV range (source      image).
 171     int dstRange;                 ///< 0 = MPG YUV range, 1 = JPG YUV range (destination image).
 172     int yuv2rgb_y_offset;
 173     int yuv2rgb_y_coeff;
 174     int yuv2rgb_v2r_coeff;
 175     int yuv2rgb_v2g_coeff;
 176     int yuv2rgb_u2g_coeff;
 177     int yuv2rgb_u2b_coeff;
 178
 179 #define RED_DITHER            "0*8"
 180 #define GREEN_DITHER          "1*8"
 181 #define BLUE_DITHER           "2*8"
 182 #define Y_COEFF               "3*8"
 183 #define VR_COEFF              "4*8"
 184 #define UB_COEFF              "5*8"
 185 #define VG_COEFF              "6*8"
 186 #define UG_COEFF              "7*8"
 187 #define Y_OFFSET              "8*8"
 188 #define U_OFFSET              "9*8"
 189 #define V_OFFSET              "10*8"
 190 #define LUM_MMX_FILTER_OFFSET "11*8"
 191 #define CHR_MMX_FILTER_OFFSET "11*8+4*4*256"
 192 #define DSTW_OFFSET           "11*8+4*4*256*2" //do not change, it is hardcoded in the ASM
 193 #define ESP_OFFSET            "11*8+4*4*256*2+8"
 194 #define VROUNDER_OFFSET       "11*8+4*4*256*2+16"
 195 #define U_TEMP                "11*8+4*4*256*2+24"
 196 #define V_TEMP                "11*8+4*4*256*2+32"
 197 #define Y_TEMP                "11*8+4*4*256*2+40"
 198 #define ALP_MMX_FILTER_OFFSET "11*8+4*4*256*2+48"
 199
 200     DECLARE_ALIGNED(8, uint64_t, redDither);
 201     DECLARE_ALIGNED(8, uint64_t, greenDither);
 202     DECLARE_ALIGNED(8, uint64_t, blueDither);
 203
 204     DECLARE_ALIGNED(8, uint64_t, yCoeff);
 205     DECLARE_ALIGNED(8, uint64_t, vrCoeff);
 206     DECLARE_ALIGNED(8, uint64_t, ubCoeff);
 207     DECLARE_ALIGNED(8, uint64_t, vgCoeff);
 208     DECLARE_ALIGNED(8, uint64_t, ugCoeff);
 209     DECLARE_ALIGNED(8, uint64_t, yOffset);
 210     DECLARE_ALIGNED(8, uint64_t, uOffset);
 211     DECLARE_ALIGNED(8, uint64_t, vOffset);
 212     int32_t  lumMmxFilter[4*MAX_FILTER_SIZE];
 213     int32_t  chrMmxFilter[4*MAX_FILTER_SIZE];
 214     int dstW;                     ///< Width  of destination luma/alpha planes.
 215     DECLARE_ALIGNED(8, uint64_t, esp);
 216     DECLARE_ALIGNED(8, uint64_t, vRounder);
 217     DECLARE_ALIGNED(8, uint64_t, u_temp);
 218     DECLARE_ALIGNED(8, uint64_t, v_temp);
 219     DECLARE_ALIGNED(8, uint64_t, y_temp);
 220     int32_t  alpMmxFilter[4*MAX_FILTER_SIZE];
 221
 222 #if HAVE_ALTIVEC
 223     vector signed short   CY;
 224     vector signed short   CRV;
 225     vector signed short   CBU;
 226     vector signed short   CGU;
 227     vector signed short   CGV;
 228     vector signed short   OY;
 229     vector unsigned short CSHIFT;
 230     vector signed short   *vYCoeffsBank, *vCCoeffsBank;
 231 #endif
 232
 233 #if ARCH_BFIN
 234     DECLARE_ALIGNED(4, uint32_t, oy);
 235     DECLARE_ALIGNED(4, uint32_t, oc);
 236     DECLARE_ALIGNED(4, uint32_t, zero);
 237     DECLARE_ALIGNED(4, uint32_t, cy);
 238     DECLARE_ALIGNED(4, uint32_t, crv);
 239     DECLARE_ALIGNED(4, uint32_t, rmask);
 240     DECLARE_ALIGNED(4, uint32_t, cbu);
 241     DECLARE_ALIGNED(4, uint32_t, bmask);
 242     DECLARE_ALIGNED(4, uint32_t, cgu);
 243     DECLARE_ALIGNED(4, uint32_t, cgv);
 244     DECLARE_ALIGNED(4, uint32_t, gmask);
 245 #endif
 246
 247 #if HAVE_VIS
 248     DECLARE_ALIGNED(8, uint64_t, sparc_coeffs)[10];
 249 #endif
 250
 251     /* function pointers for swScale() */
 252     void (*yuv2nv12X  )(struct SwsContext *c,
 253                         const int16_t *lumFilter, const int16_t **lumSrc, int lumFilterSize,
 254                         const int16_t *chrFilter, const int16_t **chrSrc, int chrFilterSize,
 255                         uint8_t *dest, uint8_t *uDest,
 256                         int dstW, int chrDstW, int dstFormat);
 257     void (*yuv2yuv1   )(struct SwsContext *c,
 258                         const int16_t *lumSrc, const int16_t *chrSrc, const int16_t *alpSrc,
 259                         uint8_t *dest,
 260                         uint8_t *uDest, uint8_t *vDest, uint8_t *aDest,
 261                         long dstW, long chrDstW);
 262     void (*yuv2yuvX   )(struct SwsContext *c,
 263                         const int16_t *lumFilter, const int16_t **lumSrc, int lumFilterSize,
 264                         const int16_t *chrFilter, const int16_t **chrSrc, int chrFilterSize,
 265                         const int16_t **alpSrc,
 266                         uint8_t *dest,
 267                         uint8_t *uDest, uint8_t *vDest, uint8_t *aDest,
 268                         long dstW, long chrDstW);
 269     void (*yuv2packed1)(struct SwsContext *c,
 270                         const uint16_t *buf0,
 271                         const uint16_t *uvbuf0, const uint16_t *uvbuf1,
 272                         const uint16_t *abuf0,
 273                         uint8_t *dest,
 274                         int dstW, int uvalpha, int dstFormat, int flags, int y);
 275     void (*yuv2packed2)(struct SwsContext *c,
 276                         const uint16_t *buf0, const uint16_t *buf1,
 277                         const uint16_t *uvbuf0, const uint16_t *uvbuf1,
 278                         const uint16_t *abuf0, const uint16_t *abuf1,
 279                         uint8_t *dest,
 280                         int dstW, int yalpha, int uvalpha, int y);
 281     void (*yuv2packedX)(struct SwsContext *c,
 282                         const int16_t *lumFilter, const int16_t **lumSrc, int lumFilterSize,
 283                         const int16_t *chrFilter, const int16_t **chrSrc, int chrFilterSize,
 284                         const int16_t **alpSrc, uint8_t *dest,
 285                         long dstW, long dstY);
 286
 287     void (*lumToYV12)(uint8_t *dst, const uint8_t *src,
 288                       long width, uint32_t *pal); ///< Unscaled conversion of luma plane to YV12 for horizontal scaler.
 289     void (*alpToYV12)(uint8_t *dst, const uint8_t *src,
 290                       long width, uint32_t *pal); ///< Unscaled conversion of alpha plane to YV12 for horizontal scaler.
 291     void (*chrToYV12)(uint8_t *dstU, uint8_t *dstV,
 292                       const uint8_t *src1, const uint8_t *src2,
 293                       long width, uint32_t *pal); ///< Unscaled conversion of chroma planes to YV12 for horizontal scaler.
 294     void (*hyscale_fast)(struct SwsContext *c,
 295                          int16_t *dst, long dstWidth,
 296                          const uint8_t *src, int srcW, int xInc);
 297     void (*hcscale_fast)(struct SwsContext *c,
 298                          int16_t *dst, long dstWidth,
 299                          const uint8_t *src1, const uint8_t *src2,
 300                          int srcW, int xInc);
 301
 302     void (*hScale)(int16_t *dst, int dstW, const uint8_t *src, int srcW,
 303                    int xInc, const int16_t *filter, const int16_t *filterPos,
 304                    long filterSize);
 305
 306     void (*lumConvertRange)(uint16_t *dst, int width); ///< Color range conversion function for luma plane if needed.
 307     void (*chrConvertRange)(uint16_t *dst, int width); ///< Color range conversion function for chroma planes if needed.
 308
 309     int lumSrcOffset; ///< Offset given to luma src pointers passed to horizontal input functions.
 310     int chrSrcOffset; ///< Offset given to chroma src pointers passed to horizontal input functions.
 311     int alpSrcOffset; ///< Offset given to alpha src pointers passed to horizontal input functions.
 312
 313     int needs_hcscale; ///< Set if there are chroma planes to be converted.
 314
 315 } SwsContext;
 316 //FIXME check init (where 0)
 317
 318 SwsFunc ff_yuv2rgb_get_func_ptr(SwsContext *c);
 319 int ff_yuv2rgb_c_init_tables(SwsContext *c, const int inv_table[4],
 320                              int fullRange, int brightness,
 321                              int contrast, int saturation);
 322
 323 void ff_yuv2rgb_init_tables_altivec(SwsContext *c, const int inv_table[4],
 324                                     int brightness, int contrast, int saturation);
 325 SwsFunc ff_yuv2rgb_init_mmx(SwsContext *c);
 326 SwsFunc ff_yuv2rgb_init_vis(SwsContext *c);
 327 SwsFunc ff_yuv2rgb_init_mlib(SwsContext *c);
 328 SwsFunc ff_yuv2rgb_init_altivec(SwsContext *c);
 329 SwsFunc ff_yuv2rgb_get_func_ptr_bfin(SwsContext *c);
 330 void ff_bfin_get_unscaled_swscale(SwsContext *c);
 331 void ff_yuv2packedX_altivec(SwsContext *c,
 332                             const int16_t *lumFilter, int16_t **lumSrc, int lumFilterSize,
 333                             const int16_t *chrFilter, int16_t **chrSrc, int chrFilterSize,
 334                             uint8_t *dest, int dstW, int dstY);
 335
 336 const char *sws_format_name(enum PixelFormat format);
 337
 338 //FIXME replace this with something faster
 339 #define is16BPS(x)      (           \
 340            (x)==PIX_FMT_GRAY16BE    \
 341         || (x)==PIX_FMT_GRAY16LE    \
 342         || (x)==PIX_FMT_RGB48BE     \
 343         || (x)==PIX_FMT_RGB48LE     \
 344         || (x)==PIX_FMT_YUV420P16LE   \
 345         || (x)==PIX_FMT_YUV422P16LE   \
 346         || (x)==PIX_FMT_YUV444P16LE   \
 347         || (x)==PIX_FMT_YUV420P16BE   \
 348         || (x)==PIX_FMT_YUV422P16BE   \
 349         || (x)==PIX_FMT_YUV444P16BE   \
 350     )
 351 #define isBE(x) ((x)&1)
 352 #define isPlanar8YUV(x) (           \
 353            (x)==PIX_FMT_YUV410P     \
 354         || (x)==PIX_FMT_YUV420P     \
 355         || (x)==PIX_FMT_YUVA420P    \
 356         || (x)==PIX_FMT_YUV411P     \
 357         || (x)==PIX_FMT_YUV422P     \
 358         || (x)==PIX_FMT_YUV444P     \
 359         || (x)==PIX_FMT_YUV440P     \
 360         || (x)==PIX_FMT_NV12        \
 361         || (x)==PIX_FMT_NV21        \
 362     )
 363 #define isPlanarYUV(x)  (           \
 364         isPlanar8YUV(x)             \
 365         || (x)==PIX_FMT_YUV420P16LE   \
 366         || (x)==PIX_FMT_YUV422P16LE   \
 367         || (x)==PIX_FMT_YUV444P16LE   \
 368         || (x)==PIX_FMT_YUV420P16BE   \
 369         || (x)==PIX_FMT_YUV422P16BE   \
 370         || (x)==PIX_FMT_YUV444P16BE   \
 371     )
 372 #define isYUV(x)        (           \
 373            (x)==PIX_FMT_UYVY422     \
 374         || (x)==PIX_FMT_YUYV422     \
 375         || isPlanarYUV(x)           \
 376     )
 377 #define isGray(x)       (           \
 378            (x)==PIX_FMT_GRAY8       \
 379         || (x)==PIX_FMT_GRAY16BE    \
 380         || (x)==PIX_FMT_GRAY16LE    \
 381     )
 382 #define isGray16(x)     (           \
 383            (x)==PIX_FMT_GRAY16BE    \
 384         || (x)==PIX_FMT_GRAY16LE    \
 385     )
 386 #define isRGB(x)        (           \
 387            (x)==PIX_FMT_RGB48BE     \
 388         || (x)==PIX_FMT_RGB48LE     \
 389         || (x)==PIX_FMT_RGB32       \
 390         || (x)==PIX_FMT_RGB32_1     \
 391         || (x)==PIX_FMT_RGB24       \
 392         || (x)==PIX_FMT_RGB565      \
 393         || (x)==PIX_FMT_RGB555      \
 394         || (x)==PIX_FMT_RGB8        \
 395         || (x)==PIX_FMT_RGB4        \
 396         || (x)==PIX_FMT_RGB4_BYTE   \
 397         || (x)==PIX_FMT_MONOBLACK   \
 398         || (x)==PIX_FMT_MONOWHITE   \
 399     )
 400 #define isBGR(x)        (           \
 401            (x)==PIX_FMT_BGR32       \
 402         || (x)==PIX_FMT_BGR32_1     \
 403         || (x)==PIX_FMT_BGR24       \
 404         || (x)==PIX_FMT_BGR565      \
 405         || (x)==PIX_FMT_BGR555      \
 406         || (x)==PIX_FMT_BGR8        \
 407         || (x)==PIX_FMT_BGR4        \
 408         || (x)==PIX_FMT_BGR4_BYTE   \
 409         || (x)==PIX_FMT_MONOBLACK   \
 410         || (x)==PIX_FMT_MONOWHITE   \
 411     )
 412 #define isALPHA(x)      (           \
 413            (x)==PIX_FMT_BGR32       \
 414         || (x)==PIX_FMT_BGR32_1     \
 415         || (x)==PIX_FMT_RGB32       \
 416         || (x)==PIX_FMT_RGB32_1     \
 417         || (x)==PIX_FMT_YUVA420P    \
 418     )
 419
 420 static inline int fmt_depth(enum PixelFormat fmt)
 421 {
 422     switch(fmt) {
 423     case PIX_FMT_RGB48BE:
 424     case PIX_FMT_RGB48LE:
 425         return 48;
 426     case PIX_FMT_BGRA:
 427     case PIX_FMT_ABGR:
 428     case PIX_FMT_RGBA:
 429     case PIX_FMT_ARGB:
 430         return 32;
 431     case PIX_FMT_BGR24:
 432     case PIX_FMT_RGB24:
 433         return 24;
 434     case PIX_FMT_BGR565:
 435     case PIX_FMT_RGB565:
 436     case PIX_FMT_GRAY16BE:
 437     case PIX_FMT_GRAY16LE:
 438         return 16;
 439     case PIX_FMT_BGR555:
 440     case PIX_FMT_RGB555:
 441         return 15;
 442     case PIX_FMT_BGR8:
 443     case PIX_FMT_RGB8:
 444         return 8;
 445     case PIX_FMT_BGR4:
 446     case PIX_FMT_RGB4:
 447     case PIX_FMT_BGR4_BYTE:
 448     case PIX_FMT_RGB4_BYTE:
 449         return 4;
 450     case PIX_FMT_MONOBLACK:
 451     case PIX_FMT_MONOWHITE:
 452         return 1;
 453     default:
 454         return 0;
 455     }
 456 }
 457
 458 extern const uint64_t ff_dither4[2];
 459 extern const uint64_t ff_dither8[2];
 460
 461 extern const AVClass sws_context_class;
 462
 463 /**
 464  * Sets c->swScale to an unscaled converter if one exists for the specific
 465  * source and destination formats, bit depths, flags, etc.
 466  */
 467 void ff_get_unscaled_swscale(SwsContext *c);
 468
 469 /**
 470  * Returns the SWS_CPU_CAPS for the optimized code compiled into swscale.
 471  */
 472 int ff_hardcodedcpuflags(void);
 473
 474 /**
 475  * Returns function pointer to fastest main scaler path function depending
 476  * on architecture and available optimizations.
 477  */
 478 SwsFunc ff_getSwsFunc(SwsContext *c);
 479
 480 #endif /* SWSCALE_SWSCALE_INTERNAL_H */