/*

  * Copyright (C) 2001-2011 Michael Niedermayer <michaelni@gmx.at>

  *
  * This file is part of FFmpeg.
  *

  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.

  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.

  *

  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software

  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

  */

 #ifndef SWSCALE_SWSCALE_INTERNAL_H
 #define SWSCALE_SWSCALE_INTERNAL_H

 #include "config.h"

 #include "version.h"
 

 #include "libavutil/avassert.h"

 #include "libavutil/avutil.h"

 #include "libavutil/common.h"

 #include "libavutil/intreadwrite.h"

 #include "libavutil/log.h"

 #include "libavutil/pixfmt.h"

 #include "libavutil/pixdesc.h"

 #include "libavutil/ppc/util_altivec.h"

 #define STR(s) AV_TOSTRING(s) // AV_STRINGIFY is too long

 #define YUVRGB_TABLE_HEADROOM 512
 #define YUVRGB_TABLE_LUMA_HEADROOM 512

 #define MAX_FILTER_SIZE SWS_MAX_FILTER_SIZE

 #define DITHER1XBPP
 

 #if HAVE_BIGENDIAN

 #define ALT32_CORR (-1)
 #else
 #define ALT32_CORR   1

 #endif
 

 #if ARCH_X86_64

 #   define APCK_PTR2  8

 #   define APCK_COEF 16
 #   define APCK_SIZE 24
 #else

 #   define APCK_PTR2  4
 #   define APCK_COEF  8

 #   define APCK_SIZE 16

 #endif
 

 #define RETCODE_USE_CASCADE -12345
 

 struct SwsContext;
 

 typedef enum SwsDither {
     SWS_DITHER_NONE = 0,
     SWS_DITHER_AUTO,
     SWS_DITHER_BAYER,
     SWS_DITHER_ED,

     SWS_DITHER_A_DITHER,
     SWS_DITHER_X_DITHER,

     NB_SWS_DITHER,
 } SwsDither;
 

 typedef enum SwsAlphaBlend {
     SWS_ALPHA_BLEND_NONE  = 0,
     SWS_ALPHA_BLEND_UNIFORM,

     SWS_ALPHA_BLEND_CHECKERBOARD,

     SWS_ALPHA_BLEND_NB,
 } SwsAlphaBlend;
 

 typedef int (*SwsFunc)(struct SwsContext *context, const uint8_t *src[],

                        int srcStride[], int srcSliceY, int srcSliceH,

                        uint8_t *dst[], int dstStride[]);

 /**

  * Write one line of horizontally scaled data to planar output

  * without any additional vertical scaling (or point-scaling).
  *

  * @param src     scaled source data, 15 bits for 8-10-bit output,
  *                19 bits for 16-bit output (in int32_t)
  * @param dest    pointer to the output plane. For >8-bit

  *                output, this is in uint16_t

  * @param dstW    width of destination in pixels
  * @param dither  ordered dither array of type int16_t and size 8
  * @param offset  Dither offset

  */

 typedef void (*yuv2planar1_fn)(const int16_t *src, uint8_t *dest, int dstW,
                                const uint8_t *dither, int offset);

 /**

  * Write one line of horizontally scaled data to planar output

  * with multi-point vertical scaling between input pixels.
  *

  * @param filter        vertical luma/alpha scaling coefficients, 12 bits [0,4096]
  * @param src           scaled luma (Y) or alpha (A) source data, 15 bits for
  *                      8-10-bit output, 19 bits for 16-bit output (in int32_t)

  * @param filterSize    number of vertical input lines to scale

  * @param dest          pointer to output plane. For >8-bit

  *                      output, this is in uint16_t
  * @param dstW          width of destination pixels
  * @param offset        Dither offset
  */

 typedef void (*yuv2planarX_fn)(const int16_t *filter, int filterSize,
                                const int16_t **src, uint8_t *dest, int dstW,
                                const uint8_t *dither, int offset);

 
 /**
  * Write one line of horizontally scaled chroma to interleaved output
  * with multi-point vertical scaling between input pixels.
  *
  * @param c             SWS scaling context

  * @param chrFilter     vertical chroma scaling coefficients, 12 bits [0,4096]
  * @param chrUSrc       scaled chroma (U) source data, 15 bits for 8-10-bit
  *                      output, 19 bits for 16-bit output (in int32_t)
  * @param chrVSrc       scaled chroma (V) source data, 15 bits for 8-10-bit
  *                      output, 19 bits for 16-bit output (in int32_t)

  * @param chrFilterSize number of vertical chroma input lines to scale

  * @param dest          pointer to the output plane. For >8-bit

  *                      output, this is in uint16_t

  * @param dstW          width of chroma planes

  */

 typedef void (*yuv2interleavedX_fn)(struct SwsContext *c,
                                     const int16_t *chrFilter,
                                     int chrFilterSize,
                                     const int16_t **chrUSrc,
                                     const int16_t **chrVSrc,
                                     uint8_t *dest, int dstW);

 /**
  * Write one line of horizontally scaled Y/U/V/A to packed-pixel YUV/RGB
  * output without any additional vertical scaling (or point-scaling). Note
  * that this function may do chroma scaling, see the "uvalpha" argument.
  *
  * @param c       SWS scaling context

  * @param lumSrc  scaled luma (Y) source data, 15 bits for 8-10-bit output,
  *                19 bits for 16-bit output (in int32_t)
  * @param chrUSrc scaled chroma (U) source data, 15 bits for 8-10-bit output,
  *                19 bits for 16-bit output (in int32_t)
  * @param chrVSrc scaled chroma (V) source data, 15 bits for 8-10-bit output,
  *                19 bits for 16-bit output (in int32_t)
  * @param alpSrc  scaled alpha (A) source data, 15 bits for 8-10-bit output,
  *                19 bits for 16-bit output (in int32_t)
  * @param dest    pointer to the output plane. For 16-bit output, this is

  *                uint16_t

  * @param dstW    width of lumSrc and alpSrc in pixels, number of pixels
  *                to write into dest[]
  * @param uvalpha chroma scaling coefficient for the second line of chroma
  *                pixels, either 2048 or 0. If 0, one chroma input is used
  *                for 2 output pixels (or if the SWS_FLAG_FULL_CHR_INT flag
  *                is set, it generates 1 output pixel). If 2048, two chroma
  *                input pixels should be averaged for 2 output pixels (this
  *                only happens if SWS_FLAG_FULL_CHR_INT is not set)
  * @param y       vertical line number for this output. This does not need
  *                to be used to calculate the offset in the destination,
  *                but can be used to generate comfort noise using dithering
  *                for some output formats.
  */

 typedef void (*yuv2packed1_fn)(struct SwsContext *c, const int16_t *lumSrc,
                                const int16_t *chrUSrc[2],
                                const int16_t *chrVSrc[2],
                                const int16_t *alpSrc, uint8_t *dest,
                                int dstW, int uvalpha, int y);

 /**
  * Write one line of horizontally scaled Y/U/V/A to packed-pixel YUV/RGB
  * output by doing bilinear scaling between two input lines.
  *
  * @param c       SWS scaling context

  * @param lumSrc  scaled luma (Y) source data, 15 bits for 8-10-bit output,
  *                19 bits for 16-bit output (in int32_t)
  * @param chrUSrc scaled chroma (U) source data, 15 bits for 8-10-bit output,
  *                19 bits for 16-bit output (in int32_t)
  * @param chrVSrc scaled chroma (V) source data, 15 bits for 8-10-bit output,
  *                19 bits for 16-bit output (in int32_t)
  * @param alpSrc  scaled alpha (A) source data, 15 bits for 8-10-bit output,
  *                19 bits for 16-bit output (in int32_t)
  * @param dest    pointer to the output plane. For 16-bit output, this is

  *                uint16_t

  * @param dstW    width of lumSrc and alpSrc in pixels, number of pixels
  *                to write into dest[]
  * @param yalpha  luma/alpha scaling coefficients for the second input line.
  *                The first line's coefficients can be calculated by using
  *                4096 - yalpha
  * @param uvalpha chroma scaling coefficient for the second input line. The
  *                first line's coefficients can be calculated by using
  *                4096 - uvalpha
  * @param y       vertical line number for this output. This does not need
  *                to be used to calculate the offset in the destination,
  *                but can be used to generate comfort noise using dithering
  *                for some output formats.
  */

 typedef void (*yuv2packed2_fn)(struct SwsContext *c, const int16_t *lumSrc[2],
                                const int16_t *chrUSrc[2],
                                const int16_t *chrVSrc[2],
                                const int16_t *alpSrc[2],
                                uint8_t *dest,
                                int dstW, int yalpha, int uvalpha, int y);

 /**
  * Write one line of horizontally scaled Y/U/V/A to packed-pixel YUV/RGB
  * output by doing multi-point vertical scaling between input pixels.
  *
  * @param c             SWS scaling context

  * @param lumFilter     vertical luma/alpha scaling coefficients, 12 bits [0,4096]
  * @param lumSrc        scaled luma (Y) source data, 15 bits for 8-10-bit output,
  *                      19 bits for 16-bit output (in int32_t)

  * @param lumFilterSize number of vertical luma/alpha input lines to scale

  * @param chrFilter     vertical chroma scaling coefficients, 12 bits [0,4096]
  * @param chrUSrc       scaled chroma (U) source data, 15 bits for 8-10-bit output,
  *                      19 bits for 16-bit output (in int32_t)
  * @param chrVSrc       scaled chroma (V) source data, 15 bits for 8-10-bit output,
  *                      19 bits for 16-bit output (in int32_t)

  * @param chrFilterSize number of vertical chroma input lines to scale

  * @param alpSrc        scaled alpha (A) source data, 15 bits for 8-10-bit output,
  *                      19 bits for 16-bit output (in int32_t)
  * @param dest          pointer to the output plane. For 16-bit output, this is

  *                      uint16_t

  * @param dstW          width of lumSrc and alpSrc in pixels, number of pixels
  *                      to write into dest[]
  * @param y             vertical line number for this output. This does not need
  *                      to be used to calculate the offset in the destination,
  *                      but can be used to generate comfort noise using dithering
  *                      or some output formats.
  */

 typedef void (*yuv2packedX_fn)(struct SwsContext *c, const int16_t *lumFilter,
                                const int16_t **lumSrc, int lumFilterSize,
                                const int16_t *chrFilter,
                                const int16_t **chrUSrc,
                                const int16_t **chrVSrc, int chrFilterSize,
                                const int16_t **alpSrc, uint8_t *dest,
                                int dstW, int y);

 /**
  * Write one line of horizontally scaled Y/U/V/A to YUV/RGB
  * output by doing multi-point vertical scaling between input pixels.
  *
  * @param c             SWS scaling context

  * @param lumFilter     vertical luma/alpha scaling coefficients, 12 bits [0,4096]
  * @param lumSrc        scaled luma (Y) source data, 15 bits for 8-10-bit output,
  *                      19 bits for 16-bit output (in int32_t)

  * @param lumFilterSize number of vertical luma/alpha input lines to scale

  * @param chrFilter     vertical chroma scaling coefficients, 12 bits [0,4096]
  * @param chrUSrc       scaled chroma (U) source data, 15 bits for 8-10-bit output,
  *                      19 bits for 16-bit output (in int32_t)
  * @param chrVSrc       scaled chroma (V) source data, 15 bits for 8-10-bit output,
  *                      19 bits for 16-bit output (in int32_t)

  * @param chrFilterSize number of vertical chroma input lines to scale

  * @param alpSrc        scaled alpha (A) source data, 15 bits for 8-10-bit output,
  *                      19 bits for 16-bit output (in int32_t)
  * @param dest          pointer to the output planes. For 16-bit output, this is

  *                      uint16_t
  * @param dstW          width of lumSrc and alpSrc in pixels, number of pixels
  *                      to write into dest[]
  * @param y             vertical line number for this output. This does not need
  *                      to be used to calculate the offset in the destination,
  *                      but can be used to generate comfort noise using dithering
  *                      or some output formats.
  */
 typedef void (*yuv2anyX_fn)(struct SwsContext *c, const int16_t *lumFilter,

                             const int16_t **lumSrc, int lumFilterSize,
                             const int16_t *chrFilter,
                             const int16_t **chrUSrc,
                             const int16_t **chrVSrc, int chrFilterSize,
                             const int16_t **alpSrc, uint8_t **dest,
                             int dstW, int y);

 struct SwsSlice;
 struct SwsFilterDescriptor;
 

 /* This struct should be aligned on at least a 32-byte boundary. */

 typedef struct SwsContext {

     /**
      * info on struct for av_log
      */

     const AVClass *av_class;

 
     /**

      * Note that src, dst, srcStride, dstStride will be copied in the
      * sws_scale() wrapper so they can be freely modified here.

      */

     SwsFunc swscale;

     int srcW;                     ///< Width  of source      luma/alpha planes.
     int srcH;                     ///< Height of source      luma/alpha planes.
     int dstH;                     ///< Height of destination luma/alpha planes.
     int chrSrcW;                  ///< Width  of source      chroma     planes.
     int chrSrcH;                  ///< Height of source      chroma     planes.
     int chrDstW;                  ///< Width  of destination chroma     planes.
     int chrDstH;                  ///< Height of destination chroma     planes.

     int lumXInc, chrXInc;
     int lumYInc, chrYInc;

     enum AVPixelFormat dstFormat; ///< Destination pixel format.
     enum AVPixelFormat srcFormat; ///< Source      pixel format.

     int dstFormatBpp;             ///< Number of bits per pixel of the destination pixel format.
     int srcFormatBpp;             ///< Number of bits per pixel of the source      pixel format.

     int dstBpc, srcBpc;

     int chrSrcHSubSample;         ///< Binary logarithm of horizontal subsampling factor between luma/alpha and chroma planes in source      image.
     int chrSrcVSubSample;         ///< Binary logarithm of vertical   subsampling factor between luma/alpha and chroma planes in source      image.
     int chrDstHSubSample;         ///< Binary logarithm of horizontal subsampling factor between luma/alpha and chroma planes in destination image.
     int chrDstVSubSample;         ///< Binary logarithm of vertical   subsampling factor between luma/alpha and chroma planes in destination image.
     int vChrDrop;                 ///< Binary logarithm of extra vertical subsampling factor in source image chroma planes specified by user.
     int sliceDir;                 ///< Direction that slices are fed to the scaler (1 = top-to-bottom, -1 = bottom-to-top).

     double param[2];              ///< Input parameters for scaling algorithms that need them.

     /* The cascaded_* fields allow spliting a scaler task into multiple
      * sequential steps, this is for example used to limit the maximum
      * downscaling factor that needs to be supported in one scaler.
      */

     struct SwsContext *cascaded_context[3];

     int cascaded_tmpStride[4];
     uint8_t *cascaded_tmp[4];

     int cascaded1_tmpStride[4];
     uint8_t *cascaded1_tmp[4];

     int cascaded_mainindex;

 
     double gamma_value;
     int gamma_flag;

     int is_internal_gamma;

     uint16_t *gamma;
     uint16_t *inv_gamma;

     int numDesc;
     int descIndex[2];
     int numSlice;
     struct SwsSlice *slice;
     struct SwsFilterDescriptor *desc;
 

     uint32_t pal_yuv[256];
     uint32_t pal_rgb[256];
 

     /**
      * @name Scaled horizontal lines ring buffer.
      * The horizontal scaler keeps just enough scaled lines in a ring buffer
      * so they may be passed to the vertical scaler. The pointers to the
      * allocated buffers for each line are duplicated in sequence in the ring
      * buffer to simplify indexing and avoid wrapping around between lines
      * inside the vertical scaler code. The wrapping is done before the
      * vertical scaler is called.
      */
     //@{

     int lastInLumBuf;             ///< Last scaled horizontal luma/alpha line from source in the ring buffer.
     int lastInChrBuf;             ///< Last scaled horizontal chroma     line from source in the ring buffer.
     int lumBufIndex;              ///< Index in ring buffer of the last scaled horizontal luma/alpha line from source.
     int chrBufIndex;              ///< Index in ring buffer of the last scaled horizontal chroma     line from source.

     //@}

     uint8_t *formatConvBuffer;

     int needAlpha;

     /**
      * @name Horizontal and vertical filters.
      * To better understand the following fields, here is a pseudo-code of
      * their usage in filtering a horizontal line:
      * @code
      * for (i = 0; i < width; i++) {
      *     dst[i] = 0;
      *     for (j = 0; j < filterSize; j++)
      *         dst[i] += src[ filterPos[i] + j ] * filter[ filterSize * i + j ];
      *     dst[i] >>= FRAC_BITS; // The actual implementation is fixed-point.
      * }
      * @endcode
      */
     //@{
     int16_t *hLumFilter;          ///< Array of horizontal filter coefficients for luma/alpha planes.
     int16_t *hChrFilter;          ///< Array of horizontal filter coefficients for chroma     planes.
     int16_t *vLumFilter;          ///< Array of vertical   filter coefficients for luma/alpha planes.
     int16_t *vChrFilter;          ///< Array of vertical   filter coefficients for chroma     planes.

     int32_t *hLumFilterPos;       ///< Array of horizontal filter starting positions for each dst[i] for luma/alpha planes.
     int32_t *hChrFilterPos;       ///< Array of horizontal filter starting positions for each dst[i] for chroma     planes.
     int32_t *vLumFilterPos;       ///< Array of vertical   filter starting positions for each dst[i] for luma/alpha planes.
     int32_t *vChrFilterPos;       ///< Array of vertical   filter starting positions for each dst[i] for chroma     planes.

     int hLumFilterSize;           ///< Horizontal filter size for luma/alpha pixels.
     int hChrFilterSize;           ///< Horizontal filter size for chroma     pixels.
     int vLumFilterSize;           ///< Vertical   filter size for luma/alpha pixels.
     int vChrFilterSize;           ///< Vertical   filter size for chroma     pixels.

     //@}

     int lumMmxextFilterCodeSize;  ///< Runtime-generated MMXEXT horizontal fast bilinear scaler code size for luma/alpha planes.
     int chrMmxextFilterCodeSize;  ///< Runtime-generated MMXEXT horizontal fast bilinear scaler code size for chroma planes.
     uint8_t *lumMmxextFilterCode; ///< Runtime-generated MMXEXT horizontal fast bilinear scaler code for luma/alpha planes.
     uint8_t *chrMmxextFilterCode; ///< Runtime-generated MMXEXT horizontal fast bilinear scaler code for chroma planes.

     int canMMXEXTBeUsed;

     int warned_unuseable_bilinear;

     int dstY;                     ///< Last destination vertical line output from last slice.
     int flags;                    ///< Flags passed by the user to select scaler algorithm, optimizations, subsampling, etc...

     void *yuvTable;             // pointer to the yuv->rgb table start so it can be freed()

     // alignment ensures the offset can be added in a single
     // instruction on e.g. ARM
     DECLARE_ALIGNED(16, int, table_gV)[256 + 2*YUVRGB_TABLE_HEADROOM];

     uint8_t *table_rV[256 + 2*YUVRGB_TABLE_HEADROOM];
     uint8_t *table_gU[256 + 2*YUVRGB_TABLE_HEADROOM];
     uint8_t *table_bU[256 + 2*YUVRGB_TABLE_HEADROOM];

     DECLARE_ALIGNED(16, int32_t, input_rgb2yuv_table)[16+40*4]; // This table can contain both C and SIMD formatted values, the C vales are always at the XY_IDX points

 #define RY_IDX 0
 #define GY_IDX 1
 #define BY_IDX 2
 #define RU_IDX 3
 #define GU_IDX 4
 #define BU_IDX 5
 #define RV_IDX 6
 #define GV_IDX 7
 #define BV_IDX 8

 #define RGB2YUV_SHIFT 15

     int *dither_error[4];
 

     //Colorspace stuff
     int contrast, brightness, saturation;    // for sws_getColorspaceDetails
     int srcColorspaceTable[4];
     int dstColorspaceTable[4];

     int srcRange;                 ///< 0 = MPG YUV range, 1 = JPG YUV range (source      image).
     int dstRange;                 ///< 0 = MPG YUV range, 1 = JPG YUV range (destination image).

     int src0Alpha;
     int dst0Alpha;

     int srcXYZ;
     int dstXYZ;

     int src_h_chr_pos;
     int dst_h_chr_pos;
     int src_v_chr_pos;
     int dst_v_chr_pos;

     int yuv2rgb_y_offset;
     int yuv2rgb_y_coeff;
     int yuv2rgb_v2r_coeff;
     int yuv2rgb_v2g_coeff;
     int yuv2rgb_u2g_coeff;
     int yuv2rgb_u2b_coeff;

 
 #define RED_DITHER            "0*8"
 #define GREEN_DITHER          "1*8"
 #define BLUE_DITHER           "2*8"
 #define Y_COEFF               "3*8"
 #define VR_COEFF              "4*8"
 #define UB_COEFF              "5*8"
 #define VG_COEFF              "6*8"
 #define UG_COEFF              "7*8"
 #define Y_OFFSET              "8*8"
 #define U_OFFSET              "9*8"
 #define V_OFFSET              "10*8"

 #define LUM_MMX_FILTER_OFFSET "11*8"

 #define CHR_MMX_FILTER_OFFSET "11*8+4*4*"AV_STRINGIFY(MAX_FILTER_SIZE)

 #define DSTW_OFFSET           "11*8+4*4*"AV_STRINGIFY(MAX_FILTER_SIZE)"*2"

 #define ESP_OFFSET            "11*8+4*4*"AV_STRINGIFY(MAX_FILTER_SIZE)"*2+8"
 #define VROUNDER_OFFSET       "11*8+4*4*"AV_STRINGIFY(MAX_FILTER_SIZE)"*2+16"
 #define U_TEMP                "11*8+4*4*"AV_STRINGIFY(MAX_FILTER_SIZE)"*2+24"
 #define V_TEMP                "11*8+4*4*"AV_STRINGIFY(MAX_FILTER_SIZE)"*2+32"
 #define Y_TEMP                "11*8+4*4*"AV_STRINGIFY(MAX_FILTER_SIZE)"*2+40"
 #define ALP_MMX_FILTER_OFFSET "11*8+4*4*"AV_STRINGIFY(MAX_FILTER_SIZE)"*2+48"
 #define UV_OFF_PX             "11*8+4*4*"AV_STRINGIFY(MAX_FILTER_SIZE)"*3+48"
 #define UV_OFF_BYTE           "11*8+4*4*"AV_STRINGIFY(MAX_FILTER_SIZE)"*3+56"
 #define DITHER16              "11*8+4*4*"AV_STRINGIFY(MAX_FILTER_SIZE)"*3+64"
 #define DITHER32              "11*8+4*4*"AV_STRINGIFY(MAX_FILTER_SIZE)"*3+80"

 #define DITHER32_INT          (11*8+4*4*MAX_FILTER_SIZE*3+80) // value equal to above, used for checking that the struct hasn't been changed by mistake

     DECLARE_ALIGNED(8, uint64_t, redDither);
     DECLARE_ALIGNED(8, uint64_t, greenDither);
     DECLARE_ALIGNED(8, uint64_t, blueDither);
 
     DECLARE_ALIGNED(8, uint64_t, yCoeff);
     DECLARE_ALIGNED(8, uint64_t, vrCoeff);
     DECLARE_ALIGNED(8, uint64_t, ubCoeff);
     DECLARE_ALIGNED(8, uint64_t, vgCoeff);
     DECLARE_ALIGNED(8, uint64_t, ugCoeff);
     DECLARE_ALIGNED(8, uint64_t, yOffset);
     DECLARE_ALIGNED(8, uint64_t, uOffset);
     DECLARE_ALIGNED(8, uint64_t, vOffset);

     int32_t lumMmxFilter[4 * MAX_FILTER_SIZE];
     int32_t chrMmxFilter[4 * MAX_FILTER_SIZE];

     int dstW;                     ///< Width  of destination luma/alpha planes.

     DECLARE_ALIGNED(8, uint64_t, esp);
     DECLARE_ALIGNED(8, uint64_t, vRounder);
     DECLARE_ALIGNED(8, uint64_t, u_temp);
     DECLARE_ALIGNED(8, uint64_t, v_temp);
     DECLARE_ALIGNED(8, uint64_t, y_temp);

     int32_t alpMmxFilter[4 * MAX_FILTER_SIZE];

     // alignment of these values is not necessary, but merely here
     // to maintain the same offset across x8632 and x86-64. Once we
     // use proper offset macros in the asm, they can be removed.

     DECLARE_ALIGNED(8, ptrdiff_t, uv_off); ///< offset (in pixels) between u and v planes

     DECLARE_ALIGNED(8, ptrdiff_t, uv_offx2); ///< offset (in bytes) between u and v planes

     DECLARE_ALIGNED(8, uint16_t, dither16)[8];
     DECLARE_ALIGNED(8, uint32_t, dither32)[8];

     const uint8_t *chrDither8, *lumDither8;
 

 #if HAVE_ALTIVEC

     vector signed short   CY;
     vector signed short   CRV;
     vector signed short   CBU;
     vector signed short   CGU;
     vector signed short   CGV;
     vector signed short   OY;
     vector unsigned short CSHIFT;

     vector signed short  *vYCoeffsBank, *vCCoeffsBank;

 #endif
 

     int use_mmx_vfilter;

 /* pre defined color-spaces gamma */
 #define XYZ_GAMMA (2.6f)
 #define RGB_GAMMA (2.2f)

     int16_t *xyzgamma;
     int16_t *rgbgamma;

     int16_t *xyzgammainv;
     int16_t *rgbgammainv;

     int16_t xyz2rgb_matrix[3][4];

     int16_t rgb2xyz_matrix[3][4];

     /* function pointers for swscale() */

     yuv2planar1_fn yuv2plane1;
     yuv2planarX_fn yuv2planeX;
     yuv2interleavedX_fn yuv2nv12cX;

     yuv2packed1_fn yuv2packed1;
     yuv2packed2_fn yuv2packed2;
     yuv2packedX_fn yuv2packedX;

     yuv2anyX_fn yuv2anyX;

     /// Unscaled conversion of luma plane to YV12 for horizontal scaler.

     void (*lumToYV12)(uint8_t *dst, const uint8_t *src, const uint8_t *src2, const uint8_t *src3,

                       int width, uint32_t *pal);
     /// Unscaled conversion of alpha plane to YV12 for horizontal scaler.

     void (*alpToYV12)(uint8_t *dst, const uint8_t *src, const uint8_t *src2, const uint8_t *src3,

                       int width, uint32_t *pal);
     /// Unscaled conversion of chroma planes to YV12 for horizontal scaler.

     void (*chrToYV12)(uint8_t *dstU, uint8_t *dstV,

                       const uint8_t *src1, const uint8_t *src2, const uint8_t *src3,

                       int width, uint32_t *pal);

 
     /**

      * Functions to read planar input, such as planar RGB, and convert

      * internally to Y/UV/A.

      */

     /** @{ */

     void (*readLumPlanar)(uint8_t *dst, const uint8_t *src[4], int width, int32_t *rgb2yuv);

     void (*readChrPlanar)(uint8_t *dstU, uint8_t *dstV, const uint8_t *src[4],

                           int width, int32_t *rgb2yuv);

     void (*readAlpPlanar)(uint8_t *dst, const uint8_t *src[4], int width, int32_t *rgb2yuv);

     /** @} */
 

     /**
      * Scale one horizontal line of input data using a bilinear filter
      * to produce one line of output data. Compared to SwsContext->hScale(),
      * please take note of the following caveats when using these:

      * - Scaling is done using only 7 bits instead of 14-bit coefficients.

      * - You can use no more than 5 input pixels to produce 4 output
      *   pixels. Therefore, this filter should not be used for downscaling
      *   by more than ~20% in width (because that equals more than 5/4th
      *   downscaling and thus more than 5 pixels input per 4 pixels output).
      * - In general, bilinear filters create artifacts during downscaling
      *   (even when <20%), because one output pixel will span more than one
      *   input pixel, and thus some pixels will need edges of both neighbor
      *   pixels to interpolate the output pixel. Since you can use at most
      *   two input pixels per output pixel in bilinear scaling, this is
      *   impossible and thus downscaling by any size will create artifacts.
      * To enable this type of scaling, set SWS_FLAG_FAST_BILINEAR
      * in SwsContext->flags.
      */
     /** @{ */

     void (*hyscale_fast)(struct SwsContext *c,

                          int16_t *dst, int dstWidth,

                          const uint8_t *src, int srcW, int xInc);
     void (*hcscale_fast)(struct SwsContext *c,

                          int16_t *dst1, int16_t *dst2, int dstWidth,

                          const uint8_t *src1, const uint8_t *src2,
                          int srcW, int xInc);

     /** @} */

     /**
      * Scale one horizontal line of input data using a filter over the input
      * lines, to produce one (differently sized) line of output data.
      *
      * @param dst        pointer to destination buffer for horizontally scaled

      *                   data. If the number of bits per component of one
      *                   destination pixel (SwsContext->dstBpc) is <= 10, data

      *                   will be 15 bpc in 16 bits (int16_t) width. Else (i.e.

      *                   SwsContext->dstBpc == 16), data will be 19bpc in

      *                   32 bits (int32_t) width.

      * @param dstW       width of destination image

      * @param src        pointer to source data to be scaled. If the number of
      *                   bits per component of a source pixel (SwsContext->srcBpc)

      *                   is 8, this is 8bpc in 8 bits (uint8_t) width. Else

      *                   (i.e. SwsContext->dstBpc > 8), this is native depth

      *                   in 16 bits (uint16_t) width. In other words, for 9-bit

      *                   YUV input, this is 9bpc, for 10-bit YUV input, this is
      *                   10bpc, and for 16-bit RGB or YUV, this is 16bpc.

      * @param filter     filter coefficients to be used per output pixel for
      *                   scaling. This contains 14bpp filtering coefficients.
      *                   Guaranteed to contain dstW * filterSize entries.
      * @param filterPos  position of the first input pixel to be used for
      *                   each output pixel during scaling. Guaranteed to
      *                   contain dstW entries.
      * @param filterSize the number of input coefficients to be used (and
      *                   thus the number of input pixels to be used) for
      *                   creating a single output pixel. Is aligned to 4
      *                   (and input coefficients thus padded with zeroes)
      *                   to simplify creating SIMD code.
      */

     /** @{ */

     void (*hyScale)(struct SwsContext *c, int16_t *dst, int dstW,
                     const uint8_t *src, const int16_t *filter,

                     const int32_t *filterPos, int filterSize);

     void (*hcScale)(struct SwsContext *c, int16_t *dst, int dstW,
                     const uint8_t *src, const int16_t *filter,

                     const int32_t *filterPos, int filterSize);

     /** @} */

     /// Color range conversion function for luma plane if needed.
     void (*lumConvertRange)(int16_t *dst, int width);
     /// Color range conversion function for chroma planes if needed.
     void (*chrConvertRange)(int16_t *dst1, int16_t *dst2, int width);

     int needs_hcscale; ///< Set if there are chroma planes to be converted.

 
     SwsDither dither;

 
     SwsAlphaBlend alphablend;

 } SwsContext;
 //FIXME check init (where 0)
 

 SwsFunc ff_yuv2rgb_get_func_ptr(SwsContext *c);

 int ff_yuv2rgb_c_init_tables(SwsContext *c, const int inv_table[4],
                              int fullRange, int brightness,
                              int contrast, int saturation);

 void ff_yuv2rgb_init_tables_ppc(SwsContext *c, const int inv_table[4],
                                 int brightness, int contrast, int saturation);

 void ff_updateMMXDitherTables(SwsContext *c, int dstY, int lumBufIndex, int chrBufIndex,

                            int lastInLumBuf, int lastInChrBuf);
 

 av_cold void ff_sws_init_range_convert(SwsContext *c);
 

 SwsFunc ff_yuv2rgb_init_x86(SwsContext *c);

 SwsFunc ff_yuv2rgb_init_ppc(SwsContext *c);

 static av_always_inline int is16BPS(enum AVPixelFormat pix_fmt)
 {
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
     av_assert0(desc);

     return desc->comp[0].depth == 16;

 }

 static av_always_inline int isNBPS(enum AVPixelFormat pix_fmt)

 {
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
     av_assert0(desc);

     return desc->comp[0].depth >= 9 && desc->comp[0].depth <= 14;

 }

 static av_always_inline int isBE(enum AVPixelFormat pix_fmt)
 {
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
     av_assert0(desc);

     return desc->flags & AV_PIX_FMT_FLAG_BE;

 }
 
 static av_always_inline int isYUV(enum AVPixelFormat pix_fmt)
 {
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
     av_assert0(desc);

     return !(desc->flags & AV_PIX_FMT_FLAG_RGB) && desc->nb_components >= 2;

 }
 
 static av_always_inline int isPlanarYUV(enum AVPixelFormat pix_fmt)
 {
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
     av_assert0(desc);

     return ((desc->flags & AV_PIX_FMT_FLAG_PLANAR) && isYUV(pix_fmt));

 }
 
 static av_always_inline int isRGB(enum AVPixelFormat pix_fmt)
 {
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
     av_assert0(desc);

     return (desc->flags & AV_PIX_FMT_FLAG_RGB);

 }

 static av_always_inline int isGray(enum AVPixelFormat pix_fmt)
 {
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
     av_assert0(desc);
     return !(desc->flags & AV_PIX_FMT_FLAG_PAL) &&
            !(desc->flags & AV_PIX_FMT_FLAG_HWACCEL) &&
            desc->nb_components <= 2 &&
            pix_fmt != AV_PIX_FMT_MONOBLACK &&
            pix_fmt != AV_PIX_FMT_MONOWHITE;
 }

 static av_always_inline int isRGBinInt(enum AVPixelFormat pix_fmt)
 {
     return pix_fmt == AV_PIX_FMT_RGB48BE     ||
            pix_fmt == AV_PIX_FMT_RGB48LE     ||
            pix_fmt == AV_PIX_FMT_RGB32       ||
            pix_fmt == AV_PIX_FMT_RGB32_1     ||
            pix_fmt == AV_PIX_FMT_RGB24       ||
            pix_fmt == AV_PIX_FMT_RGB565BE    ||
            pix_fmt == AV_PIX_FMT_RGB565LE    ||
            pix_fmt == AV_PIX_FMT_RGB555BE    ||
            pix_fmt == AV_PIX_FMT_RGB555LE    ||
            pix_fmt == AV_PIX_FMT_RGB444BE    ||
            pix_fmt == AV_PIX_FMT_RGB444LE    ||
            pix_fmt == AV_PIX_FMT_RGB8        ||
            pix_fmt == AV_PIX_FMT_RGB4        ||
            pix_fmt == AV_PIX_FMT_RGB4_BYTE   ||
            pix_fmt == AV_PIX_FMT_RGBA64BE    ||
            pix_fmt == AV_PIX_FMT_RGBA64LE    ||
            pix_fmt == AV_PIX_FMT_MONOBLACK   ||
            pix_fmt == AV_PIX_FMT_MONOWHITE;
 }
 
 static av_always_inline int isBGRinInt(enum AVPixelFormat pix_fmt)
 {
     return pix_fmt == AV_PIX_FMT_BGR48BE     ||
            pix_fmt == AV_PIX_FMT_BGR48LE     ||
            pix_fmt == AV_PIX_FMT_BGR32       ||
            pix_fmt == AV_PIX_FMT_BGR32_1     ||
            pix_fmt == AV_PIX_FMT_BGR24       ||
            pix_fmt == AV_PIX_FMT_BGR565BE    ||
            pix_fmt == AV_PIX_FMT_BGR565LE    ||
            pix_fmt == AV_PIX_FMT_BGR555BE    ||
            pix_fmt == AV_PIX_FMT_BGR555LE    ||
            pix_fmt == AV_PIX_FMT_BGR444BE    ||
            pix_fmt == AV_PIX_FMT_BGR444LE    ||
            pix_fmt == AV_PIX_FMT_BGR8        ||
            pix_fmt == AV_PIX_FMT_BGR4        ||
            pix_fmt == AV_PIX_FMT_BGR4_BYTE   ||
            pix_fmt == AV_PIX_FMT_BGRA64BE    ||
            pix_fmt == AV_PIX_FMT_BGRA64LE    ||
            pix_fmt == AV_PIX_FMT_MONOBLACK   ||
            pix_fmt == AV_PIX_FMT_MONOWHITE;
 }

 static av_always_inline int isBayer(enum AVPixelFormat pix_fmt)
 {
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
     av_assert0(desc);
     return !!(desc->flags & AV_PIX_FMT_FLAG_BAYER);
 }

 static av_always_inline int isAnyRGB(enum AVPixelFormat pix_fmt)
 {
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
     av_assert0(desc);
     return (desc->flags & AV_PIX_FMT_FLAG_RGB) ||
             pix_fmt == AV_PIX_FMT_MONOBLACK || pix_fmt == AV_PIX_FMT_MONOWHITE;
 }

 static av_always_inline int isALPHA(enum AVPixelFormat pix_fmt)
 {
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
     av_assert0(desc);

     if (pix_fmt == AV_PIX_FMT_PAL8)
         return 1;

     return desc->flags & AV_PIX_FMT_FLAG_ALPHA;

 }

 static av_always_inline int isPacked(enum AVPixelFormat pix_fmt)
 {
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
     av_assert0(desc);

     return (desc->nb_components >= 2 && !(desc->flags & AV_PIX_FMT_FLAG_PLANAR)) ||
             pix_fmt == AV_PIX_FMT_PAL8 ||
             pix_fmt == AV_PIX_FMT_MONOBLACK || pix_fmt == AV_PIX_FMT_MONOWHITE;

 }

 static av_always_inline int isPlanar(enum AVPixelFormat pix_fmt)
 {
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
     av_assert0(desc);

     return (desc->nb_components >= 2 && (desc->flags & AV_PIX_FMT_FLAG_PLANAR));

 }
 
 static av_always_inline int isPackedRGB(enum AVPixelFormat pix_fmt)
 {
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
     av_assert0(desc);

     return ((desc->flags & (AV_PIX_FMT_FLAG_PLANAR | AV_PIX_FMT_FLAG_RGB)) == AV_PIX_FMT_FLAG_RGB);

 }
 
 static av_always_inline int isPlanarRGB(enum AVPixelFormat pix_fmt)
 {
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
     av_assert0(desc);

     return ((desc->flags & (AV_PIX_FMT_FLAG_PLANAR | AV_PIX_FMT_FLAG_RGB)) ==
             (AV_PIX_FMT_FLAG_PLANAR | AV_PIX_FMT_FLAG_RGB));

 }
 
 static av_always_inline int usePal(enum AVPixelFormat pix_fmt)
 {
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt);
     av_assert0(desc);

     return (desc->flags & AV_PIX_FMT_FLAG_PAL) || (desc->flags & AV_PIX_FMT_FLAG_PSEUDOPAL);

 }

 extern const uint64_t ff_dither4[2];
 extern const uint64_t ff_dither8[2];

 extern const uint8_t ff_dither_2x2_4[3][8];
 extern const uint8_t ff_dither_2x2_8[3][8];
 extern const uint8_t ff_dither_4x4_16[5][8];
 extern const uint8_t ff_dither_8x8_32[9][8];
 extern const uint8_t ff_dither_8x8_73[9][8];

 extern const uint8_t ff_dither_8x8_128[9][8];

 extern const uint8_t ff_dither_8x8_220[9][8];

 extern const int32_t ff_yuv2rgb_coeffs[11][4];

 extern const AVClass ff_sws_context_class;

 /**

  * Set c->swscale to an unscaled converter if one exists for the specific

  * source and destination formats, bit depths, flags, etc.
  */
 void ff_get_unscaled_swscale(SwsContext *c);

 void ff_get_unscaled_swscale_ppc(SwsContext *c);

 void ff_get_unscaled_swscale_arm(SwsContext *c);

 void ff_get_unscaled_swscale_aarch64(SwsContext *c);

 /**

  * Return function pointer to fastest main scaler path function depending

  * on architecture and available optimizations.
  */
 SwsFunc ff_getSwsFunc(SwsContext *c);
 

 void ff_sws_init_input_funcs(SwsContext *c);

 void ff_sws_init_output_funcs(SwsContext *c,
                               yuv2planar1_fn *yuv2plane1,
                               yuv2planarX_fn *yuv2planeX,
                               yuv2interleavedX_fn *yuv2nv12cX,
                               yuv2packed1_fn *yuv2packed1,
                               yuv2packed2_fn *yuv2packed2,

                               yuv2packedX_fn *yuv2packedX,
                               yuv2anyX_fn *yuv2anyX);

 void ff_sws_init_swscale_ppc(SwsContext *c);

 void ff_sws_init_swscale_x86(SwsContext *c);

 void ff_sws_init_swscale_aarch64(SwsContext *c);

 void ff_sws_init_swscale_arm(SwsContext *c);

 void ff_hyscale_fast_c(SwsContext *c, int16_t *dst, int dstWidth,
                        const uint8_t *src, int srcW, int xInc);
 void ff_hcscale_fast_c(SwsContext *c, int16_t *dst1, int16_t *dst2,
                        int dstWidth, const uint8_t *src1,
                        const uint8_t *src2, int srcW, int xInc);

 int ff_init_hscaler_mmxext(int dstW, int xInc, uint8_t *filterCode,
                            int16_t *filter, int32_t *filterPos,
                            int numSplits);
 void ff_hyscale_fast_mmxext(SwsContext *c, int16_t *dst,
                             int dstWidth, const uint8_t *src,
                             int srcW, int xInc);
 void ff_hcscale_fast_mmxext(SwsContext *c, int16_t *dst1, int16_t *dst2,
                             int dstWidth, const uint8_t *src1,
                             const uint8_t *src2, int srcW, int xInc);

 /**
  * Allocate and return an SwsContext.
  * This is like sws_getContext() but does not perform the init step, allowing
  * the user to set additional AVOptions.
  *
  * @see sws_getContext()
  */
 struct SwsContext *sws_alloc_set_opts(int srcW, int srcH, enum AVPixelFormat srcFormat,
                                       int dstW, int dstH, enum AVPixelFormat dstFormat,
                                       int flags, const double *param);
 

 int ff_sws_alphablendaway(SwsContext *c, const uint8_t *src[],
                           int srcStride[], int srcSliceY, int srcSliceH,
                           uint8_t *dst[], int dstStride[]);
 

 static inline void fillPlane16(uint8_t *plane, int stride, int width, int height, int y,
                                int alpha, int bits, const int big_endian)
 {
     int i, j;
     uint8_t *ptr = plane + stride * y;

     int v = alpha ? 0xFFFF>>(16-bits) : (1<<(bits-1));

     for (i = 0; i < height; i++) {
 #define FILL(wfunc) \
         for (j = 0; j < width; j++) {\
             wfunc(ptr+2*j, v);\
         }
         if (big_endian) {
             FILL(AV_WB16);
         } else {
             FILL(AV_WL16);
         }
         ptr += stride;
     }
 }
 

 #define MAX_SLICE_PLANES 4
 
 /// Slice plane
 typedef struct SwsPlane
 {
     int available_lines;    ///< max number of lines that can be hold by this plane
     int sliceY;             ///< index of first line
     int sliceH;             ///< number of lines
     uint8_t **line;         ///< line buffer
     uint8_t **tmp;          ///< Tmp line buffer used by mmx code
 } SwsPlane;
 
 /**

  * Struct which defines a slice of an image to be scaled or an output for

  * a scaled slice.
  * A slice can also be used as intermediate ring buffer for scaling steps.
  */
 typedef struct SwsSlice
 {
     int width;              ///< Slice line width
     int h_chr_sub_sample;   ///< horizontal chroma subsampling factor
     int v_chr_sub_sample;   ///< vertical chroma subsampling factor
     int is_ring;            ///< flag to identify if this slice is a ring buffer
     int should_free_lines;  ///< flag to identify if there are dynamic allocated lines
     enum AVPixelFormat fmt; ///< planes pixel format
     SwsPlane plane[MAX_SLICE_PLANES];   ///< color planes
 } SwsSlice;
 
 /**
  * Struct which holds all necessary data for processing a slice.
  * A processing step can be a color conversion or horizontal/vertical scaling.
  */
 typedef struct SwsFilterDescriptor
 {
     SwsSlice *src;  ///< Source slice
     SwsSlice *dst;  ///< Output slice
 
     int alpha;      ///< Flag for processing alpha channel
     void *instance; ///< Filter instance data
 
     /// Function for processing input slice sliceH lines starting from line sliceY
     int (*process)(SwsContext *c, struct SwsFilterDescriptor *desc, int sliceY, int sliceH);
 } SwsFilterDescriptor;
 
 // warp input lines in the form (src + width*i + j) to slice format (line[i][j])

 // relative=true means first line src[x][0] otherwise first line is src[x][lum/crh Y]
 int ff_init_slice_from_src(SwsSlice * s, uint8_t *src[4], int stride[4], int srcW, int lumY, int lumH, int chrY, int chrH, int relative);

 
 // Initialize scaler filter descriptor chain
 int ff_init_filters(SwsContext *c);
 
 // Free all filter data
 int ff_free_filters(SwsContext *c);
 
 /*
  function for applying ring buffer logic into slice s
  It checks if the slice can hold more @lum lines, if yes
  do nothing otherwise remove @lum least used lines.

  It applies the same procedure for @chr lines.

 */
 int ff_rotate_slice(SwsSlice *s, int lum, int chr);
 

 /// initializes gamma conversion descriptor
 int ff_init_gamma_convert(SwsFilterDescriptor *desc, SwsSlice * src, uint16_t *table);
 

 /// initializes lum pixel format conversion descriptor
 int ff_init_desc_fmt_convert(SwsFilterDescriptor *desc, SwsSlice * src, SwsSlice *dst, uint32_t *pal);
 
 /// initializes lum horizontal scaling descriptor
 int ff_init_desc_hscale(SwsFilterDescriptor *desc, SwsSlice *src, SwsSlice *dst, uint16_t *filter, int * filter_pos, int filter_size, int xInc);
 

 /// initializes chr pixel format conversion descriptor

 int ff_init_desc_cfmt_convert(SwsFilterDescriptor *desc, SwsSlice * src, SwsSlice *dst, uint32_t *pal);
 
 /// initializes chr horizontal scaling descriptor
 int ff_init_desc_chscale(SwsFilterDescriptor *desc, SwsSlice *src, SwsSlice *dst, uint16_t *filter, int * filter_pos, int filter_size, int xInc);
 
 int ff_init_desc_no_chr(SwsFilterDescriptor *desc, SwsSlice * src, SwsSlice *dst);
 

 /// initializes vertical scaling descriptors
 int ff_init_vscale(SwsContext *c, SwsFilterDescriptor *desc, SwsSlice *src, SwsSlice *dst);
 
 /// setup vertical scaler functions
 void ff_init_vscale_pfn(SwsContext *c, yuv2planar1_fn yuv2plane1, yuv2planarX_fn yuv2planeX,
     yuv2interleavedX_fn yuv2nv12cX, yuv2packed1_fn yuv2packed1, yuv2packed2_fn yuv2packed2,
     yuv2packedX_fn yuv2packedX, yuv2anyX_fn yuv2anyX, int use_mmx);
 

 //number of extra lines to process
 #define MAX_LINES_AHEAD 4
 

 #endif /* SWSCALE_SWSCALE_INTERNAL_H */