aboutsummaryrefslogtreecommitdiffstats
path: root/libswscale/swscale_internal.h
blob: cfb19d9c132bae8f12e3096c14e2f9fc56aae699 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
/*
 * Copyright (C) 2001-2003 Michael Niedermayer <michaelni@gmx.at>
 *
 * This file is part of Libav.
 *
 * Libav 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.
 *
 * Libav 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 Libav; 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"

#if HAVE_ALTIVEC_H
#include <altivec.h>
#endif

#include "libavutil/avutil.h"

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

#define FAST_BGR2YV12 //use 7-bit instead of 15-bit coefficients

#define MAX_FILTER_SIZE 256

#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

struct SwsContext;

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 Y/U/V/A to planar output
 * without any additional vertical scaling (or point-scaling).
 *
 * @param c       SWS scaling context
 * @param lumSrc  scaled luma (Y) source data, 15bit for 8bit output
 * @param chrUSrc scaled chroma (U) source data, 15bit for 8bit output
 * @param chrVSrc scaled chroma (V) source data, 15bit for 8bit output
 * @param alpSrc  scaled alpha (A) source data, 15bit for 8bit output
 * @param dest    pointer to the 4 output planes (Y/U/V/A)
 * @param dstW    width of dest[0], dest[3], lumSrc and alpSrc in pixels
 * @param chrDstW width of dest[1], dest[2], chrUSrc and chrVSrc
 */
typedef void (*yuv2planar1_fn) (struct SwsContext *c,
                                const int16_t *lumSrc, const int16_t *chrUSrc,
                                const int16_t *chrVSrc, const int16_t *alpSrc,
                                uint8_t *dest[4], int dstW, int chrDstW);
/**
 * Write one line of horizontally scaled Y/U/V/A to planar output
 * with multi-point vertical scaling between input pixels.
 *
 * @param c             SWS scaling context
 * @param lumFilter     vertical luma/alpha scaling coefficients, 12bit [0,4096]
 * @param lumSrc        scaled luma (Y) source data, 15bit for 8bit output
 * @param lumFilterSize number of vertical luma/alpha input lines to scale
 * @param chrFilter     vertical chroma scaling coefficients, 12bit [0,4096]
 * @param chrUSrc       scaled chroma (U) source data, 15bit for 8bit output
 * @param chrVSrc       scaled chroma (V) source data, 15bit for 8bit output
 * @param chrFilterSize number of vertical chroma input lines to scale
 * @param alpSrc        scaled alpha (A) source data, 15bit for 8bit output
 * @param dest          pointer to the 4 output planes (Y/U/V/A)
 * @param dstW          width of dest[0], dest[3], lumSrc and alpSrc in pixels
 * @param chrDstW       width of dest[1], dest[2], chrUSrc and chrVSrc
 */
typedef void (*yuv2planarX_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[4],
                                int dstW, int chrDstW);
/**
 * 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, 15bit for 8bit output
 * @param chrUSrc scaled chroma (U) source data, 15bit for 8bit output
 * @param chrVSrc scaled chroma (V) source data, 15bit for 8bit output
 * @param alpSrc  scaled alpha (A) source data, 15bit for 8bit output
 * @param dest    pointer to the output plane
 * @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, 15bit for 8bit output
 * @param chrUSrc scaled chroma (U) source data, 15bit for 8bit output
 * @param chrVSrc scaled chroma (V) source data, 15bit for 8bit output
 * @param alpSrc  scaled alpha (A) source data, 15bit for 8bit output
 * @param dest    pointer to the output plane
 * @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, 12bit [0,4096]
 * @param lumSrc        scaled luma (Y) source data, 15bit for 8bit output
 * @param lumFilterSize number of vertical luma/alpha input lines to scale
 * @param chrFilter     vertical chroma scaling coefficients, 12bit [0,4096]
 * @param chrUSrc       scaled chroma (U) source data, 15bit for 8bit output
 * @param chrVSrc       scaled chroma (V) source data, 15bit for 8bit output
 * @param chrFilterSize number of vertical chroma input lines to scale
 * @param alpSrc        scaled alpha (A) source data, 15bit for 8bit output
 * @param dest          pointer to the output plane
 * @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);

/* 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 PixelFormat dstFormat;   ///< Destination pixel format.
    enum PixelFormat 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 scalingBpp;
    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.

    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.
     */
    //@{
    int16_t **lumPixBuf;          ///< Ring buffer for scaled horizontal luma   plane lines to be fed to the vertical scaler.
    int16_t **chrUPixBuf;         ///< Ring buffer for scaled horizontal chroma plane lines to be fed to the vertical scaler.
    int16_t **chrVPixBuf;         ///< Ring buffer for scaled horizontal chroma plane lines to be fed to the vertical scaler.
    int16_t **alpPixBuf;          ///< Ring buffer for scaled horizontal alpha  plane lines to be fed to the vertical scaler.
    int       vLumBufSize;        ///< Number of vertical luma/alpha lines allocated in the ring buffer.
    int       vChrBufSize;        ///< Number of vertical chroma     lines allocated in the ring buffer.
    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;

    /**
     * @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.
    int16_t *hLumFilterPos;       ///< Array of horizontal filter starting positions for each dst[i] for luma/alpha planes.
    int16_t *hChrFilterPos;       ///< Array of horizontal filter starting positions for each dst[i] for chroma     planes.
    int16_t *vLumFilterPos;       ///< Array of vertical   filter starting positions for each dst[i] for luma/alpha planes.
    int16_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 lumMmx2FilterCodeSize;    ///< Runtime-generated MMX2 horizontal fast bilinear scaler code size for luma/alpha planes.
    int chrMmx2FilterCodeSize;    ///< Runtime-generated MMX2 horizontal fast bilinear scaler code size for chroma     planes.
    uint8_t *lumMmx2FilterCode;   ///< Runtime-generated MMX2 horizontal fast bilinear scaler code for luma/alpha planes.
    uint8_t *chrMmx2FilterCode;   ///< Runtime-generated MMX2 horizontal fast bilinear scaler code for chroma     planes.

    int canMMX2BeUsed;

    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()
    uint8_t * table_rV[256];
    uint8_t * table_gU[256];
    int    table_gV[256];
    uint8_t * table_bU[256];

    //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 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*256"
#define DSTW_OFFSET           "11*8+4*4*256*2" //do not change, it is hardcoded in the ASM
#define ESP_OFFSET            "11*8+4*4*256*2+8"
#define VROUNDER_OFFSET       "11*8+4*4*256*2+16"
#define U_TEMP                "11*8+4*4*256*2+24"
#define V_TEMP                "11*8+4*4*256*2+32"
#define Y_TEMP                "11*8+4*4*256*2+40"
#define ALP_MMX_FILTER_OFFSET "11*8+4*4*256*2+48"
#define UV_OFF                "11*8+4*4*256*3+48"
#define UV_OFFx2              "11*8+4*4*256*3+56"

    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];
    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

#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

#if ARCH_BFIN
    DECLARE_ALIGNED(4, uint32_t, oy);
    DECLARE_ALIGNED(4, uint32_t, oc);
    DECLARE_ALIGNED(4, uint32_t, zero);
    DECLARE_ALIGNED(4, uint32_t, cy);
    DECLARE_ALIGNED(4, uint32_t, crv);
    DECLARE_ALIGNED(4, uint32_t, rmask);
    DECLARE_ALIGNED(4, uint32_t, cbu);
    DECLARE_ALIGNED(4, uint32_t, bmask);
    DECLARE_ALIGNED(4, uint32_t, cgu);
    DECLARE_ALIGNED(4, uint32_t, cgv);
    DECLARE_ALIGNED(4, uint32_t, gmask);
#endif

#if HAVE_VIS
    DECLARE_ALIGNED(8, uint64_t, sparc_coeffs)[10];
#endif

    /* function pointers for swScale() */
    yuv2planar1_fn yuv2yuv1;
    yuv2planarX_fn yuv2yuvX;
    yuv2packed1_fn yuv2packed1;
    yuv2packed2_fn yuv2packed2;
    yuv2packedX_fn yuv2packedX;

    void (*lumToYV12)(uint8_t *dst, const uint8_t *src,
                      int width, uint32_t *pal); ///< Unscaled conversion of luma plane to YV12 for horizontal scaler.
    void (*alpToYV12)(uint8_t *dst, const uint8_t *src,
                      int width, uint32_t *pal); ///< Unscaled conversion of alpha plane to YV12 for horizontal scaler.
    void (*chrToYV12)(uint8_t *dstU, uint8_t *dstV,
                      const uint8_t *src1, const uint8_t *src2,
                      int width, uint32_t *pal); ///< Unscaled conversion of chroma planes to YV12 for horizontal scaler.
    /**
     * 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 7bit instead of 14bit 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 scaling depth (SwsContext->scalingBpp) is
     *                   8, data will be 15bpp in 16bits (int16_t) width. If
     *                   scaling depth is 16, data will be 19bpp in 32bpp
     *                   (int32_t) width.
     * @param dstW       width of destination image
     * @param src        pointer to source data to be scaled. If scaling depth
     *                   is 8, this is 8bpp in 8bpp (uint8_t) width. If scaling
     *                   depth is 16, this is 16bpp in 16bpp (uint16_t) depth.
     * @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 (*hScale)(int16_t *dst, int dstW, const uint8_t *src,
                   const int16_t *filter, const int16_t *filterPos,
                   int filterSize);

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

    /**
     * dst[..] = (src[..] << 8) | src[..];
     */
    void (*scale8To16Rv)(uint16_t *dst, const uint8_t *src, int len);
    /**
     * dst[..] = src[..] >> 4;
     */
    void (*scale19To15Fw)(int16_t *dst, const int32_t *src, int len);

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

} 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_altivec(SwsContext *c, const int inv_table[4],
                                    int brightness, int contrast, int saturation);
void updateMMXDitherTables(SwsContext *c, int dstY, int lumBufIndex, int chrBufIndex,
                           int lastInLumBuf, int lastInChrBuf);

SwsFunc ff_yuv2rgb_init_mmx(SwsContext *c);
SwsFunc ff_yuv2rgb_init_vis(SwsContext *c);
SwsFunc ff_yuv2rgb_init_mlib(SwsContext *c);
SwsFunc ff_yuv2rgb_init_altivec(SwsContext *c);
SwsFunc ff_yuv2rgb_get_func_ptr_bfin(SwsContext *c);
void ff_bfin_get_unscaled_swscale(SwsContext *c);

const char *sws_format_name(enum PixelFormat format);

//FIXME replace this with something faster
#define is16BPS(x)      (           \
           (x)==PIX_FMT_GRAY16BE    \
        || (x)==PIX_FMT_GRAY16LE    \
        || (x)==PIX_FMT_BGR48BE     \
        || (x)==PIX_FMT_BGR48LE     \
        || (x)==PIX_FMT_RGB48BE     \
        || (x)==PIX_FMT_RGB48LE     \
        || (x)==PIX_FMT_YUV420P16LE \
        || (x)==PIX_FMT_YUV422P16LE \
        || (x)==PIX_FMT_YUV444P16LE \
        || (x)==PIX_FMT_YUV420P16BE \
        || (x)==PIX_FMT_YUV422P16BE \
        || (x)==PIX_FMT_YUV444P16BE \
    )
#define is9_OR_10BPS(x) (           \
           (x)==PIX_FMT_YUV420P9LE  \
        || (x)==PIX_FMT_YUV420P9BE  \
        || (x)==PIX_FMT_YUV444P9BE  \
        || (x)==PIX_FMT_YUV444P9LE  \
        || (x)==PIX_FMT_YUV422P10BE \
        || (x)==PIX_FMT_YUV422P10LE \
        || (x)==PIX_FMT_YUV444P10BE \
        || (x)==PIX_FMT_YUV444P10LE \
        || (x)==PIX_FMT_YUV420P10LE \
        || (x)==PIX_FMT_YUV420P10BE \
    )
#define isBE(x) ((x)&1)
#define isPlanar8YUV(x) (           \
           (x)==PIX_FMT_YUV410P     \
        || (x)==PIX_FMT_YUV420P     \
        || (x)==PIX_FMT_YUVA420P    \
        || (x)==PIX_FMT_YUV411P     \
        || (x)==PIX_FMT_YUV422P     \
        || (x)==PIX_FMT_YUV444P     \
        || (x)==PIX_FMT_YUV440P     \
        || (x)==PIX_FMT_NV12        \
        || (x)==PIX_FMT_NV21        \
    )
#define isPlanarYUV(x)  (           \
        isPlanar8YUV(x)             \
        || (x)==PIX_FMT_YUV420P9LE  \
        || (x)==PIX_FMT_YUV444P9LE  \
        || (x)==PIX_FMT_YUV420P10LE \
        || (x)==PIX_FMT_YUV422P10LE \
        || (x)==PIX_FMT_YUV444P10LE \
        || (x)==PIX_FMT_YUV420P16LE \
        || (x)==PIX_FMT_YUV422P16LE \
        || (x)==PIX_FMT_YUV444P16LE \
        || (x)==PIX_FMT_YUV420P9BE  \
        || (x)==PIX_FMT_YUV444P9BE  \
        || (x)==PIX_FMT_YUV420P10BE \
        || (x)==PIX_FMT_YUV422P10BE \
        || (x)==PIX_FMT_YUV444P10BE \
        || (x)==PIX_FMT_YUV420P16BE \
        || (x)==PIX_FMT_YUV422P16BE \
        || (x)==PIX_FMT_YUV444P16BE \
    )
#define isYUV(x)        (           \
           (x)==PIX_FMT_UYVY422     \
        || (x)==PIX_FMT_YUYV422     \
        || isPlanarYUV(x)           \
    )
#define isGray(x)       (           \
           (x)==PIX_FMT_GRAY8       \
        || (x)==PIX_FMT_Y400A      \
        || (x)==PIX_FMT_GRAY16BE    \
        || (x)==PIX_FMT_GRAY16LE    \
    )
#define isGray16(x)     (           \
           (x)==PIX_FMT_GRAY16BE    \
        || (x)==PIX_FMT_GRAY16LE    \
    )
#define isRGBinInt(x)   (           \
           (x)==PIX_FMT_RGB48BE     \
        || (x)==PIX_FMT_RGB48LE     \
        || (x)==PIX_FMT_RGB32       \
        || (x)==PIX_FMT_RGB32_1     \
        || (x)==PIX_FMT_RGB24       \
        || (x)==PIX_FMT_RGB565BE    \
        || (x)==PIX_FMT_RGB565LE    \
        || (x)==PIX_FMT_RGB555BE    \
        || (x)==PIX_FMT_RGB555LE    \
        || (x)==PIX_FMT_RGB444BE    \
        || (x)==PIX_FMT_RGB444LE    \
        || (x)==PIX_FMT_RGB8        \
        || (x)==PIX_FMT_RGB4        \
        || (x)==PIX_FMT_RGB4_BYTE   \
        || (x)==PIX_FMT_MONOBLACK   \
        || (x)==PIX_FMT_MONOWHITE   \
    )
#define isBGRinInt(x)   (           \
           (x)==PIX_FMT_BGR48BE     \
        || (x)==PIX_FMT_BGR48LE     \
        || (x)==PIX_FMT_BGR32       \
        || (x)==PIX_FMT_BGR32_1     \
        || (x)==PIX_FMT_BGR24       \
        || (x)==PIX_FMT_BGR565BE    \
        || (x)==PIX_FMT_BGR565LE    \
        || (x)==PIX_FMT_BGR555BE    \
        || (x)==PIX_FMT_BGR555LE    \
        || (x)==PIX_FMT_BGR444BE    \
        || (x)==PIX_FMT_BGR444LE    \
        || (x)==PIX_FMT_BGR8        \
        || (x)==PIX_FMT_BGR4        \
        || (x)==PIX_FMT_BGR4_BYTE   \
        || (x)==PIX_FMT_MONOBLACK   \
        || (x)==PIX_FMT_MONOWHITE   \
    )
#define isRGBinBytes(x) (           \
           (x)==PIX_FMT_RGB48BE     \
        || (x)==PIX_FMT_RGB48LE     \
        || (x)==PIX_FMT_RGBA        \
        || (x)==PIX_FMT_ARGB        \
        || (x)==PIX_FMT_RGB24       \
    )
#define isBGRinBytes(x) (           \
           (x)==PIX_FMT_BGR48BE     \
        || (x)==PIX_FMT_BGR48LE     \
        || (x)==PIX_FMT_BGRA        \
        || (x)==PIX_FMT_ABGR        \
        || (x)==PIX_FMT_BGR24       \
    )
#define isAnyRGB(x)     (           \
            isRGBinInt(x)           \
        ||  isBGRinInt(x)           \
    )
#define isALPHA(x)      (           \
           (x)==PIX_FMT_BGR32       \
        || (x)==PIX_FMT_BGR32_1     \
        || (x)==PIX_FMT_RGB32       \
        || (x)==PIX_FMT_RGB32_1     \
        || (x)==PIX_FMT_Y400A       \
        || (x)==PIX_FMT_YUVA420P    \
    )
#define isPacked(x)         (       \
           (x)==PIX_FMT_PAL8        \
        || (x)==PIX_FMT_YUYV422     \
        || (x)==PIX_FMT_UYVY422     \
        || (x)==PIX_FMT_Y400A       \
        || isAnyRGB(x)              \
    )
#define usePal(x) ((av_pix_fmt_descriptors[x].flags & PIX_FMT_PAL) || (x) == PIX_FMT_Y400A)

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

extern const AVClass sws_context_class;

/**
 * Sets 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_swscale_get_unscaled_altivec(SwsContext *c);

/**
 * Returns function pointer to fastest main scaler path function depending
 * on architecture and available optimizations.
 */
SwsFunc ff_getSwsFunc(SwsContext *c);

void ff_sws_init_swScale_altivec(SwsContext *c);
void ff_sws_init_swScale_mmx(SwsContext *c);

#endif /* SWSCALE_SWSCALE_INTERNAL_H */