gd-libgd / src / webpimg.c

Pierre Joye 0c21e2c 































Ondřej Surý f52b1dd 



Pierre Joye 0c21e2c 
Remi Collet e8edb92 
Pierre Joye 0c21e2c 






























































































































































































































































Remi Collet e8edb92 
Pierre Joye 0c21e2c 



























































































Remi Collet e8edb92 
Pierre Joye 0c21e2c 










































































































































































Ondřej Surý 32b1307 
Pierre Joye 0c21e2c 







Remi Collet e8edb92 

Pierre Joye 0c21e2c 






Remi Collet e8edb92 

Pierre Joye 0c21e2c 





































































































































































































































































































































  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
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
/*===========================================================================*
 - Copyright 2010 Google Inc.
 -
 - This code is licensed under the same terms as WebM:
 - Software License Agreement:  http://www.webmproject.org/license/software/
 - Additional IP Rights Grant:  http://www.webmproject.org/license/additional/
 *===========================================================================*/

/*
 * Encoding/Decoding of WebP still image compression format.
 *
 * 1. WebPDecode: Takes an array of bytes (string) corresponding to the WebP
 *                encoded image and generates output in the YUV format with
 *                the color components U, V subsampled to 1/2 resolution along
 *                each dimension.
 *
 * 2. YUV420toRGBA: Converts from YUV (with color subsampling) such as produced
 *                  by the WebPDecode routine into 32 bits per pixel RGBA data
 *                  array. This data array can be directly used by the Leptonica
 *                  Pix in-memory image format.
 *
 * 3. WebPEncode: Takes a Y, U, V data buffers (with color components U and V
 *                subsampled to 1/2 resolution) and generates the WebP string
 *
 * 4. RGBAToYUV420: Generates Y, U, V data (with color subsampling) from 32 bits
 *                  per pixel RGBA data buffer. The resulting YUV data can be
 *                  directly fed into the WebPEncode routine.
 *
 * 5. AdjustColorspace:
 *
 * 6. AdjustColorspaceBack:
 */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "gd.h"
#include "gd_errors.h"
#ifdef HAVE_LIBVPX
#include "webpimg.h"

#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>

#include "vpx/vpx_decoder.h"
#include "vpx/vp8dx.h"
#include "vpx/vpx_encoder.h"
#include "vpx/vp8cx.h"
#include "gd.h"

/*---------------------------------------------------------------------*
 *                              color conversions                      *
 *---------------------------------------------------------------------*/

#ifndef inline
# define inline __inline
#endif
static inline int clip(float v, int a, int b) {
  return (v > b) ? b : (v < 0) ? 0 : (int)(v);
}
enum {
    COLOR_RED = 0,
    COLOR_GREEN = 1,
    COLOR_BLUE = 2,
    ALPHA_CHANNEL = 3
};

/* endian neutral extractions of RGBA from a 32 bit pixel */
static const uint32  RED_SHIFT =
       8 * (sizeof(uint32) - 1 - COLOR_RED);           /* 24 */
static const uint32  GREEN_SHIFT =
       8 * (sizeof(uint32) - 1 - COLOR_GREEN);         /* 16 */
static const uint32  BLUE_SHIFT =
       8 * (sizeof(uint32) - 1 - COLOR_BLUE);          /*  8 */
static const uint32  ALPHA_SHIFT =
       8 * (sizeof(uint32) - 1 - ALPHA_CHANNEL);       /*  0 */

static inline int GetRed(const uint32* rgba) {
	return gdTrueColorGetRed(*rgba);
}

static inline int GetGreen(const uint32* rgba) {
	return gdTrueColorGetGreen(*rgba);
}

static inline int GetBlue(const uint32* rgba) {
  	return gdTrueColorGetBlue(*rgba);
}

enum { YUV_FRAC = 16 };

static inline int clip_uv(int v) {
   v = (v + (257 << (YUV_FRAC + 2 - 1))) >> (YUV_FRAC + 2);
   return ((v & ~0xff) == 0) ? v : v < 0 ? 0u : 255u;
}


/* YUV <-----> RGB conversions */
/* The exact naming is Y'CbCr, following the ITU-R BT.601 standard.
 * More information at: http://en.wikipedia.org/wiki/YCbCr
 */
static inline int GetLumaY(int r, int g, int b) {
  const int kRound = (1 << (YUV_FRAC - 1)) + (16 << YUV_FRAC);
  // Y = 0.2569 * R + 0.5044 * G + 0.0979 * B + 16
  const int luma = 16839 * r + 33059 * g + 6420 * b;
  return (luma + kRound) >> YUV_FRAC;
}

static inline int GetLumaYfromPtr(uint32* rgba) {
  const int r = GetRed(rgba);
  const int g = GetGreen(rgba);
  const int b = GetBlue(rgba);
  return GetLumaY(r, g, b);
}

static inline int GetChromaU(int r, int g, int b) {
  // U = -0.1483 * R - 0.2911 * G + 0.4394 * B + 128
  return clip_uv(-9719 * r - 19081 * g + 28800 * b);
}

static inline int GetChromaV(int r, int g, int b) {
  // V = 0.4394 * R - 0.3679 * G - 0.0715 * B + 128
  return clip_uv(+28800 * r - 24116 * g - 4684 * b);
}

/* Converts YUV to RGB and writes into a 32 bit pixel in endian
 * neutral fashion
 */
enum { RGB_FRAC = 16, RGB_HALF = (1 << RGB_FRAC) / 2,
       RGB_RANGE_MIN = -227, RGB_RANGE_MAX = 256 + 226 };

static int init_done = 0;
static int16_t kVToR[256], kUToB[256];
static int32_t kVToG[256], kUToG[256];
static uint8_t kClip[RGB_RANGE_MAX - RGB_RANGE_MIN];

static void InitTables() {
  int i;
  for (i = 0; i < 256; ++i) {
    kVToR[i] = (89858 * (i - 128) + RGB_HALF) >> RGB_FRAC;
    kUToG[i] = -22014 * (i - 128) + RGB_HALF;
    kVToG[i] = -45773 * (i - 128);
    kUToB[i] = (113618 * (i - 128) + RGB_HALF) >> RGB_FRAC;
  }
  for (i = RGB_RANGE_MIN; i < RGB_RANGE_MAX; ++i) {
    const int j = ((i - 16) * 76283 + RGB_HALF) >> RGB_FRAC;
    kClip[i - RGB_RANGE_MIN] = (j < 0) ? 0 : (j > 255) ? 255 : j;
  }

  init_done = 1;
}

static void ToRGB(int y, int u, int v, uint32* const dst) {
  const int r_off = kVToR[v];
  const int g_off = (kVToG[v] + kUToG[u]) >> RGB_FRAC;
  const int b_off = kUToB[u];
  const int r = kClip[y + r_off - RGB_RANGE_MIN];
  const int g = kClip[y + g_off - RGB_RANGE_MIN];
  const int b = kClip[y + b_off - RGB_RANGE_MIN];
  *dst = (r << RED_SHIFT) | (g << GREEN_SHIFT) | (b << BLUE_SHIFT);
}

static inline uint32 get_le32(const uint8* const data) {
  return data[0] | (data[1] << 8) | (data[2] << 16) | (data[3] << 24);
}

/* Returns the difference (in dB) between two images represented in YUV format
 *
 * Input:
 *   Y1/U1/V1: The Y/U/V data of the first image
 *   Y2/U2/V2: The Y/U/V data of the second image
 *
 * Returns the PSNR (http://en.wikipedia.org/wiki/Peak_signal-to-noise_ratio)
 * value computed bewteen the two images
 */
double GetPSNRYuv(const uint8* Y1,
                  const uint8* U1,
                  const uint8* V1,
                  const uint8* Y2,
                  const uint8* U2,
                  const uint8* V2,
                  int y_width,
                  int y_height) {
  int x, y, row_idx;
  const int uv_width = ((y_width + 1) >> 1);
  const int uv_height = ((y_height + 1) >> 1);
  double sse = 0., count = 0.;
  for (y = 0; y < y_height; ++y) {
    count += y_width;
    row_idx = y * y_width;
    for (x = 0; x < y_width; ++x) {
      double diff = Y1[row_idx + x] - Y2[row_idx + x];
      sse += diff * diff;
    }
  }
  for (y = 0; y < uv_height; ++y) {
    count += 2 * uv_width;
    row_idx = y * uv_width;
    for (x = 0; x < uv_width; ++x) {
      const double diff_U = U1[row_idx + x] - U2[row_idx + x];
      const double diff_V = V1[row_idx + x] - V2[row_idx + x];
      sse += diff_U * diff_U + diff_V * diff_V;
    }
  }
  return -4.3429448 * log(sse / (255. * 255. * count));
}

/* Returns the difference (in dB) between two images. One represented
 * using Y,U,V vectors and the other is webp image data.
 * Input:
 *   Y1/U1/V1: The Y/U/V data of the first image
 *   imgdata: data buffer containing webp image
 *   imgdata_size: size of the imgdata buffer
 *
 * Returns the PSNR value computed bewteen the two images
 */
double WebPGetPSNR(const uint8* Y1,
                   const uint8* U1,
                   const uint8* V1,
                   uint8* imgdata,
                   int imgdata_size) {
  uint8* Y2 = NULL;
  uint8* U2 = NULL;
  uint8* V2 = NULL;
  int w = 0, h = 0;
  double psnr = 0;

  WebPDecode(imgdata,
             imgdata_size,
             &Y2,
             &U2,
             &V2,
             &w,
             &h);

  psnr = GetPSNRYuv(Y1, U1, V1, Y2, U2, V2, w, h);
  free(Y2);

  return psnr;
}

/*---------------------------------------------------------------------*
 *                              Reading WebP                           *
 *---------------------------------------------------------------------*/

/* RIFF layout is:
 *   0ffset  tag
 *   0...3   "RIFF" 4-byte tag
 *   4...7   size of image data (including metadata) starting at offset 8
 *   8...11  "WEBP"  our form-type signature
 *   12..15  "VP8 " 4-byte tags, describing the raw video format used
 *   16..19  size of the raw WebP image data, starting at offset 20
 *   20....  the WebP bytes
 * There can be extra chunks after the "VP8 " chunk (ICMT, ICOP, ...)
 * All 32-bits sizes are in little-endian order.
 * Note: chunk data must be padded to multiple of 2 in size
 */

int SkipRiffHeader(const uint8** data_ptr, int *data_size_ptr) {
	/* 20 bytes RIFF header 10 bytes VP8 header */
	const int kHeaderSize = (20 + 10);
	uint32 chunk_size = 0xffffffffu;

	if (*data_size_ptr >= kHeaderSize && !memcmp(*data_ptr, "RIFF", 4)) {
	if (memcmp(*data_ptr + 8, "WEBP", 4)) {
		return 0;  /* wrong image file signature */
	} else {
		const uint32 riff_size = get_le32(*data_ptr + 4);
		if (memcmp(*data_ptr + 12, "VP8 ", 4)) {
		  return 0;   /* invalid compression format */
		}
		chunk_size = get_le32(*data_ptr + 16);
		if ((chunk_size > riff_size + 8) || (chunk_size & 1)) {
		  return 0;  /* inconsistent size information. */
		}
		/* We have a RIFF container. Skip it. */
		*data_ptr += 20;
		*data_size_ptr -= 20;
	}
	}
	return chunk_size;
}

/* Generate RGBA row from an YUV row (with width upsampling of chrome data)
 * Input:
 *    1, 2, 3. y_src, u_src, v_src - Pointers to input Y, U, V row data
 *    respectively. We reuse these variables, they iterate over all pixels in
 *    the row.
 *    4. y_width: width of the Y image plane (aka image width)
 * Output:
 *    5. rgb_dst: pointer to the output rgb row. We reuse this variable, it
 *    iterates over all pixels in the row.
 */
static void YUV420toRGBLine(uint8* y_src,
                            uint8* u_src,
                            uint8* v_src,
                            int y_width,
                            uint32* rgb_dst) {
  int x;
  for (x = 0; x < (y_width >> 1); ++x) {
    const int U = u_src[0];
    const int V = v_src[0];
    ToRGB(y_src[0], U, V, rgb_dst);
    ToRGB(y_src[1], U, V, rgb_dst + 1);
    ++u_src;
    ++v_src;
    y_src += 2;
    rgb_dst += 2;
  }
  if (y_width & 1) {      /* Rightmost pixel */
    ToRGB(y_src[0], (*u_src), (*v_src), rgb_dst);
  }
}

/* Converts from YUV (with color subsampling) such as produced by the WebPDecode
 * routine into 32 bits per pixel RGBA data array. This data array can be
 * directly used by the Leptonica Pix in-memory image format.
 * Input:
 *      1, 2, 3. Y, U, V: the input data buffers
 *      4. pixwpl: the desired words per line corresponding to the supplied
 *                 output pixdata.
 *      5. width, height: the dimensions of the image whose data resides in Y,
 *                        U, V.
 * Output:
 *     6. pixdata: the output data buffer. Caller should allocate
 *                 height * pixwpl bytes of memory before calling this routine.
 */
void YUV420toRGBA(uint8* Y,
                  uint8* U,
                  uint8* V,
                  int words_per_line,
                  int width,
                  int height,
                  uint32* pixdata) {
  int y_width = width;
  int y_stride = y_width;
  int uv_width = ((y_width + 1) >> 1);
  int uv_stride = uv_width;
  int y;

  if (!init_done)
    InitTables();

  /* note that the U, V upsampling in height is happening here as the U, V
   * buffers sent to successive odd-even pair of lines is same.
   */
  for (y = 0; y < height; ++y) {
    YUV420toRGBLine(Y + y * y_stride,
                    U + (y >> 1) * uv_stride,
                    V + (y >> 1) * uv_stride,
                    width,
                    pixdata + y * words_per_line);
  }
}

void gd_YUV420toRGBA(uint8* Y,
                  uint8* U,
                  uint8* V,
                  gdImagePtr im) {
  int width = im->sx;
  int height = im->sy;
  int y_width = width;
  int y_stride = y_width;
  int uv_width = ((y_width + 1) >> 1);
  int uv_stride = uv_width;
  int y;

  /* output im must be truecolor */
  if (!im->trueColor) {
  	return;
  }

  if (!init_done)
    InitTables();

  /* note that the U, V upsampling in height is happening here as the U, V
   * buffers sent to successive odd-even pair of lines is same.
   */
  for (y = 0; y < height; ++y) {
    YUV420toRGBLine(Y + y * y_stride,
                    U + (y >> 1) * uv_stride,
                    V + (y >> 1) * uv_stride,
                    width,
                    (uint32 *)im->tpixels[y]);
  }
}

static WebPResult VPXDecode(const uint8* data,
                            int data_size,
                            uint8** p_Y,
                            uint8** p_U,
                            uint8** p_V,
                            int* p_width,
                            int* p_height) {
  vpx_codec_ctx_t dec;
  vp8_postproc_cfg_t ppcfg;
  WebPResult result = webp_failure;

  if (!data || data_size <= 10 || !p_Y || !p_U || !p_V
      || *p_Y != NULL || *p_U != NULL || *p_V != NULL) {
    return webp_failure;
  }

  if (vpx_codec_dec_init(&dec,
                         &vpx_codec_vp8_dx_algo, NULL, 0) != VPX_CODEC_OK) {
    return webp_failure;
  }

  ppcfg.post_proc_flag = VP8_NOFILTERING;
  vpx_codec_control(&dec, VP8_SET_POSTPROC, &ppcfg);


  if (vpx_codec_decode(&dec, data, data_size, NULL, 0) == VPX_CODEC_OK) {
    vpx_codec_iter_t iter = NULL;
    vpx_image_t* const img = vpx_codec_get_frame(&dec, &iter);
    if (img) {
      int y_width = img->d_w;
      int y_height = img->d_h;
      int y_stride = y_width;
      int uv_width = (y_width + 1) >> 1;
      int uv_stride = uv_width;
      int uv_height = ((y_height + 1) >> 1);
      int y;

      *p_width = y_width;
      *p_height = y_height;
      if ((*p_Y = (uint8 *)(calloc(y_stride * y_height
                                   + 2 * uv_stride * uv_height,
                                   sizeof(uint8)))) != NULL) {
        *p_U = *p_Y + y_height * y_stride;
        *p_V = *p_U + uv_height * uv_stride;
        for (y = 0; y < y_height; ++y) {
          memcpy(*p_Y + y * y_stride,
                 img->planes[0] + y * img->stride[0],
                 y_width);
        }
        for (y = 0; y < uv_height; ++y) {
          memcpy(*p_U + y * uv_stride,
                 img->planes[1] + y * img->stride[1],
                 uv_width);
          memcpy(*p_V + y * uv_stride,
                 img->planes[2] + y * img->stride[2],
                 uv_width);
        }
        result = webp_success;
      }
    }
  }
  vpx_codec_destroy(&dec);

  return result;
}

WebPResult WebPDecode(const uint8* data,
                      int data_size,
                      uint8** p_Y,
                      uint8** p_U,
                      uint8** p_V,
                      int* p_width,
                      int* p_height) {

  const uint32 chunk_size = SkipRiffHeader(&data, &data_size);
  if (!chunk_size) {
    return webp_failure; /* unsupported RIFF header */
  }

  return VPXDecode(data, data_size, p_Y, p_U, p_V, p_width, p_height);
}

/*---------------------------------------------------------------------*
 *                             Writing WebP                            *
 *---------------------------------------------------------------------*/

/* Takes a pair of RGBA row data as input and generates 2 rows of Y data and one
 * row of subsampled U, V data as output
 * Input:
 *    1, 2. rgb_line1, rgb_line2 - input rgba rows
 *    3. width - image width
 * Outout:
 *    4, 5, 6: Output Y, U, V row
 */
static void RGBALinepairToYUV420(uint32* rgb_line1,
                                 uint32* rgb_line2,
                                 int width,
                                 uint8* Y_dst1,
                                 uint8* Y_dst2,
                                 uint8* u_dst,
                                 uint8* v_dst) {
  int x;
  for (x = (width >> 1); x > 0; --x) {
    const int sum_r =
      GetRed(rgb_line1 + 0) + GetRed(rgb_line1 + 1) +
      GetRed(rgb_line2 + 0) + GetRed(rgb_line2 + 1);
    const int sum_g =
      GetGreen(rgb_line1 + 0) + GetGreen(rgb_line1 + 1) +
      GetGreen(rgb_line2 + 0) + GetGreen(rgb_line2 + 1);
    const int sum_b =
      GetBlue(rgb_line1 + 0) + GetBlue(rgb_line1 + 1) +
      GetBlue(rgb_line2 + 0) + GetBlue(rgb_line2 + 1);

    Y_dst1[0] = GetLumaYfromPtr(rgb_line1 + 0);
    Y_dst1[1] = GetLumaYfromPtr(rgb_line1 + 1);
    Y_dst2[0] = GetLumaYfromPtr(rgb_line2 + 0);
    Y_dst2[1] = GetLumaYfromPtr(rgb_line2 + 1);

    *u_dst++ = GetChromaU(sum_r, sum_g, sum_b);
    *v_dst++ = GetChromaV(sum_r, sum_g, sum_b);

    rgb_line1 += 2;
    rgb_line2 += 2;
    Y_dst1 += 2;
    Y_dst2 += 2;
  }

  if (width & 1) {    /* rightmost pixel. */
    const int sum_r = GetRed(rgb_line1) + GetRed(rgb_line2);
    const int sum_g = GetGreen(rgb_line1) + GetGreen(rgb_line2);
    const int sum_b = GetBlue(rgb_line1) + GetBlue(rgb_line2);

    Y_dst1[0] = GetLumaYfromPtr(rgb_line1);
    Y_dst2[0] = GetLumaYfromPtr(rgb_line2);
    *u_dst = GetChromaU(2 * sum_r, 2 * sum_g, 2 * sum_b);
    *v_dst = GetChromaV(2 * sum_r, 2 * sum_g, 2 * sum_b);
  }
}

/* Generates Y, U, V data (with color subsampling) from 32 bits
 * per pixel RGBA data buffer. The resulting YUV data can be directly fed into
 * the WebPEncode routine.
 * Input:
 *    1. pixdatainput rgba data buffer
 *    2. words per line corresponding to pixdata
 *    3, 4. image width and height respectively
 * Output:
 *    5, 6, 7. Output YUV data buffers
 */
void gd_RGBAToYUV420(gdImagePtr im2,
                  uint8* Y,
                  uint8* U,
                  uint8* V) {
  int y_width = im2->sx;
  int y_height = im2->sy;
  int y_stride = y_width;
  int uv_width = ((y_width + 1) >> 1);
  int uv_stride = uv_width;
  int y;
  gdImagePtr im = NULL;
  int free_im = 0;

  if (!im2->trueColor) {
  	/* Todo: Replace the color/YUV functions with our own and simplify
  	   that should boost the conversion a bit as well, not only for 
  	   palette image. */
  	im = gdImageCreateTrueColor(im2->sx, im2->sy);
  	if (!im) {
  		gd_error("gd-webp error: cannot convert palette input to truecolor");
  		return;
	}
  	gdImageCopy(im, im2, 0, 0, 0, 0, im->sx, im->sy);
  	free_im = 1;
  } else {
  	im = im2;
  }
  for (y = 0; y < (y_height >> 1); ++y) {
	RGBALinepairToYUV420((uint32 *)im->tpixels[2 * y],
						 (uint32 *)im->tpixels[2 * y + 1],
						 y_width,
						 Y + 2 * y * y_stride,
						 Y + (2 * y + 1) * y_stride,
						 U + y * uv_stride,
						 V + y * uv_stride);
  }
  if (y_height & 1) {
	RGBALinepairToYUV420((uint32 *)im->tpixels[y_height - 1],
						 (uint32 *)im->tpixels[y_height - 1],
						 y_width,
						 Y + (y_height - 1) * y_stride,
						 Y + (y_height - 1) * y_stride,
						 U + (y_height >> 1) * uv_stride,
						 V + (y_height >> 1) * uv_stride);
  }
	if (free_im) {
		gdImageDestroy(im);
	}
}

/* Generates Y, U, V data (with color subsampling) from 32 bits
 * per pixel RGBA data buffer. The resulting YUV data can be directly fed into
 * the WebPEncode routine.
 * Input:
 *    1. pixdatainput rgba data buffer
 *    2. words per line corresponding to pixdata
 *    3, 4. image width and height respectively
 * Output:
 *    5, 6, 7. Output YUV data buffers
 */
void RGBAToYUV420(uint32* pixdata,
                  int words_per_line,
                  int width,
                  int height,
                  uint8* Y,
                  uint8* U,
                  uint8* V) {
  int y_width = width;
  int y_height = height;
  int y_stride = y_width;
  int uv_width = ((y_width + 1) >> 1);
  int uv_stride = uv_width;
  int y;

  for (y = 0; y < (y_height >> 1); ++y) {
    RGBALinepairToYUV420(pixdata + 2 * y * words_per_line,
                         pixdata + (2 * y + 1) * words_per_line,
                         y_width,
                         Y + 2 * y * y_stride,
                         Y + (2 * y + 1) * y_stride,
                         U + y * uv_stride,
                         V + y * uv_stride);
  }
  if (y_height & 1) {
    RGBALinepairToYUV420(pixdata + (y_height - 1) * words_per_line,
                         pixdata + (y_height - 1) * words_per_line,
                         y_width,
                         Y + (y_height - 1) * y_stride,
                         Y + (y_height - 1) * y_stride,
                         U + (y_height >> 1) * uv_stride,
                         V + (y_height >> 1) * uv_stride);
  }
}

static int codec_ctl(vpx_codec_ctx_t *enc,
                     enum vp8e_enc_control_id id,
                     int value) {
  const vpx_codec_err_t res = vpx_codec_control_(enc, id, value);
  if (res != VPX_CODEC_OK) {
    return webp_failure;
  }
  return webp_success;
}

static void SetupParams(vpx_codec_enc_cfg_t* cfg,
                        int QP) {
  cfg->g_threads = 2;
  cfg->rc_min_quantizer = QP;
  cfg->rc_max_quantizer = QP;
  cfg->kf_mode = VPX_KF_FIXED;
}

/* VPXEncode: Takes a Y, U, V data buffers (with color components U and V
 *            subsampled to 1/2 resolution) and generates the VPX string.
 *            Output VPX string is placed in the *p_out buffer. container_size
 *            indicates number of bytes to be left blank at the beginning of
 *            *p_out buffer to accommodate for a container header.
 *
 * Return: success/failure
 */
static WebPResult VPXEncode(const uint8* Y,
                            const uint8* U,
                            const uint8* V,
                            int y_width,
                            int y_height,
                            int y_stride,
                            int uv_width,
                            int uv_height,
                            int uv_stride,
                            int QP,
                            int container_size,
                            unsigned char** p_out,
                            int* p_out_size_bytes) {
  vpx_codec_iface_t* iface = &vpx_codec_vp8_cx_algo;
  vpx_codec_err_t res;
  vpx_codec_enc_cfg_t cfg;
  vpx_codec_ctx_t enc;
  WebPResult result = webp_failure;
  vpx_image_t img;

  *p_out = NULL;
  *p_out_size_bytes = 0;


  /* validate input parameters. */
  if (!p_out || !Y || !U || !V
      || y_width <= 0 || y_height <= 0 || uv_width <= 0 || uv_height <= 0
      || y_stride < y_width || uv_stride < uv_width
      || QP < 0 || QP > 63) {
    return webp_failure;
  }

  res = vpx_codec_enc_config_default(iface, &cfg, 0);
  if (res != VPX_CODEC_OK) {
    return webp_failure;
  }

  SetupParams(&cfg, QP);
  cfg.g_w = y_width;
  cfg.g_h = y_height;

  res = vpx_codec_enc_init(&enc, iface, &cfg, 0);

  if (res == VPX_CODEC_OK) {
    codec_ctl(&enc, VP8E_SET_CPUUSED, 3);
    codec_ctl(&enc, VP8E_SET_NOISE_SENSITIVITY, 0);
    codec_ctl(&enc, VP8E_SET_SHARPNESS, 0);
    codec_ctl(&enc, VP8E_SET_ENABLEAUTOALTREF, 0);
    codec_ctl(&enc, VP8E_SET_ARNR_MAXFRAMES, 0);
    codec_ctl(&enc, VP8E_SET_ARNR_TYPE, 0);
    codec_ctl(&enc, VP8E_SET_ARNR_STRENGTH, 0);
    codec_ctl(&enc, VP8E_SET_STATIC_THRESHOLD, 0);
    codec_ctl(&enc, VP8E_SET_TOKEN_PARTITIONS, 2);

    vpx_img_wrap(&img, IMG_FMT_I420,
                 y_width, y_height, 16, (uint8*)(Y));
    img.planes[PLANE_Y] = (uint8*)(Y);
    img.planes[PLANE_U] = (uint8*)(U);
    img.planes[PLANE_V] = (uint8*)(V);
    img.stride[PLANE_Y] = y_stride;
    img.stride[PLANE_U] = uv_stride;
    img.stride[PLANE_V] = uv_stride;

    res = vpx_codec_encode(&enc, &img, 0, 1, 0, VPX_DL_BEST_QUALITY);

    if (res == VPX_CODEC_OK) {
      vpx_codec_iter_t iter = NULL;
      const vpx_codec_cx_pkt_t* pkt = vpx_codec_get_cx_data(&enc, &iter);
      if (pkt != NULL) {
        *p_out = (unsigned char*)(calloc(container_size + pkt->data.frame.sz,
                                         1));

        memcpy(*p_out + container_size,
               (const void*)(pkt->data.frame.buf),
               pkt->data.frame.sz);
        *p_out_size_bytes = container_size + pkt->data.frame.sz;

        result = webp_success;
      }
    }
  }

  vpx_codec_destroy(&enc);

  return result;
}

WebPResult WebPEncode(const uint8* Y,
                      const uint8* U,
                      const uint8* V,
                      int y_width,
                      int y_height,
                      int y_stride,
                      int uv_width,
                      int uv_height,
                      int uv_stride,
                      int QP,
                      unsigned char** p_out,
                      int* p_out_size_bytes,
                      double *psnr) {

  const int kRiffHeaderSize = 20;

  if (VPXEncode(Y, U, V,
                y_width, y_height, y_stride,
                uv_width, uv_height, uv_stride,
                QP, kRiffHeaderSize,
                p_out, p_out_size_bytes) != webp_success) {
    return webp_failure;
  } else {
	  /* Write RIFF header */
	  const int img_size_bytes  = *p_out_size_bytes - kRiffHeaderSize;
	  const int chunk_size = (img_size_bytes + 1) & ~1;  /* make size even */
	  const int riff_size = chunk_size + 12;
	  const uint8_t kRiffHeader[20] = { 'R', 'I', 'F', 'F',
										(riff_size >>  0) & 255,
										(riff_size >>  8) & 255,
										(riff_size >> 16) & 255,
										(riff_size >> 24) & 255,
										'W', 'E', 'B', 'P',
										'V', 'P', '8', ' ',
										(chunk_size >>  0) & 255,
										(chunk_size >>  8) & 255,
										(chunk_size >> 16) & 255,
										(chunk_size >> 24) & 255 };
	  memcpy(*p_out, kRiffHeader, kRiffHeaderSize);

	  if (psnr) {
		*psnr = WebPGetPSNR(Y, U, V, *p_out, *p_out_size_bytes);
	  }

	  return webp_success;
  }
}

void AdjustColorspace(uint8* Y, uint8* U, uint8* V, int width, int height) {
  int y_width = width;
  int y_height = height;
  int y_stride = y_width;
  int uv_width = ((y_width + 1) >> 1);
  int uv_height = ((y_height + 1) >> 1);
  int uv_stride = uv_width;
  int x, y;
  /* convert luma */
  for (y = 0; y < y_height; ++y) {
    uint8* const Yrow = Y + y * y_stride;
    for (x = 0; x < y_width; ++x) {
      /* maps [0..255] to [16..235] */
      Yrow[x] = ((Yrow[x] * 55 + 32) >> 6) + 16;
    }
  }
  /* convert chroma */
  for (y = 0; y < uv_height; ++y) {
    uint8* const Urow = U + y * uv_stride;
    uint8* const Vrow = V + y * uv_stride;
    for (x = 0; x < uv_width; ++x) {
      /* maps [0..255] to [16..240] */
      Urow[x] = (((Urow[x] - 127) * 7) >> 3) + 128;
      Vrow[x] = (((Vrow[x] - 127) * 7) >> 3) + 128;
    }
  }
}

void AdjustColorspaceBack(uint8* Y, uint8* U, uint8* V, int width, int height) {
  int y_width = width;
  int y_height = height;
  int y_stride = y_width;
  int uv_width = ((y_width + 1) >> 1);
  int uv_height = ((y_height + 1) >> 1);
  int uv_stride = uv_width;
  int x, y;
  /* convert luma */
  for (y = 0; y < y_height; ++y) {
    uint8* const Yrow = Y + y * y_stride;
    for (x = 0; x < y_width; ++x) {
      /* maps [16..235] to [0..255] */
      const int v = ((Yrow[x] - 16) * 149 + 64) >> 7;
      Yrow[x] = (v < 0) ? 0 : (v > 255) ? 255u : v;
    }
  }
  /* convert chroma */
  for (y = 0; y < uv_height; ++y) {
    uint8* const Urow = U + y * uv_stride;
    uint8* const Vrow = V + y * uv_stride;
    for (x = 0; x < uv_width; ++x) {
      /* maps [0..255] to [16..240] */
      const int ru = (((Urow[x] - 128) * 73) >> 6) + 128;
      const int rv = (((Vrow[x] - 128) * 73) >> 6) + 128;
      Urow[x] = (ru < 0) ? 0 : (ru > 255) ? 255u : ru;
      Vrow[x] = (rv < 0) ? 0 : (rv > 255) ? 255u : rv;
    }
  }
}

WebPResult WebPGetInfo(const uint8* data,
                       int data_size,
                       int *width,
                       int *height) {
	const uint32 chunk_size = SkipRiffHeader(&data, &data_size);

	if (width) *width = 0;
	if (height) *height = 0;

	if (!chunk_size) {
	return webp_failure; /* unsupported RIFF header */
	}

	/* Validate raw video data */
	if (data_size < 10) {
	return webp_failure;   /* not enough data */
	}

	/* check signature */
	if (data[3] != 0x9d || data[4] != 0x01 || data[5] != 0x2a) {
		return webp_failure;       /* Wrong signature. */
	} else {
		const uint32 bits = data[0] | (data[1] << 8) | (data[2] << 16);

		if ((bits & 1)) {   /* Not a keyframe. */
			return webp_failure;
		} else {
			const int profile = (bits >> 1) & 7;
			const int show_frame  = (bits >> 4) & 1;
			const uint32 partition_length = (bits >> 5);

			if (profile > 3) {
				return webp_failure;   /* unknown profile */
			}
			if (!show_frame) {
				return webp_failure;     /* first frame is invisible! */
			}
			if (partition_length >= chunk_size) {
				return webp_failure;   /* inconsistent size information. */
			} else {
				const int w = ((data[7] << 8) | data[6]) & 0x3fff;
				const int h = ((data[9] << 8) | data[8]) & 0x3fff;
				if (width) *width = w;
				if (height) *height = h;

				return webp_success;
			}
		}
	}
	return webp_failure;
}
#endif /* HAVE_LIBVPX */
Tip: Filter by directory path e.g. /media app.js to search for public/media/app.js.
Tip: Use camelCasing e.g. ProjME to search for ProjectModifiedEvent.java.
Tip: Filter by extension type e.g. /repo .js to search for all .js files in the /repo directory.
Tip: Separate your search with spaces e.g. /ssh pom.xml to search for src/ssh/pom.xml.
Tip: Use ↑ and ↓ arrow keys to navigate and return to view the file.
Tip: You can also navigate files with Ctrl+j (next) and Ctrl+k (previous) and view the file with Ctrl+o.
Tip: You can also navigate files with Alt+j (next) and Alt+k (previous) and view the file with Alt+o.