xref: /openbmc/qemu/ui/vnc-enc-tight.c (revision 2df1eb27)
1 /*
2  * QEMU VNC display driver: tight encoding
3  *
4  * From libvncserver/libvncserver/tight.c
5  * Copyright (C) 2000, 2001 Const Kaplinsky.  All Rights Reserved.
6  * Copyright (C) 1999 AT&T Laboratories Cambridge.  All Rights Reserved.
7  *
8  * Copyright (C) 2010 Corentin Chary <corentin.chary@gmail.com>
9  *
10  * Permission is hereby granted, free of charge, to any person obtaining a copy
11  * of this software and associated documentation files (the "Software"), to deal
12  * in the Software without restriction, including without limitation the rights
13  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
14  * copies of the Software, and to permit persons to whom the Software is
15  * furnished to do so, subject to the following conditions:
16  *
17  * The above copyright notice and this permission notice shall be included in
18  * all copies or substantial portions of the Software.
19  *
20  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
21  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
23  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
24  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
25  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
26  * THE SOFTWARE.
27  */
28 
29 #include "qemu/osdep.h"
30 
31 /* This needs to be before jpeglib.h line because of conflict with
32    INT32 definitions between jmorecfg.h (included by jpeglib.h) and
33    Win32 basetsd.h (included by windows.h). */
34 
35 #ifdef CONFIG_PNG
36 /* The following define is needed by pngconf.h. Otherwise it won't compile,
37    because setjmp.h was already included by osdep.h. */
38 #define PNG_SKIP_SETJMP_CHECK
39 #include <png.h>
40 #endif
41 #ifdef CONFIG_VNC_JPEG
42 #include <jpeglib.h>
43 #endif
44 
45 #include "qemu/bswap.h"
46 #include "vnc.h"
47 #include "vnc-enc-tight.h"
48 #include "vnc-palette.h"
49 
50 /* Compression level stuff. The following array contains various
51    encoder parameters for each of 10 compression levels (0..9).
52    Last three parameters correspond to JPEG quality levels (0..9). */
53 
54 static const struct {
55     int max_rect_size, max_rect_width;
56     int mono_min_rect_size, gradient_min_rect_size;
57     int idx_zlib_level, mono_zlib_level, raw_zlib_level, gradient_zlib_level;
58     int gradient_threshold, gradient_threshold24;
59     int idx_max_colors_divisor;
60     int jpeg_quality, jpeg_threshold, jpeg_threshold24;
61 } tight_conf[] = {
62     {   512,   32,   6, 65536, 0, 0, 0, 0,   0,   0,   4,  5, 10000, 23000 },
63     {  2048,  128,   6, 65536, 1, 1, 1, 0,   0,   0,   8, 10,  8000, 18000 },
64     {  6144,  256,   8, 65536, 3, 3, 2, 0,   0,   0,  24, 15,  6500, 15000 },
65     { 10240, 1024,  12, 65536, 5, 5, 3, 0,   0,   0,  32, 25,  5000, 12000 },
66     { 16384, 2048,  12, 65536, 6, 6, 4, 0,   0,   0,  32, 37,  4000, 10000 },
67     { 32768, 2048,  12,  4096, 7, 7, 5, 4, 150, 380,  32, 50,  3000,  8000 },
68     { 65536, 2048,  16,  4096, 7, 7, 6, 4, 170, 420,  48, 60,  2000,  5000 },
69     { 65536, 2048,  16,  4096, 8, 8, 7, 5, 180, 450,  64, 70,  1000,  2500 },
70     { 65536, 2048,  32,  8192, 9, 9, 8, 6, 190, 475,  64, 75,   500,  1200 },
71     { 65536, 2048,  32,  8192, 9, 9, 9, 6, 200, 500,  96, 80,   200,   500 }
72 };
73 
74 
75 static int tight_send_framebuffer_update(VncState *vs, int x, int y,
76                                          int w, int h);
77 
78 #ifdef CONFIG_VNC_JPEG
79 static const struct {
80     double jpeg_freq_min;       /* Don't send JPEG if the freq is below */
81     double jpeg_freq_threshold; /* Always send JPEG if the freq is above */
82     int jpeg_idx;               /* Allow indexed JPEG */
83     int jpeg_full;              /* Allow full color JPEG */
84 } tight_jpeg_conf[] = {
85     { 0,   8,  1, 1 },
86     { 0,   8,  1, 1 },
87     { 0,   8,  1, 1 },
88     { 0,   8,  1, 1 },
89     { 0,   10, 1, 1 },
90     { 0.1, 10, 1, 1 },
91     { 0.2, 10, 1, 1 },
92     { 0.3, 12, 0, 0 },
93     { 0.4, 14, 0, 0 },
94     { 0.5, 16, 0, 0 },
95 };
96 #endif
97 
98 #ifdef CONFIG_PNG
99 static const struct {
100     int png_zlib_level, png_filters;
101 } tight_png_conf[] = {
102     { 0, PNG_NO_FILTERS },
103     { 1, PNG_NO_FILTERS },
104     { 2, PNG_NO_FILTERS },
105     { 3, PNG_NO_FILTERS },
106     { 4, PNG_NO_FILTERS },
107     { 5, PNG_ALL_FILTERS },
108     { 6, PNG_ALL_FILTERS },
109     { 7, PNG_ALL_FILTERS },
110     { 8, PNG_ALL_FILTERS },
111     { 9, PNG_ALL_FILTERS },
112 };
113 
114 static int send_png_rect(VncState *vs, int x, int y, int w, int h,
115                          VncPalette *palette);
116 
117 static bool tight_can_send_png_rect(VncState *vs, int w, int h)
118 {
119     if (vs->tight->type != VNC_ENCODING_TIGHT_PNG) {
120         return false;
121     }
122 
123     if (surface_bytes_per_pixel(vs->vd->ds) == 1 ||
124         vs->client_pf.bytes_per_pixel == 1) {
125         return false;
126     }
127 
128     return true;
129 }
130 #endif
131 
132 /*
133  * Code to guess if given rectangle is suitable for smooth image
134  * compression (by applying "gradient" filter or JPEG coder).
135  */
136 
137 static unsigned int
138 tight_detect_smooth_image24(VncState *vs, int w, int h)
139 {
140     int off;
141     int x, y, d, dx;
142     unsigned int c;
143     unsigned int stats[256];
144     int pixels = 0;
145     int pix, left[3];
146     unsigned int errors;
147     unsigned char *buf = vs->tight->tight.buffer;
148 
149     /*
150      * If client is big-endian, color samples begin from the second
151      * byte (offset 1) of a 32-bit pixel value.
152      */
153     off = vs->client_be;
154 
155     memset(stats, 0, sizeof (stats));
156 
157     for (y = 0, x = 0; y < h && x < w;) {
158         for (d = 0; d < h - y && d < w - x - VNC_TIGHT_DETECT_SUBROW_WIDTH;
159              d++) {
160             for (c = 0; c < 3; c++) {
161                 left[c] = buf[((y+d)*w+x+d)*4+off+c] & 0xFF;
162             }
163             for (dx = 1; dx <= VNC_TIGHT_DETECT_SUBROW_WIDTH; dx++) {
164                 for (c = 0; c < 3; c++) {
165                     pix = buf[((y+d)*w+x+d+dx)*4+off+c] & 0xFF;
166                     stats[abs(pix - left[c])]++;
167                     left[c] = pix;
168                 }
169                 pixels++;
170             }
171         }
172         if (w > h) {
173             x += h;
174             y = 0;
175         } else {
176             x = 0;
177             y += w;
178         }
179     }
180 
181     if (pixels == 0) {
182         return 0;
183     }
184 
185     /* 95% smooth or more ... */
186     if (stats[0] * 33 / pixels >= 95) {
187         return 0;
188     }
189 
190     errors = 0;
191     for (c = 1; c < 8; c++) {
192         errors += stats[c] * (c * c);
193         if (stats[c] == 0 || stats[c] > stats[c-1] * 2) {
194             return 0;
195         }
196     }
197     for (; c < 256; c++) {
198         errors += stats[c] * (c * c);
199     }
200     errors /= (pixels * 3 - stats[0]);
201 
202     return errors;
203 }
204 
205 #define DEFINE_DETECT_FUNCTION(bpp)                                     \
206                                                                         \
207     static unsigned int                                                 \
208     tight_detect_smooth_image##bpp(VncState *vs, int w, int h) {        \
209         bool endian;                                                    \
210         uint##bpp##_t pix;                                              \
211         int max[3], shift[3];                                           \
212         int x, y, d, dx;                                                \
213         unsigned int c;                                                 \
214         unsigned int stats[256];                                        \
215         int pixels = 0;                                                 \
216         int sample, sum, left[3];                                       \
217         unsigned int errors;                                            \
218         unsigned char *buf = vs->tight->tight.buffer;                    \
219                                                                         \
220         endian = 0; /* FIXME */                                         \
221                                                                         \
222                                                                         \
223         max[0] = vs->client_pf.rmax;                                  \
224         max[1] = vs->client_pf.gmax;                                  \
225         max[2] = vs->client_pf.bmax;                                  \
226         shift[0] = vs->client_pf.rshift;                              \
227         shift[1] = vs->client_pf.gshift;                              \
228         shift[2] = vs->client_pf.bshift;                              \
229                                                                         \
230         memset(stats, 0, sizeof(stats));                                \
231                                                                         \
232         y = 0, x = 0;                                                   \
233         while (y < h && x < w) {                                        \
234             for (d = 0; d < h - y &&                                    \
235                      d < w - x - VNC_TIGHT_DETECT_SUBROW_WIDTH; d++) {  \
236                 pix = ((uint##bpp##_t *)buf)[(y+d)*w+x+d];              \
237                 if (endian) {                                           \
238                     pix = bswap##bpp(pix);                              \
239                 }                                                       \
240                 for (c = 0; c < 3; c++) {                               \
241                     left[c] = (int)(pix >> shift[c] & max[c]);          \
242                 }                                                       \
243                 for (dx = 1; dx <= VNC_TIGHT_DETECT_SUBROW_WIDTH;       \
244                      dx++) {                                            \
245                     pix = ((uint##bpp##_t *)buf)[(y+d)*w+x+d+dx];       \
246                     if (endian) {                                       \
247                         pix = bswap##bpp(pix);                          \
248                     }                                                   \
249                     sum = 0;                                            \
250                     for (c = 0; c < 3; c++) {                           \
251                         sample = (int)(pix >> shift[c] & max[c]);       \
252                         sum += abs(sample - left[c]);                   \
253                         left[c] = sample;                               \
254                     }                                                   \
255                     if (sum > 255) {                                    \
256                         sum = 255;                                      \
257                     }                                                   \
258                     stats[sum]++;                                       \
259                     pixels++;                                           \
260                 }                                                       \
261             }                                                           \
262             if (w > h) {                                                \
263                 x += h;                                                 \
264                 y = 0;                                                  \
265             } else {                                                    \
266                 x = 0;                                                  \
267                 y += w;                                                 \
268             }                                                           \
269         }                                                               \
270         if (pixels == 0) {                                              \
271             return 0;                                                   \
272         }                                                               \
273         if ((stats[0] + stats[1]) * 100 / pixels >= 90) {               \
274             return 0;                                                   \
275         }                                                               \
276                                                                         \
277         errors = 0;                                                     \
278         for (c = 1; c < 8; c++) {                                       \
279             errors += stats[c] * (c * c);                               \
280             if (stats[c] == 0 || stats[c] > stats[c-1] * 2) {           \
281                 return 0;                                               \
282             }                                                           \
283         }                                                               \
284         for (; c < 256; c++) {                                          \
285             errors += stats[c] * (c * c);                               \
286         }                                                               \
287         errors /= (pixels - stats[0]);                                  \
288                                                                         \
289         return errors;                                                  \
290     }
291 
292 DEFINE_DETECT_FUNCTION(16)
293 DEFINE_DETECT_FUNCTION(32)
294 
295 static int
296 tight_detect_smooth_image(VncState *vs, int w, int h)
297 {
298     unsigned int errors;
299     int compression = vs->tight->compression;
300     int quality = vs->tight->quality;
301 
302     if (!vs->vd->lossy) {
303         return 0;
304     }
305 
306     if (surface_bytes_per_pixel(vs->vd->ds) == 1 ||
307         vs->client_pf.bytes_per_pixel == 1 ||
308         w < VNC_TIGHT_DETECT_MIN_WIDTH || h < VNC_TIGHT_DETECT_MIN_HEIGHT) {
309         return 0;
310     }
311 
312     if (vs->tight->quality != (uint8_t)-1) {
313         if (w * h < VNC_TIGHT_JPEG_MIN_RECT_SIZE) {
314             return 0;
315         }
316     } else {
317         if (w * h < tight_conf[compression].gradient_min_rect_size) {
318             return 0;
319         }
320     }
321 
322     if (vs->client_pf.bytes_per_pixel == 4) {
323         if (vs->tight->pixel24) {
324             errors = tight_detect_smooth_image24(vs, w, h);
325             if (vs->tight->quality != (uint8_t)-1) {
326                 return (errors < tight_conf[quality].jpeg_threshold24);
327             }
328             return (errors < tight_conf[compression].gradient_threshold24);
329         } else {
330             errors = tight_detect_smooth_image32(vs, w, h);
331         }
332     } else {
333         errors = tight_detect_smooth_image16(vs, w, h);
334     }
335     if (quality != (uint8_t)-1) {
336         return (errors < tight_conf[quality].jpeg_threshold);
337     }
338     return (errors < tight_conf[compression].gradient_threshold);
339 }
340 
341 /*
342  * Code to determine how many different colors used in rectangle.
343  */
344 #define DEFINE_FILL_PALETTE_FUNCTION(bpp)                               \
345                                                                         \
346     static int                                                          \
347     tight_fill_palette##bpp(VncState *vs, int x, int y,                 \
348                             int max, size_t count,                      \
349                             uint32_t *bg, uint32_t *fg,                 \
350                             VncPalette *palette) {                      \
351         uint##bpp##_t *data;                                            \
352         uint##bpp##_t c0, c1, ci;                                       \
353         int i, n0, n1;                                                  \
354                                                                         \
355         data = (uint##bpp##_t *)vs->tight->tight.buffer;                \
356                                                                         \
357         c0 = data[0];                                                   \
358         i = 1;                                                          \
359         while (i < count && data[i] == c0)                              \
360             i++;                                                        \
361         if (i >= count) {                                               \
362             *bg = *fg = c0;                                             \
363             return 1;                                                   \
364         }                                                               \
365                                                                         \
366         if (max < 2) {                                                  \
367             return 0;                                                   \
368         }                                                               \
369                                                                         \
370         n0 = i;                                                         \
371         c1 = data[i];                                                   \
372         n1 = 0;                                                         \
373         for (i++; i < count; i++) {                                     \
374             ci = data[i];                                               \
375             if (ci == c0) {                                             \
376                 n0++;                                                   \
377             } else if (ci == c1) {                                      \
378                 n1++;                                                   \
379             } else                                                      \
380                 break;                                                  \
381         }                                                               \
382         if (i >= count) {                                               \
383             if (n0 > n1) {                                              \
384                 *bg = (uint32_t)c0;                                     \
385                 *fg = (uint32_t)c1;                                     \
386             } else {                                                    \
387                 *bg = (uint32_t)c1;                                     \
388                 *fg = (uint32_t)c0;                                     \
389             }                                                           \
390             return 2;                                                   \
391         }                                                               \
392                                                                         \
393         if (max == 2) {                                                 \
394             return 0;                                                   \
395         }                                                               \
396                                                                         \
397         palette_init(palette, max, bpp);                                \
398         palette_put(palette, c0);                                       \
399         palette_put(palette, c1);                                       \
400         palette_put(palette, ci);                                       \
401                                                                         \
402         for (i++; i < count; i++) {                                     \
403             if (data[i] == ci) {                                        \
404                 continue;                                               \
405             } else {                                                    \
406                 ci = data[i];                                           \
407                 if (!palette_put(palette, (uint32_t)ci)) {              \
408                     return 0;                                           \
409                 }                                                       \
410             }                                                           \
411         }                                                               \
412                                                                         \
413         return palette_size(palette);                                   \
414     }
415 
416 DEFINE_FILL_PALETTE_FUNCTION(8)
417 DEFINE_FILL_PALETTE_FUNCTION(16)
418 DEFINE_FILL_PALETTE_FUNCTION(32)
419 
420 static int tight_fill_palette(VncState *vs, int x, int y,
421                               size_t count, uint32_t *bg, uint32_t *fg,
422                               VncPalette *palette)
423 {
424     int max;
425 
426     max = count / tight_conf[vs->tight->compression].idx_max_colors_divisor;
427     if (max < 2 &&
428         count >= tight_conf[vs->tight->compression].mono_min_rect_size) {
429         max = 2;
430     }
431     if (max >= 256) {
432         max = 256;
433     }
434 
435     switch (vs->client_pf.bytes_per_pixel) {
436     case 4:
437         return tight_fill_palette32(vs, x, y, max, count, bg, fg, palette);
438     case 2:
439         return tight_fill_palette16(vs, x, y, max, count, bg, fg, palette);
440     default:
441         max = 2;
442         return tight_fill_palette8(vs, x, y, max, count, bg, fg, palette);
443     }
444     return 0;
445 }
446 
447 /*
448  * Converting truecolor samples into palette indices.
449  */
450 #define DEFINE_IDX_ENCODE_FUNCTION(bpp)                                 \
451                                                                         \
452     static void                                                         \
453     tight_encode_indexed_rect##bpp(uint8_t *buf, int count,             \
454                                    VncPalette *palette) {               \
455         uint##bpp##_t *src;                                             \
456         uint##bpp##_t rgb;                                              \
457         int i, rep;                                                     \
458         uint8_t idx;                                                    \
459                                                                         \
460         src = (uint##bpp##_t *) buf;                                    \
461                                                                         \
462         for (i = 0; i < count; ) {                                      \
463                                                                         \
464             rgb = *src++;                                               \
465             i++;                                                        \
466             rep = 0;                                                    \
467             while (i < count && *src == rgb) {                          \
468                 rep++, src++, i++;                                      \
469             }                                                           \
470             idx = palette_idx(palette, rgb);                            \
471             /*                                                          \
472              * Should never happen, but don't break everything          \
473              * if it does, use the first color instead                  \
474              */                                                         \
475             if (idx == (uint8_t)-1) {                                   \
476                 idx = 0;                                                \
477             }                                                           \
478             while (rep >= 0) {                                          \
479                 *buf++ = idx;                                           \
480                 rep--;                                                  \
481             }                                                           \
482         }                                                               \
483     }
484 
485 DEFINE_IDX_ENCODE_FUNCTION(16)
486 DEFINE_IDX_ENCODE_FUNCTION(32)
487 
488 #define DEFINE_MONO_ENCODE_FUNCTION(bpp)                                \
489                                                                         \
490     static void                                                         \
491     tight_encode_mono_rect##bpp(uint8_t *buf, int w, int h,             \
492                                 uint##bpp##_t bg, uint##bpp##_t fg) {   \
493         uint##bpp##_t *ptr;                                             \
494         unsigned int value, mask;                                       \
495         int aligned_width;                                              \
496         int x, y, bg_bits;                                              \
497                                                                         \
498         ptr = (uint##bpp##_t *) buf;                                    \
499         aligned_width = w - w % 8;                                      \
500                                                                         \
501         for (y = 0; y < h; y++) {                                       \
502             for (x = 0; x < aligned_width; x += 8) {                    \
503                 for (bg_bits = 0; bg_bits < 8; bg_bits++) {             \
504                     if (*ptr++ != bg) {                                 \
505                         break;                                          \
506                     }                                                   \
507                 }                                                       \
508                 if (bg_bits == 8) {                                     \
509                     *buf++ = 0;                                         \
510                     continue;                                           \
511                 }                                                       \
512                 mask = 0x80 >> bg_bits;                                 \
513                 value = mask;                                           \
514                 for (bg_bits++; bg_bits < 8; bg_bits++) {               \
515                     mask >>= 1;                                         \
516                     if (*ptr++ != bg) {                                 \
517                         value |= mask;                                  \
518                     }                                                   \
519                 }                                                       \
520                 *buf++ = (uint8_t)value;                                \
521             }                                                           \
522                                                                         \
523             mask = 0x80;                                                \
524             value = 0;                                                  \
525             if (x >= w) {                                               \
526                 continue;                                               \
527             }                                                           \
528                                                                         \
529             for (; x < w; x++) {                                        \
530                 if (*ptr++ != bg) {                                     \
531                     value |= mask;                                      \
532                 }                                                       \
533                 mask >>= 1;                                             \
534             }                                                           \
535             *buf++ = (uint8_t)value;                                    \
536         }                                                               \
537     }
538 
539 DEFINE_MONO_ENCODE_FUNCTION(8)
540 DEFINE_MONO_ENCODE_FUNCTION(16)
541 DEFINE_MONO_ENCODE_FUNCTION(32)
542 
543 /*
544  * ``Gradient'' filter for 24-bit color samples.
545  * Should be called only when redMax, greenMax and blueMax are 255.
546  * Color components assumed to be byte-aligned.
547  */
548 
549 static void
550 tight_filter_gradient24(VncState *vs, uint8_t *buf, int w, int h)
551 {
552     uint32_t *buf32;
553     uint32_t pix32;
554     int shift[3];
555     int *prev;
556     int here[3], upper[3], left[3], upperleft[3];
557     int prediction;
558     int x, y, c;
559 
560     buf32 = (uint32_t *)buf;
561     memset(vs->tight->gradient.buffer, 0, w * 3 * sizeof(int));
562 
563     if (1 /* FIXME */) {
564         shift[0] = vs->client_pf.rshift;
565         shift[1] = vs->client_pf.gshift;
566         shift[2] = vs->client_pf.bshift;
567     } else {
568         shift[0] = 24 - vs->client_pf.rshift;
569         shift[1] = 24 - vs->client_pf.gshift;
570         shift[2] = 24 - vs->client_pf.bshift;
571     }
572 
573     for (y = 0; y < h; y++) {
574         for (c = 0; c < 3; c++) {
575             upper[c] = 0;
576             here[c] = 0;
577         }
578         prev = (int *)vs->tight->gradient.buffer;
579         for (x = 0; x < w; x++) {
580             pix32 = *buf32++;
581             for (c = 0; c < 3; c++) {
582                 upperleft[c] = upper[c];
583                 left[c] = here[c];
584                 upper[c] = *prev;
585                 here[c] = (int)(pix32 >> shift[c] & 0xFF);
586                 *prev++ = here[c];
587 
588                 prediction = left[c] + upper[c] - upperleft[c];
589                 if (prediction < 0) {
590                     prediction = 0;
591                 } else if (prediction > 0xFF) {
592                     prediction = 0xFF;
593                 }
594                 *buf++ = (char)(here[c] - prediction);
595             }
596         }
597     }
598 }
599 
600 
601 /*
602  * ``Gradient'' filter for other color depths.
603  */
604 
605 #define DEFINE_GRADIENT_FILTER_FUNCTION(bpp)                            \
606                                                                         \
607     static void                                                         \
608     tight_filter_gradient##bpp(VncState *vs, uint##bpp##_t *buf,        \
609                                int w, int h) {                          \
610         uint##bpp##_t pix, diff;                                        \
611         bool endian;                                                    \
612         int *prev;                                                      \
613         int max[3], shift[3];                                           \
614         int here[3], upper[3], left[3], upperleft[3];                   \
615         int prediction;                                                 \
616         int x, y, c;                                                    \
617                                                                         \
618         memset(vs->tight->gradient.buffer, 0, w * 3 * sizeof(int));     \
619                                                                         \
620         endian = 0; /* FIXME */                                         \
621                                                                         \
622         max[0] = vs->client_pf.rmax;                                    \
623         max[1] = vs->client_pf.gmax;                                    \
624         max[2] = vs->client_pf.bmax;                                    \
625         shift[0] = vs->client_pf.rshift;                                \
626         shift[1] = vs->client_pf.gshift;                                \
627         shift[2] = vs->client_pf.bshift;                                \
628                                                                         \
629         for (y = 0; y < h; y++) {                                       \
630             for (c = 0; c < 3; c++) {                                   \
631                 upper[c] = 0;                                           \
632                 here[c] = 0;                                            \
633             }                                                           \
634             prev = (int *)vs->tight->gradient.buffer;                    \
635             for (x = 0; x < w; x++) {                                   \
636                 pix = *buf;                                             \
637                 if (endian) {                                           \
638                     pix = bswap##bpp(pix);                              \
639                 }                                                       \
640                 diff = 0;                                               \
641                 for (c = 0; c < 3; c++) {                               \
642                     upperleft[c] = upper[c];                            \
643                     left[c] = here[c];                                  \
644                     upper[c] = *prev;                                   \
645                     here[c] = (int)(pix >> shift[c] & max[c]);          \
646                     *prev++ = here[c];                                  \
647                                                                         \
648                     prediction = left[c] + upper[c] - upperleft[c];     \
649                     if (prediction < 0) {                               \
650                         prediction = 0;                                 \
651                     } else if (prediction > max[c]) {                   \
652                         prediction = max[c];                            \
653                     }                                                   \
654                     diff |= ((here[c] - prediction) & max[c])           \
655                         << shift[c];                                    \
656                 }                                                       \
657                 if (endian) {                                           \
658                     diff = bswap##bpp(diff);                            \
659                 }                                                       \
660                 *buf++ = diff;                                          \
661             }                                                           \
662         }                                                               \
663     }
664 
665 DEFINE_GRADIENT_FILTER_FUNCTION(16)
666 DEFINE_GRADIENT_FILTER_FUNCTION(32)
667 
668 /*
669  * Check if a rectangle is all of the same color. If needSameColor is
670  * set to non-zero, then also check that its color equals to the
671  * *colorPtr value. The result is 1 if the test is successful, and in
672  * that case new color will be stored in *colorPtr.
673  */
674 
675 static bool
676 check_solid_tile32(VncState *vs, int x, int y, int w, int h,
677                    uint32_t *color, bool samecolor)
678 {
679     VncDisplay *vd = vs->vd;
680     uint32_t *fbptr;
681     uint32_t c;
682     int dx, dy;
683 
684     fbptr = vnc_server_fb_ptr(vd, x, y);
685 
686     c = *fbptr;
687     if (samecolor && (uint32_t)c != *color) {
688         return false;
689     }
690 
691     for (dy = 0; dy < h; dy++) {
692         for (dx = 0; dx < w; dx++) {
693             if (c != fbptr[dx]) {
694                 return false;
695             }
696         }
697         fbptr = (uint32_t *)
698             ((uint8_t *)fbptr + vnc_server_fb_stride(vd));
699     }
700 
701     *color = (uint32_t)c;
702     return true;
703 }
704 
705 static bool check_solid_tile(VncState *vs, int x, int y, int w, int h,
706                              uint32_t* color, bool samecolor)
707 {
708     QEMU_BUILD_BUG_ON(VNC_SERVER_FB_BYTES != 4);
709     return check_solid_tile32(vs, x, y, w, h, color, samecolor);
710 }
711 
712 static void find_best_solid_area(VncState *vs, int x, int y, int w, int h,
713                                  uint32_t color, int *w_ptr, int *h_ptr)
714 {
715     int dx, dy, dw, dh;
716     int w_prev;
717     int w_best = 0, h_best = 0;
718 
719     w_prev = w;
720 
721     for (dy = y; dy < y + h; dy += VNC_TIGHT_MAX_SPLIT_TILE_SIZE) {
722 
723         dh = MIN(VNC_TIGHT_MAX_SPLIT_TILE_SIZE, y + h - dy);
724         dw = MIN(VNC_TIGHT_MAX_SPLIT_TILE_SIZE, w_prev);
725 
726         if (!check_solid_tile(vs, x, dy, dw, dh, &color, true)) {
727             break;
728         }
729 
730         for (dx = x + dw; dx < x + w_prev;) {
731             dw = MIN(VNC_TIGHT_MAX_SPLIT_TILE_SIZE, x + w_prev - dx);
732 
733             if (!check_solid_tile(vs, dx, dy, dw, dh, &color, true)) {
734                 break;
735             }
736             dx += dw;
737         }
738 
739         w_prev = dx - x;
740         if (w_prev * (dy + dh - y) > w_best * h_best) {
741             w_best = w_prev;
742             h_best = dy + dh - y;
743         }
744     }
745 
746     *w_ptr = w_best;
747     *h_ptr = h_best;
748 }
749 
750 static void extend_solid_area(VncState *vs, int x, int y, int w, int h,
751                               uint32_t color, int *x_ptr, int *y_ptr,
752                               int *w_ptr, int *h_ptr)
753 {
754     int cx, cy;
755 
756     /* Try to extend the area upwards. */
757     for ( cy = *y_ptr - 1;
758           cy >= y && check_solid_tile(vs, *x_ptr, cy, *w_ptr, 1, &color, true);
759           cy-- );
760     *h_ptr += *y_ptr - (cy + 1);
761     *y_ptr = cy + 1;
762 
763     /* ... downwards. */
764     for ( cy = *y_ptr + *h_ptr;
765           cy < y + h &&
766               check_solid_tile(vs, *x_ptr, cy, *w_ptr, 1, &color, true);
767           cy++ );
768     *h_ptr += cy - (*y_ptr + *h_ptr);
769 
770     /* ... to the left. */
771     for ( cx = *x_ptr - 1;
772           cx >= x && check_solid_tile(vs, cx, *y_ptr, 1, *h_ptr, &color, true);
773           cx-- );
774     *w_ptr += *x_ptr - (cx + 1);
775     *x_ptr = cx + 1;
776 
777     /* ... to the right. */
778     for ( cx = *x_ptr + *w_ptr;
779           cx < x + w &&
780               check_solid_tile(vs, cx, *y_ptr, 1, *h_ptr, &color, true);
781           cx++ );
782     *w_ptr += cx - (*x_ptr + *w_ptr);
783 }
784 
785 static int tight_init_stream(VncState *vs, int stream_id,
786                              int level, int strategy)
787 {
788     z_streamp zstream = &vs->tight->stream[stream_id];
789 
790     if (zstream->opaque == NULL) {
791         int err;
792 
793         VNC_DEBUG("VNC: TIGHT: initializing zlib stream %d\n", stream_id);
794         VNC_DEBUG("VNC: TIGHT: opaque = %p | vs = %p\n", zstream->opaque, vs);
795         zstream->zalloc = vnc_zlib_zalloc;
796         zstream->zfree = vnc_zlib_zfree;
797 
798         err = deflateInit2(zstream, level, Z_DEFLATED, MAX_WBITS,
799                            MAX_MEM_LEVEL, strategy);
800 
801         if (err != Z_OK) {
802             fprintf(stderr, "VNC: error initializing zlib\n");
803             return -1;
804         }
805 
806         vs->tight->levels[stream_id] = level;
807         zstream->opaque = vs;
808     }
809 
810     if (vs->tight->levels[stream_id] != level) {
811         if (deflateParams(zstream, level, strategy) != Z_OK) {
812             return -1;
813         }
814         vs->tight->levels[stream_id] = level;
815     }
816     return 0;
817 }
818 
819 static void tight_send_compact_size(VncState *vs, size_t len)
820 {
821     int lpc = 0;
822     int bytes = 0;
823     char buf[3] = {0, 0, 0};
824 
825     buf[bytes++] = len & 0x7F;
826     if (len > 0x7F) {
827         buf[bytes-1] |= 0x80;
828         buf[bytes++] = (len >> 7) & 0x7F;
829         if (len > 0x3FFF) {
830             buf[bytes-1] |= 0x80;
831             buf[bytes++] = (len >> 14) & 0xFF;
832         }
833     }
834     for (lpc = 0; lpc < bytes; lpc++) {
835         vnc_write_u8(vs, buf[lpc]);
836     }
837 }
838 
839 static int tight_compress_data(VncState *vs, int stream_id, size_t bytes,
840                                int level, int strategy)
841 {
842     z_streamp zstream = &vs->tight->stream[stream_id];
843     int previous_out;
844 
845     if (bytes < VNC_TIGHT_MIN_TO_COMPRESS) {
846         vnc_write(vs, vs->tight->tight.buffer, vs->tight->tight.offset);
847         return bytes;
848     }
849 
850     if (tight_init_stream(vs, stream_id, level, strategy)) {
851         return -1;
852     }
853 
854     /* reserve memory in output buffer */
855     buffer_reserve(&vs->tight->zlib, bytes + 64);
856 
857     /* set pointers */
858     zstream->next_in = vs->tight->tight.buffer;
859     zstream->avail_in = vs->tight->tight.offset;
860     zstream->next_out = vs->tight->zlib.buffer + vs->tight->zlib.offset;
861     zstream->avail_out = vs->tight->zlib.capacity - vs->tight->zlib.offset;
862     previous_out = zstream->avail_out;
863     zstream->data_type = Z_BINARY;
864 
865     /* start encoding */
866     if (deflate(zstream, Z_SYNC_FLUSH) != Z_OK) {
867         fprintf(stderr, "VNC: error during tight compression\n");
868         return -1;
869     }
870 
871     vs->tight->zlib.offset = vs->tight->zlib.capacity - zstream->avail_out;
872     /* ...how much data has actually been produced by deflate() */
873     bytes = previous_out - zstream->avail_out;
874 
875     tight_send_compact_size(vs, bytes);
876     vnc_write(vs, vs->tight->zlib.buffer, bytes);
877 
878     buffer_reset(&vs->tight->zlib);
879 
880     return bytes;
881 }
882 
883 /*
884  * Subencoding implementations.
885  */
886 static void tight_pack24(VncState *vs, uint8_t *buf, size_t count, size_t *ret)
887 {
888     uint8_t *buf8;
889     uint32_t pix;
890     int rshift, gshift, bshift;
891 
892     buf8 = buf;
893 
894     if (1 /* FIXME */) {
895         rshift = vs->client_pf.rshift;
896         gshift = vs->client_pf.gshift;
897         bshift = vs->client_pf.bshift;
898     } else {
899         rshift = 24 - vs->client_pf.rshift;
900         gshift = 24 - vs->client_pf.gshift;
901         bshift = 24 - vs->client_pf.bshift;
902     }
903 
904     if (ret) {
905         *ret = count * 3;
906     }
907 
908     while (count--) {
909         pix = ldl_he_p(buf8);
910         *buf++ = (char)(pix >> rshift);
911         *buf++ = (char)(pix >> gshift);
912         *buf++ = (char)(pix >> bshift);
913         buf8 += 4;
914     }
915 }
916 
917 static int send_full_color_rect(VncState *vs, int x, int y, int w, int h)
918 {
919     int stream = 0;
920     ssize_t bytes;
921 
922 #ifdef CONFIG_PNG
923     if (tight_can_send_png_rect(vs, w, h)) {
924         return send_png_rect(vs, x, y, w, h, NULL);
925     }
926 #endif
927 
928     vnc_write_u8(vs, stream << 4); /* no flushing, no filter */
929 
930     if (vs->tight->pixel24) {
931         tight_pack24(vs, vs->tight->tight.buffer, w * h,
932                      &vs->tight->tight.offset);
933         bytes = 3;
934     } else {
935         bytes = vs->client_pf.bytes_per_pixel;
936     }
937 
938     bytes = tight_compress_data(vs, stream, w * h * bytes,
939                             tight_conf[vs->tight->compression].raw_zlib_level,
940                             Z_DEFAULT_STRATEGY);
941 
942     return (bytes >= 0);
943 }
944 
945 static int send_solid_rect(VncState *vs)
946 {
947     size_t bytes;
948 
949     vnc_write_u8(vs, VNC_TIGHT_FILL << 4); /* no flushing, no filter */
950 
951     if (vs->tight->pixel24) {
952         tight_pack24(vs, vs->tight->tight.buffer, 1, &vs->tight->tight.offset);
953         bytes = 3;
954     } else {
955         bytes = vs->client_pf.bytes_per_pixel;
956     }
957 
958     vnc_write(vs, vs->tight->tight.buffer, bytes);
959     return 1;
960 }
961 
962 static int send_mono_rect(VncState *vs, int x, int y,
963                           int w, int h, uint32_t bg, uint32_t fg)
964 {
965     ssize_t bytes;
966     int stream = 1;
967     int level = tight_conf[vs->tight->compression].mono_zlib_level;
968 
969 #ifdef CONFIG_PNG
970     if (tight_can_send_png_rect(vs, w, h)) {
971         int ret;
972         int bpp = vs->client_pf.bytes_per_pixel * 8;
973         VncPalette *palette = palette_new(2, bpp);
974 
975         palette_put(palette, bg);
976         palette_put(palette, fg);
977         ret = send_png_rect(vs, x, y, w, h, palette);
978         palette_destroy(palette);
979         return ret;
980     }
981 #endif
982 
983     bytes = DIV_ROUND_UP(w, 8) * h;
984 
985     vnc_write_u8(vs, (stream | VNC_TIGHT_EXPLICIT_FILTER) << 4);
986     vnc_write_u8(vs, VNC_TIGHT_FILTER_PALETTE);
987     vnc_write_u8(vs, 1);
988 
989     switch (vs->client_pf.bytes_per_pixel) {
990     case 4:
991     {
992         uint32_t buf[2] = {bg, fg};
993         size_t ret = sizeof (buf);
994 
995         if (vs->tight->pixel24) {
996             tight_pack24(vs, (unsigned char*)buf, 2, &ret);
997         }
998         vnc_write(vs, buf, ret);
999 
1000         tight_encode_mono_rect32(vs->tight->tight.buffer, w, h, bg, fg);
1001         break;
1002     }
1003     case 2:
1004         vnc_write(vs, &bg, 2);
1005         vnc_write(vs, &fg, 2);
1006         tight_encode_mono_rect16(vs->tight->tight.buffer, w, h, bg, fg);
1007         break;
1008     default:
1009         vnc_write_u8(vs, bg);
1010         vnc_write_u8(vs, fg);
1011         tight_encode_mono_rect8(vs->tight->tight.buffer, w, h, bg, fg);
1012         break;
1013     }
1014     vs->tight->tight.offset = bytes;
1015 
1016     bytes = tight_compress_data(vs, stream, bytes, level, Z_DEFAULT_STRATEGY);
1017     return (bytes >= 0);
1018 }
1019 
1020 struct palette_cb_priv {
1021     VncState *vs;
1022     uint8_t *header;
1023 #ifdef CONFIG_PNG
1024     png_colorp png_palette;
1025 #endif
1026 };
1027 
1028 static void write_palette(int idx, uint32_t color, void *opaque)
1029 {
1030     struct palette_cb_priv *priv = opaque;
1031     VncState *vs = priv->vs;
1032     uint32_t bytes = vs->client_pf.bytes_per_pixel;
1033 
1034     if (bytes == 4) {
1035         ((uint32_t*)priv->header)[idx] = color;
1036     } else {
1037         ((uint16_t*)priv->header)[idx] = color;
1038     }
1039 }
1040 
1041 static bool send_gradient_rect(VncState *vs, int x, int y, int w, int h)
1042 {
1043     int stream = 3;
1044     int level = tight_conf[vs->tight->compression].gradient_zlib_level;
1045     ssize_t bytes;
1046 
1047     if (vs->client_pf.bytes_per_pixel == 1) {
1048         return send_full_color_rect(vs, x, y, w, h);
1049     }
1050 
1051     vnc_write_u8(vs, (stream | VNC_TIGHT_EXPLICIT_FILTER) << 4);
1052     vnc_write_u8(vs, VNC_TIGHT_FILTER_GRADIENT);
1053 
1054     buffer_reserve(&vs->tight->gradient, w * 3 * sizeof(int));
1055 
1056     if (vs->tight->pixel24) {
1057         tight_filter_gradient24(vs, vs->tight->tight.buffer, w, h);
1058         bytes = 3;
1059     } else if (vs->client_pf.bytes_per_pixel == 4) {
1060         tight_filter_gradient32(vs, (uint32_t *)vs->tight->tight.buffer, w, h);
1061         bytes = 4;
1062     } else {
1063         tight_filter_gradient16(vs, (uint16_t *)vs->tight->tight.buffer, w, h);
1064         bytes = 2;
1065     }
1066 
1067     buffer_reset(&vs->tight->gradient);
1068 
1069     bytes = w * h * bytes;
1070     vs->tight->tight.offset = bytes;
1071 
1072     bytes = tight_compress_data(vs, stream, bytes,
1073                                 level, Z_FILTERED);
1074     return (bytes >= 0);
1075 }
1076 
1077 static int send_palette_rect(VncState *vs, int x, int y,
1078                              int w, int h, VncPalette *palette)
1079 {
1080     int stream = 2;
1081     int level = tight_conf[vs->tight->compression].idx_zlib_level;
1082     int colors;
1083     ssize_t bytes;
1084 
1085 #ifdef CONFIG_PNG
1086     if (tight_can_send_png_rect(vs, w, h)) {
1087         return send_png_rect(vs, x, y, w, h, palette);
1088     }
1089 #endif
1090 
1091     colors = palette_size(palette);
1092 
1093     vnc_write_u8(vs, (stream | VNC_TIGHT_EXPLICIT_FILTER) << 4);
1094     vnc_write_u8(vs, VNC_TIGHT_FILTER_PALETTE);
1095     vnc_write_u8(vs, colors - 1);
1096 
1097     switch (vs->client_pf.bytes_per_pixel) {
1098     case 4:
1099     {
1100         size_t old_offset, offset, palette_sz = palette_size(palette);
1101         g_autofree uint32_t *header = g_new(uint32_t, palette_sz);
1102         struct palette_cb_priv priv = { vs, (uint8_t *)header };
1103 
1104         old_offset = vs->output.offset;
1105         palette_iter(palette, write_palette, &priv);
1106         vnc_write(vs, header, palette_sz * sizeof(uint32_t));
1107 
1108         if (vs->tight->pixel24) {
1109             tight_pack24(vs, vs->output.buffer + old_offset, colors, &offset);
1110             vs->output.offset = old_offset + offset;
1111         }
1112 
1113         tight_encode_indexed_rect32(vs->tight->tight.buffer, w * h, palette);
1114         break;
1115     }
1116     case 2:
1117     {
1118         size_t palette_sz = palette_size(palette);
1119         g_autofree uint16_t *header = g_new(uint16_t, palette_sz);
1120         struct palette_cb_priv priv = { vs, (uint8_t *)header };
1121 
1122         palette_iter(palette, write_palette, &priv);
1123         vnc_write(vs, header, palette_sz * sizeof(uint16_t));
1124         tight_encode_indexed_rect16(vs->tight->tight.buffer, w * h, palette);
1125         break;
1126     }
1127     default:
1128         return -1; /* No palette for 8bits colors */
1129     }
1130     bytes = w * h;
1131     vs->tight->tight.offset = bytes;
1132 
1133     bytes = tight_compress_data(vs, stream, bytes,
1134                                 level, Z_DEFAULT_STRATEGY);
1135     return (bytes >= 0);
1136 }
1137 
1138 /*
1139  * JPEG compression stuff.
1140  */
1141 #ifdef CONFIG_VNC_JPEG
1142 /*
1143  * Destination manager implementation for JPEG library.
1144  */
1145 
1146 /* This is called once per encoding */
1147 static void jpeg_init_destination(j_compress_ptr cinfo)
1148 {
1149     VncState *vs = cinfo->client_data;
1150     Buffer *buffer = &vs->tight->jpeg;
1151 
1152     cinfo->dest->next_output_byte = (JOCTET *)buffer->buffer + buffer->offset;
1153     cinfo->dest->free_in_buffer = (size_t)(buffer->capacity - buffer->offset);
1154 }
1155 
1156 /* This is called when we ran out of buffer (shouldn't happen!) */
1157 static boolean jpeg_empty_output_buffer(j_compress_ptr cinfo)
1158 {
1159     VncState *vs = cinfo->client_data;
1160     Buffer *buffer = &vs->tight->jpeg;
1161 
1162     buffer->offset = buffer->capacity;
1163     buffer_reserve(buffer, 2048);
1164     jpeg_init_destination(cinfo);
1165     return TRUE;
1166 }
1167 
1168 /* This is called when we are done processing data */
1169 static void jpeg_term_destination(j_compress_ptr cinfo)
1170 {
1171     VncState *vs = cinfo->client_data;
1172     Buffer *buffer = &vs->tight->jpeg;
1173 
1174     buffer->offset = buffer->capacity - cinfo->dest->free_in_buffer;
1175 }
1176 
1177 static int send_jpeg_rect(VncState *vs, int x, int y, int w, int h, int quality)
1178 {
1179     struct jpeg_compress_struct cinfo;
1180     struct jpeg_error_mgr jerr;
1181     struct jpeg_destination_mgr manager;
1182     pixman_image_t *linebuf;
1183     JSAMPROW row[1];
1184     uint8_t *buf;
1185     int dy;
1186 
1187     if (surface_bytes_per_pixel(vs->vd->ds) == 1) {
1188         return send_full_color_rect(vs, x, y, w, h);
1189     }
1190 
1191     buffer_reserve(&vs->tight->jpeg, 2048);
1192 
1193     cinfo.err = jpeg_std_error(&jerr);
1194     jpeg_create_compress(&cinfo);
1195 
1196     cinfo.client_data = vs;
1197     cinfo.image_width = w;
1198     cinfo.image_height = h;
1199     cinfo.input_components = 3;
1200     cinfo.in_color_space = JCS_RGB;
1201 
1202     jpeg_set_defaults(&cinfo);
1203     jpeg_set_quality(&cinfo, quality, true);
1204 
1205     manager.init_destination = jpeg_init_destination;
1206     manager.empty_output_buffer = jpeg_empty_output_buffer;
1207     manager.term_destination = jpeg_term_destination;
1208     cinfo.dest = &manager;
1209 
1210     jpeg_start_compress(&cinfo, true);
1211 
1212     linebuf = qemu_pixman_linebuf_create(PIXMAN_BE_r8g8b8, w);
1213     buf = (uint8_t *)pixman_image_get_data(linebuf);
1214     row[0] = buf;
1215     for (dy = 0; dy < h; dy++) {
1216         qemu_pixman_linebuf_fill(linebuf, vs->vd->server, w, x, y + dy);
1217         jpeg_write_scanlines(&cinfo, row, 1);
1218     }
1219     qemu_pixman_image_unref(linebuf);
1220 
1221     jpeg_finish_compress(&cinfo);
1222     jpeg_destroy_compress(&cinfo);
1223 
1224     vnc_write_u8(vs, VNC_TIGHT_JPEG << 4);
1225 
1226     tight_send_compact_size(vs, vs->tight->jpeg.offset);
1227     vnc_write(vs, vs->tight->jpeg.buffer, vs->tight->jpeg.offset);
1228     buffer_reset(&vs->tight->jpeg);
1229 
1230     return 1;
1231 }
1232 #endif /* CONFIG_VNC_JPEG */
1233 
1234 /*
1235  * PNG compression stuff.
1236  */
1237 #ifdef CONFIG_PNG
1238 static void write_png_palette(int idx, uint32_t pix, void *opaque)
1239 {
1240     struct palette_cb_priv *priv = opaque;
1241     VncState *vs = priv->vs;
1242     png_colorp color = &priv->png_palette[idx];
1243 
1244     if (vs->tight->pixel24)
1245     {
1246         color->red = (pix >> vs->client_pf.rshift) & vs->client_pf.rmax;
1247         color->green = (pix >> vs->client_pf.gshift) & vs->client_pf.gmax;
1248         color->blue = (pix >> vs->client_pf.bshift) & vs->client_pf.bmax;
1249     }
1250     else
1251     {
1252         int red, green, blue;
1253 
1254         red = (pix >> vs->client_pf.rshift) & vs->client_pf.rmax;
1255         green = (pix >> vs->client_pf.gshift) & vs->client_pf.gmax;
1256         blue = (pix >> vs->client_pf.bshift) & vs->client_pf.bmax;
1257         color->red = ((red * 255 + vs->client_pf.rmax / 2) /
1258                       vs->client_pf.rmax);
1259         color->green = ((green * 255 + vs->client_pf.gmax / 2) /
1260                         vs->client_pf.gmax);
1261         color->blue = ((blue * 255 + vs->client_pf.bmax / 2) /
1262                        vs->client_pf.bmax);
1263     }
1264 }
1265 
1266 static void png_write_data(png_structp png_ptr, png_bytep data,
1267                            png_size_t length)
1268 {
1269     VncState *vs = png_get_io_ptr(png_ptr);
1270 
1271     buffer_reserve(&vs->tight->png, vs->tight->png.offset + length);
1272     memcpy(vs->tight->png.buffer + vs->tight->png.offset, data, length);
1273 
1274     vs->tight->png.offset += length;
1275 }
1276 
1277 static void png_flush_data(png_structp png_ptr)
1278 {
1279 }
1280 
1281 static void *vnc_png_malloc(png_structp png_ptr, png_size_t size)
1282 {
1283     return g_malloc(size);
1284 }
1285 
1286 static void vnc_png_free(png_structp png_ptr, png_voidp ptr)
1287 {
1288     g_free(ptr);
1289 }
1290 
1291 static int send_png_rect(VncState *vs, int x, int y, int w, int h,
1292                          VncPalette *palette)
1293 {
1294     png_byte color_type;
1295     png_structp png_ptr;
1296     png_infop info_ptr;
1297     png_colorp png_palette = NULL;
1298     pixman_image_t *linebuf;
1299     int level = tight_png_conf[vs->tight->compression].png_zlib_level;
1300     int filters = tight_png_conf[vs->tight->compression].png_filters;
1301     uint8_t *buf;
1302     int dy;
1303 
1304     png_ptr = png_create_write_struct_2(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL,
1305                                         NULL, vnc_png_malloc, vnc_png_free);
1306 
1307     if (png_ptr == NULL)
1308         return -1;
1309 
1310     info_ptr = png_create_info_struct(png_ptr);
1311 
1312     if (info_ptr == NULL) {
1313         png_destroy_write_struct(&png_ptr, NULL);
1314         return -1;
1315     }
1316 
1317     png_set_write_fn(png_ptr, (void *) vs, png_write_data, png_flush_data);
1318     png_set_compression_level(png_ptr, level);
1319     png_set_filter(png_ptr, PNG_FILTER_TYPE_DEFAULT, filters);
1320 
1321     if (palette) {
1322         color_type = PNG_COLOR_TYPE_PALETTE;
1323     } else {
1324         color_type = PNG_COLOR_TYPE_RGB;
1325     }
1326 
1327     png_set_IHDR(png_ptr, info_ptr, w, h,
1328                  8, color_type, PNG_INTERLACE_NONE,
1329                  PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
1330 
1331     if (color_type == PNG_COLOR_TYPE_PALETTE) {
1332         struct palette_cb_priv priv;
1333 
1334         png_palette = png_malloc(png_ptr, sizeof(*png_palette) *
1335                                  palette_size(palette));
1336 
1337         priv.vs = vs;
1338         priv.png_palette = png_palette;
1339         palette_iter(palette, write_png_palette, &priv);
1340 
1341         png_set_PLTE(png_ptr, info_ptr, png_palette, palette_size(palette));
1342 
1343         if (vs->client_pf.bytes_per_pixel == 4) {
1344             tight_encode_indexed_rect32(vs->tight->tight.buffer, w * h,
1345                                         palette);
1346         } else {
1347             tight_encode_indexed_rect16(vs->tight->tight.buffer, w * h,
1348                                         palette);
1349         }
1350     }
1351 
1352     png_write_info(png_ptr, info_ptr);
1353 
1354     buffer_reserve(&vs->tight->png, 2048);
1355     linebuf = qemu_pixman_linebuf_create(PIXMAN_BE_r8g8b8, w);
1356     buf = (uint8_t *)pixman_image_get_data(linebuf);
1357     for (dy = 0; dy < h; dy++)
1358     {
1359         if (color_type == PNG_COLOR_TYPE_PALETTE) {
1360             memcpy(buf, vs->tight->tight.buffer + (dy * w), w);
1361         } else {
1362             qemu_pixman_linebuf_fill(linebuf, vs->vd->server, w, x, y + dy);
1363         }
1364         png_write_row(png_ptr, buf);
1365     }
1366     qemu_pixman_image_unref(linebuf);
1367 
1368     png_write_end(png_ptr, NULL);
1369 
1370     if (color_type == PNG_COLOR_TYPE_PALETTE) {
1371         png_free(png_ptr, png_palette);
1372     }
1373 
1374     png_destroy_write_struct(&png_ptr, &info_ptr);
1375 
1376     vnc_write_u8(vs, VNC_TIGHT_PNG << 4);
1377 
1378     tight_send_compact_size(vs, vs->tight->png.offset);
1379     vnc_write(vs, vs->tight->png.buffer, vs->tight->png.offset);
1380     buffer_reset(&vs->tight->png);
1381     return 1;
1382 }
1383 #endif /* CONFIG_PNG */
1384 
1385 static void vnc_tight_start(VncState *vs)
1386 {
1387     buffer_reset(&vs->tight->tight);
1388 
1389     // make the output buffer be the zlib buffer, so we can compress it later
1390     vs->tight->tmp = vs->output;
1391     vs->output = vs->tight->tight;
1392 }
1393 
1394 static void vnc_tight_stop(VncState *vs)
1395 {
1396     // switch back to normal output/zlib buffers
1397     vs->tight->tight = vs->output;
1398     vs->output = vs->tight->tmp;
1399 }
1400 
1401 static int send_sub_rect_nojpeg(VncState *vs, int x, int y, int w, int h,
1402                                 int bg, int fg, int colors, VncPalette *palette)
1403 {
1404     int ret;
1405 
1406     if (colors == 0) {
1407         if (tight_detect_smooth_image(vs, w, h)) {
1408             ret = send_gradient_rect(vs, x, y, w, h);
1409         } else {
1410             ret = send_full_color_rect(vs, x, y, w, h);
1411         }
1412     } else if (colors == 1) {
1413         ret = send_solid_rect(vs);
1414     } else if (colors == 2) {
1415         ret = send_mono_rect(vs, x, y, w, h, bg, fg);
1416     } else if (colors <= 256) {
1417         ret = send_palette_rect(vs, x, y, w, h, palette);
1418     } else {
1419         ret = 0;
1420     }
1421     return ret;
1422 }
1423 
1424 #ifdef CONFIG_VNC_JPEG
1425 static int send_sub_rect_jpeg(VncState *vs, int x, int y, int w, int h,
1426                               int bg, int fg, int colors,
1427                               VncPalette *palette, bool force)
1428 {
1429     int ret;
1430 
1431     if (colors == 0) {
1432         if (force || (tight_jpeg_conf[vs->tight->quality].jpeg_full &&
1433                       tight_detect_smooth_image(vs, w, h))) {
1434             int quality = tight_conf[vs->tight->quality].jpeg_quality;
1435 
1436             ret = send_jpeg_rect(vs, x, y, w, h, quality);
1437         } else {
1438             ret = send_full_color_rect(vs, x, y, w, h);
1439         }
1440     } else if (colors == 1) {
1441         ret = send_solid_rect(vs);
1442     } else if (colors == 2) {
1443         ret = send_mono_rect(vs, x, y, w, h, bg, fg);
1444     } else if (colors <= 256) {
1445         if (force || (colors > 96 &&
1446                       tight_jpeg_conf[vs->tight->quality].jpeg_idx &&
1447                       tight_detect_smooth_image(vs, w, h))) {
1448             int quality = tight_conf[vs->tight->quality].jpeg_quality;
1449 
1450             ret = send_jpeg_rect(vs, x, y, w, h, quality);
1451         } else {
1452             ret = send_palette_rect(vs, x, y, w, h, palette);
1453         }
1454     } else {
1455         ret = 0;
1456     }
1457     return ret;
1458 }
1459 #endif
1460 
1461 static __thread VncPalette *color_count_palette;
1462 static __thread Notifier vnc_tight_cleanup_notifier;
1463 
1464 static void vnc_tight_cleanup(Notifier *n, void *value)
1465 {
1466     g_free(color_count_palette);
1467     color_count_palette = NULL;
1468 }
1469 
1470 static int send_sub_rect(VncState *vs, int x, int y, int w, int h)
1471 {
1472     uint32_t bg = 0, fg = 0;
1473     int colors;
1474     int ret = 0;
1475 #ifdef CONFIG_VNC_JPEG
1476     bool force_jpeg = false;
1477     bool allow_jpeg = true;
1478 #endif
1479 
1480     if (!color_count_palette) {
1481         color_count_palette = g_new(VncPalette, 1);
1482         vnc_tight_cleanup_notifier.notify = vnc_tight_cleanup;
1483         qemu_thread_atexit_add(&vnc_tight_cleanup_notifier);
1484     }
1485 
1486     vnc_framebuffer_update(vs, x, y, w, h, vs->tight->type);
1487 
1488     vnc_tight_start(vs);
1489     vnc_raw_send_framebuffer_update(vs, x, y, w, h);
1490     vnc_tight_stop(vs);
1491 
1492 #ifdef CONFIG_VNC_JPEG
1493     if (!vs->vd->non_adaptive && vs->tight->quality != (uint8_t)-1) {
1494         double freq = vnc_update_freq(vs, x, y, w, h);
1495 
1496         if (freq < tight_jpeg_conf[vs->tight->quality].jpeg_freq_min) {
1497             allow_jpeg = false;
1498         }
1499         if (freq >= tight_jpeg_conf[vs->tight->quality].jpeg_freq_threshold) {
1500             force_jpeg = true;
1501             vnc_sent_lossy_rect(vs, x, y, w, h);
1502         }
1503     }
1504 #endif
1505 
1506     colors = tight_fill_palette(vs, x, y, w * h, &bg, &fg, color_count_palette);
1507 
1508 #ifdef CONFIG_VNC_JPEG
1509     if (allow_jpeg && vs->tight->quality != (uint8_t)-1) {
1510         ret = send_sub_rect_jpeg(vs, x, y, w, h, bg, fg, colors,
1511                                  color_count_palette, force_jpeg);
1512     } else {
1513         ret = send_sub_rect_nojpeg(vs, x, y, w, h, bg, fg, colors,
1514                                    color_count_palette);
1515     }
1516 #else
1517     ret = send_sub_rect_nojpeg(vs, x, y, w, h, bg, fg, colors,
1518                                color_count_palette);
1519 #endif
1520 
1521     return ret;
1522 }
1523 
1524 static int send_sub_rect_solid(VncState *vs, int x, int y, int w, int h)
1525 {
1526     vnc_framebuffer_update(vs, x, y, w, h, vs->tight->type);
1527 
1528     vnc_tight_start(vs);
1529     vnc_raw_send_framebuffer_update(vs, x, y, w, h);
1530     vnc_tight_stop(vs);
1531 
1532     return send_solid_rect(vs);
1533 }
1534 
1535 static int send_rect_simple(VncState *vs, int x, int y, int w, int h,
1536                             bool split)
1537 {
1538     int max_size, max_width;
1539     int max_sub_width, max_sub_height;
1540     int dx, dy;
1541     int rw, rh;
1542     int n = 0;
1543 
1544     max_size = tight_conf[vs->tight->compression].max_rect_size;
1545     max_width = tight_conf[vs->tight->compression].max_rect_width;
1546 
1547     if (split && (w > max_width || w * h > max_size)) {
1548         max_sub_width = (w > max_width) ? max_width : w;
1549         max_sub_height = max_size / max_sub_width;
1550 
1551         for (dy = 0; dy < h; dy += max_sub_height) {
1552             for (dx = 0; dx < w; dx += max_width) {
1553                 rw = MIN(max_sub_width, w - dx);
1554                 rh = MIN(max_sub_height, h - dy);
1555                 n += send_sub_rect(vs, x+dx, y+dy, rw, rh);
1556             }
1557         }
1558     } else {
1559         n += send_sub_rect(vs, x, y, w, h);
1560     }
1561 
1562     return n;
1563 }
1564 
1565 static int find_large_solid_color_rect(VncState *vs, int x, int y,
1566                                        int w, int h, int max_rows)
1567 {
1568     int dx, dy, dw, dh;
1569     int n = 0;
1570 
1571     /* Try to find large solid-color areas and send them separately. */
1572 
1573     for (dy = y; dy < y + h; dy += VNC_TIGHT_MAX_SPLIT_TILE_SIZE) {
1574 
1575         /* If a rectangle becomes too large, send its upper part now. */
1576 
1577         if (dy - y >= max_rows) {
1578             n += send_rect_simple(vs, x, y, w, max_rows, true);
1579             y += max_rows;
1580             h -= max_rows;
1581         }
1582 
1583         dh = MIN(VNC_TIGHT_MAX_SPLIT_TILE_SIZE, (y + h - dy));
1584 
1585         for (dx = x; dx < x + w; dx += VNC_TIGHT_MAX_SPLIT_TILE_SIZE) {
1586             uint32_t color_value;
1587             int x_best, y_best, w_best, h_best;
1588 
1589             dw = MIN(VNC_TIGHT_MAX_SPLIT_TILE_SIZE, (x + w - dx));
1590 
1591             if (!check_solid_tile(vs, dx, dy, dw, dh, &color_value, false)) {
1592                 continue ;
1593             }
1594 
1595             /* Get dimensions of solid-color area. */
1596 
1597             find_best_solid_area(vs, dx, dy, w - (dx - x), h - (dy - y),
1598                                  color_value, &w_best, &h_best);
1599 
1600             /* Make sure a solid rectangle is large enough
1601                (or the whole rectangle is of the same color). */
1602 
1603             if (w_best * h_best != w * h &&
1604                 w_best * h_best < VNC_TIGHT_MIN_SOLID_SUBRECT_SIZE) {
1605                 continue;
1606             }
1607 
1608             /* Try to extend solid rectangle to maximum size. */
1609 
1610             x_best = dx; y_best = dy;
1611             extend_solid_area(vs, x, y, w, h, color_value,
1612                               &x_best, &y_best, &w_best, &h_best);
1613 
1614             /* Send rectangles at top and left to solid-color area. */
1615 
1616             if (y_best != y) {
1617                 n += send_rect_simple(vs, x, y, w, y_best-y, true);
1618             }
1619             if (x_best != x) {
1620                 n += tight_send_framebuffer_update(vs, x, y_best,
1621                                                    x_best-x, h_best);
1622             }
1623 
1624             /* Send solid-color rectangle. */
1625             n += send_sub_rect_solid(vs, x_best, y_best, w_best, h_best);
1626 
1627             /* Send remaining rectangles (at right and bottom). */
1628 
1629             if (x_best + w_best != x + w) {
1630                 n += tight_send_framebuffer_update(vs, x_best+w_best,
1631                                                    y_best,
1632                                                    w-(x_best-x)-w_best,
1633                                                    h_best);
1634             }
1635             if (y_best + h_best != y + h) {
1636                 n += tight_send_framebuffer_update(vs, x, y_best+h_best,
1637                                                    w, h-(y_best-y)-h_best);
1638             }
1639 
1640             /* Return after all recursive calls are done. */
1641             return n;
1642         }
1643     }
1644     return n + send_rect_simple(vs, x, y, w, h, true);
1645 }
1646 
1647 static int tight_send_framebuffer_update(VncState *vs, int x, int y,
1648                                          int w, int h)
1649 {
1650     int max_rows;
1651 
1652     if (vs->client_pf.bytes_per_pixel == 4 && vs->client_pf.rmax == 0xFF &&
1653         vs->client_pf.bmax == 0xFF && vs->client_pf.gmax == 0xFF) {
1654         vs->tight->pixel24 = true;
1655     } else {
1656         vs->tight->pixel24 = false;
1657     }
1658 
1659 #ifdef CONFIG_VNC_JPEG
1660     if (vs->tight->quality != (uint8_t)-1) {
1661         double freq = vnc_update_freq(vs, x, y, w, h);
1662 
1663         if (freq > tight_jpeg_conf[vs->tight->quality].jpeg_freq_threshold) {
1664             return send_rect_simple(vs, x, y, w, h, false);
1665         }
1666     }
1667 #endif
1668 
1669     if (w * h < VNC_TIGHT_MIN_SPLIT_RECT_SIZE) {
1670         return send_rect_simple(vs, x, y, w, h, true);
1671     }
1672 
1673     /* Calculate maximum number of rows in one non-solid rectangle. */
1674 
1675     max_rows = tight_conf[vs->tight->compression].max_rect_size;
1676     max_rows /= MIN(tight_conf[vs->tight->compression].max_rect_width, w);
1677 
1678     return find_large_solid_color_rect(vs, x, y, w, h, max_rows);
1679 }
1680 
1681 int vnc_tight_send_framebuffer_update(VncState *vs, int x, int y,
1682                                       int w, int h)
1683 {
1684     vs->tight->type = VNC_ENCODING_TIGHT;
1685     return tight_send_framebuffer_update(vs, x, y, w, h);
1686 }
1687 
1688 int vnc_tight_png_send_framebuffer_update(VncState *vs, int x, int y,
1689                                           int w, int h)
1690 {
1691     vs->tight->type = VNC_ENCODING_TIGHT_PNG;
1692     return tight_send_framebuffer_update(vs, x, y, w, h);
1693 }
1694 
1695 void vnc_tight_clear(VncState *vs)
1696 {
1697     int i;
1698     for (i = 0; i < ARRAY_SIZE(vs->tight->stream); i++) {
1699         if (vs->tight->stream[i].opaque) {
1700             deflateEnd(&vs->tight->stream[i]);
1701         }
1702     }
1703 
1704     buffer_free(&vs->tight->tight);
1705     buffer_free(&vs->tight->zlib);
1706     buffer_free(&vs->tight->gradient);
1707 #ifdef CONFIG_VNC_JPEG
1708     buffer_free(&vs->tight->jpeg);
1709 #endif
1710 #ifdef CONFIG_PNG
1711     buffer_free(&vs->tight->png);
1712 #endif
1713 }
1714