xref: /openbmc/qemu/ui/vnc-enc-tight.c (revision 14a650ec)
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 "config-host.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 #include "qemu-common.h"
35 
36 #ifdef CONFIG_VNC_PNG
37 /* The following define is needed by pngconf.h. Otherwise it won't compile,
38    because setjmp.h was already included by qemu-common.h. */
39 #define PNG_SKIP_SETJMP_CHECK
40 #include <png.h>
41 #endif
42 #ifdef CONFIG_VNC_JPEG
43 #include <stdio.h>
44 #include <jpeglib.h>
45 #endif
46 
47 #include "qemu/bswap.h"
48 #include "qapi/qmp/qint.h"
49 #include "vnc.h"
50 #include "vnc-enc-tight.h"
51 #include "vnc-palette.h"
52 
53 /* Compression level stuff. The following array contains various
54    encoder parameters for each of 10 compression levels (0..9).
55    Last three parameters correspond to JPEG quality levels (0..9). */
56 
57 static const struct {
58     int max_rect_size, max_rect_width;
59     int mono_min_rect_size, gradient_min_rect_size;
60     int idx_zlib_level, mono_zlib_level, raw_zlib_level, gradient_zlib_level;
61     int gradient_threshold, gradient_threshold24;
62     int idx_max_colors_divisor;
63     int jpeg_quality, jpeg_threshold, jpeg_threshold24;
64 } tight_conf[] = {
65     {   512,   32,   6, 65536, 0, 0, 0, 0,   0,   0,   4,  5, 10000, 23000 },
66     {  2048,  128,   6, 65536, 1, 1, 1, 0,   0,   0,   8, 10,  8000, 18000 },
67     {  6144,  256,   8, 65536, 3, 3, 2, 0,   0,   0,  24, 15,  6500, 15000 },
68     { 10240, 1024,  12, 65536, 5, 5, 3, 0,   0,   0,  32, 25,  5000, 12000 },
69     { 16384, 2048,  12, 65536, 6, 6, 4, 0,   0,   0,  32, 37,  4000, 10000 },
70     { 32768, 2048,  12,  4096, 7, 7, 5, 4, 150, 380,  32, 50,  3000,  8000 },
71     { 65536, 2048,  16,  4096, 7, 7, 6, 4, 170, 420,  48, 60,  2000,  5000 },
72     { 65536, 2048,  16,  4096, 8, 8, 7, 5, 180, 450,  64, 70,  1000,  2500 },
73     { 65536, 2048,  32,  8192, 9, 9, 8, 6, 190, 475,  64, 75,   500,  1200 },
74     { 65536, 2048,  32,  8192, 9, 9, 9, 6, 200, 500,  96, 80,   200,   500 }
75 };
76 
77 
78 static int tight_send_framebuffer_update(VncState *vs, int x, int y,
79                                          int w, int h);
80 
81 #ifdef CONFIG_VNC_JPEG
82 static const struct {
83     double jpeg_freq_min;       /* Don't send JPEG if the freq is bellow */
84     double jpeg_freq_threshold; /* Always send JPEG if the freq is above */
85     int jpeg_idx;               /* Allow indexed JPEG */
86     int jpeg_full;              /* Allow full color JPEG */
87 } tight_jpeg_conf[] = {
88     { 0,   8,  1, 1 },
89     { 0,   8,  1, 1 },
90     { 0,   8,  1, 1 },
91     { 0,   8,  1, 1 },
92     { 0,   10, 1, 1 },
93     { 0.1, 10, 1, 1 },
94     { 0.2, 10, 1, 1 },
95     { 0.3, 12, 0, 0 },
96     { 0.4, 14, 0, 0 },
97     { 0.5, 16, 0, 0 },
98 };
99 #endif
100 
101 #ifdef CONFIG_VNC_PNG
102 static const struct {
103     int png_zlib_level, png_filters;
104 } tight_png_conf[] = {
105     { 0, PNG_NO_FILTERS },
106     { 1, PNG_NO_FILTERS },
107     { 2, PNG_NO_FILTERS },
108     { 3, PNG_NO_FILTERS },
109     { 4, PNG_NO_FILTERS },
110     { 5, PNG_ALL_FILTERS },
111     { 6, PNG_ALL_FILTERS },
112     { 7, PNG_ALL_FILTERS },
113     { 8, PNG_ALL_FILTERS },
114     { 9, PNG_ALL_FILTERS },
115 };
116 
117 static int send_png_rect(VncState *vs, int x, int y, int w, int h,
118                          VncPalette *palette);
119 
120 static bool tight_can_send_png_rect(VncState *vs, int w, int h)
121 {
122     if (vs->tight.type != VNC_ENCODING_TIGHT_PNG) {
123         return false;
124     }
125 
126     if (surface_bytes_per_pixel(vs->vd->ds) == 1 ||
127         vs->client_pf.bytes_per_pixel == 1) {
128         return false;
129     }
130 
131     return true;
132 }
133 #endif
134 
135 /*
136  * Code to guess if given rectangle is suitable for smooth image
137  * compression (by applying "gradient" filter or JPEG coder).
138  */
139 
140 static unsigned int
141 tight_detect_smooth_image24(VncState *vs, int w, int h)
142 {
143     int off;
144     int x, y, d, dx;
145     unsigned int c;
146     unsigned int stats[256];
147     int pixels = 0;
148     int pix, left[3];
149     unsigned int errors;
150     unsigned char *buf = vs->tight.tight.buffer;
151 
152     /*
153      * If client is big-endian, color samples begin from the second
154      * byte (offset 1) of a 32-bit pixel value.
155      */
156     off = vs->client_be;
157 
158     memset(stats, 0, sizeof (stats));
159 
160     for (y = 0, x = 0; y < h && x < w;) {
161         for (d = 0; d < h - y && d < w - x - VNC_TIGHT_DETECT_SUBROW_WIDTH;
162              d++) {
163             for (c = 0; c < 3; c++) {
164                 left[c] = buf[((y+d)*w+x+d)*4+off+c] & 0xFF;
165             }
166             for (dx = 1; dx <= VNC_TIGHT_DETECT_SUBROW_WIDTH; dx++) {
167                 for (c = 0; c < 3; c++) {
168                     pix = buf[((y+d)*w+x+d+dx)*4+off+c] & 0xFF;
169                     stats[abs(pix - left[c])]++;
170                     left[c] = pix;
171                 }
172                 pixels++;
173             }
174         }
175         if (w > h) {
176             x += h;
177             y = 0;
178         } else {
179             x = 0;
180             y += w;
181         }
182     }
183 
184     /* 95% smooth or more ... */
185     if (stats[0] * 33 / pixels >= 95) {
186         return 0;
187     }
188 
189     errors = 0;
190     for (c = 1; c < 8; c++) {
191         errors += stats[c] * (c * c);
192         if (stats[c] == 0 || stats[c] > stats[c-1] * 2) {
193             return 0;
194         }
195     }
196     for (; c < 256; c++) {
197         errors += stats[c] * (c * c);
198     }
199     errors /= (pixels * 3 - stats[0]);
200 
201     return errors;
202 }
203 
204 #define DEFINE_DETECT_FUNCTION(bpp)                                     \
205                                                                         \
206     static unsigned int                                                 \
207     tight_detect_smooth_image##bpp(VncState *vs, int w, int h) {        \
208         bool endian;                                                    \
209         uint##bpp##_t pix;                                              \
210         int max[3], shift[3];                                           \
211         int x, y, d, dx;                                                \
212         unsigned int c;                                                 \
213         unsigned int stats[256];                                        \
214         int pixels = 0;                                                 \
215         int sample, sum, left[3];                                       \
216         unsigned int errors;                                            \
217         unsigned char *buf = vs->tight.tight.buffer;                    \
218                                                                         \
219         endian = 0; /* FIXME: ((vs->clientds.flags & QEMU_BIG_ENDIAN_FLAG) != \
220                       (vs->ds->surface->flags & QEMU_BIG_ENDIAN_FLAG)); */ \
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                                                                         \
271         if ((stats[0] + stats[1]) * 100 / pixels >= 90) {               \
272             return 0;                                                   \
273         }                                                               \
274                                                                         \
275         errors = 0;                                                     \
276         for (c = 1; c < 8; c++) {                                       \
277             errors += stats[c] * (c * c);                               \
278             if (stats[c] == 0 || stats[c] > stats[c-1] * 2) {           \
279                 return 0;                                               \
280             }                                                           \
281         }                                                               \
282         for (; c < 256; c++) {                                          \
283             errors += stats[c] * (c * c);                               \
284         }                                                               \
285         errors /= (pixels - stats[0]);                                  \
286                                                                         \
287         return errors;                                                  \
288     }
289 
290 DEFINE_DETECT_FUNCTION(16)
291 DEFINE_DETECT_FUNCTION(32)
292 
293 static int
294 tight_detect_smooth_image(VncState *vs, int w, int h)
295 {
296     unsigned int errors;
297     int compression = vs->tight.compression;
298     int quality = vs->tight.quality;
299 
300     if (!vs->vd->lossy) {
301         return 0;
302     }
303 
304     if (surface_bytes_per_pixel(vs->vd->ds) == 1 ||
305         vs->client_pf.bytes_per_pixel == 1 ||
306         w < VNC_TIGHT_DETECT_MIN_WIDTH || h < VNC_TIGHT_DETECT_MIN_HEIGHT) {
307         return 0;
308     }
309 
310     if (vs->tight.quality != (uint8_t)-1) {
311         if (w * h < VNC_TIGHT_JPEG_MIN_RECT_SIZE) {
312             return 0;
313         }
314     } else {
315         if (w * h < tight_conf[compression].gradient_min_rect_size) {
316             return 0;
317         }
318     }
319 
320     if (vs->client_pf.bytes_per_pixel == 4) {
321         if (vs->tight.pixel24) {
322             errors = tight_detect_smooth_image24(vs, w, h);
323             if (vs->tight.quality != (uint8_t)-1) {
324                 return (errors < tight_conf[quality].jpeg_threshold24);
325             }
326             return (errors < tight_conf[compression].gradient_threshold24);
327         } else {
328             errors = tight_detect_smooth_image32(vs, w, h);
329         }
330     } else {
331         errors = tight_detect_smooth_image16(vs, w, h);
332     }
333     if (quality != -1) {
334         return (errors < tight_conf[quality].jpeg_threshold);
335     }
336     return (errors < tight_conf[compression].gradient_threshold);
337 }
338 
339 /*
340  * Code to determine how many different colors used in rectangle.
341  */
342 #define DEFINE_FILL_PALETTE_FUNCTION(bpp)                               \
343                                                                         \
344     static int                                                          \
345     tight_fill_palette##bpp(VncState *vs, int x, int y,                 \
346                             int max, size_t count,                      \
347                             uint32_t *bg, uint32_t *fg,                 \
348                             VncPalette **palette) {                     \
349         uint##bpp##_t *data;                                            \
350         uint##bpp##_t c0, c1, ci;                                       \
351         int i, n0, n1;                                                  \
352                                                                         \
353         data = (uint##bpp##_t *)vs->tight.tight.buffer;                 \
354                                                                         \
355         c0 = data[0];                                                   \
356         i = 1;                                                          \
357         while (i < count && data[i] == c0)                              \
358             i++;                                                        \
359         if (i >= count) {                                               \
360             *bg = *fg = c0;                                             \
361             return 1;                                                   \
362         }                                                               \
363                                                                         \
364         if (max < 2) {                                                  \
365             return 0;                                                   \
366         }                                                               \
367                                                                         \
368         n0 = i;                                                         \
369         c1 = data[i];                                                   \
370         n1 = 0;                                                         \
371         for (i++; i < count; i++) {                                     \
372             ci = data[i];                                               \
373             if (ci == c0) {                                             \
374                 n0++;                                                   \
375             } else if (ci == c1) {                                      \
376                 n1++;                                                   \
377             } else                                                      \
378                 break;                                                  \
379         }                                                               \
380         if (i >= count) {                                               \
381             if (n0 > n1) {                                              \
382                 *bg = (uint32_t)c0;                                     \
383                 *fg = (uint32_t)c1;                                     \
384             } else {                                                    \
385                 *bg = (uint32_t)c1;                                     \
386                 *fg = (uint32_t)c0;                                     \
387             }                                                           \
388             return 2;                                                   \
389         }                                                               \
390                                                                         \
391         if (max == 2) {                                                 \
392             return 0;                                                   \
393         }                                                               \
394                                                                         \
395         *palette = palette_new(max, bpp);                               \
396         palette_put(*palette, c0);                                      \
397         palette_put(*palette, c1);                                      \
398         palette_put(*palette, ci);                                      \
399                                                                         \
400         for (i++; i < count; i++) {                                     \
401             if (data[i] == ci) {                                        \
402                 continue;                                               \
403             } else {                                                    \
404                 ci = data[i];                                           \
405                 if (!palette_put(*palette, (uint32_t)ci)) {             \
406                     return 0;                                           \
407                 }                                                       \
408             }                                                           \
409         }                                                               \
410                                                                         \
411         return palette_size(*palette);                                  \
412     }
413 
414 DEFINE_FILL_PALETTE_FUNCTION(8)
415 DEFINE_FILL_PALETTE_FUNCTION(16)
416 DEFINE_FILL_PALETTE_FUNCTION(32)
417 
418 static int tight_fill_palette(VncState *vs, int x, int y,
419                               size_t count, uint32_t *bg, uint32_t *fg,
420                               VncPalette **palette)
421 {
422     int max;
423 
424     max = count / tight_conf[vs->tight.compression].idx_max_colors_divisor;
425     if (max < 2 &&
426         count >= tight_conf[vs->tight.compression].mono_min_rect_size) {
427         max = 2;
428     }
429     if (max >= 256) {
430         max = 256;
431     }
432 
433     switch (vs->client_pf.bytes_per_pixel) {
434     case 4:
435         return tight_fill_palette32(vs, x, y, max, count, bg, fg, palette);
436     case 2:
437         return tight_fill_palette16(vs, x, y, max, count, bg, fg, palette);
438     default:
439         max = 2;
440         return tight_fill_palette8(vs, x, y, max, count, bg, fg, palette);
441     }
442     return 0;
443 }
444 
445 /*
446  * Converting truecolor samples into palette indices.
447  */
448 #define DEFINE_IDX_ENCODE_FUNCTION(bpp)                                 \
449                                                                         \
450     static void                                                         \
451     tight_encode_indexed_rect##bpp(uint8_t *buf, int count,             \
452                                    VncPalette *palette) {               \
453         uint##bpp##_t *src;                                             \
454         uint##bpp##_t rgb;                                              \
455         int i, rep;                                                     \
456         uint8_t idx;                                                    \
457                                                                         \
458         src = (uint##bpp##_t *) buf;                                    \
459                                                                         \
460         for (i = 0; i < count; i++) {                                   \
461                                                                         \
462             rgb = *src++;                                               \
463             rep = 0;                                                    \
464             while (i < count && *src == rgb) {                          \
465                 rep++, src++, i++;                                      \
466             }                                                           \
467             idx = palette_idx(palette, rgb);                            \
468             /*                                                          \
469              * Should never happen, but don't break everything          \
470              * if it does, use the first color instead                  \
471              */                                                         \
472             if (idx == (uint8_t)-1) {                                   \
473                 idx = 0;                                                \
474             }                                                           \
475             while (rep >= 0) {                                          \
476                 *buf++ = idx;                                           \
477                 rep--;                                                  \
478             }                                                           \
479         }                                                               \
480     }
481 
482 DEFINE_IDX_ENCODE_FUNCTION(16)
483 DEFINE_IDX_ENCODE_FUNCTION(32)
484 
485 #define DEFINE_MONO_ENCODE_FUNCTION(bpp)                                \
486                                                                         \
487     static void                                                         \
488     tight_encode_mono_rect##bpp(uint8_t *buf, int w, int h,             \
489                                 uint##bpp##_t bg, uint##bpp##_t fg) {   \
490         uint##bpp##_t *ptr;                                             \
491         unsigned int value, mask;                                       \
492         int aligned_width;                                              \
493         int x, y, bg_bits;                                              \
494                                                                         \
495         ptr = (uint##bpp##_t *) buf;                                    \
496         aligned_width = w - w % 8;                                      \
497                                                                         \
498         for (y = 0; y < h; y++) {                                       \
499             for (x = 0; x < aligned_width; x += 8) {                    \
500                 for (bg_bits = 0; bg_bits < 8; bg_bits++) {             \
501                     if (*ptr++ != bg) {                                 \
502                         break;                                          \
503                     }                                                   \
504                 }                                                       \
505                 if (bg_bits == 8) {                                     \
506                     *buf++ = 0;                                         \
507                     continue;                                           \
508                 }                                                       \
509                 mask = 0x80 >> bg_bits;                                 \
510                 value = mask;                                           \
511                 for (bg_bits++; bg_bits < 8; bg_bits++) {               \
512                     mask >>= 1;                                         \
513                     if (*ptr++ != bg) {                                 \
514                         value |= mask;                                  \
515                     }                                                   \
516                 }                                                       \
517                 *buf++ = (uint8_t)value;                                \
518             }                                                           \
519                                                                         \
520             mask = 0x80;                                                \
521             value = 0;                                                  \
522             if (x >= w) {                                               \
523                 continue;                                               \
524             }                                                           \
525                                                                         \
526             for (; x < w; x++) {                                        \
527                 if (*ptr++ != bg) {                                     \
528                     value |= mask;                                      \
529                 }                                                       \
530                 mask >>= 1;                                             \
531             }                                                           \
532             *buf++ = (uint8_t)value;                                    \
533         }                                                               \
534     }
535 
536 DEFINE_MONO_ENCODE_FUNCTION(8)
537 DEFINE_MONO_ENCODE_FUNCTION(16)
538 DEFINE_MONO_ENCODE_FUNCTION(32)
539 
540 /*
541  * ``Gradient'' filter for 24-bit color samples.
542  * Should be called only when redMax, greenMax and blueMax are 255.
543  * Color components assumed to be byte-aligned.
544  */
545 
546 static void
547 tight_filter_gradient24(VncState *vs, uint8_t *buf, int w, int h)
548 {
549     uint32_t *buf32;
550     uint32_t pix32;
551     int shift[3];
552     int *prev;
553     int here[3], upper[3], left[3], upperleft[3];
554     int prediction;
555     int x, y, c;
556 
557     buf32 = (uint32_t *)buf;
558     memset(vs->tight.gradient.buffer, 0, w * 3 * sizeof(int));
559 
560     if (1 /* FIXME: (vs->clientds.flags & QEMU_BIG_ENDIAN_FLAG) ==
561              (vs->ds->surface->flags & QEMU_BIG_ENDIAN_FLAG) */) {
562         shift[0] = vs->client_pf.rshift;
563         shift[1] = vs->client_pf.gshift;
564         shift[2] = vs->client_pf.bshift;
565     } else {
566         shift[0] = 24 - vs->client_pf.rshift;
567         shift[1] = 24 - vs->client_pf.gshift;
568         shift[2] = 24 - vs->client_pf.bshift;
569     }
570 
571     for (y = 0; y < h; y++) {
572         for (c = 0; c < 3; c++) {
573             upper[c] = 0;
574             here[c] = 0;
575         }
576         prev = (int *)vs->tight.gradient.buffer;
577         for (x = 0; x < w; x++) {
578             pix32 = *buf32++;
579             for (c = 0; c < 3; c++) {
580                 upperleft[c] = upper[c];
581                 left[c] = here[c];
582                 upper[c] = *prev;
583                 here[c] = (int)(pix32 >> shift[c] & 0xFF);
584                 *prev++ = here[c];
585 
586                 prediction = left[c] + upper[c] - upperleft[c];
587                 if (prediction < 0) {
588                     prediction = 0;
589                 } else if (prediction > 0xFF) {
590                     prediction = 0xFF;
591                 }
592                 *buf++ = (char)(here[c] - prediction);
593             }
594         }
595     }
596 }
597 
598 
599 /*
600  * ``Gradient'' filter for other color depths.
601  */
602 
603 #define DEFINE_GRADIENT_FILTER_FUNCTION(bpp)                            \
604                                                                         \
605     static void                                                         \
606     tight_filter_gradient##bpp(VncState *vs, uint##bpp##_t *buf,        \
607                                int w, int h) {                          \
608         uint##bpp##_t pix, diff;                                        \
609         bool endian;                                                    \
610         int *prev;                                                      \
611         int max[3], shift[3];                                           \
612         int here[3], upper[3], left[3], upperleft[3];                   \
613         int prediction;                                                 \
614         int x, y, c;                                                    \
615                                                                         \
616         memset (vs->tight.gradient.buffer, 0, w * 3 * sizeof(int));     \
617                                                                         \
618         endian = 0; /* FIXME: ((vs->clientds.flags & QEMU_BIG_ENDIAN_FLAG) != \
619                        (vs->ds->surface->flags & QEMU_BIG_ENDIAN_FLAG)); */ \
620                                                                         \
621         max[0] = vs->client_pf.rmax;                                    \
622         max[1] = vs->client_pf.gmax;                                    \
623         max[2] = vs->client_pf.bmax;                                    \
624         shift[0] = vs->client_pf.rshift;                                \
625         shift[1] = vs->client_pf.gshift;                                \
626         shift[2] = vs->client_pf.bshift;                                \
627                                                                         \
628         for (y = 0; y < h; y++) {                                       \
629             for (c = 0; c < 3; c++) {                                   \
630                 upper[c] = 0;                                           \
631                 here[c] = 0;                                            \
632             }                                                           \
633             prev = (int *)vs->tight.gradient.buffer;                    \
634             for (x = 0; x < w; x++) {                                   \
635                 pix = *buf;                                             \
636                 if (endian) {                                           \
637                     pix = bswap##bpp(pix);                              \
638                 }                                                       \
639                 diff = 0;                                               \
640                 for (c = 0; c < 3; c++) {                               \
641                     upperleft[c] = upper[c];                            \
642                     left[c] = here[c];                                  \
643                     upper[c] = *prev;                                   \
644                     here[c] = (int)(pix >> shift[c] & max[c]);          \
645                     *prev++ = here[c];                                  \
646                                                                         \
647                     prediction = left[c] + upper[c] - upperleft[c];     \
648                     if (prediction < 0) {                               \
649                         prediction = 0;                                 \
650                     } else if (prediction > max[c]) {                   \
651                         prediction = max[c];                            \
652                     }                                                   \
653                     diff |= ((here[c] - prediction) & max[c])           \
654                         << shift[c];                                    \
655                 }                                                       \
656                 if (endian) {                                           \
657                     diff = bswap##bpp(diff);                            \
658                 }                                                       \
659                 *buf++ = diff;                                          \
660             }                                                           \
661         }                                                               \
662     }
663 
664 DEFINE_GRADIENT_FILTER_FUNCTION(16)
665 DEFINE_GRADIENT_FILTER_FUNCTION(32)
666 
667 /*
668  * Check if a rectangle is all of the same color. If needSameColor is
669  * set to non-zero, then also check that its color equals to the
670  * *colorPtr value. The result is 1 if the test is successful, and in
671  * that case new color will be stored in *colorPtr.
672  */
673 
674 static bool
675 check_solid_tile32(VncState *vs, int x, int y, int w, int h,
676                    uint32_t *color, bool samecolor)
677 {
678     VncDisplay *vd = vs->vd;
679     uint32_t *fbptr;
680     uint32_t c;
681     int dx, dy;
682 
683     fbptr = vnc_server_fb_ptr(vd, x, y);
684 
685     c = *fbptr;
686     if (samecolor && (uint32_t)c != *color) {
687         return false;
688     }
689 
690     for (dy = 0; dy < h; dy++) {
691         for (dx = 0; dx < w; dx++) {
692             if (c != fbptr[dx]) {
693                 return false;
694             }
695         }
696         fbptr = (uint32_t *)
697             ((uint8_t *)fbptr + vnc_server_fb_stride(vd));
698     }
699 
700     *color = (uint32_t)c;
701     return true;
702 }
703 
704 static bool check_solid_tile(VncState *vs, int x, int y, int w, int h,
705                              uint32_t* color, bool samecolor)
706 {
707     switch (VNC_SERVER_FB_BYTES) {
708     case 4:
709         return check_solid_tile32(vs, x, y, w, h, color, samecolor);
710     }
711 }
712 
713 static void find_best_solid_area(VncState *vs, int x, int y, int w, int h,
714                                  uint32_t color, int *w_ptr, int *h_ptr)
715 {
716     int dx, dy, dw, dh;
717     int w_prev;
718     int w_best = 0, h_best = 0;
719 
720     w_prev = w;
721 
722     for (dy = y; dy < y + h; dy += VNC_TIGHT_MAX_SPLIT_TILE_SIZE) {
723 
724         dh = MIN(VNC_TIGHT_MAX_SPLIT_TILE_SIZE, y + h - dy);
725         dw = MIN(VNC_TIGHT_MAX_SPLIT_TILE_SIZE, w_prev);
726 
727         if (!check_solid_tile(vs, x, dy, dw, dh, &color, true)) {
728             break;
729         }
730 
731         for (dx = x + dw; dx < x + w_prev;) {
732             dw = MIN(VNC_TIGHT_MAX_SPLIT_TILE_SIZE, x + w_prev - dx);
733 
734             if (!check_solid_tile(vs, dx, dy, dw, dh, &color, true)) {
735                 break;
736             }
737             dx += dw;
738         }
739 
740         w_prev = dx - x;
741         if (w_prev * (dy + dh - y) > w_best * h_best) {
742             w_best = w_prev;
743             h_best = dy + dh - y;
744         }
745     }
746 
747     *w_ptr = w_best;
748     *h_ptr = h_best;
749 }
750 
751 static void extend_solid_area(VncState *vs, int x, int y, int w, int h,
752                               uint32_t color, int *x_ptr, int *y_ptr,
753                               int *w_ptr, int *h_ptr)
754 {
755     int cx, cy;
756 
757     /* Try to extend the area upwards. */
758     for ( cy = *y_ptr - 1;
759           cy >= y && check_solid_tile(vs, *x_ptr, cy, *w_ptr, 1, &color, true);
760           cy-- );
761     *h_ptr += *y_ptr - (cy + 1);
762     *y_ptr = cy + 1;
763 
764     /* ... downwards. */
765     for ( cy = *y_ptr + *h_ptr;
766           cy < y + h &&
767               check_solid_tile(vs, *x_ptr, cy, *w_ptr, 1, &color, true);
768           cy++ );
769     *h_ptr += cy - (*y_ptr + *h_ptr);
770 
771     /* ... to the left. */
772     for ( cx = *x_ptr - 1;
773           cx >= x && check_solid_tile(vs, cx, *y_ptr, 1, *h_ptr, &color, true);
774           cx-- );
775     *w_ptr += *x_ptr - (cx + 1);
776     *x_ptr = cx + 1;
777 
778     /* ... to the right. */
779     for ( cx = *x_ptr + *w_ptr;
780           cx < x + w &&
781               check_solid_tile(vs, cx, *y_ptr, 1, *h_ptr, &color, true);
782           cx++ );
783     *w_ptr += cx - (*x_ptr + *w_ptr);
784 }
785 
786 static int tight_init_stream(VncState *vs, int stream_id,
787                              int level, int strategy)
788 {
789     z_streamp zstream = &vs->tight.stream[stream_id];
790 
791     if (zstream->opaque == NULL) {
792         int err;
793 
794         VNC_DEBUG("VNC: TIGHT: initializing zlib stream %d\n", stream_id);
795         VNC_DEBUG("VNC: TIGHT: opaque = %p | vs = %p\n", zstream->opaque, vs);
796         zstream->zalloc = vnc_zlib_zalloc;
797         zstream->zfree = vnc_zlib_zfree;
798 
799         err = deflateInit2(zstream, level, Z_DEFLATED, MAX_WBITS,
800                            MAX_MEM_LEVEL, strategy);
801 
802         if (err != Z_OK) {
803             fprintf(stderr, "VNC: error initializing zlib\n");
804             return -1;
805         }
806 
807         vs->tight.levels[stream_id] = level;
808         zstream->opaque = vs;
809     }
810 
811     if (vs->tight.levels[stream_id] != level) {
812         if (deflateParams(zstream, level, strategy) != Z_OK) {
813             return -1;
814         }
815         vs->tight.levels[stream_id] = level;
816     }
817     return 0;
818 }
819 
820 static void tight_send_compact_size(VncState *vs, size_t len)
821 {
822     int lpc = 0;
823     int bytes = 0;
824     char buf[3] = {0, 0, 0};
825 
826     buf[bytes++] = len & 0x7F;
827     if (len > 0x7F) {
828         buf[bytes-1] |= 0x80;
829         buf[bytes++] = (len >> 7) & 0x7F;
830         if (len > 0x3FFF) {
831             buf[bytes-1] |= 0x80;
832             buf[bytes++] = (len >> 14) & 0xFF;
833         }
834     }
835     for (lpc = 0; lpc < bytes; lpc++) {
836         vnc_write_u8(vs, buf[lpc]);
837     }
838 }
839 
840 static int tight_compress_data(VncState *vs, int stream_id, size_t bytes,
841                                int level, int strategy)
842 {
843     z_streamp zstream = &vs->tight.stream[stream_id];
844     int previous_out;
845 
846     if (bytes < VNC_TIGHT_MIN_TO_COMPRESS) {
847         vnc_write(vs, vs->tight.tight.buffer, vs->tight.tight.offset);
848         return bytes;
849     }
850 
851     if (tight_init_stream(vs, stream_id, level, strategy)) {
852         return -1;
853     }
854 
855     /* reserve memory in output buffer */
856     buffer_reserve(&vs->tight.zlib, bytes + 64);
857 
858     /* set pointers */
859     zstream->next_in = vs->tight.tight.buffer;
860     zstream->avail_in = vs->tight.tight.offset;
861     zstream->next_out = vs->tight.zlib.buffer + vs->tight.zlib.offset;
862     zstream->avail_out = vs->tight.zlib.capacity - vs->tight.zlib.offset;
863     previous_out = zstream->avail_out;
864     zstream->data_type = Z_BINARY;
865 
866     /* start encoding */
867     if (deflate(zstream, Z_SYNC_FLUSH) != Z_OK) {
868         fprintf(stderr, "VNC: error during tight compression\n");
869         return -1;
870     }
871 
872     vs->tight.zlib.offset = vs->tight.zlib.capacity - zstream->avail_out;
873     /* ...how much data has actually been produced by deflate() */
874     bytes = previous_out - zstream->avail_out;
875 
876     tight_send_compact_size(vs, bytes);
877     vnc_write(vs, vs->tight.zlib.buffer, bytes);
878 
879     buffer_reset(&vs->tight.zlib);
880 
881     return bytes;
882 }
883 
884 /*
885  * Subencoding implementations.
886  */
887 static void tight_pack24(VncState *vs, uint8_t *buf, size_t count, size_t *ret)
888 {
889     uint32_t *buf32;
890     uint32_t pix;
891     int rshift, gshift, bshift;
892 
893     buf32 = (uint32_t *)buf;
894 
895     if (1 /* FIXME: (vs->clientds.flags & QEMU_BIG_ENDIAN_FLAG) ==
896              (vs->ds->surface->flags & QEMU_BIG_ENDIAN_FLAG) */) {
897         rshift = vs->client_pf.rshift;
898         gshift = vs->client_pf.gshift;
899         bshift = vs->client_pf.bshift;
900     } else {
901         rshift = 24 - vs->client_pf.rshift;
902         gshift = 24 - vs->client_pf.gshift;
903         bshift = 24 - vs->client_pf.bshift;
904     }
905 
906     if (ret) {
907         *ret = count * 3;
908     }
909 
910     while (count--) {
911         pix = *buf32++;
912         *buf++ = (char)(pix >> rshift);
913         *buf++ = (char)(pix >> gshift);
914         *buf++ = (char)(pix >> bshift);
915     }
916 }
917 
918 static int send_full_color_rect(VncState *vs, int x, int y, int w, int h)
919 {
920     int stream = 0;
921     ssize_t bytes;
922 
923 #ifdef CONFIG_VNC_PNG
924     if (tight_can_send_png_rect(vs, w, h)) {
925         return send_png_rect(vs, x, y, w, h, NULL);
926     }
927 #endif
928 
929     vnc_write_u8(vs, stream << 4); /* no flushing, no filter */
930 
931     if (vs->tight.pixel24) {
932         tight_pack24(vs, vs->tight.tight.buffer, w * h, &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_VNC_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 = ((w + 7) / 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_VNC_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_VNC_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;
1101         uint32_t header[palette_size(palette)];
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, sizeof(header));
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         uint16_t header[palette_size(palette)];
1119         struct palette_cb_priv priv = { vs, (uint8_t *)header };
1120 
1121         palette_iter(palette, write_palette, &priv);
1122         vnc_write(vs, header, sizeof(header));
1123         tight_encode_indexed_rect16(vs->tight.tight.buffer, w * h, palette);
1124         break;
1125     }
1126     default:
1127         return -1; /* No palette for 8bits colors */
1128         break;
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_VNC_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, palette);
1345         } else {
1346             tight_encode_indexed_rect16(vs->tight.tight.buffer, w * h, palette);
1347         }
1348     }
1349 
1350     png_write_info(png_ptr, info_ptr);
1351 
1352     buffer_reserve(&vs->tight.png, 2048);
1353     linebuf = qemu_pixman_linebuf_create(PIXMAN_BE_r8g8b8, w);
1354     buf = (uint8_t *)pixman_image_get_data(linebuf);
1355     for (dy = 0; dy < h; dy++)
1356     {
1357         if (color_type == PNG_COLOR_TYPE_PALETTE) {
1358             memcpy(buf, vs->tight.tight.buffer + (dy * w), w);
1359         } else {
1360             qemu_pixman_linebuf_fill(linebuf, vs->vd->server, w, x, y + dy);
1361         }
1362         png_write_row(png_ptr, buf);
1363     }
1364     qemu_pixman_image_unref(linebuf);
1365 
1366     png_write_end(png_ptr, NULL);
1367 
1368     if (color_type == PNG_COLOR_TYPE_PALETTE) {
1369         png_free(png_ptr, png_palette);
1370     }
1371 
1372     png_destroy_write_struct(&png_ptr, &info_ptr);
1373 
1374     vnc_write_u8(vs, VNC_TIGHT_PNG << 4);
1375 
1376     tight_send_compact_size(vs, vs->tight.png.offset);
1377     vnc_write(vs, vs->tight.png.buffer, vs->tight.png.offset);
1378     buffer_reset(&vs->tight.png);
1379     return 1;
1380 }
1381 #endif /* CONFIG_VNC_PNG */
1382 
1383 static void vnc_tight_start(VncState *vs)
1384 {
1385     buffer_reset(&vs->tight.tight);
1386 
1387     // make the output buffer be the zlib buffer, so we can compress it later
1388     vs->tight.tmp = vs->output;
1389     vs->output = vs->tight.tight;
1390 }
1391 
1392 static void vnc_tight_stop(VncState *vs)
1393 {
1394     // switch back to normal output/zlib buffers
1395     vs->tight.tight = vs->output;
1396     vs->output = vs->tight.tmp;
1397 }
1398 
1399 static int send_sub_rect_nojpeg(VncState *vs, int x, int y, int w, int h,
1400                                 int bg, int fg, int colors, VncPalette *palette)
1401 {
1402     int ret;
1403 
1404     if (colors == 0) {
1405         if (tight_detect_smooth_image(vs, w, h)) {
1406             ret = send_gradient_rect(vs, x, y, w, h);
1407         } else {
1408             ret = send_full_color_rect(vs, x, y, w, h);
1409         }
1410     } else if (colors == 1) {
1411         ret = send_solid_rect(vs);
1412     } else if (colors == 2) {
1413         ret = send_mono_rect(vs, x, y, w, h, bg, fg);
1414     } else if (colors <= 256) {
1415         ret = send_palette_rect(vs, x, y, w, h, palette);
1416     } else {
1417         ret = 0;
1418     }
1419     return ret;
1420 }
1421 
1422 #ifdef CONFIG_VNC_JPEG
1423 static int send_sub_rect_jpeg(VncState *vs, int x, int y, int w, int h,
1424                               int bg, int fg, int colors,
1425                               VncPalette *palette, bool force)
1426 {
1427     int ret;
1428 
1429     if (colors == 0) {
1430         if (force || (tight_jpeg_conf[vs->tight.quality].jpeg_full &&
1431                       tight_detect_smooth_image(vs, w, h))) {
1432             int quality = tight_conf[vs->tight.quality].jpeg_quality;
1433 
1434             ret = send_jpeg_rect(vs, x, y, w, h, quality);
1435         } else {
1436             ret = send_full_color_rect(vs, x, y, w, h);
1437         }
1438     } else if (colors == 1) {
1439         ret = send_solid_rect(vs);
1440     } else if (colors == 2) {
1441         ret = send_mono_rect(vs, x, y, w, h, bg, fg);
1442     } else if (colors <= 256) {
1443         if (force || (colors > 96 &&
1444                       tight_jpeg_conf[vs->tight.quality].jpeg_idx &&
1445                       tight_detect_smooth_image(vs, w, h))) {
1446             int quality = tight_conf[vs->tight.quality].jpeg_quality;
1447 
1448             ret = send_jpeg_rect(vs, x, y, w, h, quality);
1449         } else {
1450             ret = send_palette_rect(vs, x, y, w, h, palette);
1451         }
1452     } else {
1453         ret = 0;
1454     }
1455     return ret;
1456 }
1457 #endif
1458 
1459 static int send_sub_rect(VncState *vs, int x, int y, int w, int h)
1460 {
1461     VncPalette *palette = NULL;
1462     uint32_t bg = 0, fg = 0;
1463     int colors;
1464     int ret = 0;
1465 #ifdef CONFIG_VNC_JPEG
1466     bool force_jpeg = false;
1467     bool allow_jpeg = true;
1468 #endif
1469 
1470     vnc_framebuffer_update(vs, x, y, w, h, vs->tight.type);
1471 
1472     vnc_tight_start(vs);
1473     vnc_raw_send_framebuffer_update(vs, x, y, w, h);
1474     vnc_tight_stop(vs);
1475 
1476 #ifdef CONFIG_VNC_JPEG
1477     if (!vs->vd->non_adaptive && vs->tight.quality != (uint8_t)-1) {
1478         double freq = vnc_update_freq(vs, x, y, w, h);
1479 
1480         if (freq < tight_jpeg_conf[vs->tight.quality].jpeg_freq_min) {
1481             allow_jpeg = false;
1482         }
1483         if (freq >= tight_jpeg_conf[vs->tight.quality].jpeg_freq_threshold) {
1484             force_jpeg = true;
1485             vnc_sent_lossy_rect(vs, x, y, w, h);
1486         }
1487     }
1488 #endif
1489 
1490     colors = tight_fill_palette(vs, x, y, w * h, &fg, &bg, &palette);
1491 
1492 #ifdef CONFIG_VNC_JPEG
1493     if (allow_jpeg && vs->tight.quality != (uint8_t)-1) {
1494         ret = send_sub_rect_jpeg(vs, x, y, w, h, bg, fg, colors, palette,
1495                                  force_jpeg);
1496     } else {
1497         ret = send_sub_rect_nojpeg(vs, x, y, w, h, bg, fg, colors, palette);
1498     }
1499 #else
1500     ret = send_sub_rect_nojpeg(vs, x, y, w, h, bg, fg, colors, palette);
1501 #endif
1502 
1503     palette_destroy(palette);
1504     return ret;
1505 }
1506 
1507 static int send_sub_rect_solid(VncState *vs, int x, int y, int w, int h)
1508 {
1509     vnc_framebuffer_update(vs, x, y, w, h, vs->tight.type);
1510 
1511     vnc_tight_start(vs);
1512     vnc_raw_send_framebuffer_update(vs, x, y, w, h);
1513     vnc_tight_stop(vs);
1514 
1515     return send_solid_rect(vs);
1516 }
1517 
1518 static int send_rect_simple(VncState *vs, int x, int y, int w, int h,
1519                             bool split)
1520 {
1521     int max_size, max_width;
1522     int max_sub_width, max_sub_height;
1523     int dx, dy;
1524     int rw, rh;
1525     int n = 0;
1526 
1527     max_size = tight_conf[vs->tight.compression].max_rect_size;
1528     max_width = tight_conf[vs->tight.compression].max_rect_width;
1529 
1530     if (split && (w > max_width || w * h > max_size)) {
1531         max_sub_width = (w > max_width) ? max_width : w;
1532         max_sub_height = max_size / max_sub_width;
1533 
1534         for (dy = 0; dy < h; dy += max_sub_height) {
1535             for (dx = 0; dx < w; dx += max_width) {
1536                 rw = MIN(max_sub_width, w - dx);
1537                 rh = MIN(max_sub_height, h - dy);
1538                 n += send_sub_rect(vs, x+dx, y+dy, rw, rh);
1539             }
1540         }
1541     } else {
1542         n += send_sub_rect(vs, x, y, w, h);
1543     }
1544 
1545     return n;
1546 }
1547 
1548 static int find_large_solid_color_rect(VncState *vs, int x, int y,
1549                                        int w, int h, int max_rows)
1550 {
1551     int dx, dy, dw, dh;
1552     int n = 0;
1553 
1554     /* Try to find large solid-color areas and send them separately. */
1555 
1556     for (dy = y; dy < y + h; dy += VNC_TIGHT_MAX_SPLIT_TILE_SIZE) {
1557 
1558         /* If a rectangle becomes too large, send its upper part now. */
1559 
1560         if (dy - y >= max_rows) {
1561             n += send_rect_simple(vs, x, y, w, max_rows, true);
1562             y += max_rows;
1563             h -= max_rows;
1564         }
1565 
1566         dh = MIN(VNC_TIGHT_MAX_SPLIT_TILE_SIZE, (y + h - dy));
1567 
1568         for (dx = x; dx < x + w; dx += VNC_TIGHT_MAX_SPLIT_TILE_SIZE) {
1569             uint32_t color_value;
1570             int x_best, y_best, w_best, h_best;
1571 
1572             dw = MIN(VNC_TIGHT_MAX_SPLIT_TILE_SIZE, (x + w - dx));
1573 
1574             if (!check_solid_tile(vs, dx, dy, dw, dh, &color_value, false)) {
1575                 continue ;
1576             }
1577 
1578             /* Get dimensions of solid-color area. */
1579 
1580             find_best_solid_area(vs, dx, dy, w - (dx - x), h - (dy - y),
1581                                  color_value, &w_best, &h_best);
1582 
1583             /* Make sure a solid rectangle is large enough
1584                (or the whole rectangle is of the same color). */
1585 
1586             if (w_best * h_best != w * h &&
1587                 w_best * h_best < VNC_TIGHT_MIN_SOLID_SUBRECT_SIZE) {
1588                 continue;
1589             }
1590 
1591             /* Try to extend solid rectangle to maximum size. */
1592 
1593             x_best = dx; y_best = dy;
1594             extend_solid_area(vs, x, y, w, h, color_value,
1595                               &x_best, &y_best, &w_best, &h_best);
1596 
1597             /* Send rectangles at top and left to solid-color area. */
1598 
1599             if (y_best != y) {
1600                 n += send_rect_simple(vs, x, y, w, y_best-y, true);
1601             }
1602             if (x_best != x) {
1603                 n += tight_send_framebuffer_update(vs, x, y_best,
1604                                                    x_best-x, h_best);
1605             }
1606 
1607             /* Send solid-color rectangle. */
1608             n += send_sub_rect_solid(vs, x_best, y_best, w_best, h_best);
1609 
1610             /* Send remaining rectangles (at right and bottom). */
1611 
1612             if (x_best + w_best != x + w) {
1613                 n += tight_send_framebuffer_update(vs, x_best+w_best,
1614                                                    y_best,
1615                                                    w-(x_best-x)-w_best,
1616                                                    h_best);
1617             }
1618             if (y_best + h_best != y + h) {
1619                 n += tight_send_framebuffer_update(vs, x, y_best+h_best,
1620                                                    w, h-(y_best-y)-h_best);
1621             }
1622 
1623             /* Return after all recursive calls are done. */
1624             return n;
1625         }
1626     }
1627     return n + send_rect_simple(vs, x, y, w, h, true);
1628 }
1629 
1630 static int tight_send_framebuffer_update(VncState *vs, int x, int y,
1631                                          int w, int h)
1632 {
1633     int max_rows;
1634 
1635     if (vs->client_pf.bytes_per_pixel == 4 && vs->client_pf.rmax == 0xFF &&
1636         vs->client_pf.bmax == 0xFF && vs->client_pf.gmax == 0xFF) {
1637         vs->tight.pixel24 = true;
1638     } else {
1639         vs->tight.pixel24 = false;
1640     }
1641 
1642 #ifdef CONFIG_VNC_JPEG
1643     if (vs->tight.quality != (uint8_t)-1) {
1644         double freq = vnc_update_freq(vs, x, y, w, h);
1645 
1646         if (freq > tight_jpeg_conf[vs->tight.quality].jpeg_freq_threshold) {
1647             return send_rect_simple(vs, x, y, w, h, false);
1648         }
1649     }
1650 #endif
1651 
1652     if (w * h < VNC_TIGHT_MIN_SPLIT_RECT_SIZE) {
1653         return send_rect_simple(vs, x, y, w, h, true);
1654     }
1655 
1656     /* Calculate maximum number of rows in one non-solid rectangle. */
1657 
1658     max_rows = tight_conf[vs->tight.compression].max_rect_size;
1659     max_rows /= MIN(tight_conf[vs->tight.compression].max_rect_width, w);
1660 
1661     return find_large_solid_color_rect(vs, x, y, w, h, max_rows);
1662 }
1663 
1664 int vnc_tight_send_framebuffer_update(VncState *vs, int x, int y,
1665                                       int w, int h)
1666 {
1667     vs->tight.type = VNC_ENCODING_TIGHT;
1668     return tight_send_framebuffer_update(vs, x, y, w, h);
1669 }
1670 
1671 int vnc_tight_png_send_framebuffer_update(VncState *vs, int x, int y,
1672                                           int w, int h)
1673 {
1674     vs->tight.type = VNC_ENCODING_TIGHT_PNG;
1675     return tight_send_framebuffer_update(vs, x, y, w, h);
1676 }
1677 
1678 void vnc_tight_clear(VncState *vs)
1679 {
1680     int i;
1681     for (i=0; i<ARRAY_SIZE(vs->tight.stream); i++) {
1682         if (vs->tight.stream[i].opaque) {
1683             deflateEnd(&vs->tight.stream[i]);
1684         }
1685     }
1686 
1687     buffer_free(&vs->tight.tight);
1688     buffer_free(&vs->tight.zlib);
1689     buffer_free(&vs->tight.gradient);
1690 #ifdef CONFIG_VNC_JPEG
1691     buffer_free(&vs->tight.jpeg);
1692 #endif
1693 #ifdef CONFIG_VNC_PNG
1694     buffer_free(&vs->tight.png);
1695 #endif
1696 }
1697