xref: /openbmc/qemu/ui/vnc-enc-tight.c (revision 41a1a9c4)
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     if (pixels == 0) {
185         return 0;
186     }
187 
188     /* 95% smooth or more ... */
189     if (stats[0] * 33 / pixels >= 95) {
190         return 0;
191     }
192 
193     errors = 0;
194     for (c = 1; c < 8; c++) {
195         errors += stats[c] * (c * c);
196         if (stats[c] == 0 || stats[c] > stats[c-1] * 2) {
197             return 0;
198         }
199     }
200     for (; c < 256; c++) {
201         errors += stats[c] * (c * c);
202     }
203     errors /= (pixels * 3 - stats[0]);
204 
205     return errors;
206 }
207 
208 #define DEFINE_DETECT_FUNCTION(bpp)                                     \
209                                                                         \
210     static unsigned int                                                 \
211     tight_detect_smooth_image##bpp(VncState *vs, int w, int h) {        \
212         bool endian;                                                    \
213         uint##bpp##_t pix;                                              \
214         int max[3], shift[3];                                           \
215         int x, y, d, dx;                                                \
216         unsigned int c;                                                 \
217         unsigned int stats[256];                                        \
218         int pixels = 0;                                                 \
219         int sample, sum, left[3];                                       \
220         unsigned int errors;                                            \
221         unsigned char *buf = vs->tight.tight.buffer;                    \
222                                                                         \
223         endian = 0; /* FIXME: ((vs->clientds.flags & QEMU_BIG_ENDIAN_FLAG) != \
224                       (vs->ds->surface->flags & QEMU_BIG_ENDIAN_FLAG)); */ \
225                                                                         \
226                                                                         \
227         max[0] = vs->client_pf.rmax;                                  \
228         max[1] = vs->client_pf.gmax;                                  \
229         max[2] = vs->client_pf.bmax;                                  \
230         shift[0] = vs->client_pf.rshift;                              \
231         shift[1] = vs->client_pf.gshift;                              \
232         shift[2] = vs->client_pf.bshift;                              \
233                                                                         \
234         memset(stats, 0, sizeof(stats));                                \
235                                                                         \
236         y = 0, x = 0;                                                   \
237         while (y < h && x < w) {                                        \
238             for (d = 0; d < h - y &&                                    \
239                      d < w - x - VNC_TIGHT_DETECT_SUBROW_WIDTH; d++) {  \
240                 pix = ((uint##bpp##_t *)buf)[(y+d)*w+x+d];              \
241                 if (endian) {                                           \
242                     pix = bswap##bpp(pix);                              \
243                 }                                                       \
244                 for (c = 0; c < 3; c++) {                               \
245                     left[c] = (int)(pix >> shift[c] & max[c]);          \
246                 }                                                       \
247                 for (dx = 1; dx <= VNC_TIGHT_DETECT_SUBROW_WIDTH;       \
248                      dx++) {                                            \
249                     pix = ((uint##bpp##_t *)buf)[(y+d)*w+x+d+dx];       \
250                     if (endian) {                                       \
251                         pix = bswap##bpp(pix);                          \
252                     }                                                   \
253                     sum = 0;                                            \
254                     for (c = 0; c < 3; c++) {                           \
255                         sample = (int)(pix >> shift[c] & max[c]);       \
256                         sum += abs(sample - left[c]);                   \
257                         left[c] = sample;                               \
258                     }                                                   \
259                     if (sum > 255) {                                    \
260                         sum = 255;                                      \
261                     }                                                   \
262                     stats[sum]++;                                       \
263                     pixels++;                                           \
264                 }                                                       \
265             }                                                           \
266             if (w > h) {                                                \
267                 x += h;                                                 \
268                 y = 0;                                                  \
269             } else {                                                    \
270                 x = 0;                                                  \
271                 y += w;                                                 \
272             }                                                           \
273         }                                                               \
274         if (pixels == 0) {                                              \
275             return 0;                                                   \
276         }                                                               \
277         if ((stats[0] + stats[1]) * 100 / pixels >= 90) {               \
278             return 0;                                                   \
279         }                                                               \
280                                                                         \
281         errors = 0;                                                     \
282         for (c = 1; c < 8; c++) {                                       \
283             errors += stats[c] * (c * c);                               \
284             if (stats[c] == 0 || stats[c] > stats[c-1] * 2) {           \
285                 return 0;                                               \
286             }                                                           \
287         }                                                               \
288         for (; c < 256; c++) {                                          \
289             errors += stats[c] * (c * c);                               \
290         }                                                               \
291         errors /= (pixels - stats[0]);                                  \
292                                                                         \
293         return errors;                                                  \
294     }
295 
296 DEFINE_DETECT_FUNCTION(16)
297 DEFINE_DETECT_FUNCTION(32)
298 
299 static int
300 tight_detect_smooth_image(VncState *vs, int w, int h)
301 {
302     unsigned int errors;
303     int compression = vs->tight.compression;
304     int quality = vs->tight.quality;
305 
306     if (!vs->vd->lossy) {
307         return 0;
308     }
309 
310     if (surface_bytes_per_pixel(vs->vd->ds) == 1 ||
311         vs->client_pf.bytes_per_pixel == 1 ||
312         w < VNC_TIGHT_DETECT_MIN_WIDTH || h < VNC_TIGHT_DETECT_MIN_HEIGHT) {
313         return 0;
314     }
315 
316     if (vs->tight.quality != (uint8_t)-1) {
317         if (w * h < VNC_TIGHT_JPEG_MIN_RECT_SIZE) {
318             return 0;
319         }
320     } else {
321         if (w * h < tight_conf[compression].gradient_min_rect_size) {
322             return 0;
323         }
324     }
325 
326     if (vs->client_pf.bytes_per_pixel == 4) {
327         if (vs->tight.pixel24) {
328             errors = tight_detect_smooth_image24(vs, w, h);
329             if (vs->tight.quality != (uint8_t)-1) {
330                 return (errors < tight_conf[quality].jpeg_threshold24);
331             }
332             return (errors < tight_conf[compression].gradient_threshold24);
333         } else {
334             errors = tight_detect_smooth_image32(vs, w, h);
335         }
336     } else {
337         errors = tight_detect_smooth_image16(vs, w, h);
338     }
339     if (quality != (uint8_t)-1) {
340         return (errors < tight_conf[quality].jpeg_threshold);
341     }
342     return (errors < tight_conf[compression].gradient_threshold);
343 }
344 
345 /*
346  * Code to determine how many different colors used in rectangle.
347  */
348 #define DEFINE_FILL_PALETTE_FUNCTION(bpp)                               \
349                                                                         \
350     static int                                                          \
351     tight_fill_palette##bpp(VncState *vs, int x, int y,                 \
352                             int max, size_t count,                      \
353                             uint32_t *bg, uint32_t *fg,                 \
354                             VncPalette **palette) {                     \
355         uint##bpp##_t *data;                                            \
356         uint##bpp##_t c0, c1, ci;                                       \
357         int i, n0, n1;                                                  \
358                                                                         \
359         data = (uint##bpp##_t *)vs->tight.tight.buffer;                 \
360                                                                         \
361         c0 = data[0];                                                   \
362         i = 1;                                                          \
363         while (i < count && data[i] == c0)                              \
364             i++;                                                        \
365         if (i >= count) {                                               \
366             *bg = *fg = c0;                                             \
367             return 1;                                                   \
368         }                                                               \
369                                                                         \
370         if (max < 2) {                                                  \
371             return 0;                                                   \
372         }                                                               \
373                                                                         \
374         n0 = i;                                                         \
375         c1 = data[i];                                                   \
376         n1 = 0;                                                         \
377         for (i++; i < count; i++) {                                     \
378             ci = data[i];                                               \
379             if (ci == c0) {                                             \
380                 n0++;                                                   \
381             } else if (ci == c1) {                                      \
382                 n1++;                                                   \
383             } else                                                      \
384                 break;                                                  \
385         }                                                               \
386         if (i >= count) {                                               \
387             if (n0 > n1) {                                              \
388                 *bg = (uint32_t)c0;                                     \
389                 *fg = (uint32_t)c1;                                     \
390             } else {                                                    \
391                 *bg = (uint32_t)c1;                                     \
392                 *fg = (uint32_t)c0;                                     \
393             }                                                           \
394             return 2;                                                   \
395         }                                                               \
396                                                                         \
397         if (max == 2) {                                                 \
398             return 0;                                                   \
399         }                                                               \
400                                                                         \
401         *palette = palette_new(max, bpp);                               \
402         palette_put(*palette, c0);                                      \
403         palette_put(*palette, c1);                                      \
404         palette_put(*palette, ci);                                      \
405                                                                         \
406         for (i++; i < count; i++) {                                     \
407             if (data[i] == ci) {                                        \
408                 continue;                                               \
409             } else {                                                    \
410                 ci = data[i];                                           \
411                 if (!palette_put(*palette, (uint32_t)ci)) {             \
412                     return 0;                                           \
413                 }                                                       \
414             }                                                           \
415         }                                                               \
416                                                                         \
417         return palette_size(*palette);                                  \
418     }
419 
420 DEFINE_FILL_PALETTE_FUNCTION(8)
421 DEFINE_FILL_PALETTE_FUNCTION(16)
422 DEFINE_FILL_PALETTE_FUNCTION(32)
423 
424 static int tight_fill_palette(VncState *vs, int x, int y,
425                               size_t count, uint32_t *bg, uint32_t *fg,
426                               VncPalette **palette)
427 {
428     int max;
429 
430     max = count / tight_conf[vs->tight.compression].idx_max_colors_divisor;
431     if (max < 2 &&
432         count >= tight_conf[vs->tight.compression].mono_min_rect_size) {
433         max = 2;
434     }
435     if (max >= 256) {
436         max = 256;
437     }
438 
439     switch (vs->client_pf.bytes_per_pixel) {
440     case 4:
441         return tight_fill_palette32(vs, x, y, max, count, bg, fg, palette);
442     case 2:
443         return tight_fill_palette16(vs, x, y, max, count, bg, fg, palette);
444     default:
445         max = 2;
446         return tight_fill_palette8(vs, x, y, max, count, bg, fg, palette);
447     }
448     return 0;
449 }
450 
451 /*
452  * Converting truecolor samples into palette indices.
453  */
454 #define DEFINE_IDX_ENCODE_FUNCTION(bpp)                                 \
455                                                                         \
456     static void                                                         \
457     tight_encode_indexed_rect##bpp(uint8_t *buf, int count,             \
458                                    VncPalette *palette) {               \
459         uint##bpp##_t *src;                                             \
460         uint##bpp##_t rgb;                                              \
461         int i, rep;                                                     \
462         uint8_t idx;                                                    \
463                                                                         \
464         src = (uint##bpp##_t *) buf;                                    \
465                                                                         \
466         for (i = 0; i < count; i++) {                                   \
467                                                                         \
468             rgb = *src++;                                               \
469             rep = 0;                                                    \
470             while (i < count && *src == rgb) {                          \
471                 rep++, src++, i++;                                      \
472             }                                                           \
473             idx = palette_idx(palette, rgb);                            \
474             /*                                                          \
475              * Should never happen, but don't break everything          \
476              * if it does, use the first color instead                  \
477              */                                                         \
478             if (idx == (uint8_t)-1) {                                   \
479                 idx = 0;                                                \
480             }                                                           \
481             while (rep >= 0) {                                          \
482                 *buf++ = idx;                                           \
483                 rep--;                                                  \
484             }                                                           \
485         }                                                               \
486     }
487 
488 DEFINE_IDX_ENCODE_FUNCTION(16)
489 DEFINE_IDX_ENCODE_FUNCTION(32)
490 
491 #define DEFINE_MONO_ENCODE_FUNCTION(bpp)                                \
492                                                                         \
493     static void                                                         \
494     tight_encode_mono_rect##bpp(uint8_t *buf, int w, int h,             \
495                                 uint##bpp##_t bg, uint##bpp##_t fg) {   \
496         uint##bpp##_t *ptr;                                             \
497         unsigned int value, mask;                                       \
498         int aligned_width;                                              \
499         int x, y, bg_bits;                                              \
500                                                                         \
501         ptr = (uint##bpp##_t *) buf;                                    \
502         aligned_width = w - w % 8;                                      \
503                                                                         \
504         for (y = 0; y < h; y++) {                                       \
505             for (x = 0; x < aligned_width; x += 8) {                    \
506                 for (bg_bits = 0; bg_bits < 8; bg_bits++) {             \
507                     if (*ptr++ != bg) {                                 \
508                         break;                                          \
509                     }                                                   \
510                 }                                                       \
511                 if (bg_bits == 8) {                                     \
512                     *buf++ = 0;                                         \
513                     continue;                                           \
514                 }                                                       \
515                 mask = 0x80 >> bg_bits;                                 \
516                 value = mask;                                           \
517                 for (bg_bits++; bg_bits < 8; bg_bits++) {               \
518                     mask >>= 1;                                         \
519                     if (*ptr++ != bg) {                                 \
520                         value |= mask;                                  \
521                     }                                                   \
522                 }                                                       \
523                 *buf++ = (uint8_t)value;                                \
524             }                                                           \
525                                                                         \
526             mask = 0x80;                                                \
527             value = 0;                                                  \
528             if (x >= w) {                                               \
529                 continue;                                               \
530             }                                                           \
531                                                                         \
532             for (; x < w; x++) {                                        \
533                 if (*ptr++ != bg) {                                     \
534                     value |= mask;                                      \
535                 }                                                       \
536                 mask >>= 1;                                             \
537             }                                                           \
538             *buf++ = (uint8_t)value;                                    \
539         }                                                               \
540     }
541 
542 DEFINE_MONO_ENCODE_FUNCTION(8)
543 DEFINE_MONO_ENCODE_FUNCTION(16)
544 DEFINE_MONO_ENCODE_FUNCTION(32)
545 
546 /*
547  * ``Gradient'' filter for 24-bit color samples.
548  * Should be called only when redMax, greenMax and blueMax are 255.
549  * Color components assumed to be byte-aligned.
550  */
551 
552 static void
553 tight_filter_gradient24(VncState *vs, uint8_t *buf, int w, int h)
554 {
555     uint32_t *buf32;
556     uint32_t pix32;
557     int shift[3];
558     int *prev;
559     int here[3], upper[3], left[3], upperleft[3];
560     int prediction;
561     int x, y, c;
562 
563     buf32 = (uint32_t *)buf;
564     memset(vs->tight.gradient.buffer, 0, w * 3 * sizeof(int));
565 
566     if (1 /* FIXME: (vs->clientds.flags & QEMU_BIG_ENDIAN_FLAG) ==
567              (vs->ds->surface->flags & QEMU_BIG_ENDIAN_FLAG) */) {
568         shift[0] = vs->client_pf.rshift;
569         shift[1] = vs->client_pf.gshift;
570         shift[2] = vs->client_pf.bshift;
571     } else {
572         shift[0] = 24 - vs->client_pf.rshift;
573         shift[1] = 24 - vs->client_pf.gshift;
574         shift[2] = 24 - vs->client_pf.bshift;
575     }
576 
577     for (y = 0; y < h; y++) {
578         for (c = 0; c < 3; c++) {
579             upper[c] = 0;
580             here[c] = 0;
581         }
582         prev = (int *)vs->tight.gradient.buffer;
583         for (x = 0; x < w; x++) {
584             pix32 = *buf32++;
585             for (c = 0; c < 3; c++) {
586                 upperleft[c] = upper[c];
587                 left[c] = here[c];
588                 upper[c] = *prev;
589                 here[c] = (int)(pix32 >> shift[c] & 0xFF);
590                 *prev++ = here[c];
591 
592                 prediction = left[c] + upper[c] - upperleft[c];
593                 if (prediction < 0) {
594                     prediction = 0;
595                 } else if (prediction > 0xFF) {
596                     prediction = 0xFF;
597                 }
598                 *buf++ = (char)(here[c] - prediction);
599             }
600         }
601     }
602 }
603 
604 
605 /*
606  * ``Gradient'' filter for other color depths.
607  */
608 
609 #define DEFINE_GRADIENT_FILTER_FUNCTION(bpp)                            \
610                                                                         \
611     static void                                                         \
612     tight_filter_gradient##bpp(VncState *vs, uint##bpp##_t *buf,        \
613                                int w, int h) {                          \
614         uint##bpp##_t pix, diff;                                        \
615         bool endian;                                                    \
616         int *prev;                                                      \
617         int max[3], shift[3];                                           \
618         int here[3], upper[3], left[3], upperleft[3];                   \
619         int prediction;                                                 \
620         int x, y, c;                                                    \
621                                                                         \
622         memset (vs->tight.gradient.buffer, 0, w * 3 * sizeof(int));     \
623                                                                         \
624         endian = 0; /* FIXME: ((vs->clientds.flags & QEMU_BIG_ENDIAN_FLAG) != \
625                        (vs->ds->surface->flags & QEMU_BIG_ENDIAN_FLAG)); */ \
626                                                                         \
627         max[0] = vs->client_pf.rmax;                                    \
628         max[1] = vs->client_pf.gmax;                                    \
629         max[2] = vs->client_pf.bmax;                                    \
630         shift[0] = vs->client_pf.rshift;                                \
631         shift[1] = vs->client_pf.gshift;                                \
632         shift[2] = vs->client_pf.bshift;                                \
633                                                                         \
634         for (y = 0; y < h; y++) {                                       \
635             for (c = 0; c < 3; c++) {                                   \
636                 upper[c] = 0;                                           \
637                 here[c] = 0;                                            \
638             }                                                           \
639             prev = (int *)vs->tight.gradient.buffer;                    \
640             for (x = 0; x < w; x++) {                                   \
641                 pix = *buf;                                             \
642                 if (endian) {                                           \
643                     pix = bswap##bpp(pix);                              \
644                 }                                                       \
645                 diff = 0;                                               \
646                 for (c = 0; c < 3; c++) {                               \
647                     upperleft[c] = upper[c];                            \
648                     left[c] = here[c];                                  \
649                     upper[c] = *prev;                                   \
650                     here[c] = (int)(pix >> shift[c] & max[c]);          \
651                     *prev++ = here[c];                                  \
652                                                                         \
653                     prediction = left[c] + upper[c] - upperleft[c];     \
654                     if (prediction < 0) {                               \
655                         prediction = 0;                                 \
656                     } else if (prediction > max[c]) {                   \
657                         prediction = max[c];                            \
658                     }                                                   \
659                     diff |= ((here[c] - prediction) & max[c])           \
660                         << shift[c];                                    \
661                 }                                                       \
662                 if (endian) {                                           \
663                     diff = bswap##bpp(diff);                            \
664                 }                                                       \
665                 *buf++ = diff;                                          \
666             }                                                           \
667         }                                                               \
668     }
669 
670 DEFINE_GRADIENT_FILTER_FUNCTION(16)
671 DEFINE_GRADIENT_FILTER_FUNCTION(32)
672 
673 /*
674  * Check if a rectangle is all of the same color. If needSameColor is
675  * set to non-zero, then also check that its color equals to the
676  * *colorPtr value. The result is 1 if the test is successful, and in
677  * that case new color will be stored in *colorPtr.
678  */
679 
680 static bool
681 check_solid_tile32(VncState *vs, int x, int y, int w, int h,
682                    uint32_t *color, bool samecolor)
683 {
684     VncDisplay *vd = vs->vd;
685     uint32_t *fbptr;
686     uint32_t c;
687     int dx, dy;
688 
689     fbptr = vnc_server_fb_ptr(vd, x, y);
690 
691     c = *fbptr;
692     if (samecolor && (uint32_t)c != *color) {
693         return false;
694     }
695 
696     for (dy = 0; dy < h; dy++) {
697         for (dx = 0; dx < w; dx++) {
698             if (c != fbptr[dx]) {
699                 return false;
700             }
701         }
702         fbptr = (uint32_t *)
703             ((uint8_t *)fbptr + vnc_server_fb_stride(vd));
704     }
705 
706     *color = (uint32_t)c;
707     return true;
708 }
709 
710 static bool check_solid_tile(VncState *vs, int x, int y, int w, int h,
711                              uint32_t* color, bool samecolor)
712 {
713     switch (VNC_SERVER_FB_BYTES) {
714     case 4:
715         return check_solid_tile32(vs, x, y, w, h, color, samecolor);
716     }
717 }
718 
719 static void find_best_solid_area(VncState *vs, int x, int y, int w, int h,
720                                  uint32_t color, int *w_ptr, int *h_ptr)
721 {
722     int dx, dy, dw, dh;
723     int w_prev;
724     int w_best = 0, h_best = 0;
725 
726     w_prev = w;
727 
728     for (dy = y; dy < y + h; dy += VNC_TIGHT_MAX_SPLIT_TILE_SIZE) {
729 
730         dh = MIN(VNC_TIGHT_MAX_SPLIT_TILE_SIZE, y + h - dy);
731         dw = MIN(VNC_TIGHT_MAX_SPLIT_TILE_SIZE, w_prev);
732 
733         if (!check_solid_tile(vs, x, dy, dw, dh, &color, true)) {
734             break;
735         }
736 
737         for (dx = x + dw; dx < x + w_prev;) {
738             dw = MIN(VNC_TIGHT_MAX_SPLIT_TILE_SIZE, x + w_prev - dx);
739 
740             if (!check_solid_tile(vs, dx, dy, dw, dh, &color, true)) {
741                 break;
742             }
743             dx += dw;
744         }
745 
746         w_prev = dx - x;
747         if (w_prev * (dy + dh - y) > w_best * h_best) {
748             w_best = w_prev;
749             h_best = dy + dh - y;
750         }
751     }
752 
753     *w_ptr = w_best;
754     *h_ptr = h_best;
755 }
756 
757 static void extend_solid_area(VncState *vs, int x, int y, int w, int h,
758                               uint32_t color, int *x_ptr, int *y_ptr,
759                               int *w_ptr, int *h_ptr)
760 {
761     int cx, cy;
762 
763     /* Try to extend the area upwards. */
764     for ( cy = *y_ptr - 1;
765           cy >= y && check_solid_tile(vs, *x_ptr, cy, *w_ptr, 1, &color, true);
766           cy-- );
767     *h_ptr += *y_ptr - (cy + 1);
768     *y_ptr = cy + 1;
769 
770     /* ... downwards. */
771     for ( cy = *y_ptr + *h_ptr;
772           cy < y + h &&
773               check_solid_tile(vs, *x_ptr, cy, *w_ptr, 1, &color, true);
774           cy++ );
775     *h_ptr += cy - (*y_ptr + *h_ptr);
776 
777     /* ... to the left. */
778     for ( cx = *x_ptr - 1;
779           cx >= x && check_solid_tile(vs, cx, *y_ptr, 1, *h_ptr, &color, true);
780           cx-- );
781     *w_ptr += *x_ptr - (cx + 1);
782     *x_ptr = cx + 1;
783 
784     /* ... to the right. */
785     for ( cx = *x_ptr + *w_ptr;
786           cx < x + w &&
787               check_solid_tile(vs, cx, *y_ptr, 1, *h_ptr, &color, true);
788           cx++ );
789     *w_ptr += cx - (*x_ptr + *w_ptr);
790 }
791 
792 static int tight_init_stream(VncState *vs, int stream_id,
793                              int level, int strategy)
794 {
795     z_streamp zstream = &vs->tight.stream[stream_id];
796 
797     if (zstream->opaque == NULL) {
798         int err;
799 
800         VNC_DEBUG("VNC: TIGHT: initializing zlib stream %d\n", stream_id);
801         VNC_DEBUG("VNC: TIGHT: opaque = %p | vs = %p\n", zstream->opaque, vs);
802         zstream->zalloc = vnc_zlib_zalloc;
803         zstream->zfree = vnc_zlib_zfree;
804 
805         err = deflateInit2(zstream, level, Z_DEFLATED, MAX_WBITS,
806                            MAX_MEM_LEVEL, strategy);
807 
808         if (err != Z_OK) {
809             fprintf(stderr, "VNC: error initializing zlib\n");
810             return -1;
811         }
812 
813         vs->tight.levels[stream_id] = level;
814         zstream->opaque = vs;
815     }
816 
817     if (vs->tight.levels[stream_id] != level) {
818         if (deflateParams(zstream, level, strategy) != Z_OK) {
819             return -1;
820         }
821         vs->tight.levels[stream_id] = level;
822     }
823     return 0;
824 }
825 
826 static void tight_send_compact_size(VncState *vs, size_t len)
827 {
828     int lpc = 0;
829     int bytes = 0;
830     char buf[3] = {0, 0, 0};
831 
832     buf[bytes++] = len & 0x7F;
833     if (len > 0x7F) {
834         buf[bytes-1] |= 0x80;
835         buf[bytes++] = (len >> 7) & 0x7F;
836         if (len > 0x3FFF) {
837             buf[bytes-1] |= 0x80;
838             buf[bytes++] = (len >> 14) & 0xFF;
839         }
840     }
841     for (lpc = 0; lpc < bytes; lpc++) {
842         vnc_write_u8(vs, buf[lpc]);
843     }
844 }
845 
846 static int tight_compress_data(VncState *vs, int stream_id, size_t bytes,
847                                int level, int strategy)
848 {
849     z_streamp zstream = &vs->tight.stream[stream_id];
850     int previous_out;
851 
852     if (bytes < VNC_TIGHT_MIN_TO_COMPRESS) {
853         vnc_write(vs, vs->tight.tight.buffer, vs->tight.tight.offset);
854         return bytes;
855     }
856 
857     if (tight_init_stream(vs, stream_id, level, strategy)) {
858         return -1;
859     }
860 
861     /* reserve memory in output buffer */
862     buffer_reserve(&vs->tight.zlib, bytes + 64);
863 
864     /* set pointers */
865     zstream->next_in = vs->tight.tight.buffer;
866     zstream->avail_in = vs->tight.tight.offset;
867     zstream->next_out = vs->tight.zlib.buffer + vs->tight.zlib.offset;
868     zstream->avail_out = vs->tight.zlib.capacity - vs->tight.zlib.offset;
869     previous_out = zstream->avail_out;
870     zstream->data_type = Z_BINARY;
871 
872     /* start encoding */
873     if (deflate(zstream, Z_SYNC_FLUSH) != Z_OK) {
874         fprintf(stderr, "VNC: error during tight compression\n");
875         return -1;
876     }
877 
878     vs->tight.zlib.offset = vs->tight.zlib.capacity - zstream->avail_out;
879     /* ...how much data has actually been produced by deflate() */
880     bytes = previous_out - zstream->avail_out;
881 
882     tight_send_compact_size(vs, bytes);
883     vnc_write(vs, vs->tight.zlib.buffer, bytes);
884 
885     buffer_reset(&vs->tight.zlib);
886 
887     return bytes;
888 }
889 
890 /*
891  * Subencoding implementations.
892  */
893 static void tight_pack24(VncState *vs, uint8_t *buf, size_t count, size_t *ret)
894 {
895     uint32_t *buf32;
896     uint32_t pix;
897     int rshift, gshift, bshift;
898 
899     buf32 = (uint32_t *)buf;
900 
901     if (1 /* FIXME: (vs->clientds.flags & QEMU_BIG_ENDIAN_FLAG) ==
902              (vs->ds->surface->flags & QEMU_BIG_ENDIAN_FLAG) */) {
903         rshift = vs->client_pf.rshift;
904         gshift = vs->client_pf.gshift;
905         bshift = vs->client_pf.bshift;
906     } else {
907         rshift = 24 - vs->client_pf.rshift;
908         gshift = 24 - vs->client_pf.gshift;
909         bshift = 24 - vs->client_pf.bshift;
910     }
911 
912     if (ret) {
913         *ret = count * 3;
914     }
915 
916     while (count--) {
917         pix = *buf32++;
918         *buf++ = (char)(pix >> rshift);
919         *buf++ = (char)(pix >> gshift);
920         *buf++ = (char)(pix >> bshift);
921     }
922 }
923 
924 static int send_full_color_rect(VncState *vs, int x, int y, int w, int h)
925 {
926     int stream = 0;
927     ssize_t bytes;
928 
929 #ifdef CONFIG_VNC_PNG
930     if (tight_can_send_png_rect(vs, w, h)) {
931         return send_png_rect(vs, x, y, w, h, NULL);
932     }
933 #endif
934 
935     vnc_write_u8(vs, stream << 4); /* no flushing, no filter */
936 
937     if (vs->tight.pixel24) {
938         tight_pack24(vs, vs->tight.tight.buffer, w * h, &vs->tight.tight.offset);
939         bytes = 3;
940     } else {
941         bytes = vs->client_pf.bytes_per_pixel;
942     }
943 
944     bytes = tight_compress_data(vs, stream, w * h * bytes,
945                                 tight_conf[vs->tight.compression].raw_zlib_level,
946                                 Z_DEFAULT_STRATEGY);
947 
948     return (bytes >= 0);
949 }
950 
951 static int send_solid_rect(VncState *vs)
952 {
953     size_t bytes;
954 
955     vnc_write_u8(vs, VNC_TIGHT_FILL << 4); /* no flushing, no filter */
956 
957     if (vs->tight.pixel24) {
958         tight_pack24(vs, vs->tight.tight.buffer, 1, &vs->tight.tight.offset);
959         bytes = 3;
960     } else {
961         bytes = vs->client_pf.bytes_per_pixel;
962     }
963 
964     vnc_write(vs, vs->tight.tight.buffer, bytes);
965     return 1;
966 }
967 
968 static int send_mono_rect(VncState *vs, int x, int y,
969                           int w, int h, uint32_t bg, uint32_t fg)
970 {
971     ssize_t bytes;
972     int stream = 1;
973     int level = tight_conf[vs->tight.compression].mono_zlib_level;
974 
975 #ifdef CONFIG_VNC_PNG
976     if (tight_can_send_png_rect(vs, w, h)) {
977         int ret;
978         int bpp = vs->client_pf.bytes_per_pixel * 8;
979         VncPalette *palette = palette_new(2, bpp);
980 
981         palette_put(palette, bg);
982         palette_put(palette, fg);
983         ret = send_png_rect(vs, x, y, w, h, palette);
984         palette_destroy(palette);
985         return ret;
986     }
987 #endif
988 
989     bytes = ((w + 7) / 8) * h;
990 
991     vnc_write_u8(vs, (stream | VNC_TIGHT_EXPLICIT_FILTER) << 4);
992     vnc_write_u8(vs, VNC_TIGHT_FILTER_PALETTE);
993     vnc_write_u8(vs, 1);
994 
995     switch (vs->client_pf.bytes_per_pixel) {
996     case 4:
997     {
998         uint32_t buf[2] = {bg, fg};
999         size_t ret = sizeof (buf);
1000 
1001         if (vs->tight.pixel24) {
1002             tight_pack24(vs, (unsigned char*)buf, 2, &ret);
1003         }
1004         vnc_write(vs, buf, ret);
1005 
1006         tight_encode_mono_rect32(vs->tight.tight.buffer, w, h, bg, fg);
1007         break;
1008     }
1009     case 2:
1010         vnc_write(vs, &bg, 2);
1011         vnc_write(vs, &fg, 2);
1012         tight_encode_mono_rect16(vs->tight.tight.buffer, w, h, bg, fg);
1013         break;
1014     default:
1015         vnc_write_u8(vs, bg);
1016         vnc_write_u8(vs, fg);
1017         tight_encode_mono_rect8(vs->tight.tight.buffer, w, h, bg, fg);
1018         break;
1019     }
1020     vs->tight.tight.offset = bytes;
1021 
1022     bytes = tight_compress_data(vs, stream, bytes, level, Z_DEFAULT_STRATEGY);
1023     return (bytes >= 0);
1024 }
1025 
1026 struct palette_cb_priv {
1027     VncState *vs;
1028     uint8_t *header;
1029 #ifdef CONFIG_VNC_PNG
1030     png_colorp png_palette;
1031 #endif
1032 };
1033 
1034 static void write_palette(int idx, uint32_t color, void *opaque)
1035 {
1036     struct palette_cb_priv *priv = opaque;
1037     VncState *vs = priv->vs;
1038     uint32_t bytes = vs->client_pf.bytes_per_pixel;
1039 
1040     if (bytes == 4) {
1041         ((uint32_t*)priv->header)[idx] = color;
1042     } else {
1043         ((uint16_t*)priv->header)[idx] = color;
1044     }
1045 }
1046 
1047 static bool send_gradient_rect(VncState *vs, int x, int y, int w, int h)
1048 {
1049     int stream = 3;
1050     int level = tight_conf[vs->tight.compression].gradient_zlib_level;
1051     ssize_t bytes;
1052 
1053     if (vs->client_pf.bytes_per_pixel == 1) {
1054         return send_full_color_rect(vs, x, y, w, h);
1055     }
1056 
1057     vnc_write_u8(vs, (stream | VNC_TIGHT_EXPLICIT_FILTER) << 4);
1058     vnc_write_u8(vs, VNC_TIGHT_FILTER_GRADIENT);
1059 
1060     buffer_reserve(&vs->tight.gradient, w * 3 * sizeof (int));
1061 
1062     if (vs->tight.pixel24) {
1063         tight_filter_gradient24(vs, vs->tight.tight.buffer, w, h);
1064         bytes = 3;
1065     } else if (vs->client_pf.bytes_per_pixel == 4) {
1066         tight_filter_gradient32(vs, (uint32_t *)vs->tight.tight.buffer, w, h);
1067         bytes = 4;
1068     } else {
1069         tight_filter_gradient16(vs, (uint16_t *)vs->tight.tight.buffer, w, h);
1070         bytes = 2;
1071     }
1072 
1073     buffer_reset(&vs->tight.gradient);
1074 
1075     bytes = w * h * bytes;
1076     vs->tight.tight.offset = bytes;
1077 
1078     bytes = tight_compress_data(vs, stream, bytes,
1079                                 level, Z_FILTERED);
1080     return (bytes >= 0);
1081 }
1082 
1083 static int send_palette_rect(VncState *vs, int x, int y,
1084                              int w, int h, VncPalette *palette)
1085 {
1086     int stream = 2;
1087     int level = tight_conf[vs->tight.compression].idx_zlib_level;
1088     int colors;
1089     ssize_t bytes;
1090 
1091 #ifdef CONFIG_VNC_PNG
1092     if (tight_can_send_png_rect(vs, w, h)) {
1093         return send_png_rect(vs, x, y, w, h, palette);
1094     }
1095 #endif
1096 
1097     colors = palette_size(palette);
1098 
1099     vnc_write_u8(vs, (stream | VNC_TIGHT_EXPLICIT_FILTER) << 4);
1100     vnc_write_u8(vs, VNC_TIGHT_FILTER_PALETTE);
1101     vnc_write_u8(vs, colors - 1);
1102 
1103     switch (vs->client_pf.bytes_per_pixel) {
1104     case 4:
1105     {
1106         size_t old_offset, offset;
1107         uint32_t header[palette_size(palette)];
1108         struct palette_cb_priv priv = { vs, (uint8_t *)header };
1109 
1110         old_offset = vs->output.offset;
1111         palette_iter(palette, write_palette, &priv);
1112         vnc_write(vs, header, sizeof(header));
1113 
1114         if (vs->tight.pixel24) {
1115             tight_pack24(vs, vs->output.buffer + old_offset, colors, &offset);
1116             vs->output.offset = old_offset + offset;
1117         }
1118 
1119         tight_encode_indexed_rect32(vs->tight.tight.buffer, w * h, palette);
1120         break;
1121     }
1122     case 2:
1123     {
1124         uint16_t header[palette_size(palette)];
1125         struct palette_cb_priv priv = { vs, (uint8_t *)header };
1126 
1127         palette_iter(palette, write_palette, &priv);
1128         vnc_write(vs, header, sizeof(header));
1129         tight_encode_indexed_rect16(vs->tight.tight.buffer, w * h, palette);
1130         break;
1131     }
1132     default:
1133         return -1; /* No palette for 8bits colors */
1134         break;
1135     }
1136     bytes = w * h;
1137     vs->tight.tight.offset = bytes;
1138 
1139     bytes = tight_compress_data(vs, stream, bytes,
1140                                 level, Z_DEFAULT_STRATEGY);
1141     return (bytes >= 0);
1142 }
1143 
1144 /*
1145  * JPEG compression stuff.
1146  */
1147 #ifdef CONFIG_VNC_JPEG
1148 /*
1149  * Destination manager implementation for JPEG library.
1150  */
1151 
1152 /* This is called once per encoding */
1153 static void jpeg_init_destination(j_compress_ptr cinfo)
1154 {
1155     VncState *vs = cinfo->client_data;
1156     Buffer *buffer = &vs->tight.jpeg;
1157 
1158     cinfo->dest->next_output_byte = (JOCTET *)buffer->buffer + buffer->offset;
1159     cinfo->dest->free_in_buffer = (size_t)(buffer->capacity - buffer->offset);
1160 }
1161 
1162 /* This is called when we ran out of buffer (shouldn't happen!) */
1163 static boolean jpeg_empty_output_buffer(j_compress_ptr cinfo)
1164 {
1165     VncState *vs = cinfo->client_data;
1166     Buffer *buffer = &vs->tight.jpeg;
1167 
1168     buffer->offset = buffer->capacity;
1169     buffer_reserve(buffer, 2048);
1170     jpeg_init_destination(cinfo);
1171     return TRUE;
1172 }
1173 
1174 /* This is called when we are done processing data */
1175 static void jpeg_term_destination(j_compress_ptr cinfo)
1176 {
1177     VncState *vs = cinfo->client_data;
1178     Buffer *buffer = &vs->tight.jpeg;
1179 
1180     buffer->offset = buffer->capacity - cinfo->dest->free_in_buffer;
1181 }
1182 
1183 static int send_jpeg_rect(VncState *vs, int x, int y, int w, int h, int quality)
1184 {
1185     struct jpeg_compress_struct cinfo;
1186     struct jpeg_error_mgr jerr;
1187     struct jpeg_destination_mgr manager;
1188     pixman_image_t *linebuf;
1189     JSAMPROW row[1];
1190     uint8_t *buf;
1191     int dy;
1192 
1193     if (surface_bytes_per_pixel(vs->vd->ds) == 1) {
1194         return send_full_color_rect(vs, x, y, w, h);
1195     }
1196 
1197     buffer_reserve(&vs->tight.jpeg, 2048);
1198 
1199     cinfo.err = jpeg_std_error(&jerr);
1200     jpeg_create_compress(&cinfo);
1201 
1202     cinfo.client_data = vs;
1203     cinfo.image_width = w;
1204     cinfo.image_height = h;
1205     cinfo.input_components = 3;
1206     cinfo.in_color_space = JCS_RGB;
1207 
1208     jpeg_set_defaults(&cinfo);
1209     jpeg_set_quality(&cinfo, quality, true);
1210 
1211     manager.init_destination = jpeg_init_destination;
1212     manager.empty_output_buffer = jpeg_empty_output_buffer;
1213     manager.term_destination = jpeg_term_destination;
1214     cinfo.dest = &manager;
1215 
1216     jpeg_start_compress(&cinfo, true);
1217 
1218     linebuf = qemu_pixman_linebuf_create(PIXMAN_BE_r8g8b8, w);
1219     buf = (uint8_t *)pixman_image_get_data(linebuf);
1220     row[0] = buf;
1221     for (dy = 0; dy < h; dy++) {
1222         qemu_pixman_linebuf_fill(linebuf, vs->vd->server, w, x, y + dy);
1223         jpeg_write_scanlines(&cinfo, row, 1);
1224     }
1225     qemu_pixman_image_unref(linebuf);
1226 
1227     jpeg_finish_compress(&cinfo);
1228     jpeg_destroy_compress(&cinfo);
1229 
1230     vnc_write_u8(vs, VNC_TIGHT_JPEG << 4);
1231 
1232     tight_send_compact_size(vs, vs->tight.jpeg.offset);
1233     vnc_write(vs, vs->tight.jpeg.buffer, vs->tight.jpeg.offset);
1234     buffer_reset(&vs->tight.jpeg);
1235 
1236     return 1;
1237 }
1238 #endif /* CONFIG_VNC_JPEG */
1239 
1240 /*
1241  * PNG compression stuff.
1242  */
1243 #ifdef CONFIG_VNC_PNG
1244 static void write_png_palette(int idx, uint32_t pix, void *opaque)
1245 {
1246     struct palette_cb_priv *priv = opaque;
1247     VncState *vs = priv->vs;
1248     png_colorp color = &priv->png_palette[idx];
1249 
1250     if (vs->tight.pixel24)
1251     {
1252         color->red = (pix >> vs->client_pf.rshift) & vs->client_pf.rmax;
1253         color->green = (pix >> vs->client_pf.gshift) & vs->client_pf.gmax;
1254         color->blue = (pix >> vs->client_pf.bshift) & vs->client_pf.bmax;
1255     }
1256     else
1257     {
1258         int red, green, blue;
1259 
1260         red = (pix >> vs->client_pf.rshift) & vs->client_pf.rmax;
1261         green = (pix >> vs->client_pf.gshift) & vs->client_pf.gmax;
1262         blue = (pix >> vs->client_pf.bshift) & vs->client_pf.bmax;
1263         color->red = ((red * 255 + vs->client_pf.rmax / 2) /
1264                       vs->client_pf.rmax);
1265         color->green = ((green * 255 + vs->client_pf.gmax / 2) /
1266                         vs->client_pf.gmax);
1267         color->blue = ((blue * 255 + vs->client_pf.bmax / 2) /
1268                        vs->client_pf.bmax);
1269     }
1270 }
1271 
1272 static void png_write_data(png_structp png_ptr, png_bytep data,
1273                            png_size_t length)
1274 {
1275     VncState *vs = png_get_io_ptr(png_ptr);
1276 
1277     buffer_reserve(&vs->tight.png, vs->tight.png.offset + length);
1278     memcpy(vs->tight.png.buffer + vs->tight.png.offset, data, length);
1279 
1280     vs->tight.png.offset += length;
1281 }
1282 
1283 static void png_flush_data(png_structp png_ptr)
1284 {
1285 }
1286 
1287 static void *vnc_png_malloc(png_structp png_ptr, png_size_t size)
1288 {
1289     return g_malloc(size);
1290 }
1291 
1292 static void vnc_png_free(png_structp png_ptr, png_voidp ptr)
1293 {
1294     g_free(ptr);
1295 }
1296 
1297 static int send_png_rect(VncState *vs, int x, int y, int w, int h,
1298                          VncPalette *palette)
1299 {
1300     png_byte color_type;
1301     png_structp png_ptr;
1302     png_infop info_ptr;
1303     png_colorp png_palette = NULL;
1304     pixman_image_t *linebuf;
1305     int level = tight_png_conf[vs->tight.compression].png_zlib_level;
1306     int filters = tight_png_conf[vs->tight.compression].png_filters;
1307     uint8_t *buf;
1308     int dy;
1309 
1310     png_ptr = png_create_write_struct_2(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL,
1311                                         NULL, vnc_png_malloc, vnc_png_free);
1312 
1313     if (png_ptr == NULL)
1314         return -1;
1315 
1316     info_ptr = png_create_info_struct(png_ptr);
1317 
1318     if (info_ptr == NULL) {
1319         png_destroy_write_struct(&png_ptr, NULL);
1320         return -1;
1321     }
1322 
1323     png_set_write_fn(png_ptr, (void *) vs, png_write_data, png_flush_data);
1324     png_set_compression_level(png_ptr, level);
1325     png_set_filter(png_ptr, PNG_FILTER_TYPE_DEFAULT, filters);
1326 
1327     if (palette) {
1328         color_type = PNG_COLOR_TYPE_PALETTE;
1329     } else {
1330         color_type = PNG_COLOR_TYPE_RGB;
1331     }
1332 
1333     png_set_IHDR(png_ptr, info_ptr, w, h,
1334                  8, color_type, PNG_INTERLACE_NONE,
1335                  PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
1336 
1337     if (color_type == PNG_COLOR_TYPE_PALETTE) {
1338         struct palette_cb_priv priv;
1339 
1340         png_palette = png_malloc(png_ptr, sizeof(*png_palette) *
1341                                  palette_size(palette));
1342 
1343         priv.vs = vs;
1344         priv.png_palette = png_palette;
1345         palette_iter(palette, write_png_palette, &priv);
1346 
1347         png_set_PLTE(png_ptr, info_ptr, png_palette, palette_size(palette));
1348 
1349         if (vs->client_pf.bytes_per_pixel == 4) {
1350             tight_encode_indexed_rect32(vs->tight.tight.buffer, w * h, palette);
1351         } else {
1352             tight_encode_indexed_rect16(vs->tight.tight.buffer, w * h, palette);
1353         }
1354     }
1355 
1356     png_write_info(png_ptr, info_ptr);
1357 
1358     buffer_reserve(&vs->tight.png, 2048);
1359     linebuf = qemu_pixman_linebuf_create(PIXMAN_BE_r8g8b8, w);
1360     buf = (uint8_t *)pixman_image_get_data(linebuf);
1361     for (dy = 0; dy < h; dy++)
1362     {
1363         if (color_type == PNG_COLOR_TYPE_PALETTE) {
1364             memcpy(buf, vs->tight.tight.buffer + (dy * w), w);
1365         } else {
1366             qemu_pixman_linebuf_fill(linebuf, vs->vd->server, w, x, y + dy);
1367         }
1368         png_write_row(png_ptr, buf);
1369     }
1370     qemu_pixman_image_unref(linebuf);
1371 
1372     png_write_end(png_ptr, NULL);
1373 
1374     if (color_type == PNG_COLOR_TYPE_PALETTE) {
1375         png_free(png_ptr, png_palette);
1376     }
1377 
1378     png_destroy_write_struct(&png_ptr, &info_ptr);
1379 
1380     vnc_write_u8(vs, VNC_TIGHT_PNG << 4);
1381 
1382     tight_send_compact_size(vs, vs->tight.png.offset);
1383     vnc_write(vs, vs->tight.png.buffer, vs->tight.png.offset);
1384     buffer_reset(&vs->tight.png);
1385     return 1;
1386 }
1387 #endif /* CONFIG_VNC_PNG */
1388 
1389 static void vnc_tight_start(VncState *vs)
1390 {
1391     buffer_reset(&vs->tight.tight);
1392 
1393     // make the output buffer be the zlib buffer, so we can compress it later
1394     vs->tight.tmp = vs->output;
1395     vs->output = vs->tight.tight;
1396 }
1397 
1398 static void vnc_tight_stop(VncState *vs)
1399 {
1400     // switch back to normal output/zlib buffers
1401     vs->tight.tight = vs->output;
1402     vs->output = vs->tight.tmp;
1403 }
1404 
1405 static int send_sub_rect_nojpeg(VncState *vs, int x, int y, int w, int h,
1406                                 int bg, int fg, int colors, VncPalette *palette)
1407 {
1408     int ret;
1409 
1410     if (colors == 0) {
1411         if (tight_detect_smooth_image(vs, w, h)) {
1412             ret = send_gradient_rect(vs, x, y, w, h);
1413         } else {
1414             ret = send_full_color_rect(vs, x, y, w, h);
1415         }
1416     } else if (colors == 1) {
1417         ret = send_solid_rect(vs);
1418     } else if (colors == 2) {
1419         ret = send_mono_rect(vs, x, y, w, h, bg, fg);
1420     } else if (colors <= 256) {
1421         ret = send_palette_rect(vs, x, y, w, h, palette);
1422     } else {
1423         ret = 0;
1424     }
1425     return ret;
1426 }
1427 
1428 #ifdef CONFIG_VNC_JPEG
1429 static int send_sub_rect_jpeg(VncState *vs, int x, int y, int w, int h,
1430                               int bg, int fg, int colors,
1431                               VncPalette *palette, bool force)
1432 {
1433     int ret;
1434 
1435     if (colors == 0) {
1436         if (force || (tight_jpeg_conf[vs->tight.quality].jpeg_full &&
1437                       tight_detect_smooth_image(vs, w, h))) {
1438             int quality = tight_conf[vs->tight.quality].jpeg_quality;
1439 
1440             ret = send_jpeg_rect(vs, x, y, w, h, quality);
1441         } else {
1442             ret = send_full_color_rect(vs, x, y, w, h);
1443         }
1444     } else if (colors == 1) {
1445         ret = send_solid_rect(vs);
1446     } else if (colors == 2) {
1447         ret = send_mono_rect(vs, x, y, w, h, bg, fg);
1448     } else if (colors <= 256) {
1449         if (force || (colors > 96 &&
1450                       tight_jpeg_conf[vs->tight.quality].jpeg_idx &&
1451                       tight_detect_smooth_image(vs, w, h))) {
1452             int quality = tight_conf[vs->tight.quality].jpeg_quality;
1453 
1454             ret = send_jpeg_rect(vs, x, y, w, h, quality);
1455         } else {
1456             ret = send_palette_rect(vs, x, y, w, h, palette);
1457         }
1458     } else {
1459         ret = 0;
1460     }
1461     return ret;
1462 }
1463 #endif
1464 
1465 static int send_sub_rect(VncState *vs, int x, int y, int w, int h)
1466 {
1467     VncPalette *palette = NULL;
1468     uint32_t bg = 0, fg = 0;
1469     int colors;
1470     int ret = 0;
1471 #ifdef CONFIG_VNC_JPEG
1472     bool force_jpeg = false;
1473     bool allow_jpeg = true;
1474 #endif
1475 
1476     vnc_framebuffer_update(vs, x, y, w, h, vs->tight.type);
1477 
1478     vnc_tight_start(vs);
1479     vnc_raw_send_framebuffer_update(vs, x, y, w, h);
1480     vnc_tight_stop(vs);
1481 
1482 #ifdef CONFIG_VNC_JPEG
1483     if (!vs->vd->non_adaptive && vs->tight.quality != (uint8_t)-1) {
1484         double freq = vnc_update_freq(vs, x, y, w, h);
1485 
1486         if (freq < tight_jpeg_conf[vs->tight.quality].jpeg_freq_min) {
1487             allow_jpeg = false;
1488         }
1489         if (freq >= tight_jpeg_conf[vs->tight.quality].jpeg_freq_threshold) {
1490             force_jpeg = true;
1491             vnc_sent_lossy_rect(vs, x, y, w, h);
1492         }
1493     }
1494 #endif
1495 
1496     colors = tight_fill_palette(vs, x, y, w * h, &fg, &bg, &palette);
1497 
1498 #ifdef CONFIG_VNC_JPEG
1499     if (allow_jpeg && vs->tight.quality != (uint8_t)-1) {
1500         ret = send_sub_rect_jpeg(vs, x, y, w, h, bg, fg, colors, palette,
1501                                  force_jpeg);
1502     } else {
1503         ret = send_sub_rect_nojpeg(vs, x, y, w, h, bg, fg, colors, palette);
1504     }
1505 #else
1506     ret = send_sub_rect_nojpeg(vs, x, y, w, h, bg, fg, colors, palette);
1507 #endif
1508 
1509     palette_destroy(palette);
1510     return ret;
1511 }
1512 
1513 static int send_sub_rect_solid(VncState *vs, int x, int y, int w, int h)
1514 {
1515     vnc_framebuffer_update(vs, x, y, w, h, vs->tight.type);
1516 
1517     vnc_tight_start(vs);
1518     vnc_raw_send_framebuffer_update(vs, x, y, w, h);
1519     vnc_tight_stop(vs);
1520 
1521     return send_solid_rect(vs);
1522 }
1523 
1524 static int send_rect_simple(VncState *vs, int x, int y, int w, int h,
1525                             bool split)
1526 {
1527     int max_size, max_width;
1528     int max_sub_width, max_sub_height;
1529     int dx, dy;
1530     int rw, rh;
1531     int n = 0;
1532 
1533     max_size = tight_conf[vs->tight.compression].max_rect_size;
1534     max_width = tight_conf[vs->tight.compression].max_rect_width;
1535 
1536     if (split && (w > max_width || w * h > max_size)) {
1537         max_sub_width = (w > max_width) ? max_width : w;
1538         max_sub_height = max_size / max_sub_width;
1539 
1540         for (dy = 0; dy < h; dy += max_sub_height) {
1541             for (dx = 0; dx < w; dx += max_width) {
1542                 rw = MIN(max_sub_width, w - dx);
1543                 rh = MIN(max_sub_height, h - dy);
1544                 n += send_sub_rect(vs, x+dx, y+dy, rw, rh);
1545             }
1546         }
1547     } else {
1548         n += send_sub_rect(vs, x, y, w, h);
1549     }
1550 
1551     return n;
1552 }
1553 
1554 static int find_large_solid_color_rect(VncState *vs, int x, int y,
1555                                        int w, int h, int max_rows)
1556 {
1557     int dx, dy, dw, dh;
1558     int n = 0;
1559 
1560     /* Try to find large solid-color areas and send them separately. */
1561 
1562     for (dy = y; dy < y + h; dy += VNC_TIGHT_MAX_SPLIT_TILE_SIZE) {
1563 
1564         /* If a rectangle becomes too large, send its upper part now. */
1565 
1566         if (dy - y >= max_rows) {
1567             n += send_rect_simple(vs, x, y, w, max_rows, true);
1568             y += max_rows;
1569             h -= max_rows;
1570         }
1571 
1572         dh = MIN(VNC_TIGHT_MAX_SPLIT_TILE_SIZE, (y + h - dy));
1573 
1574         for (dx = x; dx < x + w; dx += VNC_TIGHT_MAX_SPLIT_TILE_SIZE) {
1575             uint32_t color_value;
1576             int x_best, y_best, w_best, h_best;
1577 
1578             dw = MIN(VNC_TIGHT_MAX_SPLIT_TILE_SIZE, (x + w - dx));
1579 
1580             if (!check_solid_tile(vs, dx, dy, dw, dh, &color_value, false)) {
1581                 continue ;
1582             }
1583 
1584             /* Get dimensions of solid-color area. */
1585 
1586             find_best_solid_area(vs, dx, dy, w - (dx - x), h - (dy - y),
1587                                  color_value, &w_best, &h_best);
1588 
1589             /* Make sure a solid rectangle is large enough
1590                (or the whole rectangle is of the same color). */
1591 
1592             if (w_best * h_best != w * h &&
1593                 w_best * h_best < VNC_TIGHT_MIN_SOLID_SUBRECT_SIZE) {
1594                 continue;
1595             }
1596 
1597             /* Try to extend solid rectangle to maximum size. */
1598 
1599             x_best = dx; y_best = dy;
1600             extend_solid_area(vs, x, y, w, h, color_value,
1601                               &x_best, &y_best, &w_best, &h_best);
1602 
1603             /* Send rectangles at top and left to solid-color area. */
1604 
1605             if (y_best != y) {
1606                 n += send_rect_simple(vs, x, y, w, y_best-y, true);
1607             }
1608             if (x_best != x) {
1609                 n += tight_send_framebuffer_update(vs, x, y_best,
1610                                                    x_best-x, h_best);
1611             }
1612 
1613             /* Send solid-color rectangle. */
1614             n += send_sub_rect_solid(vs, x_best, y_best, w_best, h_best);
1615 
1616             /* Send remaining rectangles (at right and bottom). */
1617 
1618             if (x_best + w_best != x + w) {
1619                 n += tight_send_framebuffer_update(vs, x_best+w_best,
1620                                                    y_best,
1621                                                    w-(x_best-x)-w_best,
1622                                                    h_best);
1623             }
1624             if (y_best + h_best != y + h) {
1625                 n += tight_send_framebuffer_update(vs, x, y_best+h_best,
1626                                                    w, h-(y_best-y)-h_best);
1627             }
1628 
1629             /* Return after all recursive calls are done. */
1630             return n;
1631         }
1632     }
1633     return n + send_rect_simple(vs, x, y, w, h, true);
1634 }
1635 
1636 static int tight_send_framebuffer_update(VncState *vs, int x, int y,
1637                                          int w, int h)
1638 {
1639     int max_rows;
1640 
1641     if (vs->client_pf.bytes_per_pixel == 4 && vs->client_pf.rmax == 0xFF &&
1642         vs->client_pf.bmax == 0xFF && vs->client_pf.gmax == 0xFF) {
1643         vs->tight.pixel24 = true;
1644     } else {
1645         vs->tight.pixel24 = false;
1646     }
1647 
1648 #ifdef CONFIG_VNC_JPEG
1649     if (vs->tight.quality != (uint8_t)-1) {
1650         double freq = vnc_update_freq(vs, x, y, w, h);
1651 
1652         if (freq > tight_jpeg_conf[vs->tight.quality].jpeg_freq_threshold) {
1653             return send_rect_simple(vs, x, y, w, h, false);
1654         }
1655     }
1656 #endif
1657 
1658     if (w * h < VNC_TIGHT_MIN_SPLIT_RECT_SIZE) {
1659         return send_rect_simple(vs, x, y, w, h, true);
1660     }
1661 
1662     /* Calculate maximum number of rows in one non-solid rectangle. */
1663 
1664     max_rows = tight_conf[vs->tight.compression].max_rect_size;
1665     max_rows /= MIN(tight_conf[vs->tight.compression].max_rect_width, w);
1666 
1667     return find_large_solid_color_rect(vs, x, y, w, h, max_rows);
1668 }
1669 
1670 int vnc_tight_send_framebuffer_update(VncState *vs, int x, int y,
1671                                       int w, int h)
1672 {
1673     vs->tight.type = VNC_ENCODING_TIGHT;
1674     return tight_send_framebuffer_update(vs, x, y, w, h);
1675 }
1676 
1677 int vnc_tight_png_send_framebuffer_update(VncState *vs, int x, int y,
1678                                           int w, int h)
1679 {
1680     vs->tight.type = VNC_ENCODING_TIGHT_PNG;
1681     return tight_send_framebuffer_update(vs, x, y, w, h);
1682 }
1683 
1684 void vnc_tight_clear(VncState *vs)
1685 {
1686     int i;
1687     for (i=0; i<ARRAY_SIZE(vs->tight.stream); i++) {
1688         if (vs->tight.stream[i].opaque) {
1689             deflateEnd(&vs->tight.stream[i]);
1690         }
1691     }
1692 
1693     buffer_free(&vs->tight.tight);
1694     buffer_free(&vs->tight.zlib);
1695     buffer_free(&vs->tight.gradient);
1696 #ifdef CONFIG_VNC_JPEG
1697     buffer_free(&vs->tight.jpeg);
1698 #endif
1699 #ifdef CONFIG_VNC_PNG
1700     buffer_free(&vs->tight.png);
1701 #endif
1702 }
1703