xref: /openbmc/qemu/ui/vnc-enc-tight.c (revision 7f623d08)
1 /*
2  * QEMU VNC display driver: tight encoding
3  *
4  * From libvncserver/libvncserver/tight.c
5  * Copyright (C) 2000, 2001 Const Kaplinsky.  All Rights Reserved.
6  * Copyright (C) 1999 AT&T Laboratories Cambridge.  All Rights Reserved.
7  *
8  * Copyright (C) 2010 Corentin Chary <corentin.chary@gmail.com>
9  *
10  * Permission is hereby granted, free of charge, to any person obtaining a copy
11  * of this software and associated documentation files (the "Software"), to deal
12  * in the Software without restriction, including without limitation the rights
13  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
14  * copies of the Software, and to permit persons to whom the Software is
15  * furnished to do so, subject to the following conditions:
16  *
17  * The above copyright notice and this permission notice shall be included in
18  * all copies or substantial portions of the Software.
19  *
20  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
21  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
23  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
24  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
25  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
26  * THE SOFTWARE.
27  */
28 
29 #include "qemu/osdep.h"
30 
31 /* This needs to be before jpeglib.h line because of conflict with
32    INT32 definitions between jmorecfg.h (included by jpeglib.h) and
33    Win32 basetsd.h (included by windows.h). */
34 #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 <jpeglib.h>
44 #endif
45 
46 #include "qemu/bswap.h"
47 #include "vnc.h"
48 #include "vnc-enc-tight.h"
49 #include "vnc-palette.h"
50 
51 /* Compression level stuff. The following array contains various
52    encoder parameters for each of 10 compression levels (0..9).
53    Last three parameters correspond to JPEG quality levels (0..9). */
54 
55 static const struct {
56     int max_rect_size, max_rect_width;
57     int mono_min_rect_size, gradient_min_rect_size;
58     int idx_zlib_level, mono_zlib_level, raw_zlib_level, gradient_zlib_level;
59     int gradient_threshold, gradient_threshold24;
60     int idx_max_colors_divisor;
61     int jpeg_quality, jpeg_threshold, jpeg_threshold24;
62 } tight_conf[] = {
63     {   512,   32,   6, 65536, 0, 0, 0, 0,   0,   0,   4,  5, 10000, 23000 },
64     {  2048,  128,   6, 65536, 1, 1, 1, 0,   0,   0,   8, 10,  8000, 18000 },
65     {  6144,  256,   8, 65536, 3, 3, 2, 0,   0,   0,  24, 15,  6500, 15000 },
66     { 10240, 1024,  12, 65536, 5, 5, 3, 0,   0,   0,  32, 25,  5000, 12000 },
67     { 16384, 2048,  12, 65536, 6, 6, 4, 0,   0,   0,  32, 37,  4000, 10000 },
68     { 32768, 2048,  12,  4096, 7, 7, 5, 4, 150, 380,  32, 50,  3000,  8000 },
69     { 65536, 2048,  16,  4096, 7, 7, 6, 4, 170, 420,  48, 60,  2000,  5000 },
70     { 65536, 2048,  16,  4096, 8, 8, 7, 5, 180, 450,  64, 70,  1000,  2500 },
71     { 65536, 2048,  32,  8192, 9, 9, 8, 6, 190, 475,  64, 75,   500,  1200 },
72     { 65536, 2048,  32,  8192, 9, 9, 9, 6, 200, 500,  96, 80,   200,   500 }
73 };
74 
75 
76 static int tight_send_framebuffer_update(VncState *vs, int x, int y,
77                                          int w, int h);
78 
79 #ifdef CONFIG_VNC_JPEG
80 static const struct {
81     double jpeg_freq_min;       /* Don't send JPEG if the freq is bellow */
82     double jpeg_freq_threshold; /* Always send JPEG if the freq is above */
83     int jpeg_idx;               /* Allow indexed JPEG */
84     int jpeg_full;              /* Allow full color JPEG */
85 } tight_jpeg_conf[] = {
86     { 0,   8,  1, 1 },
87     { 0,   8,  1, 1 },
88     { 0,   8,  1, 1 },
89     { 0,   8,  1, 1 },
90     { 0,   10, 1, 1 },
91     { 0.1, 10, 1, 1 },
92     { 0.2, 10, 1, 1 },
93     { 0.3, 12, 0, 0 },
94     { 0.4, 14, 0, 0 },
95     { 0.5, 16, 0, 0 },
96 };
97 #endif
98 
99 #ifdef CONFIG_VNC_PNG
100 static const struct {
101     int png_zlib_level, png_filters;
102 } tight_png_conf[] = {
103     { 0, PNG_NO_FILTERS },
104     { 1, PNG_NO_FILTERS },
105     { 2, PNG_NO_FILTERS },
106     { 3, PNG_NO_FILTERS },
107     { 4, PNG_NO_FILTERS },
108     { 5, PNG_ALL_FILTERS },
109     { 6, PNG_ALL_FILTERS },
110     { 7, PNG_ALL_FILTERS },
111     { 8, PNG_ALL_FILTERS },
112     { 9, PNG_ALL_FILTERS },
113 };
114 
115 static int send_png_rect(VncState *vs, int x, int y, int w, int h,
116                          VncPalette *palette);
117 
118 static bool tight_can_send_png_rect(VncState *vs, int w, int h)
119 {
120     if (vs->tight.type != VNC_ENCODING_TIGHT_PNG) {
121         return false;
122     }
123 
124     if (surface_bytes_per_pixel(vs->vd->ds) == 1 ||
125         vs->client_pf.bytes_per_pixel == 1) {
126         return false;
127     }
128 
129     return true;
130 }
131 #endif
132 
133 /*
134  * Code to guess if given rectangle is suitable for smooth image
135  * compression (by applying "gradient" filter or JPEG coder).
136  */
137 
138 static unsigned int
139 tight_detect_smooth_image24(VncState *vs, int w, int h)
140 {
141     int off;
142     int x, y, d, dx;
143     unsigned int c;
144     unsigned int stats[256];
145     int pixels = 0;
146     int pix, left[3];
147     unsigned int errors;
148     unsigned char *buf = vs->tight.tight.buffer;
149 
150     /*
151      * If client is big-endian, color samples begin from the second
152      * byte (offset 1) of a 32-bit pixel value.
153      */
154     off = vs->client_be;
155 
156     memset(stats, 0, sizeof (stats));
157 
158     for (y = 0, x = 0; y < h && x < w;) {
159         for (d = 0; d < h - y && d < w - x - VNC_TIGHT_DETECT_SUBROW_WIDTH;
160              d++) {
161             for (c = 0; c < 3; c++) {
162                 left[c] = buf[((y+d)*w+x+d)*4+off+c] & 0xFF;
163             }
164             for (dx = 1; dx <= VNC_TIGHT_DETECT_SUBROW_WIDTH; dx++) {
165                 for (c = 0; c < 3; c++) {
166                     pix = buf[((y+d)*w+x+d+dx)*4+off+c] & 0xFF;
167                     stats[abs(pix - left[c])]++;
168                     left[c] = pix;
169                 }
170                 pixels++;
171             }
172         }
173         if (w > h) {
174             x += h;
175             y = 0;
176         } else {
177             x = 0;
178             y += w;
179         }
180     }
181 
182     if (pixels == 0) {
183         return 0;
184     }
185 
186     /* 95% smooth or more ... */
187     if (stats[0] * 33 / pixels >= 95) {
188         return 0;
189     }
190 
191     errors = 0;
192     for (c = 1; c < 8; c++) {
193         errors += stats[c] * (c * c);
194         if (stats[c] == 0 || stats[c] > stats[c-1] * 2) {
195             return 0;
196         }
197     }
198     for (; c < 256; c++) {
199         errors += stats[c] * (c * c);
200     }
201     errors /= (pixels * 3 - stats[0]);
202 
203     return errors;
204 }
205 
206 #define DEFINE_DETECT_FUNCTION(bpp)                                     \
207                                                                         \
208     static unsigned int                                                 \
209     tight_detect_smooth_image##bpp(VncState *vs, int w, int h) {        \
210         bool endian;                                                    \
211         uint##bpp##_t pix;                                              \
212         int max[3], shift[3];                                           \
213         int x, y, d, dx;                                                \
214         unsigned int c;                                                 \
215         unsigned int stats[256];                                        \
216         int pixels = 0;                                                 \
217         int sample, sum, left[3];                                       \
218         unsigned int errors;                                            \
219         unsigned char *buf = vs->tight.tight.buffer;                    \
220                                                                         \
221         endian = 0; /* FIXME */                                         \
222                                                                         \
223                                                                         \
224         max[0] = vs->client_pf.rmax;                                  \
225         max[1] = vs->client_pf.gmax;                                  \
226         max[2] = vs->client_pf.bmax;                                  \
227         shift[0] = vs->client_pf.rshift;                              \
228         shift[1] = vs->client_pf.gshift;                              \
229         shift[2] = vs->client_pf.bshift;                              \
230                                                                         \
231         memset(stats, 0, sizeof(stats));                                \
232                                                                         \
233         y = 0, x = 0;                                                   \
234         while (y < h && x < w) {                                        \
235             for (d = 0; d < h - y &&                                    \
236                      d < w - x - VNC_TIGHT_DETECT_SUBROW_WIDTH; d++) {  \
237                 pix = ((uint##bpp##_t *)buf)[(y+d)*w+x+d];              \
238                 if (endian) {                                           \
239                     pix = bswap##bpp(pix);                              \
240                 }                                                       \
241                 for (c = 0; c < 3; c++) {                               \
242                     left[c] = (int)(pix >> shift[c] & max[c]);          \
243                 }                                                       \
244                 for (dx = 1; dx <= VNC_TIGHT_DETECT_SUBROW_WIDTH;       \
245                      dx++) {                                            \
246                     pix = ((uint##bpp##_t *)buf)[(y+d)*w+x+d+dx];       \
247                     if (endian) {                                       \
248                         pix = bswap##bpp(pix);                          \
249                     }                                                   \
250                     sum = 0;                                            \
251                     for (c = 0; c < 3; c++) {                           \
252                         sample = (int)(pix >> shift[c] & max[c]);       \
253                         sum += abs(sample - left[c]);                   \
254                         left[c] = sample;                               \
255                     }                                                   \
256                     if (sum > 255) {                                    \
257                         sum = 255;                                      \
258                     }                                                   \
259                     stats[sum]++;                                       \
260                     pixels++;                                           \
261                 }                                                       \
262             }                                                           \
263             if (w > h) {                                                \
264                 x += h;                                                 \
265                 y = 0;                                                  \
266             } else {                                                    \
267                 x = 0;                                                  \
268                 y += w;                                                 \
269             }                                                           \
270         }                                                               \
271         if (pixels == 0) {                                              \
272             return 0;                                                   \
273         }                                                               \
274         if ((stats[0] + stats[1]) * 100 / pixels >= 90) {               \
275             return 0;                                                   \
276         }                                                               \
277                                                                         \
278         errors = 0;                                                     \
279         for (c = 1; c < 8; c++) {                                       \
280             errors += stats[c] * (c * c);                               \
281             if (stats[c] == 0 || stats[c] > stats[c-1] * 2) {           \
282                 return 0;                                               \
283             }                                                           \
284         }                                                               \
285         for (; c < 256; c++) {                                          \
286             errors += stats[c] * (c * c);                               \
287         }                                                               \
288         errors /= (pixels - stats[0]);                                  \
289                                                                         \
290         return errors;                                                  \
291     }
292 
293 DEFINE_DETECT_FUNCTION(16)
294 DEFINE_DETECT_FUNCTION(32)
295 
296 static int
297 tight_detect_smooth_image(VncState *vs, int w, int h)
298 {
299     unsigned int errors;
300     int compression = vs->tight.compression;
301     int quality = vs->tight.quality;
302 
303     if (!vs->vd->lossy) {
304         return 0;
305     }
306 
307     if (surface_bytes_per_pixel(vs->vd->ds) == 1 ||
308         vs->client_pf.bytes_per_pixel == 1 ||
309         w < VNC_TIGHT_DETECT_MIN_WIDTH || h < VNC_TIGHT_DETECT_MIN_HEIGHT) {
310         return 0;
311     }
312 
313     if (vs->tight.quality != (uint8_t)-1) {
314         if (w * h < VNC_TIGHT_JPEG_MIN_RECT_SIZE) {
315             return 0;
316         }
317     } else {
318         if (w * h < tight_conf[compression].gradient_min_rect_size) {
319             return 0;
320         }
321     }
322 
323     if (vs->client_pf.bytes_per_pixel == 4) {
324         if (vs->tight.pixel24) {
325             errors = tight_detect_smooth_image24(vs, w, h);
326             if (vs->tight.quality != (uint8_t)-1) {
327                 return (errors < tight_conf[quality].jpeg_threshold24);
328             }
329             return (errors < tight_conf[compression].gradient_threshold24);
330         } else {
331             errors = tight_detect_smooth_image32(vs, w, h);
332         }
333     } else {
334         errors = tight_detect_smooth_image16(vs, w, h);
335     }
336     if (quality != (uint8_t)-1) {
337         return (errors < tight_conf[quality].jpeg_threshold);
338     }
339     return (errors < tight_conf[compression].gradient_threshold);
340 }
341 
342 /*
343  * Code to determine how many different colors used in rectangle.
344  */
345 #define DEFINE_FILL_PALETTE_FUNCTION(bpp)                               \
346                                                                         \
347     static int                                                          \
348     tight_fill_palette##bpp(VncState *vs, int x, int y,                 \
349                             int max, size_t count,                      \
350                             uint32_t *bg, uint32_t *fg,                 \
351                             VncPalette *palette) {                      \
352         uint##bpp##_t *data;                                            \
353         uint##bpp##_t c0, c1, ci;                                       \
354         int i, n0, n1;                                                  \
355                                                                         \
356         data = (uint##bpp##_t *)vs->tight.tight.buffer;                 \
357                                                                         \
358         c0 = data[0];                                                   \
359         i = 1;                                                          \
360         while (i < count && data[i] == c0)                              \
361             i++;                                                        \
362         if (i >= count) {                                               \
363             *bg = *fg = c0;                                             \
364             return 1;                                                   \
365         }                                                               \
366                                                                         \
367         if (max < 2) {                                                  \
368             return 0;                                                   \
369         }                                                               \
370                                                                         \
371         n0 = i;                                                         \
372         c1 = data[i];                                                   \
373         n1 = 0;                                                         \
374         for (i++; i < count; i++) {                                     \
375             ci = data[i];                                               \
376             if (ci == c0) {                                             \
377                 n0++;                                                   \
378             } else if (ci == c1) {                                      \
379                 n1++;                                                   \
380             } else                                                      \
381                 break;                                                  \
382         }                                                               \
383         if (i >= count) {                                               \
384             if (n0 > n1) {                                              \
385                 *bg = (uint32_t)c0;                                     \
386                 *fg = (uint32_t)c1;                                     \
387             } else {                                                    \
388                 *bg = (uint32_t)c1;                                     \
389                 *fg = (uint32_t)c0;                                     \
390             }                                                           \
391             return 2;                                                   \
392         }                                                               \
393                                                                         \
394         if (max == 2) {                                                 \
395             return 0;                                                   \
396         }                                                               \
397                                                                         \
398         palette_init(palette, max, bpp);                                \
399         palette_put(palette, c0);                                       \
400         palette_put(palette, c1);                                       \
401         palette_put(palette, ci);                                       \
402                                                                         \
403         for (i++; i < count; i++) {                                     \
404             if (data[i] == ci) {                                        \
405                 continue;                                               \
406             } else {                                                    \
407                 ci = data[i];                                           \
408                 if (!palette_put(palette, (uint32_t)ci)) {              \
409                     return 0;                                           \
410                 }                                                       \
411             }                                                           \
412         }                                                               \
413                                                                         \
414         return palette_size(palette);                                   \
415     }
416 
417 DEFINE_FILL_PALETTE_FUNCTION(8)
418 DEFINE_FILL_PALETTE_FUNCTION(16)
419 DEFINE_FILL_PALETTE_FUNCTION(32)
420 
421 static int tight_fill_palette(VncState *vs, int x, int y,
422                               size_t count, uint32_t *bg, uint32_t *fg,
423                               VncPalette *palette)
424 {
425     int max;
426 
427     max = count / tight_conf[vs->tight.compression].idx_max_colors_divisor;
428     if (max < 2 &&
429         count >= tight_conf[vs->tight.compression].mono_min_rect_size) {
430         max = 2;
431     }
432     if (max >= 256) {
433         max = 256;
434     }
435 
436     switch (vs->client_pf.bytes_per_pixel) {
437     case 4:
438         return tight_fill_palette32(vs, x, y, max, count, bg, fg, palette);
439     case 2:
440         return tight_fill_palette16(vs, x, y, max, count, bg, fg, palette);
441     default:
442         max = 2;
443         return tight_fill_palette8(vs, x, y, max, count, bg, fg, palette);
444     }
445     return 0;
446 }
447 
448 /*
449  * Converting truecolor samples into palette indices.
450  */
451 #define DEFINE_IDX_ENCODE_FUNCTION(bpp)                                 \
452                                                                         \
453     static void                                                         \
454     tight_encode_indexed_rect##bpp(uint8_t *buf, int count,             \
455                                    VncPalette *palette) {               \
456         uint##bpp##_t *src;                                             \
457         uint##bpp##_t rgb;                                              \
458         int i, rep;                                                     \
459         uint8_t idx;                                                    \
460                                                                         \
461         src = (uint##bpp##_t *) buf;                                    \
462                                                                         \
463         for (i = 0; i < count; ) {                                      \
464                                                                         \
465             rgb = *src++;                                               \
466             i++;                                                        \
467             rep = 0;                                                    \
468             while (i < count && *src == rgb) {                          \
469                 rep++, src++, i++;                                      \
470             }                                                           \
471             idx = palette_idx(palette, rgb);                            \
472             /*                                                          \
473              * Should never happen, but don't break everything          \
474              * if it does, use the first color instead                  \
475              */                                                         \
476             if (idx == (uint8_t)-1) {                                   \
477                 idx = 0;                                                \
478             }                                                           \
479             while (rep >= 0) {                                          \
480                 *buf++ = idx;                                           \
481                 rep--;                                                  \
482             }                                                           \
483         }                                                               \
484     }
485 
486 DEFINE_IDX_ENCODE_FUNCTION(16)
487 DEFINE_IDX_ENCODE_FUNCTION(32)
488 
489 #define DEFINE_MONO_ENCODE_FUNCTION(bpp)                                \
490                                                                         \
491     static void                                                         \
492     tight_encode_mono_rect##bpp(uint8_t *buf, int w, int h,             \
493                                 uint##bpp##_t bg, uint##bpp##_t fg) {   \
494         uint##bpp##_t *ptr;                                             \
495         unsigned int value, mask;                                       \
496         int aligned_width;                                              \
497         int x, y, bg_bits;                                              \
498                                                                         \
499         ptr = (uint##bpp##_t *) buf;                                    \
500         aligned_width = w - w % 8;                                      \
501                                                                         \
502         for (y = 0; y < h; y++) {                                       \
503             for (x = 0; x < aligned_width; x += 8) {                    \
504                 for (bg_bits = 0; bg_bits < 8; bg_bits++) {             \
505                     if (*ptr++ != bg) {                                 \
506                         break;                                          \
507                     }                                                   \
508                 }                                                       \
509                 if (bg_bits == 8) {                                     \
510                     *buf++ = 0;                                         \
511                     continue;                                           \
512                 }                                                       \
513                 mask = 0x80 >> bg_bits;                                 \
514                 value = mask;                                           \
515                 for (bg_bits++; bg_bits < 8; bg_bits++) {               \
516                     mask >>= 1;                                         \
517                     if (*ptr++ != bg) {                                 \
518                         value |= mask;                                  \
519                     }                                                   \
520                 }                                                       \
521                 *buf++ = (uint8_t)value;                                \
522             }                                                           \
523                                                                         \
524             mask = 0x80;                                                \
525             value = 0;                                                  \
526             if (x >= w) {                                               \
527                 continue;                                               \
528             }                                                           \
529                                                                         \
530             for (; x < w; x++) {                                        \
531                 if (*ptr++ != bg) {                                     \
532                     value |= mask;                                      \
533                 }                                                       \
534                 mask >>= 1;                                             \
535             }                                                           \
536             *buf++ = (uint8_t)value;                                    \
537         }                                                               \
538     }
539 
540 DEFINE_MONO_ENCODE_FUNCTION(8)
541 DEFINE_MONO_ENCODE_FUNCTION(16)
542 DEFINE_MONO_ENCODE_FUNCTION(32)
543 
544 /*
545  * ``Gradient'' filter for 24-bit color samples.
546  * Should be called only when redMax, greenMax and blueMax are 255.
547  * Color components assumed to be byte-aligned.
548  */
549 
550 static void
551 tight_filter_gradient24(VncState *vs, uint8_t *buf, int w, int h)
552 {
553     uint32_t *buf32;
554     uint32_t pix32;
555     int shift[3];
556     int *prev;
557     int here[3], upper[3], left[3], upperleft[3];
558     int prediction;
559     int x, y, c;
560 
561     buf32 = (uint32_t *)buf;
562     memset(vs->tight.gradient.buffer, 0, w * 3 * sizeof(int));
563 
564     if (1 /* FIXME */) {
565         shift[0] = vs->client_pf.rshift;
566         shift[1] = vs->client_pf.gshift;
567         shift[2] = vs->client_pf.bshift;
568     } else {
569         shift[0] = 24 - vs->client_pf.rshift;
570         shift[1] = 24 - vs->client_pf.gshift;
571         shift[2] = 24 - vs->client_pf.bshift;
572     }
573 
574     for (y = 0; y < h; y++) {
575         for (c = 0; c < 3; c++) {
576             upper[c] = 0;
577             here[c] = 0;
578         }
579         prev = (int *)vs->tight.gradient.buffer;
580         for (x = 0; x < w; x++) {
581             pix32 = *buf32++;
582             for (c = 0; c < 3; c++) {
583                 upperleft[c] = upper[c];
584                 left[c] = here[c];
585                 upper[c] = *prev;
586                 here[c] = (int)(pix32 >> shift[c] & 0xFF);
587                 *prev++ = here[c];
588 
589                 prediction = left[c] + upper[c] - upperleft[c];
590                 if (prediction < 0) {
591                     prediction = 0;
592                 } else if (prediction > 0xFF) {
593                     prediction = 0xFF;
594                 }
595                 *buf++ = (char)(here[c] - prediction);
596             }
597         }
598     }
599 }
600 
601 
602 /*
603  * ``Gradient'' filter for other color depths.
604  */
605 
606 #define DEFINE_GRADIENT_FILTER_FUNCTION(bpp)                            \
607                                                                         \
608     static void                                                         \
609     tight_filter_gradient##bpp(VncState *vs, uint##bpp##_t *buf,        \
610                                int w, int h) {                          \
611         uint##bpp##_t pix, diff;                                        \
612         bool endian;                                                    \
613         int *prev;                                                      \
614         int max[3], shift[3];                                           \
615         int here[3], upper[3], left[3], upperleft[3];                   \
616         int prediction;                                                 \
617         int x, y, c;                                                    \
618                                                                         \
619         memset (vs->tight.gradient.buffer, 0, w * 3 * sizeof(int));     \
620                                                                         \
621         endian = 0; /* FIXME */                                         \
622                                                                         \
623         max[0] = vs->client_pf.rmax;                                    \
624         max[1] = vs->client_pf.gmax;                                    \
625         max[2] = vs->client_pf.bmax;                                    \
626         shift[0] = vs->client_pf.rshift;                                \
627         shift[1] = vs->client_pf.gshift;                                \
628         shift[2] = vs->client_pf.bshift;                                \
629                                                                         \
630         for (y = 0; y < h; y++) {                                       \
631             for (c = 0; c < 3; c++) {                                   \
632                 upper[c] = 0;                                           \
633                 here[c] = 0;                                            \
634             }                                                           \
635             prev = (int *)vs->tight.gradient.buffer;                    \
636             for (x = 0; x < w; x++) {                                   \
637                 pix = *buf;                                             \
638                 if (endian) {                                           \
639                     pix = bswap##bpp(pix);                              \
640                 }                                                       \
641                 diff = 0;                                               \
642                 for (c = 0; c < 3; c++) {                               \
643                     upperleft[c] = upper[c];                            \
644                     left[c] = here[c];                                  \
645                     upper[c] = *prev;                                   \
646                     here[c] = (int)(pix >> shift[c] & max[c]);          \
647                     *prev++ = here[c];                                  \
648                                                                         \
649                     prediction = left[c] + upper[c] - upperleft[c];     \
650                     if (prediction < 0) {                               \
651                         prediction = 0;                                 \
652                     } else if (prediction > max[c]) {                   \
653                         prediction = max[c];                            \
654                     }                                                   \
655                     diff |= ((here[c] - prediction) & max[c])           \
656                         << shift[c];                                    \
657                 }                                                       \
658                 if (endian) {                                           \
659                     diff = bswap##bpp(diff);                            \
660                 }                                                       \
661                 *buf++ = diff;                                          \
662             }                                                           \
663         }                                                               \
664     }
665 
666 DEFINE_GRADIENT_FILTER_FUNCTION(16)
667 DEFINE_GRADIENT_FILTER_FUNCTION(32)
668 
669 /*
670  * Check if a rectangle is all of the same color. If needSameColor is
671  * set to non-zero, then also check that its color equals to the
672  * *colorPtr value. The result is 1 if the test is successful, and in
673  * that case new color will be stored in *colorPtr.
674  */
675 
676 static bool
677 check_solid_tile32(VncState *vs, int x, int y, int w, int h,
678                    uint32_t *color, bool samecolor)
679 {
680     VncDisplay *vd = vs->vd;
681     uint32_t *fbptr;
682     uint32_t c;
683     int dx, dy;
684 
685     fbptr = vnc_server_fb_ptr(vd, x, y);
686 
687     c = *fbptr;
688     if (samecolor && (uint32_t)c != *color) {
689         return false;
690     }
691 
692     for (dy = 0; dy < h; dy++) {
693         for (dx = 0; dx < w; dx++) {
694             if (c != fbptr[dx]) {
695                 return false;
696             }
697         }
698         fbptr = (uint32_t *)
699             ((uint8_t *)fbptr + vnc_server_fb_stride(vd));
700     }
701 
702     *color = (uint32_t)c;
703     return true;
704 }
705 
706 static bool check_solid_tile(VncState *vs, int x, int y, int w, int h,
707                              uint32_t* color, bool samecolor)
708 {
709     QEMU_BUILD_BUG_ON(VNC_SERVER_FB_BYTES != 4);
710     return check_solid_tile32(vs, x, y, w, h, color, samecolor);
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 */) {
896         rshift = vs->client_pf.rshift;
897         gshift = vs->client_pf.gshift;
898         bshift = vs->client_pf.bshift;
899     } else {
900         rshift = 24 - vs->client_pf.rshift;
901         gshift = 24 - vs->client_pf.gshift;
902         bshift = 24 - vs->client_pf.bshift;
903     }
904 
905     if (ret) {
906         *ret = count * 3;
907     }
908 
909     while (count--) {
910         pix = *buf32++;
911         *buf++ = (char)(pix >> rshift);
912         *buf++ = (char)(pix >> gshift);
913         *buf++ = (char)(pix >> bshift);
914     }
915 }
916 
917 static int send_full_color_rect(VncState *vs, int x, int y, int w, int h)
918 {
919     int stream = 0;
920     ssize_t bytes;
921 
922 #ifdef CONFIG_VNC_PNG
923     if (tight_can_send_png_rect(vs, w, h)) {
924         return send_png_rect(vs, x, y, w, h, NULL);
925     }
926 #endif
927 
928     vnc_write_u8(vs, stream << 4); /* no flushing, no filter */
929 
930     if (vs->tight.pixel24) {
931         tight_pack24(vs, vs->tight.tight.buffer, w * h, &vs->tight.tight.offset);
932         bytes = 3;
933     } else {
934         bytes = vs->client_pf.bytes_per_pixel;
935     }
936 
937     bytes = tight_compress_data(vs, stream, w * h * bytes,
938                                 tight_conf[vs->tight.compression].raw_zlib_level,
939                                 Z_DEFAULT_STRATEGY);
940 
941     return (bytes >= 0);
942 }
943 
944 static int send_solid_rect(VncState *vs)
945 {
946     size_t bytes;
947 
948     vnc_write_u8(vs, VNC_TIGHT_FILL << 4); /* no flushing, no filter */
949 
950     if (vs->tight.pixel24) {
951         tight_pack24(vs, vs->tight.tight.buffer, 1, &vs->tight.tight.offset);
952         bytes = 3;
953     } else {
954         bytes = vs->client_pf.bytes_per_pixel;
955     }
956 
957     vnc_write(vs, vs->tight.tight.buffer, bytes);
958     return 1;
959 }
960 
961 static int send_mono_rect(VncState *vs, int x, int y,
962                           int w, int h, uint32_t bg, uint32_t fg)
963 {
964     ssize_t bytes;
965     int stream = 1;
966     int level = tight_conf[vs->tight.compression].mono_zlib_level;
967 
968 #ifdef CONFIG_VNC_PNG
969     if (tight_can_send_png_rect(vs, w, h)) {
970         int ret;
971         int bpp = vs->client_pf.bytes_per_pixel * 8;
972         VncPalette *palette = palette_new(2, bpp);
973 
974         palette_put(palette, bg);
975         palette_put(palette, fg);
976         ret = send_png_rect(vs, x, y, w, h, palette);
977         palette_destroy(palette);
978         return ret;
979     }
980 #endif
981 
982     bytes = DIV_ROUND_UP(w, 8) * h;
983 
984     vnc_write_u8(vs, (stream | VNC_TIGHT_EXPLICIT_FILTER) << 4);
985     vnc_write_u8(vs, VNC_TIGHT_FILTER_PALETTE);
986     vnc_write_u8(vs, 1);
987 
988     switch (vs->client_pf.bytes_per_pixel) {
989     case 4:
990     {
991         uint32_t buf[2] = {bg, fg};
992         size_t ret = sizeof (buf);
993 
994         if (vs->tight.pixel24) {
995             tight_pack24(vs, (unsigned char*)buf, 2, &ret);
996         }
997         vnc_write(vs, buf, ret);
998 
999         tight_encode_mono_rect32(vs->tight.tight.buffer, w, h, bg, fg);
1000         break;
1001     }
1002     case 2:
1003         vnc_write(vs, &bg, 2);
1004         vnc_write(vs, &fg, 2);
1005         tight_encode_mono_rect16(vs->tight.tight.buffer, w, h, bg, fg);
1006         break;
1007     default:
1008         vnc_write_u8(vs, bg);
1009         vnc_write_u8(vs, fg);
1010         tight_encode_mono_rect8(vs->tight.tight.buffer, w, h, bg, fg);
1011         break;
1012     }
1013     vs->tight.tight.offset = bytes;
1014 
1015     bytes = tight_compress_data(vs, stream, bytes, level, Z_DEFAULT_STRATEGY);
1016     return (bytes >= 0);
1017 }
1018 
1019 struct palette_cb_priv {
1020     VncState *vs;
1021     uint8_t *header;
1022 #ifdef CONFIG_VNC_PNG
1023     png_colorp png_palette;
1024 #endif
1025 };
1026 
1027 static void write_palette(int idx, uint32_t color, void *opaque)
1028 {
1029     struct palette_cb_priv *priv = opaque;
1030     VncState *vs = priv->vs;
1031     uint32_t bytes = vs->client_pf.bytes_per_pixel;
1032 
1033     if (bytes == 4) {
1034         ((uint32_t*)priv->header)[idx] = color;
1035     } else {
1036         ((uint16_t*)priv->header)[idx] = color;
1037     }
1038 }
1039 
1040 static bool send_gradient_rect(VncState *vs, int x, int y, int w, int h)
1041 {
1042     int stream = 3;
1043     int level = tight_conf[vs->tight.compression].gradient_zlib_level;
1044     ssize_t bytes;
1045 
1046     if (vs->client_pf.bytes_per_pixel == 1) {
1047         return send_full_color_rect(vs, x, y, w, h);
1048     }
1049 
1050     vnc_write_u8(vs, (stream | VNC_TIGHT_EXPLICIT_FILTER) << 4);
1051     vnc_write_u8(vs, VNC_TIGHT_FILTER_GRADIENT);
1052 
1053     buffer_reserve(&vs->tight.gradient, w * 3 * sizeof (int));
1054 
1055     if (vs->tight.pixel24) {
1056         tight_filter_gradient24(vs, vs->tight.tight.buffer, w, h);
1057         bytes = 3;
1058     } else if (vs->client_pf.bytes_per_pixel == 4) {
1059         tight_filter_gradient32(vs, (uint32_t *)vs->tight.tight.buffer, w, h);
1060         bytes = 4;
1061     } else {
1062         tight_filter_gradient16(vs, (uint16_t *)vs->tight.tight.buffer, w, h);
1063         bytes = 2;
1064     }
1065 
1066     buffer_reset(&vs->tight.gradient);
1067 
1068     bytes = w * h * bytes;
1069     vs->tight.tight.offset = bytes;
1070 
1071     bytes = tight_compress_data(vs, stream, bytes,
1072                                 level, Z_FILTERED);
1073     return (bytes >= 0);
1074 }
1075 
1076 static int send_palette_rect(VncState *vs, int x, int y,
1077                              int w, int h, VncPalette *palette)
1078 {
1079     int stream = 2;
1080     int level = tight_conf[vs->tight.compression].idx_zlib_level;
1081     int colors;
1082     ssize_t bytes;
1083 
1084 #ifdef CONFIG_VNC_PNG
1085     if (tight_can_send_png_rect(vs, w, h)) {
1086         return send_png_rect(vs, x, y, w, h, palette);
1087     }
1088 #endif
1089 
1090     colors = palette_size(palette);
1091 
1092     vnc_write_u8(vs, (stream | VNC_TIGHT_EXPLICIT_FILTER) << 4);
1093     vnc_write_u8(vs, VNC_TIGHT_FILTER_PALETTE);
1094     vnc_write_u8(vs, colors - 1);
1095 
1096     switch (vs->client_pf.bytes_per_pixel) {
1097     case 4:
1098     {
1099         size_t old_offset, offset;
1100         uint32_t header[palette_size(palette)];
1101         struct palette_cb_priv priv = { vs, (uint8_t *)header };
1102 
1103         old_offset = vs->output.offset;
1104         palette_iter(palette, write_palette, &priv);
1105         vnc_write(vs, header, sizeof(header));
1106 
1107         if (vs->tight.pixel24) {
1108             tight_pack24(vs, vs->output.buffer + old_offset, colors, &offset);
1109             vs->output.offset = old_offset + offset;
1110         }
1111 
1112         tight_encode_indexed_rect32(vs->tight.tight.buffer, w * h, palette);
1113         break;
1114     }
1115     case 2:
1116     {
1117         uint16_t header[palette_size(palette)];
1118         struct palette_cb_priv priv = { vs, (uint8_t *)header };
1119 
1120         palette_iter(palette, write_palette, &priv);
1121         vnc_write(vs, header, sizeof(header));
1122         tight_encode_indexed_rect16(vs->tight.tight.buffer, w * h, palette);
1123         break;
1124     }
1125     default:
1126         return -1; /* No palette for 8bits colors */
1127         break;
1128     }
1129     bytes = w * h;
1130     vs->tight.tight.offset = bytes;
1131 
1132     bytes = tight_compress_data(vs, stream, bytes,
1133                                 level, Z_DEFAULT_STRATEGY);
1134     return (bytes >= 0);
1135 }
1136 
1137 /*
1138  * JPEG compression stuff.
1139  */
1140 #ifdef CONFIG_VNC_JPEG
1141 /*
1142  * Destination manager implementation for JPEG library.
1143  */
1144 
1145 /* This is called once per encoding */
1146 static void jpeg_init_destination(j_compress_ptr cinfo)
1147 {
1148     VncState *vs = cinfo->client_data;
1149     Buffer *buffer = &vs->tight.jpeg;
1150 
1151     cinfo->dest->next_output_byte = (JOCTET *)buffer->buffer + buffer->offset;
1152     cinfo->dest->free_in_buffer = (size_t)(buffer->capacity - buffer->offset);
1153 }
1154 
1155 /* This is called when we ran out of buffer (shouldn't happen!) */
1156 static boolean jpeg_empty_output_buffer(j_compress_ptr cinfo)
1157 {
1158     VncState *vs = cinfo->client_data;
1159     Buffer *buffer = &vs->tight.jpeg;
1160 
1161     buffer->offset = buffer->capacity;
1162     buffer_reserve(buffer, 2048);
1163     jpeg_init_destination(cinfo);
1164     return TRUE;
1165 }
1166 
1167 /* This is called when we are done processing data */
1168 static void jpeg_term_destination(j_compress_ptr cinfo)
1169 {
1170     VncState *vs = cinfo->client_data;
1171     Buffer *buffer = &vs->tight.jpeg;
1172 
1173     buffer->offset = buffer->capacity - cinfo->dest->free_in_buffer;
1174 }
1175 
1176 static int send_jpeg_rect(VncState *vs, int x, int y, int w, int h, int quality)
1177 {
1178     struct jpeg_compress_struct cinfo;
1179     struct jpeg_error_mgr jerr;
1180     struct jpeg_destination_mgr manager;
1181     pixman_image_t *linebuf;
1182     JSAMPROW row[1];
1183     uint8_t *buf;
1184     int dy;
1185 
1186     if (surface_bytes_per_pixel(vs->vd->ds) == 1) {
1187         return send_full_color_rect(vs, x, y, w, h);
1188     }
1189 
1190     buffer_reserve(&vs->tight.jpeg, 2048);
1191 
1192     cinfo.err = jpeg_std_error(&jerr);
1193     jpeg_create_compress(&cinfo);
1194 
1195     cinfo.client_data = vs;
1196     cinfo.image_width = w;
1197     cinfo.image_height = h;
1198     cinfo.input_components = 3;
1199     cinfo.in_color_space = JCS_RGB;
1200 
1201     jpeg_set_defaults(&cinfo);
1202     jpeg_set_quality(&cinfo, quality, true);
1203 
1204     manager.init_destination = jpeg_init_destination;
1205     manager.empty_output_buffer = jpeg_empty_output_buffer;
1206     manager.term_destination = jpeg_term_destination;
1207     cinfo.dest = &manager;
1208 
1209     jpeg_start_compress(&cinfo, true);
1210 
1211     linebuf = qemu_pixman_linebuf_create(PIXMAN_BE_r8g8b8, w);
1212     buf = (uint8_t *)pixman_image_get_data(linebuf);
1213     row[0] = buf;
1214     for (dy = 0; dy < h; dy++) {
1215         qemu_pixman_linebuf_fill(linebuf, vs->vd->server, w, x, y + dy);
1216         jpeg_write_scanlines(&cinfo, row, 1);
1217     }
1218     qemu_pixman_image_unref(linebuf);
1219 
1220     jpeg_finish_compress(&cinfo);
1221     jpeg_destroy_compress(&cinfo);
1222 
1223     vnc_write_u8(vs, VNC_TIGHT_JPEG << 4);
1224 
1225     tight_send_compact_size(vs, vs->tight.jpeg.offset);
1226     vnc_write(vs, vs->tight.jpeg.buffer, vs->tight.jpeg.offset);
1227     buffer_reset(&vs->tight.jpeg);
1228 
1229     return 1;
1230 }
1231 #endif /* CONFIG_VNC_JPEG */
1232 
1233 /*
1234  * PNG compression stuff.
1235  */
1236 #ifdef CONFIG_VNC_PNG
1237 static void write_png_palette(int idx, uint32_t pix, void *opaque)
1238 {
1239     struct palette_cb_priv *priv = opaque;
1240     VncState *vs = priv->vs;
1241     png_colorp color = &priv->png_palette[idx];
1242 
1243     if (vs->tight.pixel24)
1244     {
1245         color->red = (pix >> vs->client_pf.rshift) & vs->client_pf.rmax;
1246         color->green = (pix >> vs->client_pf.gshift) & vs->client_pf.gmax;
1247         color->blue = (pix >> vs->client_pf.bshift) & vs->client_pf.bmax;
1248     }
1249     else
1250     {
1251         int red, green, blue;
1252 
1253         red = (pix >> vs->client_pf.rshift) & vs->client_pf.rmax;
1254         green = (pix >> vs->client_pf.gshift) & vs->client_pf.gmax;
1255         blue = (pix >> vs->client_pf.bshift) & vs->client_pf.bmax;
1256         color->red = ((red * 255 + vs->client_pf.rmax / 2) /
1257                       vs->client_pf.rmax);
1258         color->green = ((green * 255 + vs->client_pf.gmax / 2) /
1259                         vs->client_pf.gmax);
1260         color->blue = ((blue * 255 + vs->client_pf.bmax / 2) /
1261                        vs->client_pf.bmax);
1262     }
1263 }
1264 
1265 static void png_write_data(png_structp png_ptr, png_bytep data,
1266                            png_size_t length)
1267 {
1268     VncState *vs = png_get_io_ptr(png_ptr);
1269 
1270     buffer_reserve(&vs->tight.png, vs->tight.png.offset + length);
1271     memcpy(vs->tight.png.buffer + vs->tight.png.offset, data, length);
1272 
1273     vs->tight.png.offset += length;
1274 }
1275 
1276 static void png_flush_data(png_structp png_ptr)
1277 {
1278 }
1279 
1280 static void *vnc_png_malloc(png_structp png_ptr, png_size_t size)
1281 {
1282     return g_malloc(size);
1283 }
1284 
1285 static void vnc_png_free(png_structp png_ptr, png_voidp ptr)
1286 {
1287     g_free(ptr);
1288 }
1289 
1290 static int send_png_rect(VncState *vs, int x, int y, int w, int h,
1291                          VncPalette *palette)
1292 {
1293     png_byte color_type;
1294     png_structp png_ptr;
1295     png_infop info_ptr;
1296     png_colorp png_palette = NULL;
1297     pixman_image_t *linebuf;
1298     int level = tight_png_conf[vs->tight.compression].png_zlib_level;
1299     int filters = tight_png_conf[vs->tight.compression].png_filters;
1300     uint8_t *buf;
1301     int dy;
1302 
1303     png_ptr = png_create_write_struct_2(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL,
1304                                         NULL, vnc_png_malloc, vnc_png_free);
1305 
1306     if (png_ptr == NULL)
1307         return -1;
1308 
1309     info_ptr = png_create_info_struct(png_ptr);
1310 
1311     if (info_ptr == NULL) {
1312         png_destroy_write_struct(&png_ptr, NULL);
1313         return -1;
1314     }
1315 
1316     png_set_write_fn(png_ptr, (void *) vs, png_write_data, png_flush_data);
1317     png_set_compression_level(png_ptr, level);
1318     png_set_filter(png_ptr, PNG_FILTER_TYPE_DEFAULT, filters);
1319 
1320     if (palette) {
1321         color_type = PNG_COLOR_TYPE_PALETTE;
1322     } else {
1323         color_type = PNG_COLOR_TYPE_RGB;
1324     }
1325 
1326     png_set_IHDR(png_ptr, info_ptr, w, h,
1327                  8, color_type, PNG_INTERLACE_NONE,
1328                  PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
1329 
1330     if (color_type == PNG_COLOR_TYPE_PALETTE) {
1331         struct palette_cb_priv priv;
1332 
1333         png_palette = png_malloc(png_ptr, sizeof(*png_palette) *
1334                                  palette_size(palette));
1335 
1336         priv.vs = vs;
1337         priv.png_palette = png_palette;
1338         palette_iter(palette, write_png_palette, &priv);
1339 
1340         png_set_PLTE(png_ptr, info_ptr, png_palette, palette_size(palette));
1341 
1342         if (vs->client_pf.bytes_per_pixel == 4) {
1343             tight_encode_indexed_rect32(vs->tight.tight.buffer, w * h, palette);
1344         } else {
1345             tight_encode_indexed_rect16(vs->tight.tight.buffer, w * h, palette);
1346         }
1347     }
1348 
1349     png_write_info(png_ptr, info_ptr);
1350 
1351     buffer_reserve(&vs->tight.png, 2048);
1352     linebuf = qemu_pixman_linebuf_create(PIXMAN_BE_r8g8b8, w);
1353     buf = (uint8_t *)pixman_image_get_data(linebuf);
1354     for (dy = 0; dy < h; dy++)
1355     {
1356         if (color_type == PNG_COLOR_TYPE_PALETTE) {
1357             memcpy(buf, vs->tight.tight.buffer + (dy * w), w);
1358         } else {
1359             qemu_pixman_linebuf_fill(linebuf, vs->vd->server, w, x, y + dy);
1360         }
1361         png_write_row(png_ptr, buf);
1362     }
1363     qemu_pixman_image_unref(linebuf);
1364 
1365     png_write_end(png_ptr, NULL);
1366 
1367     if (color_type == PNG_COLOR_TYPE_PALETTE) {
1368         png_free(png_ptr, png_palette);
1369     }
1370 
1371     png_destroy_write_struct(&png_ptr, &info_ptr);
1372 
1373     vnc_write_u8(vs, VNC_TIGHT_PNG << 4);
1374 
1375     tight_send_compact_size(vs, vs->tight.png.offset);
1376     vnc_write(vs, vs->tight.png.buffer, vs->tight.png.offset);
1377     buffer_reset(&vs->tight.png);
1378     return 1;
1379 }
1380 #endif /* CONFIG_VNC_PNG */
1381 
1382 static void vnc_tight_start(VncState *vs)
1383 {
1384     buffer_reset(&vs->tight.tight);
1385 
1386     // make the output buffer be the zlib buffer, so we can compress it later
1387     vs->tight.tmp = vs->output;
1388     vs->output = vs->tight.tight;
1389 }
1390 
1391 static void vnc_tight_stop(VncState *vs)
1392 {
1393     // switch back to normal output/zlib buffers
1394     vs->tight.tight = vs->output;
1395     vs->output = vs->tight.tmp;
1396 }
1397 
1398 static int send_sub_rect_nojpeg(VncState *vs, int x, int y, int w, int h,
1399                                 int bg, int fg, int colors, VncPalette *palette)
1400 {
1401     int ret;
1402 
1403     if (colors == 0) {
1404         if (tight_detect_smooth_image(vs, w, h)) {
1405             ret = send_gradient_rect(vs, x, y, w, h);
1406         } else {
1407             ret = send_full_color_rect(vs, x, y, w, h);
1408         }
1409     } else if (colors == 1) {
1410         ret = send_solid_rect(vs);
1411     } else if (colors == 2) {
1412         ret = send_mono_rect(vs, x, y, w, h, bg, fg);
1413     } else if (colors <= 256) {
1414         ret = send_palette_rect(vs, x, y, w, h, palette);
1415     } else {
1416         ret = 0;
1417     }
1418     return ret;
1419 }
1420 
1421 #ifdef CONFIG_VNC_JPEG
1422 static int send_sub_rect_jpeg(VncState *vs, int x, int y, int w, int h,
1423                               int bg, int fg, int colors,
1424                               VncPalette *palette, bool force)
1425 {
1426     int ret;
1427 
1428     if (colors == 0) {
1429         if (force || (tight_jpeg_conf[vs->tight.quality].jpeg_full &&
1430                       tight_detect_smooth_image(vs, w, h))) {
1431             int quality = tight_conf[vs->tight.quality].jpeg_quality;
1432 
1433             ret = send_jpeg_rect(vs, x, y, w, h, quality);
1434         } else {
1435             ret = send_full_color_rect(vs, x, y, w, h);
1436         }
1437     } else if (colors == 1) {
1438         ret = send_solid_rect(vs);
1439     } else if (colors == 2) {
1440         ret = send_mono_rect(vs, x, y, w, h, bg, fg);
1441     } else if (colors <= 256) {
1442         if (force || (colors > 96 &&
1443                       tight_jpeg_conf[vs->tight.quality].jpeg_idx &&
1444                       tight_detect_smooth_image(vs, w, h))) {
1445             int quality = tight_conf[vs->tight.quality].jpeg_quality;
1446 
1447             ret = send_jpeg_rect(vs, x, y, w, h, quality);
1448         } else {
1449             ret = send_palette_rect(vs, x, y, w, h, palette);
1450         }
1451     } else {
1452         ret = 0;
1453     }
1454     return ret;
1455 }
1456 #endif
1457 
1458 static __thread VncPalette *color_count_palette;
1459 static __thread Notifier vnc_tight_cleanup_notifier;
1460 
1461 static void vnc_tight_cleanup(Notifier *n, void *value)
1462 {
1463     g_free(color_count_palette);
1464     color_count_palette = NULL;
1465 }
1466 
1467 static int send_sub_rect(VncState *vs, int x, int y, int w, int h)
1468 {
1469     uint32_t bg = 0, fg = 0;
1470     int colors;
1471     int ret = 0;
1472 #ifdef CONFIG_VNC_JPEG
1473     bool force_jpeg = false;
1474     bool allow_jpeg = true;
1475 #endif
1476 
1477     if (!color_count_palette) {
1478         color_count_palette = g_malloc(sizeof(VncPalette));
1479         vnc_tight_cleanup_notifier.notify = vnc_tight_cleanup;
1480         qemu_thread_atexit_add(&vnc_tight_cleanup_notifier);
1481     }
1482 
1483     vnc_framebuffer_update(vs, x, y, w, h, vs->tight.type);
1484 
1485     vnc_tight_start(vs);
1486     vnc_raw_send_framebuffer_update(vs, x, y, w, h);
1487     vnc_tight_stop(vs);
1488 
1489 #ifdef CONFIG_VNC_JPEG
1490     if (!vs->vd->non_adaptive && vs->tight.quality != (uint8_t)-1) {
1491         double freq = vnc_update_freq(vs, x, y, w, h);
1492 
1493         if (freq < tight_jpeg_conf[vs->tight.quality].jpeg_freq_min) {
1494             allow_jpeg = false;
1495         }
1496         if (freq >= tight_jpeg_conf[vs->tight.quality].jpeg_freq_threshold) {
1497             force_jpeg = true;
1498             vnc_sent_lossy_rect(vs, x, y, w, h);
1499         }
1500     }
1501 #endif
1502 
1503     colors = tight_fill_palette(vs, x, y, w * h, &bg, &fg, color_count_palette);
1504 
1505 #ifdef CONFIG_VNC_JPEG
1506     if (allow_jpeg && vs->tight.quality != (uint8_t)-1) {
1507         ret = send_sub_rect_jpeg(vs, x, y, w, h, bg, fg, colors,
1508                                  color_count_palette, force_jpeg);
1509     } else {
1510         ret = send_sub_rect_nojpeg(vs, x, y, w, h, bg, fg, colors,
1511                                    color_count_palette);
1512     }
1513 #else
1514     ret = send_sub_rect_nojpeg(vs, x, y, w, h, bg, fg, colors,
1515                                color_count_palette);
1516 #endif
1517 
1518     return ret;
1519 }
1520 
1521 static int send_sub_rect_solid(VncState *vs, int x, int y, int w, int h)
1522 {
1523     vnc_framebuffer_update(vs, x, y, w, h, vs->tight.type);
1524 
1525     vnc_tight_start(vs);
1526     vnc_raw_send_framebuffer_update(vs, x, y, w, h);
1527     vnc_tight_stop(vs);
1528 
1529     return send_solid_rect(vs);
1530 }
1531 
1532 static int send_rect_simple(VncState *vs, int x, int y, int w, int h,
1533                             bool split)
1534 {
1535     int max_size, max_width;
1536     int max_sub_width, max_sub_height;
1537     int dx, dy;
1538     int rw, rh;
1539     int n = 0;
1540 
1541     max_size = tight_conf[vs->tight.compression].max_rect_size;
1542     max_width = tight_conf[vs->tight.compression].max_rect_width;
1543 
1544     if (split && (w > max_width || w * h > max_size)) {
1545         max_sub_width = (w > max_width) ? max_width : w;
1546         max_sub_height = max_size / max_sub_width;
1547 
1548         for (dy = 0; dy < h; dy += max_sub_height) {
1549             for (dx = 0; dx < w; dx += max_width) {
1550                 rw = MIN(max_sub_width, w - dx);
1551                 rh = MIN(max_sub_height, h - dy);
1552                 n += send_sub_rect(vs, x+dx, y+dy, rw, rh);
1553             }
1554         }
1555     } else {
1556         n += send_sub_rect(vs, x, y, w, h);
1557     }
1558 
1559     return n;
1560 }
1561 
1562 static int find_large_solid_color_rect(VncState *vs, int x, int y,
1563                                        int w, int h, int max_rows)
1564 {
1565     int dx, dy, dw, dh;
1566     int n = 0;
1567 
1568     /* Try to find large solid-color areas and send them separately. */
1569 
1570     for (dy = y; dy < y + h; dy += VNC_TIGHT_MAX_SPLIT_TILE_SIZE) {
1571 
1572         /* If a rectangle becomes too large, send its upper part now. */
1573 
1574         if (dy - y >= max_rows) {
1575             n += send_rect_simple(vs, x, y, w, max_rows, true);
1576             y += max_rows;
1577             h -= max_rows;
1578         }
1579 
1580         dh = MIN(VNC_TIGHT_MAX_SPLIT_TILE_SIZE, (y + h - dy));
1581 
1582         for (dx = x; dx < x + w; dx += VNC_TIGHT_MAX_SPLIT_TILE_SIZE) {
1583             uint32_t color_value;
1584             int x_best, y_best, w_best, h_best;
1585 
1586             dw = MIN(VNC_TIGHT_MAX_SPLIT_TILE_SIZE, (x + w - dx));
1587 
1588             if (!check_solid_tile(vs, dx, dy, dw, dh, &color_value, false)) {
1589                 continue ;
1590             }
1591 
1592             /* Get dimensions of solid-color area. */
1593 
1594             find_best_solid_area(vs, dx, dy, w - (dx - x), h - (dy - y),
1595                                  color_value, &w_best, &h_best);
1596 
1597             /* Make sure a solid rectangle is large enough
1598                (or the whole rectangle is of the same color). */
1599 
1600             if (w_best * h_best != w * h &&
1601                 w_best * h_best < VNC_TIGHT_MIN_SOLID_SUBRECT_SIZE) {
1602                 continue;
1603             }
1604 
1605             /* Try to extend solid rectangle to maximum size. */
1606 
1607             x_best = dx; y_best = dy;
1608             extend_solid_area(vs, x, y, w, h, color_value,
1609                               &x_best, &y_best, &w_best, &h_best);
1610 
1611             /* Send rectangles at top and left to solid-color area. */
1612 
1613             if (y_best != y) {
1614                 n += send_rect_simple(vs, x, y, w, y_best-y, true);
1615             }
1616             if (x_best != x) {
1617                 n += tight_send_framebuffer_update(vs, x, y_best,
1618                                                    x_best-x, h_best);
1619             }
1620 
1621             /* Send solid-color rectangle. */
1622             n += send_sub_rect_solid(vs, x_best, y_best, w_best, h_best);
1623 
1624             /* Send remaining rectangles (at right and bottom). */
1625 
1626             if (x_best + w_best != x + w) {
1627                 n += tight_send_framebuffer_update(vs, x_best+w_best,
1628                                                    y_best,
1629                                                    w-(x_best-x)-w_best,
1630                                                    h_best);
1631             }
1632             if (y_best + h_best != y + h) {
1633                 n += tight_send_framebuffer_update(vs, x, y_best+h_best,
1634                                                    w, h-(y_best-y)-h_best);
1635             }
1636 
1637             /* Return after all recursive calls are done. */
1638             return n;
1639         }
1640     }
1641     return n + send_rect_simple(vs, x, y, w, h, true);
1642 }
1643 
1644 static int tight_send_framebuffer_update(VncState *vs, int x, int y,
1645                                          int w, int h)
1646 {
1647     int max_rows;
1648 
1649     if (vs->client_pf.bytes_per_pixel == 4 && vs->client_pf.rmax == 0xFF &&
1650         vs->client_pf.bmax == 0xFF && vs->client_pf.gmax == 0xFF) {
1651         vs->tight.pixel24 = true;
1652     } else {
1653         vs->tight.pixel24 = false;
1654     }
1655 
1656 #ifdef CONFIG_VNC_JPEG
1657     if (vs->tight.quality != (uint8_t)-1) {
1658         double freq = vnc_update_freq(vs, x, y, w, h);
1659 
1660         if (freq > tight_jpeg_conf[vs->tight.quality].jpeg_freq_threshold) {
1661             return send_rect_simple(vs, x, y, w, h, false);
1662         }
1663     }
1664 #endif
1665 
1666     if (w * h < VNC_TIGHT_MIN_SPLIT_RECT_SIZE) {
1667         return send_rect_simple(vs, x, y, w, h, true);
1668     }
1669 
1670     /* Calculate maximum number of rows in one non-solid rectangle. */
1671 
1672     max_rows = tight_conf[vs->tight.compression].max_rect_size;
1673     max_rows /= MIN(tight_conf[vs->tight.compression].max_rect_width, w);
1674 
1675     return find_large_solid_color_rect(vs, x, y, w, h, max_rows);
1676 }
1677 
1678 int vnc_tight_send_framebuffer_update(VncState *vs, int x, int y,
1679                                       int w, int h)
1680 {
1681     vs->tight.type = VNC_ENCODING_TIGHT;
1682     return tight_send_framebuffer_update(vs, x, y, w, h);
1683 }
1684 
1685 int vnc_tight_png_send_framebuffer_update(VncState *vs, int x, int y,
1686                                           int w, int h)
1687 {
1688     vs->tight.type = VNC_ENCODING_TIGHT_PNG;
1689     return tight_send_framebuffer_update(vs, x, y, w, h);
1690 }
1691 
1692 void vnc_tight_clear(VncState *vs)
1693 {
1694     int i;
1695     for (i=0; i<ARRAY_SIZE(vs->tight.stream); i++) {
1696         if (vs->tight.stream[i].opaque) {
1697             deflateEnd(&vs->tight.stream[i]);
1698         }
1699     }
1700 
1701     buffer_free(&vs->tight.tight);
1702     buffer_free(&vs->tight.zlib);
1703     buffer_free(&vs->tight.gradient);
1704 #ifdef CONFIG_VNC_JPEG
1705     buffer_free(&vs->tight.jpeg);
1706 #endif
1707 #ifdef CONFIG_VNC_PNG
1708     buffer_free(&vs->tight.png);
1709 #endif
1710 }
1711