1 /*
2 * QEMU VNC display driver: Zlib Run-length Encoding (ZRLE)
3 *
4 * From libvncserver/libvncserver/zrle.c
5 * Copyright (C) 2002 RealVNC Ltd. All Rights Reserved.
6 * Copyright (C) 2003 Sun Microsystems, Inc.
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 #include "vnc.h"
31 #include "vnc-enc-zrle.h"
32
33 static const int bits_per_packed_pixel[] = {
34 0, 1, 2, 2, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4
35 };
36
37
vnc_zrle_start(VncState * vs)38 static void vnc_zrle_start(VncState *vs)
39 {
40 buffer_reset(&vs->zrle->zrle);
41
42 /* make the output buffer be the zlib buffer, so we can compress it later */
43 vs->zrle->tmp = vs->output;
44 vs->output = vs->zrle->zrle;
45 }
46
vnc_zrle_stop(VncState * vs)47 static void vnc_zrle_stop(VncState *vs)
48 {
49 /* switch back to normal output/zlib buffers */
50 vs->zrle->zrle = vs->output;
51 vs->output = vs->zrle->tmp;
52 }
53
zrle_convert_fb(VncState * vs,int x,int y,int w,int h,int bpp)54 static void *zrle_convert_fb(VncState *vs, int x, int y, int w, int h,
55 int bpp)
56 {
57 Buffer tmp;
58
59 buffer_reset(&vs->zrle->fb);
60 buffer_reserve(&vs->zrle->fb, w * h * bpp + bpp);
61
62 tmp = vs->output;
63 vs->output = vs->zrle->fb;
64
65 vnc_raw_send_framebuffer_update(vs, x, y, w, h);
66
67 vs->zrle->fb = vs->output;
68 vs->output = tmp;
69 return vs->zrle->fb.buffer;
70 }
71
zrle_compress_data(VncState * vs,int level)72 static int zrle_compress_data(VncState *vs, int level)
73 {
74 z_streamp zstream = &vs->zrle->stream;
75
76 buffer_reset(&vs->zrle->zlib);
77
78 if (zstream->opaque != vs) {
79 int err;
80
81 zstream->zalloc = vnc_zlib_zalloc;
82 zstream->zfree = vnc_zlib_zfree;
83
84 err = deflateInit2(zstream, level, Z_DEFLATED, MAX_WBITS,
85 MAX_MEM_LEVEL, Z_DEFAULT_STRATEGY);
86
87 if (err != Z_OK) {
88 fprintf(stderr, "VNC: error initializing zlib\n");
89 return -1;
90 }
91
92 zstream->opaque = vs;
93 }
94
95 /* reserve memory in output buffer */
96 buffer_reserve(&vs->zrle->zlib, vs->zrle->zrle.offset + 64);
97
98 /* set pointers */
99 zstream->next_in = vs->zrle->zrle.buffer;
100 zstream->avail_in = vs->zrle->zrle.offset;
101 zstream->next_out = vs->zrle->zlib.buffer;
102 zstream->avail_out = vs->zrle->zlib.capacity;
103 zstream->data_type = Z_BINARY;
104
105 /* start encoding */
106 if (deflate(zstream, Z_SYNC_FLUSH) != Z_OK) {
107 fprintf(stderr, "VNC: error during zrle compression\n");
108 return -1;
109 }
110
111 vs->zrle->zlib.offset = vs->zrle->zlib.capacity - zstream->avail_out;
112 return vs->zrle->zlib.offset;
113 }
114
115 /* Try to work out whether to use RLE and/or a palette. We do this by
116 * estimating the number of bytes which will be generated and picking the
117 * method which results in the fewest bytes. Of course this may not result
118 * in the fewest bytes after compression... */
zrle_choose_palette_rle(VncState * vs,int w,int h,VncPalette * palette,int bpp_out,int runs,int single_pixels,int zywrle_level,bool * use_rle,bool * use_palette)119 static void zrle_choose_palette_rle(VncState *vs, int w, int h,
120 VncPalette *palette, int bpp_out,
121 int runs, int single_pixels,
122 int zywrle_level,
123 bool *use_rle, bool *use_palette)
124 {
125 size_t estimated_bytes;
126 size_t plain_rle_bytes;
127
128 *use_palette = *use_rle = false;
129
130 estimated_bytes = w * h * (bpp_out / 8); /* start assuming raw */
131
132 if (bpp_out != 8) {
133 if (zywrle_level > 0 && !(zywrle_level & 0x80))
134 estimated_bytes >>= zywrle_level;
135 }
136
137 plain_rle_bytes = ((bpp_out / 8) + 1) * (runs + single_pixels);
138
139 if (plain_rle_bytes < estimated_bytes) {
140 *use_rle = true;
141 estimated_bytes = plain_rle_bytes;
142 }
143
144 if (palette_size(palette) < 128) {
145 int palette_rle_bytes;
146
147 palette_rle_bytes = (bpp_out / 8) * palette_size(palette);
148 palette_rle_bytes += 2 * runs + single_pixels;
149
150 if (palette_rle_bytes < estimated_bytes) {
151 *use_rle = true;
152 *use_palette = true;
153 estimated_bytes = palette_rle_bytes;
154 }
155
156 if (palette_size(palette) < 17) {
157 int packed_bytes;
158
159 packed_bytes = (bpp_out / 8) * palette_size(palette);
160 packed_bytes += w * h *
161 bits_per_packed_pixel[palette_size(palette)-1] / 8;
162
163 if (packed_bytes < estimated_bytes) {
164 *use_rle = false;
165 *use_palette = true;
166 }
167 }
168 }
169 }
170
zrle_write_u32(VncState * vs,uint32_t value)171 static void zrle_write_u32(VncState *vs, uint32_t value)
172 {
173 vnc_write(vs, (uint8_t *)&value, 4);
174 }
175
zrle_write_u24a(VncState * vs,uint32_t value)176 static void zrle_write_u24a(VncState *vs, uint32_t value)
177 {
178 vnc_write(vs, (uint8_t *)&value, 3);
179 }
180
zrle_write_u24b(VncState * vs,uint32_t value)181 static void zrle_write_u24b(VncState *vs, uint32_t value)
182 {
183 vnc_write(vs, ((uint8_t *)&value) + 1, 3);
184 }
185
zrle_write_u16(VncState * vs,uint16_t value)186 static void zrle_write_u16(VncState *vs, uint16_t value)
187 {
188 vnc_write(vs, (uint8_t *)&value, 2);
189 }
190
zrle_write_u8(VncState * vs,uint8_t value)191 static void zrle_write_u8(VncState *vs, uint8_t value)
192 {
193 vnc_write_u8(vs, value);
194 }
195
196 #define ENDIAN_LITTLE 0
197 #define ENDIAN_BIG 1
198 #define ENDIAN_NO 2
199
200 #define ZRLE_BPP 8
201 #define ZYWRLE_ENDIAN ENDIAN_NO
202 #include "vnc-enc-zrle.c.inc"
203 #undef ZRLE_BPP
204
205 #define ZRLE_BPP 15
206 #undef ZYWRLE_ENDIAN
207 #define ZYWRLE_ENDIAN ENDIAN_LITTLE
208 #include "vnc-enc-zrle.c.inc"
209
210 #undef ZYWRLE_ENDIAN
211 #define ZYWRLE_ENDIAN ENDIAN_BIG
212 #include "vnc-enc-zrle.c.inc"
213
214 #undef ZRLE_BPP
215 #define ZRLE_BPP 16
216 #undef ZYWRLE_ENDIAN
217 #define ZYWRLE_ENDIAN ENDIAN_LITTLE
218 #include "vnc-enc-zrle.c.inc"
219
220 #undef ZYWRLE_ENDIAN
221 #define ZYWRLE_ENDIAN ENDIAN_BIG
222 #include "vnc-enc-zrle.c.inc"
223
224 #undef ZRLE_BPP
225 #define ZRLE_BPP 32
226 #undef ZYWRLE_ENDIAN
227 #define ZYWRLE_ENDIAN ENDIAN_LITTLE
228 #include "vnc-enc-zrle.c.inc"
229
230 #undef ZYWRLE_ENDIAN
231 #define ZYWRLE_ENDIAN ENDIAN_BIG
232 #include "vnc-enc-zrle.c.inc"
233
234 #define ZRLE_COMPACT_PIXEL 24a
235 #undef ZYWRLE_ENDIAN
236 #define ZYWRLE_ENDIAN ENDIAN_LITTLE
237 #include "vnc-enc-zrle.c.inc"
238
239 #undef ZYWRLE_ENDIAN
240 #define ZYWRLE_ENDIAN ENDIAN_BIG
241 #include "vnc-enc-zrle.c.inc"
242
243 #undef ZRLE_COMPACT_PIXEL
244 #define ZRLE_COMPACT_PIXEL 24b
245 #undef ZYWRLE_ENDIAN
246 #define ZYWRLE_ENDIAN ENDIAN_LITTLE
247 #include "vnc-enc-zrle.c.inc"
248
249 #undef ZYWRLE_ENDIAN
250 #define ZYWRLE_ENDIAN ENDIAN_BIG
251 #include "vnc-enc-zrle.c.inc"
252 #undef ZRLE_COMPACT_PIXEL
253 #undef ZRLE_BPP
254
zrle_send_framebuffer_update(VncState * vs,int x,int y,int w,int h)255 static int zrle_send_framebuffer_update(VncState *vs, int x, int y,
256 int w, int h)
257 {
258 bool be = vs->client_be;
259 size_t bytes;
260 int zywrle_level;
261
262 if (vs->zrle->type == VNC_ENCODING_ZYWRLE) {
263 if (!vs->vd->lossy || vs->tight->quality == (uint8_t)-1
264 || vs->tight->quality == 9) {
265 zywrle_level = 0;
266 vs->zrle->type = VNC_ENCODING_ZRLE;
267 } else if (vs->tight->quality < 3) {
268 zywrle_level = 3;
269 } else if (vs->tight->quality < 6) {
270 zywrle_level = 2;
271 } else {
272 zywrle_level = 1;
273 }
274 } else {
275 zywrle_level = 0;
276 }
277
278 vnc_zrle_start(vs);
279
280 switch (vs->client_pf.bytes_per_pixel) {
281 case 1:
282 zrle_encode_8ne(vs, x, y, w, h, zywrle_level);
283 break;
284
285 case 2:
286 if (vs->client_pf.gmax > 0x1F) {
287 if (be) {
288 zrle_encode_16be(vs, x, y, w, h, zywrle_level);
289 } else {
290 zrle_encode_16le(vs, x, y, w, h, zywrle_level);
291 }
292 } else {
293 if (be) {
294 zrle_encode_15be(vs, x, y, w, h, zywrle_level);
295 } else {
296 zrle_encode_15le(vs, x, y, w, h, zywrle_level);
297 }
298 }
299 break;
300
301 case 4:
302 {
303 bool fits_in_ls3bytes;
304 bool fits_in_ms3bytes;
305
306 fits_in_ls3bytes =
307 ((vs->client_pf.rmax << vs->client_pf.rshift) < (1 << 24) &&
308 (vs->client_pf.gmax << vs->client_pf.gshift) < (1 << 24) &&
309 (vs->client_pf.bmax << vs->client_pf.bshift) < (1 << 24));
310
311 fits_in_ms3bytes = (vs->client_pf.rshift > 7 &&
312 vs->client_pf.gshift > 7 &&
313 vs->client_pf.bshift > 7);
314
315 if ((fits_in_ls3bytes && !be) || (fits_in_ms3bytes && be)) {
316 if (be) {
317 zrle_encode_24abe(vs, x, y, w, h, zywrle_level);
318 } else {
319 zrle_encode_24ale(vs, x, y, w, h, zywrle_level);
320 }
321 } else if ((fits_in_ls3bytes && be) || (fits_in_ms3bytes && !be)) {
322 if (be) {
323 zrle_encode_24bbe(vs, x, y, w, h, zywrle_level);
324 } else {
325 zrle_encode_24ble(vs, x, y, w, h, zywrle_level);
326 }
327 } else {
328 if (be) {
329 zrle_encode_32be(vs, x, y, w, h, zywrle_level);
330 } else {
331 zrle_encode_32le(vs, x, y, w, h, zywrle_level);
332 }
333 }
334 }
335 break;
336 }
337
338 vnc_zrle_stop(vs);
339 bytes = zrle_compress_data(vs, Z_DEFAULT_COMPRESSION);
340 vnc_framebuffer_update(vs, x, y, w, h, vs->zrle->type);
341 vnc_write_u32(vs, bytes);
342 vnc_write(vs, vs->zrle->zlib.buffer, vs->zrle->zlib.offset);
343 return 1;
344 }
345
vnc_zrle_send_framebuffer_update(VncState * vs,int x,int y,int w,int h)346 int vnc_zrle_send_framebuffer_update(VncState *vs, int x, int y, int w, int h)
347 {
348 vs->zrle->type = VNC_ENCODING_ZRLE;
349 return zrle_send_framebuffer_update(vs, x, y, w, h);
350 }
351
vnc_zywrle_send_framebuffer_update(VncState * vs,int x,int y,int w,int h)352 int vnc_zywrle_send_framebuffer_update(VncState *vs, int x, int y, int w, int h)
353 {
354 vs->zrle->type = VNC_ENCODING_ZYWRLE;
355 return zrle_send_framebuffer_update(vs, x, y, w, h);
356 }
357
vnc_zrle_clear(VncState * vs)358 void vnc_zrle_clear(VncState *vs)
359 {
360 if (vs->zrle->stream.opaque) {
361 deflateEnd(&vs->zrle->stream);
362 }
363 buffer_free(&vs->zrle->zrle);
364 buffer_free(&vs->zrle->fb);
365 buffer_free(&vs->zrle->zlib);
366 }
367