1/*
2 * QEMU VNC display driver: Zlib Run-length Encoding (ZRLE)
3 *
4 * From libvncserver/libvncserver/zrleencodetemplate.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 * This work is licensed under the terms of the GNU GPL, version 2 or later.
11 * See the COPYING file in the top-level directory.
12 */
13
14/*
15 * Before including this file, you must define a number of CPP macros.
16 *
17 * ZRLE_BPP should be 8, 16 or 32 depending on the bits per pixel.
18 *
19 * Note that the buf argument to ZRLE_ENCODE needs to be at least one pixel
20 * bigger than the largest tile of pixel data, since the ZRLE encoding
21 * algorithm writes to the position one past the end of the pixel data.
22 */
23
24
25#include "qemu/osdep.h"
26
27#undef ZRLE_ENDIAN_SUFFIX
28
29#if ZYWRLE_ENDIAN == ENDIAN_LITTLE
30#define ZRLE_ENDIAN_SUFFIX le
31#elif ZYWRLE_ENDIAN == ENDIAN_BIG
32#define ZRLE_ENDIAN_SUFFIX be
33#else
34#define ZRLE_ENDIAN_SUFFIX ne
35#endif
36
37#ifndef ZRLE_CONCAT
38#define ZRLE_CONCAT_I(a, b) a##b
39#define ZRLE_CONCAT2(a, b) ZRLE_CONCAT_I(a, b)
40#define ZRLE_CONCAT3(a, b, c) ZRLE_CONCAT2(a, ZRLE_CONCAT2(b, c))
41#endif
42
43#ifdef ZRLE_COMPACT_PIXEL
44#define ZRLE_ENCODE_SUFFIX ZRLE_CONCAT2(ZRLE_COMPACT_PIXEL,ZRLE_ENDIAN_SUFFIX)
45#define ZRLE_WRITE_SUFFIX ZRLE_COMPACT_PIXEL
46#define ZRLE_PIXEL ZRLE_CONCAT3(uint,ZRLE_BPP,_t)
47#define ZRLE_BPP_OUT 24
48#elif ZRLE_BPP == 15
49#define ZRLE_ENCODE_SUFFIX ZRLE_CONCAT2(ZRLE_BPP,ZRLE_ENDIAN_SUFFIX)
50#define ZRLE_WRITE_SUFFIX 16
51#define ZRLE_PIXEL uint16_t
52#define ZRLE_BPP_OUT 16
53#else
54#define ZRLE_ENCODE_SUFFIX ZRLE_CONCAT2(ZRLE_BPP,ZRLE_ENDIAN_SUFFIX)
55#define ZRLE_WRITE_SUFFIX ZRLE_BPP
56#define ZRLE_BPP_OUT ZRLE_BPP
57#define ZRLE_PIXEL ZRLE_CONCAT3(uint,ZRLE_BPP,_t)
58#endif
59
60#define ZRLE_WRITE_PIXEL ZRLE_CONCAT2(zrle_write_u, ZRLE_WRITE_SUFFIX)
61#define ZRLE_ENCODE ZRLE_CONCAT2(zrle_encode_, ZRLE_ENCODE_SUFFIX)
62#define ZRLE_ENCODE_TILE ZRLE_CONCAT2(zrle_encode_tile, ZRLE_ENCODE_SUFFIX)
63#define ZRLE_WRITE_PALETTE ZRLE_CONCAT2(zrle_write_palette,ZRLE_ENCODE_SUFFIX)
64
65static void ZRLE_ENCODE_TILE(VncState *vs, ZRLE_PIXEL *data, int w, int h,
66 int zywrle_level);
67
68#if ZRLE_BPP != 8
69#include "vnc-enc-zywrle-template.c"
70#endif
71
72
73static void ZRLE_ENCODE(VncState *vs, int x, int y, int w, int h,
74 int zywrle_level)
75{
76 int ty;
77
78 for (ty = y; ty < y + h; ty += VNC_ZRLE_TILE_HEIGHT) {
79
80 int tx, th;
81
82 th = MIN(VNC_ZRLE_TILE_HEIGHT, y + h - ty);
83
84 for (tx = x; tx < x + w; tx += VNC_ZRLE_TILE_WIDTH) {
85 int tw;
86 ZRLE_PIXEL *buf;
87
88 tw = MIN(VNC_ZRLE_TILE_WIDTH, x + w - tx);
89
90 buf = zrle_convert_fb(vs, tx, ty, tw, th, ZRLE_BPP);
91 ZRLE_ENCODE_TILE(vs, buf, tw, th, zywrle_level);
92 }
93 }
94}
95
96static void ZRLE_ENCODE_TILE(VncState *vs, ZRLE_PIXEL *data, int w, int h,
97 int zywrle_level)
98{
99 VncPalette *palette = &vs->zrle.palette;
100
101 int runs = 0;
102 int single_pixels = 0;
103
104 bool use_rle;
105 bool use_palette;
106
107 int i;
108
109 ZRLE_PIXEL *ptr = data;
110 ZRLE_PIXEL *end = ptr + h * w;
111 *end = ~*(end-1); /* one past the end is different so the while loop ends */
112
113 /* Real limit is 127 but we wan't a way to know if there is more than 127 */
114 palette_init(palette, 256, ZRLE_BPP);
115
116 while (ptr < end) {
117 ZRLE_PIXEL pix = *ptr;
118 if (*++ptr != pix) { /* FIXME */
119 single_pixels++;
120 } else {
121 while (*++ptr == pix) ;
122 runs++;
123 }
124 palette_put(palette, pix);
125 }
126
127 /* Solid tile is a special case */
128
129 if (palette_size(palette) == 1) {
130 bool found;
131
132 vnc_write_u8(vs, 1);
133 ZRLE_WRITE_PIXEL(vs, palette_color(palette, 0, &found));
134 return;
135 }
136
137 zrle_choose_palette_rle(vs, w, h, palette, ZRLE_BPP_OUT,
138 runs, single_pixels, zywrle_level,
139 &use_rle, &use_palette);
140
141 if (!use_palette) {
142 vnc_write_u8(vs, (use_rle ? 128 : 0));
143 } else {
144 uint32_t colors[VNC_PALETTE_MAX_SIZE];
145 size_t size = palette_size(palette);
146
147 vnc_write_u8(vs, (use_rle ? 128 : 0) | size);
148 palette_fill(palette, colors);
149
150 for (i = 0; i < size; i++) {
151 ZRLE_WRITE_PIXEL(vs, colors[i]);
152 }
153 }
154
155 if (use_rle) {
156 ZRLE_PIXEL *ptr = data;
157 ZRLE_PIXEL *end = ptr + w * h;
158 ZRLE_PIXEL *run_start;
159 ZRLE_PIXEL pix;
160
161 while (ptr < end) {
162 int len;
163 int index = 0;
164
165 run_start = ptr;
166 pix = *ptr++;
167
168 while (*ptr == pix && ptr < end) {
169 ptr++;
170 }
171
172 len = ptr - run_start;
173
174 if (use_palette)
175 index = palette_idx(palette, pix);
176
177 if (len <= 2 && use_palette) {
178 if (len == 2) {
179 vnc_write_u8(vs, index);
180 }
181 vnc_write_u8(vs, index);
182 continue;
183 }
184 if (use_palette) {
185 vnc_write_u8(vs, index | 128);
186 } else {
187 ZRLE_WRITE_PIXEL(vs, pix);
188 }
189
190 len -= 1;
191
192 while (len >= 255) {
193 vnc_write_u8(vs, 255);
194 len -= 255;
195 }
196
197 vnc_write_u8(vs, len);
198 }
199 } else if (use_palette) { /* no RLE */
200 int bppp;
201 ZRLE_PIXEL *ptr = data;
202
203 /* packed pixels */
204
205 assert (palette_size(palette) < 17);
206
207 bppp = bits_per_packed_pixel[palette_size(palette)-1];
208
209 for (i = 0; i < h; i++) {
210 uint8_t nbits = 0;
211 uint8_t byte = 0;
212
213 ZRLE_PIXEL *eol = ptr + w;
214
215 while (ptr < eol) {
216 ZRLE_PIXEL pix = *ptr++;
217 uint8_t index = palette_idx(palette, pix);
218
219 byte = (byte << bppp) | index;
220 nbits += bppp;
221 if (nbits >= 8) {
222 vnc_write_u8(vs, byte);
223 nbits = 0;
224 }
225 }
226 if (nbits > 0) {
227 byte <<= 8 - nbits;
228 vnc_write_u8(vs, byte);
229 }
230 }
231 } else {
232
233 /* raw */
234
235#if ZRLE_BPP != 8
236 if (zywrle_level > 0 && !(zywrle_level & 0x80)) {
237 ZYWRLE_ANALYZE(data, data, w, h, w, zywrle_level, vs->zywrle.buf);
238 ZRLE_ENCODE_TILE(vs, data, w, h, zywrle_level | 0x80);
239 }
240 else
241#endif
242 {
243#ifdef ZRLE_COMPACT_PIXEL
244 ZRLE_PIXEL *ptr;
245
246 for (ptr = data; ptr < data + w * h; ptr++) {
247 ZRLE_WRITE_PIXEL(vs, *ptr);
248 }
249#else
250 vnc_write(vs, data, w * h * (ZRLE_BPP / 8));
251#endif
252 }
253 }
254}
255
256#undef ZRLE_PIXEL
257#undef ZRLE_WRITE_PIXEL
258#undef ZRLE_ENCODE
259#undef ZRLE_ENCODE_TILE
260#undef ZYWRLE_ENCODE_TILE
261#undef ZRLE_BPP_OUT
262#undef ZRLE_WRITE_SUFFIX
263#undef ZRLE_ENCODE_SUFFIX
264