xref: /qemu/ui/vnc-enc-zrle.c.inc (revision 14f5a7ba) 
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 want 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 *run_start;
157        ZRLE_PIXEL pix;
158
159        ptr = data;
160        end = ptr + w * h;
161
162        while (ptr < end) {
163            int len;
164            int index = 0;
165
166            run_start = ptr;
167            pix = *ptr++;
168
169            while (*ptr == pix && ptr < end) {
170                ptr++;
171            }
172
173            len = ptr - run_start;
174
175            if (use_palette)
176                index = palette_idx(palette, pix);
177
178            if (len <= 2 && use_palette) {
179                if (len == 2) {
180                    vnc_write_u8(vs, index);
181                }
182                vnc_write_u8(vs, index);
183                continue;
184            }
185            if (use_palette) {
186                vnc_write_u8(vs, index | 128);
187            } else {
188                ZRLE_WRITE_PIXEL(vs, pix);
189            }
190
191            len -= 1;
192
193            while (len >= 255) {
194                vnc_write_u8(vs, 255);
195                len -= 255;
196            }
197
198            vnc_write_u8(vs, len);
199        }
200    } else if (use_palette) { /* no RLE */
201        int bppp;
202        ptr = data;
203
204        /* packed pixels */
205
206        assert (palette_size(palette) < 17);
207
208        bppp = bits_per_packed_pixel[palette_size(palette)-1];
209
210        for (i = 0; i < h; i++) {
211            uint8_t nbits = 0;
212            uint8_t byte = 0;
213
214            ZRLE_PIXEL *eol = ptr + w;
215
216            while (ptr < eol) {
217                ZRLE_PIXEL pix = *ptr++;
218                uint8_t index = palette_idx(palette, pix);
219
220                byte = (byte << bppp) | index;
221                nbits += bppp;
222                if (nbits >= 8) {
223                    vnc_write_u8(vs, byte);
224                    nbits = 0;
225                }
226            }
227            if (nbits > 0) {
228                byte <<= 8 - nbits;
229                vnc_write_u8(vs, byte);
230            }
231        }
232    } else {
233
234        /* raw */
235
236#if ZRLE_BPP != 8
237        if (zywrle_level > 0 && !(zywrle_level & 0x80)) {
238            ZYWRLE_ANALYZE(data, data, w, h, w, zywrle_level, vs->zywrle.buf);
239            ZRLE_ENCODE_TILE(vs, data, w, h, zywrle_level | 0x80);
240        }
241        else
242#endif
243        {
244#ifdef ZRLE_COMPACT_PIXEL
245            for (ptr = data; ptr < data + w * h; ptr++) {
246                ZRLE_WRITE_PIXEL(vs, *ptr);
247            }
248#else
249            vnc_write(vs, data, w * h * (ZRLE_BPP / 8));
250#endif
251        }
252    }
253}
254
255#undef ZRLE_PIXEL
256#undef ZRLE_WRITE_PIXEL
257#undef ZRLE_ENCODE
258#undef ZRLE_ENCODE_TILE
259#undef ZYWRLE_ENCODE_TILE
260#undef ZRLE_BPP_OUT
261#undef ZRLE_WRITE_SUFFIX
262#undef ZRLE_ENCODE_SUFFIX
263