xrdp/libxrdp/xrdp_bitmap32_compress.c

306 lines
7.5 KiB
C

/**
* xrdp: A Remote Desktop Protocol server.
*
* Copyright (C) Jay Sorg 2014
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* planar bitmap compressor
* 32 bpp compression
*/
/*
RDP 6.0 Bitmap Compression
http://msdn.microsoft.com/en-us/library/cc241877.aspx
*/
#include "libxrdp.h"
#define FLAGS_RLE 0x10
#define FLAGS_NOALPHA 0x20
#define LLOG_LEVEL 1
#define LLOGLN(_level, _args) \
do { if (_level < LLOG_LEVEL) { g_writeln _args ; } } while (0)
#define LHEXDUMP(_level, _args) \
do { if (_level < LLOG_LEVEL) { g_hexdump _args ; } } while (0)
/*****************************************************************************/
static int APP_CC
fdelta(char *plane, int cx, int cy)
{
char delta;
char *ptr8;
int index;
int jndex;
for (jndex = cy - 2; jndex >= 0; jndex--)
{
ptr8 = plane + jndex * cx;
for (index = 0; index < cx; index++)
{
delta = ptr8[cx] - ptr8[0];
if (delta & 0x80)
{
delta = (((~delta) + 1) << 1) - 1;
}
else
{
delta = delta << 1;
}
ptr8[cx] = delta;
ptr8++;
}
}
return 0;
}
/*****************************************************************************/
static int APP_CC
fout(int collen, int replen, char *colptr, struct stream *s)
{
int code;
int lcollen;
int lreplen;
int cont;
LLOGLN(10, ("fout: collen %d replen %d", collen, replen));
cont = collen > 13;
while (cont)
{
lcollen = collen;
if (lcollen > 15)
{
lcollen = 15;
}
code = lcollen << 4;
out_uint8(s, code);
out_uint8a(s, colptr, lcollen);
colptr += lcollen;
collen -= lcollen;
cont = collen > 13;
}
cont = (collen > 0) || (replen > 0);
while (cont)
{
lreplen = replen;
if ((collen == 0) && (lreplen > 15))
{
/* big run */
if (lreplen > 47)
{
lreplen = 47;
}
LLOGLN(10, ("fout: big run lreplen %d", lreplen));
replen -= lreplen;
code = ((lreplen & 0xF) << 4) | ((lreplen & 0xF0) >> 4);
}
else
{
if (lreplen > 15)
{
lreplen = 15;
}
replen -= lreplen;
if (lreplen < 3)
{
collen += lreplen;
lreplen = 0;
}
code = (collen << 4) | lreplen;
}
out_uint8(s, code);
out_uint8a(s, colptr, collen);
colptr += collen + lreplen;
collen = 0;
cont = replen > 0;
}
return 0;
}
/*****************************************************************************/
static int APP_CC
fpack(char *plane, int cx, int cy, struct stream *s)
{
char *ptr8;
char *colptr;
char *lend;
int jndex;
int collen;
int replen;
LLOGLN(10, ("fpack:"));
for (jndex = 0; jndex < cy; jndex++)
{
LLOGLN(10, ("line start line %d cx %d cy %d", jndex, cx, cy));
ptr8 = plane + jndex * cx;
LHEXDUMP(10, (ptr8, cx));
lend = ptr8 + (cx - 1);
colptr = ptr8;
if (colptr[0] == 0)
{
collen = 0;
replen = 1;
}
else
{
collen = 1;
replen = 0;
}
while (ptr8 < lend)
{
if (ptr8[0] == ptr8[1])
{
replen++;
}
else
{
if (replen > 0)
{
if (replen < 3)
{
collen += replen + 1;
replen = 0;
}
else
{
fout(collen, replen, colptr, s);
colptr = ptr8 + 1;
replen = 0;
collen = 1;
}
}
else
{
collen++;
}
}
ptr8++;
}
/* end of line */
fout(collen, replen, colptr, s);
}
return 0;
}
/*****************************************************************************/
/* returns the number of lines compressed */
int APP_CC
xrdp_bitmap32_compress(char *in_data, int width, int height,
struct stream *s, int bpp, int byte_limit,
int start_line, struct stream *temp_s,
int e)
{
int pixel;
int *ptr32;
char *alpha_data;
char *red_data;
char *green_data;
char *blue_data;
int alpha_bytes;
int red_bytes;
int green_bytes;
int blue_bytes;
int index;
int cx;
int cy;
int header;
LLOGLN(10, ("xrdp_bitmap32_compress:"));
//header = FLAGS_NOALPHA | FLAGS_RLE;
//header = FLAGS_NOALPHA;
header = FLAGS_RLE;
cx = width + e;
cy = 0;
alpha_data = temp_s->data;
red_data = alpha_data + cx * height;
green_data = red_data + cx * height;
blue_data = green_data + cx * height;
alpha_bytes = 0;
red_bytes = 0;
green_bytes = 0;
blue_bytes = 0;
/* split planes */
while (start_line >= 0)
{
ptr32 = (int *) (in_data + start_line * width * 4);
for (index = 0; index < width; index++)
{
pixel = *ptr32;
ptr32++;
alpha_data[alpha_bytes] = pixel >> 24;
alpha_bytes++;
red_data[red_bytes] = pixel >> 16;
red_bytes++;
green_data[green_bytes] = pixel >> 8;
green_bytes++;
blue_data[blue_bytes] = pixel >> 0;
blue_bytes++;
}
for (index = 0; index < e; index++)
{
alpha_data[alpha_bytes] = 0;
alpha_bytes++;
red_data[red_bytes] = 0;
red_bytes++;
green_data[green_bytes] = 0;
green_bytes++;
blue_data[blue_bytes] = 0;
blue_bytes++;
}
start_line--;
cy++;
}
if (header & FLAGS_RLE)
{
out_uint8(s, header);
/* delta, other steps */
if ((header & FLAGS_NOALPHA) == 0)
{
fdelta(alpha_data, cx, cy);
}
fdelta(red_data, cx, cy);
fdelta(green_data, cx, cy);
fdelta(blue_data, cx, cy);
/* pack */
if ((header & FLAGS_NOALPHA) == 0)
{
fpack(alpha_data, cx, cy, s);
}
fpack(red_data, cx, cy, s);
fpack(green_data, cx, cy, s);
fpack(blue_data, cx, cy, s);
}
else
{
out_uint8(s, header);
if ((header & FLAGS_NOALPHA) == 0)
{
out_uint8a(s, alpha_data, alpha_bytes);
}
out_uint8a(s, red_data, red_bytes);
out_uint8a(s, green_data, green_bytes);
out_uint8a(s, blue_data, blue_bytes);
/* pad if no RLE */
out_uint8(s, 0x00);
}
return cy;
}