xine-lib: xine-lib-1.2.13/src/demuxers/demux_real_common.h Source File

xine-lib 1.2.13-20230125hg15249

demux_real_common.h
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1/*
2 * Copyright (C) 2008-2018 the xine project
3 *
4 * This file is part of xine, a free video player.
5 *
6 * xine is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * xine is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
19 */
20
21 static inline void demux_real_sipro_swap (char buffer[], int bs)
22{
23 /* bs = nybbles per subpacket */
24 static const unsigned char sipr_swaps[38][2] = {
25 {0, 63}, {1, 22}, {2, 44}, {3, 90}, {5, 81}, {7, 31}, {8, 86}, {9, 58},
26 {10, 36}, {12, 68}, {13, 39}, {14, 73}, {15, 53}, {16, 69}, {17, 57},
27 {19, 88}, {20, 34}, {21, 71}, {24, 46}, {25, 94}, {26, 54}, {28, 75},
28 {29, 50}, {32, 70}, {33, 92}, {35, 74}, {38, 85}, {40, 56}, {42, 87},
29 {43, 65}, {45, 59}, {48, 79}, {49, 93}, {51, 89}, {55, 95}, {61, 76},
30 {67, 83}, {77, 80}
31 };
32 int n;
33
34 for (n = 0; n < 38; ++n)
35 {
36 int j;
37 int i = bs * sipr_swaps[n][0];
38 int o = bs * sipr_swaps[n][1];
39 /* swap nibbles of block 'i' with 'o' TODO: optimize */
40 for (j = 0; j < bs; ++j)
41 {
42 int x = (i & 1) ? (buffer[i >> 1] >> 4) : (buffer[i >> 1] & 0x0F);
43 int y = (o & 1) ? (buffer[o >> 1] >> 4) : (buffer[o >> 1] & 0x0F);
44 if (o & 1)
45 buffer[o >> 1] = (buffer[o >> 1] & 0x0F) | (x << 4);
46 else
47 buffer[o >> 1] = (buffer[o >> 1] & 0xF0) | x;
48 if (i & 1)
49 buffer[i >> 1] = (buffer[i >> 1] & 0x0F) | (y << 4);
50 else
51 buffer[i >> 1] = (buffer[i >> 1] & 0xF0) | y;
52 ++i;
53 ++o;
54 }
55 }
56}
demux_real_sipro_swap
static void demux_real_sipro_swap(char buffer[], int bs)
Definition demux_real_common.h:21