1 /*
2 * MLP codec common code
3 * Copyright (c) 2007-2008 Ian Caulfield
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 #include <stdint.h>
23
24 #include "libavutil/crc.h"
25 #include "libavutil/intreadwrite.h"
26 #include "libavutil/thread.h"
27 #include "mlp.h"
28
29 const uint8_t ff_mlp_huffman_tables[3][18][2] = {
30 { /* Huffman table 0, -7 - +10 */
31 {0x01, 9}, {0x01, 8}, {0x01, 7}, {0x01, 6}, {0x01, 5}, {0x01, 4}, {0x01, 3},
32 {0x04, 3}, {0x05, 3}, {0x06, 3}, {0x07, 3},
33 {0x03, 3}, {0x05, 4}, {0x09, 5}, {0x11, 6}, {0x21, 7}, {0x41, 8}, {0x81, 9},
34 }, { /* Huffman table 1, -7 - +8 */
35 {0x01, 9}, {0x01, 8}, {0x01, 7}, {0x01, 6}, {0x01, 5}, {0x01, 4}, {0x01, 3},
36 {0x02, 2}, {0x03, 2},
37 {0x03, 3}, {0x05, 4}, {0x09, 5}, {0x11, 6}, {0x21, 7}, {0x41, 8}, {0x81, 9},
38 }, { /* Huffman table 2, -7 - +7 */
39 {0x01, 9}, {0x01, 8}, {0x01, 7}, {0x01, 6}, {0x01, 5}, {0x01, 4}, {0x01, 3},
40 {0x01, 1},
41 {0x03, 3}, {0x05, 4}, {0x09, 5}, {0x11, 6}, {0x21, 7}, {0x41, 8}, {0x81, 9},
42 }
43 };
44
45 const ChannelInformation ff_mlp_ch_info[21] = {
46 { 0x01, 0x01, 0x00, 0x1f }, { 0x03, 0x02, 0x00, 0x1b },
47 { 0x07, 0x02, 0x01, 0x1f }, { 0x0F, 0x02, 0x02, 0x19 },
48 { 0x07, 0x02, 0x01, 0x03 }, { 0x0F, 0x02, 0x02, 0x1f },
49 { 0x1F, 0x02, 0x03, 0x01 }, { 0x07, 0x02, 0x01, 0x1a },
50 { 0x0F, 0x02, 0x02, 0x1f }, { 0x1F, 0x02, 0x03, 0x18 },
51 { 0x0F, 0x02, 0x02, 0x02 }, { 0x1F, 0x02, 0x03, 0x1f },
52 { 0x3F, 0x02, 0x04, 0x00 }, { 0x0F, 0x03, 0x01, 0x1f },
53 { 0x1F, 0x03, 0x02, 0x18 }, { 0x0F, 0x03, 0x01, 0x02 },
54 { 0x1F, 0x03, 0x02, 0x1f }, { 0x3F, 0x03, 0x03, 0x00 },
55 { 0x1F, 0x04, 0x01, 0x01 }, { 0x1F, 0x04, 0x01, 0x18 },
56 { 0x3F, 0x04, 0x02, 0x00 },
57 };
58
59 const uint64_t ff_mlp_channel_layouts[12] = {
60 AV_CH_LAYOUT_MONO, AV_CH_LAYOUT_STEREO, AV_CH_LAYOUT_2_1,
61 AV_CH_LAYOUT_QUAD, AV_CH_LAYOUT_2POINT1, AV_CH_LAYOUT_SURROUND,
62 AV_CH_LAYOUT_4POINT0, AV_CH_LAYOUT_5POINT0_BACK, AV_CH_LAYOUT_3POINT1,
63 AV_CH_LAYOUT_4POINT1, AV_CH_LAYOUT_5POINT1_BACK, 0,
64 };
65
66 #if CONFIG_SMALL
67 #define CRC_TABLE_SIZE 257
68 #else
69 #define CRC_TABLE_SIZE 1024
70 #endif
71 static AVCRC crc_63[CRC_TABLE_SIZE];
72 static AVCRC crc_1D[CRC_TABLE_SIZE];
73 static AVCRC crc_2D[CRC_TABLE_SIZE];
74
mlp_init_crc(void)75 static av_cold void mlp_init_crc(void)
76 {
77 av_crc_init(crc_63, 0, 8, 0x63, sizeof(crc_63));
78 av_crc_init(crc_1D, 0, 8, 0x1D, sizeof(crc_1D));
79 av_crc_init(crc_2D, 0, 16, 0x002D, sizeof(crc_2D));
80 }
81
ff_mlp_init_crc(void)82 av_cold void ff_mlp_init_crc(void)
83 {
84 static AVOnce init_static_once = AV_ONCE_INIT;
85 ff_thread_once(&init_static_once, mlp_init_crc);
86 }
87
ff_mlp_checksum16(const uint8_t * buf,unsigned int buf_size)88 uint16_t ff_mlp_checksum16(const uint8_t *buf, unsigned int buf_size)
89 {
90 uint16_t crc;
91
92 crc = av_crc(crc_2D, 0, buf, buf_size - 2);
93 crc ^= AV_RL16(buf + buf_size - 2);
94 return crc;
95 }
96
ff_mlp_checksum8(const uint8_t * buf,unsigned int buf_size)97 uint8_t ff_mlp_checksum8(const uint8_t *buf, unsigned int buf_size)
98 {
99 uint8_t checksum = av_crc(crc_63, 0x3c, buf, buf_size - 1); // crc_63[0xa2] == 0x3c
100 checksum ^= buf[buf_size-1];
101 return checksum;
102 }
103
ff_mlp_restart_checksum(const uint8_t * buf,unsigned int bit_size)104 uint8_t ff_mlp_restart_checksum(const uint8_t *buf, unsigned int bit_size)
105 {
106 int i;
107 int num_bytes = (bit_size + 2) / 8;
108
109 int crc = crc_1D[buf[0] & 0x3f];
110 crc = av_crc(crc_1D, crc, buf + 1, num_bytes - 2);
111 crc ^= buf[num_bytes - 1];
112
113 for (i = 0; i < ((bit_size + 2) & 7); i++) {
114 crc <<= 1;
115 if (crc & 0x100)
116 crc ^= 0x11D;
117 crc ^= (buf[num_bytes] >> (7 - i)) & 1;
118 }
119
120 return crc;
121 }
122
ff_mlp_calculate_parity(const uint8_t * buf,unsigned int buf_size)123 uint8_t ff_mlp_calculate_parity(const uint8_t *buf, unsigned int buf_size)
124 {
125 uint32_t scratch = 0;
126 const uint8_t *buf_end = buf + buf_size;
127
128 for (; ((intptr_t) buf & 3) && buf < buf_end; buf++)
129 scratch ^= *buf;
130 for (; buf < buf_end - 3; buf += 4)
131 scratch ^= *((const uint32_t*)buf);
132
133 scratch = xor_32_to_8(scratch);
134
135 for (; buf < buf_end; buf++)
136 scratch ^= *buf;
137
138 return scratch;
139 }
140