1 /*
2 * Copyright (C) 2017 foo86
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg 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 GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21 #include "get_bits.h"
22 #include "put_bits.h"
23 #include "dolby_e.h"
24
25 static const uint8_t nb_programs_tab[MAX_PROG_CONF + 1] = {
26 2, 3, 2, 3, 4, 5, 4, 5, 6, 7, 8, 1, 2, 3, 3, 4, 5, 6, 1, 2, 3, 4, 1, 1
27 };
28
29 static const uint8_t nb_channels_tab[MAX_PROG_CONF + 1] = {
30 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 6, 6, 6, 6, 6, 6, 6, 4, 4, 4, 4, 8, 8
31 };
32
33 static const uint16_t sample_rate_tab[16] = {
34 0, 42965, 43008, 44800, 53706, 53760
35 };
36
skip_input(DBEContext * s,int nb_words)37 static int skip_input(DBEContext *s, int nb_words)
38 {
39 if (nb_words > s->input_size) {
40 return AVERROR_INVALIDDATA;
41 }
42
43 s->input += nb_words * s->word_bytes;
44 s->input_size -= nb_words;
45 return 0;
46 }
47
parse_key(DBEContext * s)48 static int parse_key(DBEContext *s)
49 {
50 if (s->key_present) {
51 const uint8_t *key = s->input;
52 int ret = skip_input(s, 1);
53 if (ret < 0)
54 return ret;
55 return AV_RB24(key) >> 24 - s->word_bits;
56 }
57 return 0;
58 }
59
ff_dolby_e_convert_input(DBEContext * s,int nb_words,int key)60 int ff_dolby_e_convert_input(DBEContext *s, int nb_words, int key)
61 {
62 const uint8_t *src = s->input;
63 uint8_t *dst = s->buffer;
64 PutBitContext pb;
65 int i;
66
67 av_assert0(nb_words <= 1024u);
68
69 if (nb_words > s->input_size) {
70 if (s->avctx)
71 av_log(s->avctx, AV_LOG_ERROR, "Packet too short\n");
72 return AVERROR_INVALIDDATA;
73 }
74
75 switch (s->word_bits) {
76 case 16:
77 for (i = 0; i < nb_words; i++, src += 2, dst += 2)
78 AV_WB16(dst, AV_RB16(src) ^ key);
79 break;
80 case 20:
81 init_put_bits(&pb, s->buffer, sizeof(s->buffer));
82 for (i = 0; i < nb_words; i++, src += 3)
83 put_bits(&pb, 20, AV_RB24(src) >> 4 ^ key);
84 flush_put_bits(&pb);
85 break;
86 case 24:
87 for (i = 0; i < nb_words; i++, src += 3, dst += 3)
88 AV_WB24(dst, AV_RB24(src) ^ key);
89 break;
90 default:
91 av_assert0(0);
92 }
93
94 return init_get_bits(&s->gb, s->buffer, nb_words * s->word_bits);
95 }
96
ff_dolby_e_parse_header(DBEContext * s,const uint8_t * buf,int buf_size)97 int ff_dolby_e_parse_header(DBEContext *s, const uint8_t *buf, int buf_size)
98 {
99 DolbyEHeaderInfo *const header = &s->metadata;
100 int hdr, ret, key, mtd_size;
101
102 if (buf_size < 3)
103 return AVERROR_INVALIDDATA;
104
105 hdr = AV_RB24(buf);
106 if ((hdr & 0xfffffe) == 0x7888e) {
107 s->word_bits = 24;
108 } else if ((hdr & 0xffffe0) == 0x788e0) {
109 s->word_bits = 20;
110 } else if ((hdr & 0xfffe00) == 0x78e00) {
111 s->word_bits = 16;
112 } else {
113 if (s->avctx)
114 av_log(s->avctx, AV_LOG_ERROR, "Invalid frame header\n");
115 return AVERROR_INVALIDDATA;
116 }
117
118 s->word_bytes = s->word_bits + 7 >> 3;
119 s->input = buf + s->word_bytes;
120 s->input_size = buf_size / s->word_bytes - 1;
121 s->key_present = hdr >> 24 - s->word_bits & 1;
122
123 if ((key = parse_key(s)) < 0)
124 return key;
125 if ((ret = ff_dolby_e_convert_input(s, 1, key)) < 0)
126 return ret;
127
128 skip_bits(&s->gb, 4);
129 mtd_size = get_bits(&s->gb, 10);
130 if (!mtd_size) {
131 if (s->avctx)
132 av_log(s->avctx, AV_LOG_ERROR, "Invalid metadata size\n");
133 return AVERROR_INVALIDDATA;
134 }
135
136 if ((ret = ff_dolby_e_convert_input(s, mtd_size, key)) < 0)
137 return ret;
138
139 skip_bits(&s->gb, 14);
140 header->prog_conf = get_bits(&s->gb, 6);
141 if (header->prog_conf > MAX_PROG_CONF) {
142 if (s->avctx)
143 av_log(s->avctx, AV_LOG_ERROR, "Invalid program configuration\n");
144 return AVERROR_INVALIDDATA;
145 }
146
147 header->nb_channels = nb_channels_tab[header->prog_conf];
148 header->nb_programs = nb_programs_tab[header->prog_conf];
149
150 header->fr_code = get_bits(&s->gb, 4);
151 header->fr_code_orig = get_bits(&s->gb, 4);
152 if (!(header->sample_rate = sample_rate_tab[header->fr_code]) ||
153 !sample_rate_tab[header->fr_code_orig]) {
154 if (s->avctx)
155 av_log(s->avctx, AV_LOG_ERROR, "Invalid frame rate code\n");
156 return AVERROR_INVALIDDATA;
157 }
158
159 skip_bits_long(&s->gb, 88);
160 for (int i = 0; i < header->nb_channels; i++)
161 header->ch_size[i] = get_bits(&s->gb, 10);
162 header->mtd_ext_size = get_bits(&s->gb, 8);
163 header->meter_size = get_bits(&s->gb, 8);
164
165 skip_bits_long(&s->gb, 10 * header->nb_programs);
166 for (int i = 0; i < header->nb_channels; i++) {
167 header->rev_id[i] = get_bits(&s->gb, 4);
168 skip_bits1(&s->gb);
169 header->begin_gain[i] = get_bits(&s->gb, 10);
170 header->end_gain[i] = get_bits(&s->gb, 10);
171 }
172
173 if (get_bits_left(&s->gb) < 0) {
174 if (s->avctx)
175 av_log(s->avctx, AV_LOG_ERROR, "Read past end of metadata\n");
176 return AVERROR_INVALIDDATA;
177 }
178
179 return skip_input(s, mtd_size + 1);
180 }
181