1 /*
2 * This file is part of FFmpeg.
3 *
4 * FFmpeg is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * FFmpeg is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with FFmpeg; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19 #include <stddef.h>
20 #include <stdint.h>
21
22 #include "atsc_a53.h"
23 #include "get_bits.h"
24
ff_alloc_a53_sei(const AVFrame * frame,size_t prefix_len,void ** data,size_t * sei_size)25 int ff_alloc_a53_sei(const AVFrame *frame, size_t prefix_len,
26 void **data, size_t *sei_size)
27 {
28 AVFrameSideData *side_data = NULL;
29 uint8_t *sei_data;
30
31 if (frame)
32 side_data = av_frame_get_side_data(frame, AV_FRAME_DATA_A53_CC);
33
34 if (!side_data) {
35 *data = NULL;
36 return 0;
37 }
38
39 *sei_size = side_data->size + 11;
40 *data = av_mallocz(*sei_size + prefix_len);
41 if (!*data)
42 return AVERROR(ENOMEM);
43 sei_data = (uint8_t*)*data + prefix_len;
44
45 // country code
46 sei_data[0] = 181;
47 sei_data[1] = 0;
48 sei_data[2] = 49;
49
50 /**
51 * 'GA94' is standard in North America for ATSC, but hard coding
52 * this style may not be the right thing to do -- other formats
53 * do exist. This information is not available in the side_data
54 * so we are going with this right now.
55 */
56 AV_WL32(sei_data + 3, MKTAG('G', 'A', '9', '4'));
57 sei_data[7] = 3;
58 sei_data[8] = ((side_data->size/3) & 0x1f) | 0x40;
59 sei_data[9] = 0;
60
61 memcpy(sei_data + 10, side_data->data, side_data->size);
62
63 sei_data[side_data->size+10] = 255;
64
65 return 0;
66 }
67
ff_parse_a53_cc(AVBufferRef ** pbuf,const uint8_t * data,int size)68 int ff_parse_a53_cc(AVBufferRef **pbuf, const uint8_t *data, int size)
69 {
70 AVBufferRef *buf = *pbuf;
71 GetBitContext gb;
72 size_t new_size, old_size = buf ? buf->size : 0;
73 int ret, cc_count;
74
75 if (size < 3)
76 return AVERROR(EINVAL);
77
78 ret = init_get_bits8(&gb, data, size);
79 if (ret < 0)
80 return ret;
81
82 if (get_bits(&gb, 8) != 0x3) // user_data_type_code
83 return 0;
84
85 skip_bits(&gb, 1); // reserved
86 if (!get_bits(&gb, 1)) // process_cc_data_flag
87 return 0;
88
89 skip_bits(&gb, 1); // zero bit
90 cc_count = get_bits(&gb, 5);
91 if (!cc_count)
92 return 0;
93
94 skip_bits(&gb, 8); // reserved
95
96 /* 3 bytes per CC plus one byte marker_bits at the end */
97 if (cc_count * 3 >= (get_bits_left(&gb) >> 3))
98 return AVERROR(EINVAL);
99
100 new_size = (old_size + cc_count * 3);
101
102 if (new_size > INT_MAX)
103 return AVERROR(EINVAL);
104
105 /* Allow merging of the cc data from two fields. */
106 ret = av_buffer_realloc(pbuf, new_size);
107 if (ret < 0)
108 return ret;
109
110 buf = *pbuf;
111 /* Use of av_buffer_realloc assumes buffer is writeable */
112 for (int i = 0; i < cc_count; i++) {
113 buf->data[old_size++] = get_bits(&gb, 8);
114 buf->data[old_size++] = get_bits(&gb, 8);
115 buf->data[old_size++] = get_bits(&gb, 8);
116 }
117
118 return cc_count;
119 }
120