FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavformat/mccdec.c
Date: 2022-12-05 20:26:17
Exec Total Coverage
Lines: 7 87 8.0%
Functions: 1 3 33.3%
Branches: 5 54 9.3%

Line Branch Exec Source
1 /*
2 * MCC subtitle demuxer
3 * Copyright (c) 2020 Paul B Mahol
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 "avformat.h"
23 #include "internal.h"
24 #include "subtitles.h"
25 #include "libavutil/avstring.h"
26 #include "libavutil/bprint.h"
27 #include "libavutil/intreadwrite.h"
28
29 typedef struct MCCContext {
30 FFDemuxSubtitlesQueue q;
31 } MCCContext;
32
33 6782 static int mcc_probe(const AVProbeData *p)
34 {
35 char buf[28];
36 FFTextReader tr;
37
38 6782 ff_text_init_buf(&tr, p->buf, p->buf_size);
39
40
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6789 while (ff_text_peek_r8(&tr) == '\r' || ff_text_peek_r8(&tr) == '\n')
41 7 ff_text_r8(&tr);
42
43 6782 ff_text_read(&tr, buf, sizeof(buf));
44
45
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6782 if (!memcmp(buf, "File Format=MacCaption_MCC V", 28))
46 return AVPROBE_SCORE_MAX;
47
48 6782 return 0;
49 }
50
51 static int convert(uint8_t x)
52 {
53 if (x >= 'a')
54 x -= 87;
55 else if (x >= 'A')
56 x -= 55;
57 else
58 x -= '0';
59 return x;
60 }
61
62 typedef struct alias {
63 uint8_t key;
64 int len;
65 const char *value;
66 } alias;
67
68 static const alias aliases[20] = {
69 { .key = 16, .len = 3, .value = "\xFA\x0\x0", },
70 { .key = 17, .len = 6, .value = "\xFA\x0\x0\xFA\x0\x0", },
71 { .key = 18, .len = 9, .value = "\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0", },
72 { .key = 19, .len = 12, .value = "\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0", },
73 { .key = 20, .len = 15, .value = "\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0", },
74 { .key = 21, .len = 18, .value = "\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0", },
75 { .key = 22, .len = 21, .value = "\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0", },
76 { .key = 23, .len = 24, .value = "\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0", },
77 { .key = 24, .len = 27, .value = "\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0", },
78 { .key = 25, .len = 3, .value = "\xFB\x80\x80", },
79 { .key = 26, .len = 3, .value = "\xFC\x80\x80", },
80 { .key = 27, .len = 3, .value = "\xFD\x80\x80", },
81 { .key = 28, .len = 2, .value = "\x96\x69", },
82 { .key = 29, .len = 2, .value = "\x61\x01", },
83 { .key = 30, .len = 3, .value = "\xFC\x80\x80", },
84 { .key = 31, .len = 3, .value = "\xFC\x80\x80", },
85 { .key = 32, .len = 4, .value = "\xE1\x00\x00\x00", },
86 { .key = 33, .len = 0, .value = NULL, },
87 { .key = 34, .len = 0, .value = NULL, },
88 { .key = 35, .len = 1, .value = "\x0", },
89 };
90
91 static int mcc_read_header(AVFormatContext *s)
92 {
93 MCCContext *mcc = s->priv_data;
94 AVStream *st = avformat_new_stream(s, NULL);
95 AVRational rate;
96 int64_t ts, pos;
97 uint8_t out[4096];
98 char line[4096];
99 FFTextReader tr;
100 int ret = 0;
101
102 ff_text_init_avio(s, &tr, s->pb);
103
104 if (!st)
105 return AVERROR(ENOMEM);
106 st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
107 st->codecpar->codec_id = AV_CODEC_ID_EIA_608;
108 avpriv_set_pts_info(st, 64, 1, 30);
109
110 while (!ff_text_eof(&tr)) {
111 int hh, mm, ss, fs, i = 0, j = 0;
112 int start = 12, count = 0;
113 AVPacket *sub;
114 char *lline;
115
116 ff_subtitles_read_line(&tr, line, sizeof(line));
117 if (!strncmp(line, "File Format=MacCaption_MCC V", 28))
118 continue;
119 if (!strncmp(line, "//", 2))
120 continue;
121 if (!strncmp(line, "Time Code Rate=", 15)) {
122 char *rate_str = line + 15;
123 char *df = NULL;
124 int num = -1, den = -1;
125
126 if (rate_str[0]) {
127 num = strtol(rate_str, &df, 10);
128 den = 1;
129 if (df && !av_strncasecmp(df, "DF", 2)) {
130 av_reduce(&num, &den, num * 1000LL, 1001, INT_MAX);
131 }
132 }
133
134 if (num > 0 && den > 0) {
135 rate = av_make_q(num, den);
136 avpriv_set_pts_info(st, 64, rate.den, rate.num);
137 }
138 continue;
139 }
140
141 if (av_sscanf(line, "%d:%d:%d:%d", &hh, &mm, &ss, &fs) != 4)
142 continue;
143
144 ts = av_sat_add64(av_rescale(hh * 3600LL + mm * 60LL + ss, rate.num, rate.den), fs);
145
146 lline = (char *)&line;
147 lline += 12;
148 pos = ff_text_pos(&tr);
149
150 while (lline[i]) {
151 uint8_t v = convert(lline[i]);
152
153 if (v >= 16 && v <= 35) {
154 int idx = v - 16;
155 if (aliases[idx].len) {
156 if (j >= sizeof(out) - 1 - aliases[idx].len) {
157 j = 0;
158 break;
159 }
160 memcpy(out + j, aliases[idx].value, aliases[idx].len);
161 j += aliases[idx].len;
162 }
163 } else {
164 uint8_t vv;
165
166 if (i + 13 >= sizeof(line) - 1)
167 break;
168 vv = convert(lline[i + 1]);
169 if (j >= sizeof(out) - 1) {
170 j = 0;
171 break;
172 }
173 out[j++] = vv | (v << 4);
174 i++;
175 }
176
177 i++;
178 }
179 out[j] = 0;
180
181 if (out[7] & 0x80)
182 start += 4;
183 count = (out[11] & 0x1f) * 3;
184 if (j < start + count + 1)
185 continue;
186
187 if (!count)
188 continue;
189 sub = ff_subtitles_queue_insert(&mcc->q, out + start, count, 0);
190 if (!sub)
191 return AVERROR(ENOMEM);
192
193 sub->pos = pos;
194 sub->pts = ts;
195 sub->duration = 1;
196 }
197
198 ff_subtitles_queue_finalize(s, &mcc->q);
199
200 return ret;
201 }
202
203 const AVInputFormat ff_mcc_demuxer = {
204 .name = "mcc",
205 .long_name = NULL_IF_CONFIG_SMALL("MacCaption"),
206 .priv_data_size = sizeof(MCCContext),
207 .flags_internal = FF_FMT_INIT_CLEANUP,
208 .read_probe = mcc_probe,
209 .read_header = mcc_read_header,
210 .extensions = "mcc",
211 .read_packet = ff_subtitles_read_packet,
212 .read_seek2 = ff_subtitles_read_seek,
213 .read_close = ff_subtitles_read_close,
214 };
215