FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavformat/mccdec.c
Date: 2024-05-11 02:28:20
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 "demux.h"
24 #include "internal.h"
25 #include "subtitles.h"
26 #include "libavutil/avstring.h"
27 #include "libavutil/bprint.h"
28 #include "libavutil/intreadwrite.h"
29
30 typedef struct MCCContext {
31 FFDemuxSubtitlesQueue q;
32 } MCCContext;
33
34 7128 static int mcc_probe(const AVProbeData *p)
35 {
36 char buf[28];
37 FFTextReader tr;
38
39 7128 ff_text_init_buf(&tr, p->buf, p->buf_size);
40
41
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7135 while (ff_text_peek_r8(&tr) == '\r' || ff_text_peek_r8(&tr) == '\n')
42 7 ff_text_r8(&tr);
43
44 7128 ff_text_read(&tr, buf, sizeof(buf));
45
46
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7128 if (!memcmp(buf, "File Format=MacCaption_MCC V", 28))
47 return AVPROBE_SCORE_MAX;
48
49 7128 return 0;
50 }
51
52 static int convert(uint8_t x)
53 {
54 if (x >= 'a')
55 x -= 87;
56 else if (x >= 'A')
57 x -= 55;
58 else
59 x -= '0';
60 return x;
61 }
62
63 typedef struct alias {
64 uint8_t key;
65 int len;
66 const char *value;
67 } alias;
68
69 static const alias aliases[20] = {
70 { .key = 16, .len = 3, .value = "\xFA\x0\x0", },
71 { .key = 17, .len = 6, .value = "\xFA\x0\x0\xFA\x0\x0", },
72 { .key = 18, .len = 9, .value = "\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0", },
73 { .key = 19, .len = 12, .value = "\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0", },
74 { .key = 20, .len = 15, .value = "\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0", },
75 { .key = 21, .len = 18, .value = "\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0", },
76 { .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", },
77 { .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", },
78 { .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", },
79 { .key = 25, .len = 3, .value = "\xFB\x80\x80", },
80 { .key = 26, .len = 3, .value = "\xFC\x80\x80", },
81 { .key = 27, .len = 3, .value = "\xFD\x80\x80", },
82 { .key = 28, .len = 2, .value = "\x96\x69", },
83 { .key = 29, .len = 2, .value = "\x61\x01", },
84 { .key = 30, .len = 3, .value = "\xFC\x80\x80", },
85 { .key = 31, .len = 3, .value = "\xFC\x80\x80", },
86 { .key = 32, .len = 4, .value = "\xE1\x00\x00\x00", },
87 { .key = 33, .len = 0, .value = NULL, },
88 { .key = 34, .len = 0, .value = NULL, },
89 { .key = 35, .len = 1, .value = "\x0", },
90 };
91
92 static int mcc_read_header(AVFormatContext *s)
93 {
94 MCCContext *mcc = s->priv_data;
95 AVStream *st = avformat_new_stream(s, NULL);
96 AVRational rate;
97 int64_t ts, pos;
98 uint8_t out[4096];
99 char line[4096];
100 FFTextReader tr;
101 int ret = 0;
102
103 ff_text_init_avio(s, &tr, s->pb);
104
105 if (!st)
106 return AVERROR(ENOMEM);
107 st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
108 st->codecpar->codec_id = AV_CODEC_ID_EIA_608;
109 avpriv_set_pts_info(st, 64, 1, 30);
110
111 while (!ff_text_eof(&tr)) {
112 int hh, mm, ss, fs, i = 0, j = 0;
113 int start = 12, count = 0;
114 AVPacket *sub;
115 char *lline;
116
117 ff_subtitles_read_line(&tr, line, sizeof(line));
118 if (!strncmp(line, "File Format=MacCaption_MCC V", 28))
119 continue;
120 if (!strncmp(line, "//", 2))
121 continue;
122 if (!strncmp(line, "Time Code Rate=", 15)) {
123 char *rate_str = line + 15;
124 char *df = NULL;
125 int num = -1, den = -1;
126
127 if (rate_str[0]) {
128 num = strtol(rate_str, &df, 10);
129 den = 1;
130 if (df && !av_strncasecmp(df, "DF", 2)) {
131 av_reduce(&num, &den, num * 1000LL, 1001, INT_MAX);
132 }
133 }
134
135 if (num > 0 && den > 0) {
136 rate = av_make_q(num, den);
137 avpriv_set_pts_info(st, 64, rate.den, rate.num);
138 }
139 continue;
140 }
141
142 if (av_sscanf(line, "%d:%d:%d:%d", &hh, &mm, &ss, &fs) != 4)
143 continue;
144
145 ts = av_sat_add64(av_rescale(hh * 3600LL + mm * 60LL + ss, rate.num, rate.den), fs);
146
147 lline = (char *)&line;
148 lline += 12;
149 pos = ff_text_pos(&tr);
150
151 while (lline[i]) {
152 uint8_t v = convert(lline[i]);
153
154 if (v >= 16 && v <= 35) {
155 int idx = v - 16;
156 if (aliases[idx].len) {
157 if (j >= sizeof(out) - 1 - aliases[idx].len) {
158 j = 0;
159 break;
160 }
161 memcpy(out + j, aliases[idx].value, aliases[idx].len);
162 j += aliases[idx].len;
163 }
164 } else {
165 uint8_t vv;
166
167 if (i + 13 >= sizeof(line) - 1)
168 break;
169 vv = convert(lline[i + 1]);
170 if (j >= sizeof(out) - 1) {
171 j = 0;
172 break;
173 }
174 out[j++] = vv | (v << 4);
175 i++;
176 }
177
178 i++;
179 }
180 out[j] = 0;
181
182 if (out[7] & 0x80)
183 start += 4;
184 count = (out[11] & 0x1f) * 3;
185 if (j < start + count + 1)
186 continue;
187
188 if (!count)
189 continue;
190 sub = ff_subtitles_queue_insert(&mcc->q, out + start, count, 0);
191 if (!sub)
192 return AVERROR(ENOMEM);
193
194 sub->pos = pos;
195 sub->pts = ts;
196 sub->duration = 1;
197 }
198
199 ff_subtitles_queue_finalize(s, &mcc->q);
200
201 return ret;
202 }
203
204 const FFInputFormat ff_mcc_demuxer = {
205 .p.name = "mcc",
206 .p.long_name = NULL_IF_CONFIG_SMALL("MacCaption"),
207 .p.extensions = "mcc",
208 .priv_data_size = sizeof(MCCContext),
209 .flags_internal = FF_INFMT_FLAG_INIT_CLEANUP,
210 .read_probe = mcc_probe,
211 .read_header = mcc_read_header,
212 .read_packet = ff_subtitles_read_packet,
213 .read_seek2 = ff_subtitles_read_seek,
214 .read_close = ff_subtitles_read_close,
215 };
216