1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
|
/*
* Metadata demuxer
* Copyright (c) 2010 Anton Khirnov
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libavutil/bprint.h"
#include "libavutil/mathematics.h"
#include "avformat.h"
#include "demux.h"
#include "ffmeta.h"
#include "libavutil/dict.h"
static int probe(const AVProbeData *p)
{
if(!memcmp(p->buf, ID_STRING, strlen(ID_STRING)))
return AVPROBE_SCORE_MAX;
return 0;
}
static int64_t read_line_to_bprint_escaped(AVIOContext *s, AVBPrint *bp)
{
int len, end;
int64_t read = 0;
char tmp[1024];
char c;
char prev = ' ';
do {
len = 0;
do {
c = avio_r8(s);
end = prev != '\\' && (c == '\r' || c == '\n' || c == '\0');
if (!end)
tmp[len++] = c;
prev = c;
} while (!end && len < sizeof(tmp));
av_bprint_append_data(bp, tmp, len);
read += len;
} while (!end);
if (c == '\r' && avio_r8(s) != '\n' && !avio_feof(s))
avio_skip(s, -1);
if (!c && s->error)
return s->error;
if (!c && !read && avio_feof(s))
return AVERROR_EOF;
return read;
}
static void get_bprint_line(AVIOContext *s, AVBPrint *bp)
{
do {
av_bprint_clear(bp);
read_line_to_bprint_escaped(s, bp);
} while (!avio_feof(s) && (bp->str[0] == ';' || bp->str[0] == '#' || bp->str[0] == 0));
}
static void get_line(AVIOContext *s, uint8_t *buf, int size)
{
do {
uint8_t c;
int i = 0;
while ((c = avio_r8(s))) {
if (c == '\\') {
if (i < size - 1)
buf[i++] = c;
c = avio_r8(s);
} else if (c == '\n')
break;
if (i < size - 1)
buf[i++] = c;
}
buf[i] = 0;
} while (!avio_feof(s) && (buf[0] == ';' || buf[0] == '#' || buf[0] == 0));
}
static AVChapter *read_chapter(AVFormatContext *s)
{
uint8_t line[256];
int64_t start, end;
AVRational tb = {1, 1e9};
int ret;
get_line(s->pb, line, sizeof(line));
if (sscanf(line, "TIMEBASE=%d/%d", &tb.num, &tb.den))
get_line(s->pb, line, sizeof(line));
ret = sscanf(line, "START=%"SCNd64, &start);
if (ret <= 0) {
av_log(s, AV_LOG_ERROR, "Expected chapter start timestamp, found %s.\n", line);
start = (s->nb_chapters && s->chapters[s->nb_chapters - 1]->end != AV_NOPTS_VALUE) ?
s->chapters[s->nb_chapters - 1]->end : 0;
} else
get_line(s->pb, line, sizeof(line));
ret = sscanf(line, "END=%"SCNd64, &end);
if (ret <= 0) {
av_log(s, AV_LOG_ERROR, "Expected chapter end timestamp, found %s.\n", line);
end = AV_NOPTS_VALUE;
}
return avpriv_new_chapter(s, s->nb_chapters, tb, start, end, NULL);
}
static uint8_t *unescape(const uint8_t *buf, int size)
{
uint8_t *ret = av_malloc(size + 1);
uint8_t *p1 = ret;
const uint8_t *p2 = buf;
if (!ret)
return NULL;
while (p2 < buf + size) {
if (*p2 == '\\')
p2++;
*p1++ = *p2++;
}
*p1 = 0;
return ret;
}
static int read_tag(const uint8_t *line, AVDictionary **m)
{
uint8_t *key, *value;
const uint8_t *p = line;
/* find first not escaped '=' */
while (1) {
if (*p == '=')
break;
else if (*p == '\\')
p++;
if (*p++)
continue;
return 0;
}
if (!(key = unescape(line, p - line)))
return AVERROR(ENOMEM);
if (!(value = unescape(p + 1, strlen(p + 1)))) {
av_free(key);
return AVERROR(ENOMEM);
}
av_dict_set(m, key, value, AV_DICT_DONT_STRDUP_KEY | AV_DICT_DONT_STRDUP_VAL);
return 0;
}
static int read_header(AVFormatContext *s)
{
AVDictionary **m = &s->metadata;
AVBPrint bp;
av_bprint_init(&bp, 0, AV_BPRINT_SIZE_UNLIMITED);
while(!avio_feof(s->pb)) {
get_bprint_line(s->pb, &bp);
if (!memcmp(bp.str, ID_STREAM, strlen(ID_STREAM))) {
AVStream *st = avformat_new_stream(s, NULL);
if (!st)
goto nomem;
st->codecpar->codec_type = AVMEDIA_TYPE_DATA;
st->codecpar->codec_id = AV_CODEC_ID_FFMETADATA;
m = &st->metadata;
} else if (!memcmp(bp.str, ID_CHAPTER, strlen(ID_CHAPTER))) {
AVChapter *ch = read_chapter(s);
if (!ch)
goto nomem;
m = &ch->metadata;
} else
read_tag(bp.str, m);
}
av_bprint_finalize(&bp, NULL);
s->start_time = 0;
if (s->nb_chapters)
s->duration = av_rescale_q(s->chapters[s->nb_chapters - 1]->end,
s->chapters[s->nb_chapters - 1]->time_base,
AV_TIME_BASE_Q);
return 0;
nomem:
av_bprint_finalize(&bp, NULL);
return AVERROR(ENOMEM);
}
static int read_packet(AVFormatContext *s, AVPacket *pkt)
{
return AVERROR_EOF;
}
const FFInputFormat ff_ffmetadata_demuxer = {
.p.name = "ffmetadata",
.p.long_name = NULL_IF_CONFIG_SMALL("FFmpeg metadata in text"),
.read_probe = probe,
.read_header = read_header,
.read_packet = read_packet,
};
|
