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
|
/*
* MicroDVD subtitle demuxer
* Copyright (c) 2010 Aurelien Jacobs <aurel@gnuage.org>
*
* 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 "avformat.h"
#include "internal.h"
#include "libavutil/intreadwrite.h"
#define MAX_LINESIZE 2048
typedef struct {
uint8_t lines[3][MAX_LINESIZE];
int64_t pos[3];
AVPacket last_pkt;
int last_pkt_ready;
} MicroDVDContext;
static int microdvd_probe(AVProbeData *p)
{
unsigned char c, *ptr = p->buf;
int i;
if (AV_RB24(ptr) == 0xEFBBBF)
ptr += 3; /* skip UTF-8 BOM */
for (i=0; i<3; i++) {
if (sscanf(ptr, "{%*d}{}%c", &c) != 1 &&
sscanf(ptr, "{%*d}{%*d}%c", &c) != 1 &&
sscanf(ptr, "{DEFAULT}{}%c", &c) != 1)
return 0;
ptr += strcspn(ptr, "\n") + 1;
}
return AVPROBE_SCORE_MAX;
}
static int microdvd_read_header(AVFormatContext *s)
{
AVRational pts_info = (AVRational){ 2997, 125 }; /* default: 23.976 fps */
MicroDVDContext *microdvd = s->priv_data;
AVStream *st = avformat_new_stream(s, NULL);
int i, frame;
double fps;
char c;
if (!st)
return AVERROR(ENOMEM);
for (i=0; i<FF_ARRAY_ELEMS(microdvd->lines); i++) {
microdvd->pos[i] = avio_tell(s->pb);
ff_get_line(s->pb, microdvd->lines[i], sizeof(microdvd->lines[i]));
if ((sscanf(microdvd->lines[i], "{%d}{}%6lf", &frame, &fps) == 2 ||
sscanf(microdvd->lines[i], "{%d}{%*d}%6lf", &frame, &fps) == 2)
&& frame <= 1 && fps > 3 && fps < 100)
pts_info = av_d2q(fps, 100000);
if (sscanf(microdvd->lines[i], "{DEFAULT}{}%c", &c) == 1) {
st->codec->extradata = av_strdup(microdvd->lines[i] + 11);
st->codec->extradata_size = strlen(st->codec->extradata);
i--;
}
}
avpriv_set_pts_info(st, 64, pts_info.den, pts_info.num);
st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE;
st->codec->codec_id = CODEC_ID_MICRODVD;
return 0;
}
static int64_t get_pts(const char *buf)
{
int frame;
char c;
if (sscanf(buf, "{%d}{%c", &frame, &c) == 2)
return frame;
return AV_NOPTS_VALUE;
}
static int get_duration(const char *buf)
{
int frame_start, frame_end;
if (sscanf(buf, "{%d}{%d}", &frame_start, &frame_end) == 2)
return frame_end - frame_start;
return -1;
}
static int microdvd_read_packet(AVFormatContext *s, AVPacket *pkt)
{
MicroDVDContext *microdvd = s->priv_data;
char buffer[MAX_LINESIZE];
int64_t pos = avio_tell(s->pb);
int i, len = 0, res = AVERROR_EOF;
// last packet has its duration set but couldn't be raised earlier
if (microdvd->last_pkt_ready) {
*pkt = microdvd->last_pkt;
microdvd->last_pkt_ready = 0;
return 0;
}
for (i=0; i<FF_ARRAY_ELEMS(microdvd->lines); i++) {
if (microdvd->lines[i][0]) {
strcpy(buffer, microdvd->lines[i]);
pos = microdvd->pos[i];
len = strlen(buffer);
microdvd->lines[i][0] = 0;
break;
}
}
if (!len)
len = ff_get_line(s->pb, buffer, sizeof(buffer));
if (microdvd->last_pkt.duration == -1 && !buffer[0]) {
// if the previous subtitle line had no duration, last until the end of
// the presentation
microdvd->last_pkt.duration = 0;
*pkt = microdvd->last_pkt;
pkt->duration = -1;
res = 0;
} else if (buffer[0] && !(res = av_new_packet(pkt, len))) {
memcpy(pkt->data, buffer, len);
pkt->flags |= AV_PKT_FLAG_KEY;
pkt->pos = pos;
pkt->pts = pkt->dts = get_pts(buffer);
if (pkt->pts != AV_NOPTS_VALUE) {
pkt->duration = get_duration(buffer);
if (microdvd->last_pkt.duration == -1) {
// previous packet wasn't raised because it was lacking the
// duration info, so set its duration with the new packet pts
// and raise it
AVPacket tmp_pkt;
tmp_pkt = microdvd->last_pkt;
tmp_pkt.duration = pkt->pts - tmp_pkt.pts;
microdvd->last_pkt = *pkt;
microdvd->last_pkt_ready = pkt->duration != -1;
*pkt = tmp_pkt;
} else if (pkt->duration == -1) {
// no packet without duration queued, and current one is
// lacking the duration info, we need to parse another subtitle
// event.
microdvd->last_pkt = *pkt;
res = AVERROR(EAGAIN);
}
}
}
return res;
}
AVInputFormat ff_microdvd_demuxer = {
.name = "microdvd",
.long_name = NULL_IF_CONFIG_SMALL("MicroDVD subtitle format"),
.priv_data_size = sizeof(MicroDVDContext),
.read_probe = microdvd_probe,
.read_header = microdvd_read_header,
.read_packet = microdvd_read_packet,
.flags = AVFMT_GENERIC_INDEX,
};
|
