FFmpeg  4.4.5
mpl2dec.c
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1 /*
2  * Copyright (c) 2012 Clément Bœsch
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 /**
22  * @file
23  * MPL2 subtitles format demuxer
24  */
25 
26 #include "libavutil/intreadwrite.h"
27 
28 #include "avformat.h"
29 #include "internal.h"
30 #include "subtitles.h"
31 
32 typedef struct {
34 } MPL2Context;
35 
36 static int mpl2_probe(const AVProbeData *p)
37 {
38  int i;
39  char c;
40  int64_t start, end;
41  const unsigned char *ptr = p->buf;
42  const unsigned char *ptr_end = ptr + p->buf_size;
43 
44  if (AV_RB24(ptr) == 0xefbbbf)
45  ptr += 3;
46 
47  for (i = 0; i < 2; i++) {
48  if (sscanf(ptr, "[%"SCNd64"][%"SCNd64"]%c", &start, &end, &c) != 3 &&
49  sscanf(ptr, "[%"SCNd64"][]%c", &start, &c) != 2)
50  return 0;
51  ptr += ff_subtitles_next_line(ptr);
52  if (ptr >= ptr_end)
53  return 0;
54  }
55  return AVPROBE_SCORE_MAX;
56 }
57 
58 static int read_ts(char **line, int64_t *pts_start, int64_t *duration)
59 {
60  char c;
61  int len;
62  int64_t end;
63 
64  if (sscanf(*line, "[%"SCNd64"][]%c%n",
65  pts_start, &c, &len) >= 2) {
66  *duration = -1;
67  *line += len - 1;
68  return 0;
69  }
70  if (sscanf(*line, "[%"SCNd64"][%"SCNd64"]%c%n",
71  pts_start, &end, &c, &len) >= 3) {
72  if (end < *pts_start || end - (uint64_t)*pts_start > INT64_MAX) {
73  *duration = -1;
74  } else
75  *duration = end - *pts_start;
76  *line += len - 1;
77  return 0;
78  }
79  return -1;
80 }
81 
83 {
84  MPL2Context *mpl2 = s->priv_data;
86 
87  if (!st)
88  return AVERROR(ENOMEM);
89  avpriv_set_pts_info(st, 64, 1, 10);
92 
93  if (avio_rb24(s->pb) != 0xefbbbf)
94  avio_seek(s->pb, -3, SEEK_CUR);
95 
96  while (!avio_feof(s->pb)) {
97  char line[4096];
98  char *p = line;
99  const int64_t pos = avio_tell(s->pb);
100  int len = ff_get_line(s->pb, line, sizeof(line));
101  int64_t pts_start;
103 
104  if (!len)
105  break;
106 
107  line[strcspn(line, "\r\n")] = 0;
108 
109  if (!read_ts(&p, &pts_start, &duration)) {
110  AVPacket *sub;
111 
112  sub = ff_subtitles_queue_insert(&mpl2->q, p, strlen(p), 0);
113  if (!sub) {
114  ff_subtitles_queue_clean(&mpl2->q);
115  return AVERROR(ENOMEM);
116  }
117  sub->pos = pos;
118  sub->pts = pts_start;
119  sub->duration = duration;
120  }
121  }
122 
124  return 0;
125 }
126 
128 {
129  MPL2Context *mpl2 = s->priv_data;
130  return ff_subtitles_queue_read_packet(&mpl2->q, pkt);
131 }
132 
133 static int mpl2_read_seek(AVFormatContext *s, int stream_index,
134  int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
135 {
136  MPL2Context *mpl2 = s->priv_data;
137  return ff_subtitles_queue_seek(&mpl2->q, s, stream_index,
138  min_ts, ts, max_ts, flags);
139 }
140 
142 {
143  MPL2Context *mpl2 = s->priv_data;
144  ff_subtitles_queue_clean(&mpl2->q);
145  return 0;
146 }
147 
149  .name = "mpl2",
150  .long_name = NULL_IF_CONFIG_SMALL("MPL2 subtitles"),
151  .priv_data_size = sizeof(MPL2Context),
155  .read_seek2 = mpl2_read_seek,
157  .extensions = "txt,mpl2",
158 };
Main libavformat public API header.
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:453
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:253
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:364
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:557
unsigned int avio_rb24(AVIOContext *s)
Definition: aviobuf.c:774
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
int ff_get_line(AVIOContext *s, char *buf, int maxlen)
Read a whole line of text from AVIOContext.
Definition: aviobuf.c:789
#define AV_RB24
Definition: intreadwrite.h:64
#define flags(name, subs,...)
Definition: cbs_av1.c:572
#define s(width, name)
Definition: cbs_vp9.c:257
#define NULL
Definition: coverity.c:32
long long int64_t
Definition: coverity.c:34
static float sub(float src0, float src1)
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:545
@ AV_CODEC_ID_MPL2
Definition: codec_id.h:543
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4509
#define AVERROR(e)
Definition: error.h:43
@ AVMEDIA_TYPE_SUBTITLE
Definition: avutil.h:204
int i
Definition: input.c:407
void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: utils.c:4945
static int read_probe(const AVProbeData *pd)
Definition: jvdec.c:55
static int mpl2_read_header(AVFormatContext *s)
Definition: mpl2dec.c:82
static int mpl2_probe(const AVProbeData *p)
Definition: mpl2dec.c:36
static int mpl2_read_seek(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
Definition: mpl2dec.c:133
static int mpl2_read_close(AVFormatContext *s)
Definition: mpl2dec.c:141
static int mpl2_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: mpl2dec.c:127
static int read_ts(char **line, int64_t *pts_start, int64_t *duration)
Definition: mpl2dec.c:58
AVInputFormat ff_mpl2_demuxer
Definition: mpl2dec.c:148
common internal API header
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:145
unsigned int pos
Definition: spdifenc.c:412
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
Format I/O context.
Definition: avformat.h:1232
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:645
This structure stores compressed data.
Definition: packet.h:346
This structure contains the data a format has to probe a file.
Definition: avformat.h:441
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:444
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:443
Stream structure.
Definition: avformat.h:873
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1038
FFDemuxSubtitlesQueue q
Definition: mpl2dec.c:33
Definition: graph2dot.c:48
int ff_subtitles_queue_seek(FFDemuxSubtitlesQueue *q, AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
Update current_sub_idx to emulate a seek.
Definition: subtitles.c:255
int ff_subtitles_queue_read_packet(FFDemuxSubtitlesQueue *q, AVPacket *pkt)
Generic read_packet() callback for subtitles demuxers using this queue system.
Definition: subtitles.c:216
void ff_subtitles_queue_finalize(void *log_ctx, FFDemuxSubtitlesQueue *q)
Set missing durations, sort subtitles by PTS (and then byte position), and drop duplicated events.
Definition: subtitles.c:198
void ff_subtitles_queue_clean(FFDemuxSubtitlesQueue *q)
Remove and destroy all the subtitles packets.
Definition: subtitles.c:307
AVPacket * ff_subtitles_queue_insert(FFDemuxSubtitlesQueue *q, const uint8_t *event, size_t len, int merge)
Insert a new subtitle event.
Definition: subtitles.c:111
static av_always_inline int ff_subtitles_next_line(const char *ptr)
Get the number of characters to increment to jump to the next line, or to the end of the string.
Definition: subtitles.h:187
int64_t duration
Definition: movenc.c:64
AVPacket * pkt
Definition: movenc.c:59
int len
static double c[64]