FFmpeg
subviewerdec.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  * SubViewer subtitle demuxer
24  * @see https://en.wikipedia.org/wiki/SubViewer
25  */
26 
27 #include "avformat.h"
28 #include "internal.h"
29 #include "subtitles.h"
30 #include "avio_internal.h"
31 #include "libavcodec/internal.h"
32 #include "libavutil/avstring.h"
33 #include "libavutil/bprint.h"
34 #include "libavutil/intreadwrite.h"
35 
36 typedef struct {
39 
40 static int subviewer_probe(const AVProbeData *p)
41 {
42  char c;
43  const unsigned char *ptr = p->buf;
44 
45  if (AV_RB24(ptr) == 0xEFBBBF)
46  ptr += 3; /* skip UTF-8 BOM */
47  if (sscanf(ptr, "%*u:%*u:%*u.%*u,%*u:%*u:%*u.%*u%c", &c) == 1)
49  if (!strncmp(ptr, "[INFORMATION]", 13))
50  return AVPROBE_SCORE_MAX/3;
51  return 0;
52 }
53 
54 static int read_ts(const char *s, int64_t *start, int *duration)
55 {
56  int64_t end;
57  int hh1, mm1, ss1, ms1;
58  int hh2, mm2, ss2, ms2;
59  int multiplier = 1;
60 
61  if (sscanf(s, "%u:%u:%u.%2u,%u:%u:%u.%2u",
62  &hh1, &mm1, &ss1, &ms1, &hh2, &mm2, &ss2, &ms2) == 8) {
63  multiplier = 10;
64  } else if (sscanf(s, "%u:%u:%u.%1u,%u:%u:%u.%1u",
65  &hh1, &mm1, &ss1, &ms1, &hh2, &mm2, &ss2, &ms2) == 8) {
66  multiplier = 100;
67  }
68  if (sscanf(s, "%u:%u:%u.%u,%u:%u:%u.%u",
69  &hh1, &mm1, &ss1, &ms1, &hh2, &mm2, &ss2, &ms2) == 8) {
70  ms1 = FFMIN(ms1, 999);
71  ms2 = FFMIN(ms2, 999);
72  end = (hh2*3600LL + mm2*60LL + ss2) * 1000LL + ms2 * multiplier;
73  *start = (hh1*3600LL + mm1*60LL + ss1) * 1000LL + ms1 * multiplier;
74  *duration = end - *start;
75  return 0;
76  }
77  return -1;
78 }
79 
81 {
82  SubViewerContext *subviewer = s->priv_data;
84  AVBPrint header;
85  int res = 0, new_event = 1;
86  int64_t pts_start = AV_NOPTS_VALUE;
87  int duration = -1;
88  AVPacket *sub = NULL;
89 
90  if (!st)
91  return AVERROR(ENOMEM);
92  res = ffio_ensure_seekback(s->pb, 3);
93  if (res < 0)
94  return res;
95  if (avio_rb24(s->pb) != 0xefbbbf)
96  avio_seek(s->pb, -3, SEEK_CUR);
97  avpriv_set_pts_info(st, 64, 1, 1000);
100 
102 
103  while (!avio_feof(s->pb)) {
104  char line[2048];
105  int64_t pos = 0;
106  int len = ff_get_line(s->pb, line, sizeof(line));
107 
108  if (!len)
109  break;
110 
111  line[strcspn(line, "\r\n")] = 0;
112 
113  if (line[0] == '[' && strncmp(line, "[br]", 4)) {
114 
115  /* ignore event style, XXX: add to side_data? */
116  if (strstr(line, "[COLF]") || strstr(line, "[SIZE]") ||
117  strstr(line, "[FONT]") || strstr(line, "[STYLE]"))
118  continue;
119 
120  if (!st->codecpar->extradata) { // header not finalized yet
121  av_bprintf(&header, "%s\n", line);
122  if (!strncmp(line, "[END INFORMATION]", 17) || !strncmp(line, "[SUBTITLE]", 10)) {
123  /* end of header */
125  if (res < 0)
126  goto end;
127  } else if (strncmp(line, "[INFORMATION]", 13)) {
128  /* assume file metadata at this point */
129  int i, j = 0;
130  char key[32], value[128];
131 
132  for (i = 1; i < sizeof(key) - 1 && line[i] && line[i] != ']'; i++)
133  key[i - 1] = av_tolower(line[i]);
134  key[i - 1] = 0;
135 
136  if (line[i] == ']')
137  i++;
138  while (line[i] == ' ')
139  i++;
140  while (j < sizeof(value) - 1 && line[i] && line[i] != ']')
141  value[j++] = line[i++];
142  value[j] = 0;
143 
144  av_dict_set(&s->metadata, key, value, 0);
145  }
146  }
147  } else if (read_ts(line, &pts_start, &duration) >= 0) {
148  new_event = 1;
149  pos = avio_tell(s->pb);
150  } else if (*line) {
151  if (pts_start == AV_NOPTS_VALUE) {
152  res = AVERROR_INVALIDDATA;
153  goto end;
154  }
155  if (!new_event) {
156  sub = ff_subtitles_queue_insert(&subviewer->q, "\n", 1, 1);
157  if (!sub) {
158  res = AVERROR(ENOMEM);
159  goto end;
160  }
161  }
162  sub = ff_subtitles_queue_insert(&subviewer->q, line, strlen(line), !new_event);
163  if (!sub) {
164  res = AVERROR(ENOMEM);
165  goto end;
166  }
167  if (new_event) {
168  sub->pos = pos;
169  sub->pts = pts_start;
170  sub->duration = duration;
171  }
172  new_event = 0;
173  }
174  }
175 
176  ff_subtitles_queue_finalize(s, &subviewer->q);
177 
178 end:
179  if (res < 0)
180  ff_subtitles_queue_clean(&subviewer->q);
182  return res;
183 }
184 
186 {
187  SubViewerContext *subviewer = s->priv_data;
188  return ff_subtitles_queue_read_packet(&subviewer->q, pkt);
189 }
190 
191 static int subviewer_read_seek(AVFormatContext *s, int stream_index,
192  int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
193 {
194  SubViewerContext *subviewer = s->priv_data;
195  return ff_subtitles_queue_seek(&subviewer->q, s, stream_index,
196  min_ts, ts, max_ts, flags);
197 }
198 
200 {
201  SubViewerContext *subviewer = s->priv_data;
202  ff_subtitles_queue_clean(&subviewer->q);
203  return 0;
204 }
205 
207  .name = "subviewer",
208  .long_name = NULL_IF_CONFIG_SMALL("SubViewer subtitle format"),
209  .priv_data_size = sizeof(SubViewerContext),
213  .read_seek2 = subviewer_read_seek,
215  .extensions = "sub",
216 };
AVMEDIA_TYPE_SUBTITLE
@ AVMEDIA_TYPE_SUBTITLE
Definition: avutil.h:204
AV_BPRINT_SIZE_UNLIMITED
#define AV_BPRINT_SIZE_UNLIMITED
AVCodecParameters::extradata
uint8_t * extradata
Extra binary data needed for initializing the decoder, codec-dependent.
Definition: codec_par.h:74
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4553
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
av_bprint_finalize
int av_bprint_finalize(AVBPrint *buf, char **ret_str)
Finalize a print buffer.
Definition: bprint.c:235
av_bprint_init
void av_bprint_init(AVBPrint *buf, unsigned size_init, unsigned size_max)
Definition: bprint.c:69
sub
static float sub(float src0, float src1)
Definition: dnn_backend_native_layer_mathbinary.c:32
subviewer_read_seek
static int subviewer_read_seek(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
Definition: subviewerdec.c:191
internal.h
ff_bprint_to_codecpar_extradata
int ff_bprint_to_codecpar_extradata(AVCodecParameters *par, struct AVBPrint *buf)
Finalize buf into extradata and set its size appropriately.
Definition: utils.c:5809
AVPROBE_SCORE_MAX
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:453
read_close
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:145
avio_tell
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:557
AV_CODEC_ID_SUBVIEWER
@ AV_CODEC_ID_SUBVIEWER
Definition: codec_id.h:540
ff_subtitles_queue_seek
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
pkt
AVPacket * pkt
Definition: movenc.c:59
AVInputFormat
Definition: avformat.h:640
duration
int64_t duration
Definition: movenc.c:64
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:257
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:645
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:443
key
const char * key
Definition: hwcontext_opencl.c:168
ff_subtitles_queue_read_packet
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
AVFormatContext
Format I/O context.
Definition: avformat.h:1231
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1038
read_header
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:527
NULL
#define NULL
Definition: coverity.c:32
read_probe
static int read_probe(const AVProbeData *pd)
Definition: jvdec.c:55
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:441
ff_subtitles_queue_insert
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
c
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
AVPROBE_SCORE_EXTENSION
#define AVPROBE_SCORE_EXTENSION
score for file extension
Definition: avformat.h:451
avio_rb24
unsigned int avio_rb24(AVIOContext *s)
Definition: aviobuf.c:774
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
avpriv_set_pts_info
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:4999
AV_NOPTS_VALUE
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:248
ff_subtitles_queue_finalize
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
FFDemuxSubtitlesQueue
Definition: subtitles.h:102
header
static const uint8_t header[24]
Definition: sdr2.c:67
FFMIN
#define FFMIN(a, b)
Definition: common.h:105
ffio_ensure_seekback
int ffio_ensure_seekback(AVIOContext *s, int64_t buf_size)
Ensures that the requested seekback buffer size will be available.
Definition: aviobuf.c:998
ff_subtitles_queue_clean
void ff_subtitles_queue_clean(FFDemuxSubtitlesQueue *q)
Remove and destroy all the subtitles packets.
Definition: subtitles.c:307
line
Definition: graph2dot.c:48
subviewer_probe
static int subviewer_probe(const AVProbeData *p)
Definition: subviewerdec.c:40
SubViewerContext
Definition: subviewerdec.c:36
bprint.h
i
int i
Definition: input.c:407
avio_internal.h
read_ts
static int read_ts(const char *s, int64_t *start, int *duration)
Definition: subviewerdec.c:54
value
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf default value
Definition: writing_filters.txt:86
ff_get_line
int ff_get_line(AVIOContext *s, char *buf, int maxlen)
Read a whole line of text from AVIOContext.
Definition: aviobuf.c:789
len
int len
Definition: vorbis_enc_data.h:452
read_packet
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
AVStream
Stream structure.
Definition: avformat.h:873
avio_seek
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:253
pos
unsigned int pos
Definition: spdifenc.c:412
avformat.h
av_bprintf
void av_bprintf(AVBPrint *buf, const char *fmt,...)
Definition: bprint.c:94
ff_subviewer_demuxer
AVInputFormat ff_subviewer_demuxer
Definition: subviewerdec.c:206
subtitles.h
subviewer_read_packet
static int subviewer_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: subviewerdec.c:185
subviewer_read_header
static int subviewer_read_header(AVFormatContext *s)
Definition: subviewerdec.c:80
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
AVPacket
This structure stores compressed data.
Definition: packet.h:346
av_dict_set
int av_dict_set(AVDictionary **pm, const char *key, const char *value, int flags)
Set the given entry in *pm, overwriting an existing entry.
Definition: dict.c:70
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:561
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
subviewer_read_close
static int subviewer_read_close(AVFormatContext *s)
Definition: subviewerdec.c:199
avstring.h
AV_RB24
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_WB32 unsigned int_TMPL AV_RB24
Definition: bytestream.h:97
SubViewerContext::q
FFDemuxSubtitlesQueue q
Definition: subviewerdec.c:37
av_tolower
static av_const int av_tolower(int c)
Locale-independent conversion of ASCII characters to lowercase.
Definition: avstring.h:246
avio_feof
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:364