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srtdec.c
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1 /*
2  * SubRip subtitle demuxer
3  * Copyright (c) 2010 Aurelien Jacobs <aurel@gnuage.org>
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 "internal.h"
24 #include "subtitles.h"
25 #include "libavutil/bprint.h"
26 #include "libavutil/intreadwrite.h"
27 
28 typedef struct {
30 } SRTContext;
31 
32 static int srt_probe(AVProbeData *p)
33 {
34  int v;
35  char buf[64], *pbuf;
36  FFTextReader tr;
37 
38  ff_text_init_buf(&tr, p->buf, p->buf_size);
39 
40  while (ff_text_peek_r8(&tr) == '\r' || ff_text_peek_r8(&tr) == '\n')
41  ff_text_r8(&tr);
42 
43  /* Check if the first non-empty line is a number. We do not check what the
44  * number is because in practice it can be anything. */
45  if (ff_subtitles_read_line(&tr, buf, sizeof(buf)) < 0 ||
46  strtol(buf, &pbuf, 10) < 0 || *pbuf)
47  return 0;
48 
49  /* Check if the next line matches a SRT timestamp */
50  if (ff_subtitles_read_line(&tr, buf, sizeof(buf)) < 0)
51  return 0;
52  if (buf[0] >= '0' && buf[1] <= '9' && strstr(buf, " --> ")
53  && sscanf(buf, "%*d:%*2d:%*2d%*1[,.]%*3d --> %*d:%*2d:%*2d%*1[,.]%3d", &v) == 1)
54  return AVPROBE_SCORE_MAX;
55 
56  return 0;
57 }
58 
59 static int64_t get_pts(const char **buf, int *duration,
60  int32_t *x1, int32_t *y1, int32_t *x2, int32_t *y2)
61 {
62  int i;
63 
64  for (i=0; i<2; i++) {
65  int hh1, mm1, ss1, ms1;
66  int hh2, mm2, ss2, ms2;
67  if (sscanf(*buf, "%d:%2d:%2d%*1[,.]%3d --> %d:%2d:%2d%*1[,.]%3d"
68  "%*[ ]X1:%u X2:%u Y1:%u Y2:%u",
69  &hh1, &mm1, &ss1, &ms1,
70  &hh2, &mm2, &ss2, &ms2,
71  x1, x2, y1, y2) >= 8) {
72  int64_t start = (hh1*3600LL + mm1*60LL + ss1) * 1000LL + ms1;
73  int64_t end = (hh2*3600LL + mm2*60LL + ss2) * 1000LL + ms2;
74  *duration = end - start;
75  *buf += ff_subtitles_next_line(*buf);
76  return start;
77  }
78  *buf += ff_subtitles_next_line(*buf);
79  }
80  return AV_NOPTS_VALUE;
81 }
82 
84 {
85  SRTContext *srt = s->priv_data;
86  AVBPrint buf;
88  int res = 0;
89  FFTextReader tr;
90  ff_text_init_avio(s, &tr, s->pb);
91 
92  if (!st)
93  return AVERROR(ENOMEM);
94  avpriv_set_pts_info(st, 64, 1, 1000);
97 
99 
100  while (!ff_text_eof(&tr)) {
101  ff_subtitles_read_text_chunk(&tr, &buf);
102 
103  if (buf.len) {
104  int64_t pos = ff_text_pos(&tr);
105  int64_t pts;
106  int duration;
107  const char *ptr = buf.str;
108  int32_t x1 = -1, y1 = -1, x2 = -1, y2 = -1;
109  AVPacket *sub;
110 
111  pts = get_pts(&ptr, &duration, &x1, &y1, &x2, &y2);
112  if (pts != AV_NOPTS_VALUE) {
113  int len = buf.len - (ptr - buf.str);
114  if (len <= 0)
115  continue;
116  sub = ff_subtitles_queue_insert(&srt->q, ptr, len, 0);
117  if (!sub) {
118  res = AVERROR(ENOMEM);
119  goto end;
120  }
121  sub->pos = pos;
122  sub->pts = pts;
123  sub->duration = duration;
124  if (x1 != -1) {
126  if (p) {
127  AV_WL32(p, x1);
128  AV_WL32(p + 4, y1);
129  AV_WL32(p + 8, x2);
130  AV_WL32(p + 12, y2);
131  }
132  }
133  }
134  }
135  }
136 
138 
139 end:
140  av_bprint_finalize(&buf, NULL);
141  return res;
142 }
143 
145 {
146  SRTContext *srt = s->priv_data;
147  return ff_subtitles_queue_read_packet(&srt->q, pkt);
148 }
149 
150 static int srt_read_seek(AVFormatContext *s, int stream_index,
151  int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
152 {
153  SRTContext *srt = s->priv_data;
154  return ff_subtitles_queue_seek(&srt->q, s, stream_index,
155  min_ts, ts, max_ts, flags);
156 }
157 
159 {
160  SRTContext *srt = s->priv_data;
162  return 0;
163 }
164 
166  .name = "srt",
167  .long_name = NULL_IF_CONFIG_SMALL("SubRip subtitle"),
168  .priv_data_size = sizeof(SRTContext),
172  .read_seek2 = srt_read_seek,
174 };
#define NULL
Definition: coverity.c:32
float v
const char * s
Definition: avisynth_c.h:631
int64_t pos
byte position in stream, -1 if unknown
Definition: avcodec.h:1447
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:4071
Subtitle event position.
Definition: avcodec.h:1340
void ff_subtitles_queue_clean(FFDemuxSubtitlesQueue *q)
Remove and destroy all the subtitles packets.
Definition: subtitles.c:270
FFDemuxSubtitlesQueue q
Definition: srtdec.c:29
int ff_text_peek_r8(FFTextReader *r)
Like ff_text_r8(), but don't remove the byte from the buffer.
Definition: subtitles.c:97
static int srt_read_close(AVFormatContext *s)
Definition: srtdec.c:158
static AVPacket pkt
int av_bprint_finalize(AVBPrint *buf, char **ret_str)
Finalize a print buffer.
Definition: bprint.c:235
Format I/O context.
Definition: avformat.h:1272
uint8_t
int ff_subtitles_queue_read_packet(FFDemuxSubtitlesQueue *q, AVPacket *pkt)
Generic read_packet() callback for subtitles demuxers using this queue system.
Definition: subtitles.c:181
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:3737
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:145
static int64_t duration
Definition: ffplay.c:325
int duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: avcodec.h:1440
#define AV_BPRINT_SIZE_UNLIMITED
int ff_text_eof(FFTextReader *r)
Return non-zero if EOF was reached.
Definition: subtitles.c:92
#define AVERROR(e)
Definition: error.h:43
ptrdiff_t ff_subtitles_read_line(FFTextReader *tr, char *buf, size_t size)
Read a line of text.
Definition: subtitles.c:379
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:175
void av_bprint_init(AVBPrint *buf, unsigned size_init, unsigned size_max)
Definition: bprint.c:69
void ff_text_init_avio(void *s, FFTextReader *r, AVIOContext *pb)
Initialize the FFTextReader from the given AVIOContext.
Definition: subtitles.c:27
static int srt_probe(AVProbeData *p)
Definition: srtdec.c:32
AVCodecContext * codec
Codec context associated with this stream.
Definition: avformat.h:861
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:451
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:450
int64_t ff_text_pos(FFTextReader *r)
Return the byte position of the next byte returned by ff_text_r8().
Definition: subtitles.c:60
static int read_probe(AVProbeData *pd)
Definition: jvdec.c:55
int32_t
void ff_subtitles_queue_finalize(FFDemuxSubtitlesQueue *q)
Set missing durations and sort subtitles by PTS, and then byte position.
Definition: subtitles.c:169
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:620
int ff_text_r8(FFTextReader *r)
Return the next byte.
Definition: subtitles.c:65
Stream structure.
Definition: avformat.h:842
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
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:218
enum AVMediaType codec_type
Definition: avcodec.h:1509
enum AVCodecID codec_id
Definition: avcodec.h:1518
AVIOContext * pb
I/O context.
Definition: avformat.h:1314
void ff_subtitles_read_text_chunk(FFTextReader *tr, AVBPrint *buf)
Read a subtitles chunk from FFTextReader.
Definition: subtitles.c:328
static int64_t get_pts(const char **buf, int *duration, int32_t *x1, int32_t *y1, int32_t *x2, int32_t *y2)
Definition: srtdec.c:59
void * buf
Definition: avisynth_c.h:553
AVInputFormat ff_srt_demuxer
Definition: srtdec.c:165
This structure contains the data a format has to probe a file.
Definition: avformat.h:448
static int64_t pts
Global timestamp for the audio frames.
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:185
static int flags
Definition: cpu.c:47
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:460
Main libavformat public API header.
static int srt_read_seek(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
Definition: srtdec.c:150
void ff_text_init_buf(FFTextReader *r, void *buf, size_t size)
Similar to ff_text_init_avio(), but sets it up to read from a bounded buffer.
Definition: subtitles.c:53
static int srt_read_header(AVFormatContext *s)
Definition: srtdec.c:83
static int srt_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: srtdec.c:144
int len
void * priv_data
Format private data.
Definition: avformat.h:1300
void INT64 start
Definition: avisynth_c.h:553
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:628
uint8_t * av_packet_new_side_data(AVPacket *pkt, enum AVPacketSideDataType type, int size)
Allocate new information of a packet.
Definition: avpacket.c:299
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
This structure stores compressed data.
Definition: avcodec.h:1399
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:1415
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:248
#define AV_WL32(p, v)
Definition: intreadwrite.h:426