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assdec.c
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1 /*
2  * SSA/ASS demuxer
3  * Copyright (c) 2008 Michael Niedermayer
4  * Copyright (c) 2014 Clément Bœsch
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 #include <stdint.h>
24 
25 #include "avformat.h"
26 #include "internal.h"
27 #include "subtitles.h"
28 #include "libavcodec/internal.h"
29 #include "libavutil/bprint.h"
30 
31 typedef struct ASSContext {
33  unsigned readorder;
34 } ASSContext;
35 
36 static int ass_probe(AVProbeData *p)
37 {
38  char buf[13];
39  FFTextReader tr;
40  ff_text_init_buf(&tr, p->buf, p->buf_size);
41 
42  while (ff_text_peek_r8(&tr) == '\r' || ff_text_peek_r8(&tr) == '\n')
43  ff_text_r8(&tr);
44 
45  ff_text_read(&tr, buf, sizeof(buf));
46 
47  if (!memcmp(buf, "[Script Info]", 13))
48  return AVPROBE_SCORE_MAX;
49 
50  return 0;
51 }
52 
54 {
55  ASSContext *ass = s->priv_data;
57  return 0;
58 }
59 
60 static int read_dialogue(ASSContext *ass, AVBPrint *dst, const uint8_t *p,
61  int64_t *start, int *duration)
62 {
63  int pos = 0;
64  int64_t end;
65  int hh1, mm1, ss1, ms1;
66  int hh2, mm2, ss2, ms2;
67 
68  if (sscanf(p, "Dialogue: %*[^,],%d:%d:%d%*c%d,%d:%d:%d%*c%d,%n",
69  &hh1, &mm1, &ss1, &ms1,
70  &hh2, &mm2, &ss2, &ms2, &pos) >= 8 && pos > 0) {
71 
72  /* This is not part of the sscanf itself in order to handle an actual
73  * number (which would be the Layer) or the form "Marked=N" (which is
74  * the old SSA field, now replaced by Layer, and will lead to Layer
75  * being 0 here). */
76  const int layer = atoi(p + 10);
77 
78  end = (hh2*3600LL + mm2*60LL + ss2) * 100LL + ms2;
79  *start = (hh1*3600LL + mm1*60LL + ss1) * 100LL + ms1;
80  *duration = end - *start;
81 
82  av_bprint_clear(dst);
83  av_bprintf(dst, "%u,%d,%s", ass->readorder++, layer, p + pos);
84 
85  /* right strip the buffer */
86  while (dst->len > 0 &&
87  dst->str[dst->len - 1] == '\r' ||
88  dst->str[dst->len - 1] == '\n')
89  dst->str[--dst->len] = 0;
90  return 0;
91  }
92  return -1;
93 }
94 
95 static int64_t get_line(AVBPrint *buf, FFTextReader *tr)
96 {
97  int64_t pos = ff_text_pos(tr);
98 
99  av_bprint_clear(buf);
100  for (;;) {
101  char c = ff_text_r8(tr);
102  if (!c)
103  break;
104  av_bprint_chars(buf, c, 1);
105  if (c == '\n')
106  break;
107  }
108  return pos;
109 }
110 
112 {
113  ASSContext *ass = s->priv_data;
114  AVBPrint header, line, rline;
115  int res = 0;
116  AVStream *st;
117  FFTextReader tr;
118  ff_text_init_avio(s, &tr, s->pb);
119 
120  st = avformat_new_stream(s, NULL);
121  if (!st)
122  return AVERROR(ENOMEM);
123  avpriv_set_pts_info(st, 64, 1, 100);
126 
130 
131  ass->q.keep_duplicates = 1;
132 
133  for (;;) {
134  int64_t pos = get_line(&line, &tr);
135  int64_t ts_start = AV_NOPTS_VALUE;
136  int duration = -1;
137  AVPacket *sub;
138 
139  if (!line.str[0]) // EOF
140  break;
141 
142  if (read_dialogue(ass, &rline, line.str, &ts_start, &duration) < 0) {
143  av_bprintf(&header, "%s", line.str);
144  continue;
145  }
146  sub = ff_subtitles_queue_insert(&ass->q, rline.str, rline.len, 0);
147  if (!sub) {
148  res = AVERROR(ENOMEM);
149  goto end;
150  }
151  sub->pos = pos;
152  sub->pts = ts_start;
153  sub->duration = duration;
154  }
155 
156  res = ff_bprint_to_codecpar_extradata(st->codecpar, &header);
157  if (res < 0)
158  goto end;
159 
160  ff_subtitles_queue_finalize(s, &ass->q);
161 
162 end:
163  av_bprint_finalize(&header, NULL);
164  av_bprint_finalize(&line, NULL);
165  av_bprint_finalize(&rline, NULL);
166  return res;
167 }
168 
170 {
171  ASSContext *ass = s->priv_data;
172  return ff_subtitles_queue_read_packet(&ass->q, pkt);
173 }
174 
175 static int ass_read_seek(AVFormatContext *s, int stream_index,
176  int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
177 {
178  ASSContext *ass = s->priv_data;
179  return ff_subtitles_queue_seek(&ass->q, s, stream_index,
180  min_ts, ts, max_ts, flags);
181 }
182 
184  .name = "ass",
185  .long_name = NULL_IF_CONFIG_SMALL("SSA (SubStation Alpha) subtitle"),
186  .priv_data_size = sizeof(ASSContext),
191  .read_seek2 = ass_read_seek,
192 };
int keep_duplicates
set to 1 to keep duplicated subtitle events
Definition: subtitles.h:108
#define NULL
Definition: coverity.c:32
const char * s
Definition: avisynth_c.h:631
void av_bprintf(AVBPrint *buf, const char *fmt,...)
Definition: bprint.c:94
int64_t pos
byte position in stream, -1 if unknown
Definition: avcodec.h:1597
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:4405
AVInputFormat ff_ass_demuxer
Definition: assdec.c:183
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3915
static int ass_read_close(AVFormatContext *s)
Definition: assdec.c:53
void ff_subtitles_queue_clean(FFDemuxSubtitlesQueue *q)
Remove and destroy all the subtitles packets.
Definition: subtitles.c:297
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 AVPacket pkt
int av_bprint_finalize(AVBPrint *buf, char **ret_str)
Finalize a print buffer.
Definition: bprint.c:235
unsigned readorder
Definition: assdec.c:33
Format I/O context.
Definition: avformat.h:1319
static int ass_read_header(AVFormatContext *s)
Definition: assdec.c:111
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:208
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: avcodec.h:1595
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4043
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:145
static const uint8_t header[24]
Definition: sdr2.c:67
static int ass_read_seek(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
Definition: assdec.c:175
#define AV_BPRINT_SIZE_UNLIMITED
#define AVERROR(e)
Definition: error.h:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:176
void av_bprint_init(AVBPrint *buf, unsigned size_init, unsigned size_max)
Definition: bprint.c:69
FFDemuxSubtitlesQueue q
Definition: assdec.c:32
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3911
Definition: graph2dot.c:48
static int ass_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: assdec.c:169
void ff_text_init_avio(void *s, FFTextReader *r, AVIOContext *pb)
Initialize the FFTextReader from the given AVIOContext.
Definition: subtitles.c:27
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:462
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:461
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
int64_t duration
Definition: movenc-test.c:63
static int64_t get_line(AVBPrint *buf, FFTextReader *tr)
Definition: assdec.c:95
void ff_text_read(FFTextReader *r, char *buf, size_t size)
Read the given number of bytes (in UTF-8).
Definition: subtitles.c:86
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:638
int ff_text_r8(FFTextReader *r)
Return the next byte.
Definition: subtitles.c:65
Stream structure.
Definition: avformat.h:876
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:245
AVIOContext * pb
I/O context.
Definition: avformat.h:1361
void * buf
Definition: avisynth_c.h:553
int ff_bprint_to_codecpar_extradata(AVCodecParameters *par, struct AVBPrint *buf)
Finalize buf into extradata and set its size appropriately.
Definition: utils.c:5115
This structure contains the data a format has to probe a file.
Definition: avformat.h:459
static int flags
Definition: cpu.c:47
void av_bprint_clear(AVBPrint *buf)
Reset the string to "" but keep internal allocated data.
Definition: bprint.c:227
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:471
Main libavformat public API header.
common internal api header.
static double c[64]
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
void * priv_data
Format private data.
Definition: avformat.h:1347
static int ass_probe(AVProbeData *p)
Definition: assdec.c:36
void INT64 start
Definition: avisynth_c.h:553
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:660
AVCodecParameters * codecpar
Definition: avformat.h:1006
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 int read_dialogue(ASSContext *ass, AVBPrint *dst, const uint8_t *p, int64_t *start, int *duration)
Definition: assdec.c:60
This structure stores compressed data.
Definition: avcodec.h:1554
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:193
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:1570
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:240
void av_bprint_chars(AVBPrint *buf, char c, unsigned n)
Append char c n times to a print buffer.
Definition: bprint.c:140