FFmpeg  2.1.1
assdec.c
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1 /*
2  * SSA/ASS demuxer
3  * Copyright (c) 2008 Michael Niedermayer
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 "libavcodec/internal.h"
26 #include "libavutil/bprint.h"
27 
28 typedef struct ASSContext{
30 }ASSContext;
31 
32 static int ass_probe(AVProbeData *p)
33 {
34  const char *header= "[Script Info]";
35 
36  if( !memcmp(p->buf , header, strlen(header))
37  || !memcmp(p->buf+3, header, strlen(header)))
38  return AVPROBE_SCORE_MAX;
39 
40  return 0;
41 }
42 
44 {
45  ASSContext *ass = s->priv_data;
47  return 0;
48 }
49 
50 static int read_ts(const uint8_t *p, int64_t *start, int *duration)
51 {
52  int64_t end;
53  int hh1, mm1, ss1, ms1;
54  int hh2, mm2, ss2, ms2;
55 
56  if (sscanf(p, "%*[^,],%d:%d:%d%*c%d,%d:%d:%d%*c%d",
57  &hh1, &mm1, &ss1, &ms1,
58  &hh2, &mm2, &ss2, &ms2) == 8) {
59  end = (hh2*3600LL + mm2*60LL + ss2) * 100LL + ms2;
60  *start = (hh1*3600LL + mm1*60LL + ss1) * 100LL + ms1;
61  *duration = end - *start;
62  return 0;
63  }
64  return -1;
65 }
66 
67 static int64_t get_line(AVBPrint *buf, AVIOContext *pb)
68 {
69  int64_t pos = avio_tell(pb);
70 
71  av_bprint_clear(buf);
72  for (;;) {
73  char c = avio_r8(pb);
74  if (!c)
75  break;
76  av_bprint_chars(buf, c, 1);
77  if (c == '\n')
78  break;
79  }
80  return pos;
81 }
82 
84 {
85  ASSContext *ass = s->priv_data;
86  AVBPrint header, line;
87  int header_remaining, res = 0;
88  AVStream *st;
89 
90  st = avformat_new_stream(s, NULL);
91  if (!st)
92  return AVERROR(ENOMEM);
93  avpriv_set_pts_info(st, 64, 1, 100);
96 
97  header_remaining= INT_MAX;
98 
101 
102  for (;;) {
103  int64_t pos = get_line(&line, s->pb);
104 
105  if (!line.str[0]) // EOF
106  break;
107 
108  if (!memcmp(line.str, "[Events]", 8))
109  header_remaining= 2;
110  else if (line.str[0]=='[')
111  header_remaining= INT_MAX;
112 
113  if (header_remaining) {
114  av_bprintf(&header, "%s", line.str);
115  header_remaining--;
116  } else {
117  int64_t ts_start = AV_NOPTS_VALUE;
118  int duration = -1;
119  AVPacket *sub;
120 
121  if (read_ts(line.str, &ts_start, &duration) < 0)
122  continue;
123  sub = ff_subtitles_queue_insert(&ass->q, line.str, line.len, 0);
124  if (!sub) {
125  res = AVERROR(ENOMEM);
126  goto end;
127  }
128  sub->pos = pos;
129  sub->pts = ts_start;
130  sub->duration = duration;
131  }
132  }
133 
134  av_bprint_finalize(&line, NULL);
135 
136  res = avpriv_bprint_to_extradata(st->codec, &header);
137  if (res < 0)
138  goto end;
139 
141 
142 end:
143  return res;
144 }
145 
147 {
148  ASSContext *ass = s->priv_data;
149  return ff_subtitles_queue_read_packet(&ass->q, pkt);
150 }
151 
152 static int ass_read_seek(AVFormatContext *s, int stream_index,
153  int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
154 {
155  ASSContext *ass = s->priv_data;
156  return ff_subtitles_queue_seek(&ass->q, s, stream_index,
157  min_ts, ts, max_ts, flags);
158 }
159 
161  .name = "ass",
162  .long_name = NULL_IF_CONFIG_SMALL("SSA (SubStation Alpha) subtitle"),
163  .priv_data_size = sizeof(ASSContext),
168  .read_seek2 = ass_read_seek,
169 };
void av_bprint_chars(AVBPrint *buf, char c, unsigned n)
Append char c n times to a print buffer.
Definition: bprint.c:140
const char * s
Definition: avisynth_c.h:668
Bytestream IO Context.
Definition: avio.h:68
static int64_t get_line(AVBPrint *buf, AVIOContext *pb)
Definition: assdec.c:67
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:478
int64_t pos
byte position in stream, -1 if unknown
Definition: avcodec.h:1092
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:3922
AVInputFormat ff_ass_demuxer
Definition: assdec.c:160
AVCodecContext * codec
Codec context associated with this stream.
Definition: avformat.h:686
static int ass_read_close(AVFormatContext *s)
Definition: assdec.c:43
void ff_subtitles_queue_clean(FFDemuxSubtitlesQueue *q)
Remove and destroy all the subtitles packets.
Definition: subtitles.c:185
AVPacket * ff_subtitles_queue_insert(FFDemuxSubtitlesQueue *q, const uint8_t *event, int len, int merge)
Insert a new subtitle event.
Definition: subtitles.c:26
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:471
Format I/O context.
Definition: avformat.h:968
static int ass_read_header(AVFormatContext *s)
Definition: assdec.c:83
static uint8_t * res
Definition: ffhash.c:43
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:96
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:67
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:336
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:248
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:145
static int64_t duration
Definition: ffplay.c:306
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:3348
int duration
Duration of this packet in AVStream-&gt;time_base units, 0 if unknown.
Definition: avcodec.h:1085
int avpriv_bprint_to_extradata(AVCodecContext *avctx, struct AVBPrint *buf)
Finalize buf into extradata and set its size appropriately.
Definition: utils.c:3371
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:152
void * priv_data
Format private data.
Definition: avformat.h:988
#define AV_BPRINT_SIZE_UNLIMITED
Convenience macros for special values for av_bprint_init() size_max parameter.
Definition: bprint.h:91
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:151
FFDemuxSubtitlesQueue q
Definition: assdec.c:29
Definition: graph2dot.c:48
int av_bprint_finalize(AVBPrint *buf, char **ret_str)
Finalize a print buffer.
Definition: bprint.c:235
static int ass_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: assdec.c:146
void av_bprint_init(AVBPrint *buf, unsigned size_init, unsigned size_max)
Init a print buffer.
Definition: bprint.c:69
Buffer to print data progressively.
Definition: bprint.h:77
static int read_probe(AVProbeData *pd)
Definition: jvdec.c:54
void ff_subtitles_queue_finalize(FFDemuxSubtitlesQueue *q)
Set missing durations and sort subtitles by PTS, and then byte position.
Definition: subtitles.c:84
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:592
Stream structure.
Definition: avformat.h:667
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:133
enum AVMediaType codec_type
Definition: avcodec.h:1154
enum AVCodecID codec_id
Definition: avcodec.h:1157
AVIOContext * pb
I/O context.
Definition: avformat.h:1001
void * buf
Definition: avisynth_c.h:594
static int read_packet(AVFormatContext *ctx, AVPacket *pkt)
Definition: libcdio.c:114
void av_bprint_clear(AVBPrint *buf)
Reset the string to &quot;&quot; but keep internal allocated data.
Definition: bprint.c:227
static int read_ts(const uint8_t *p, int64_t *start, int *duration)
Definition: assdec.c:50
This structure contains the data a format has to probe a file.
Definition: avformat.h:334
static int flags
Definition: cpu.c:45
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:342
common internal api header.
static double c[64]
Main libavformat public API header.
void av_bprintf(AVBPrint *buf, const char *fmt,...) av_printf_format(2
Append a formatted string to a print buffer.
#define AVERROR(e)
static int ass_probe(AVProbeData *p)
Definition: assdec.c:32
void INT64 start
Definition: avisynth_c.h:594
static AVPacket pkt
Definition: demuxing.c:52
This structure stores compressed data.
Definition: avcodec.h:1040
int64_t pts
Presentation timestamp in AVStream-&gt;time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:1056
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avcodec.h:2278