FFmpeg
mpsubdec.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  * MPlayer subtitles format demuxer
24  */
25 
26 #include "avformat.h"
27 #include "internal.h"
28 #include "subtitles.h"
29 
30 #define TSBASE 10000000
31 
32 typedef struct {
34 } MPSubContext;
35 
36 static int mpsub_probe(const AVProbeData *p)
37 {
38  const char *ptr = p->buf;
39  const char *ptr_end = p->buf + p->buf_size;
40 
41  while (ptr < ptr_end) {
42  int inc;
43 
44  if (!memcmp(ptr, "FORMAT=TIME", 11))
46  if (!memcmp(ptr, "FORMAT=", 7))
47  return AVPROBE_SCORE_EXTENSION / 3;
48  inc = ff_subtitles_next_line(ptr);
49  if (!inc)
50  break;
51  ptr += inc;
52  }
53  return 0;
54 }
55 
56 static int parse_line(const char *line, int64_t *value, int64_t *value2)
57 {
58  int vi, p1, p2;
59 
60  for (vi = 0; vi < 2; vi++) {
61  long long intval, fracval;
62  int n = av_sscanf(line, "%lld%n.%lld%n", &intval, &p1, &fracval, &p2);
63  if (n <= 0 || intval < INT64_MIN / TSBASE || intval > INT64_MAX / TSBASE)
64  return AVERROR_INVALIDDATA;
65 
66  intval *= TSBASE;
67 
68  if (n == 2) {
69  if (fracval < 0)
70  return AVERROR_INVALIDDATA;
71  for (;p2 - p1 < 7 + 1; p1--)
72  fracval *= 10;
73  for (;p2 - p1 > 7 + 1; p1++)
74  fracval /= 10;
75  if (intval > 0) intval += fracval;
76  else intval -= fracval;
77  line += p2;
78  } else
79  line += p1;
80 
81  *value = intval;
82 
83  value = value2;
84  }
85 
86  return 0;
87 }
88 
90 {
91  MPSubContext *mpsub = s->priv_data;
92  AVStream *st;
93  AVBPrint buf;
94  AVRational pts_info = (AVRational){ TSBASE, 1 }; // ts based by default
95  int res = 0;
96  int64_t current_pts = 0;
97  int i;
98  int common_factor = 0;
99 
101 
102  while (!avio_feof(s->pb)) {
103  char line[1024];
104  int64_t start, duration;
105  int fps, len = ff_get_line(s->pb, line, sizeof(line));
106 
107  if (!len)
108  break;
109 
110  line[strcspn(line, "\r\n")] = 0;
111 
112  if (sscanf(line, "FORMAT=%d", &fps) == 1 && fps > 3 && fps < 100) {
113  /* frame based timing */
114  pts_info = (AVRational){ TSBASE * fps, 1 };
115  } else if (parse_line(line, &start, &duration) >= 0) {
116  AVPacket *sub;
117  const int64_t pos = avio_tell(s->pb);
118 
119  ff_subtitles_read_chunk(s->pb, &buf);
120  if (buf.len) {
121  sub = ff_subtitles_queue_insert(&mpsub->q, buf.str, buf.len, 0);
122  if (!sub) {
123  res = AVERROR(ENOMEM);
124  goto end;
125  }
126  if ( current_pts < 0 && start < INT64_MIN - current_pts
127  || current_pts > 0 && start > INT64_MAX - current_pts) {
128  res = AVERROR_INVALIDDATA;
129  goto end;
130  }
131  sub->pts = current_pts + start;
132  if (duration < 0 || sub->pts > INT64_MAX - duration) {
133  res = AVERROR_INVALIDDATA;
134  goto end;
135  }
136  sub->duration = duration;
137 
138  common_factor = av_gcd(duration, common_factor);
139  common_factor = av_gcd(sub->pts, common_factor);
140 
141  current_pts = sub->pts + duration;
142  sub->pos = pos;
143  }
144  }
145  }
146 
147  if (common_factor > 1) {
148  common_factor = av_gcd(pts_info.num, common_factor);
149  for (i = 0; i < mpsub->q.nb_subs; i++) {
150  mpsub->q.subs[i].pts /= common_factor;
151  mpsub->q.subs[i].duration /= common_factor;
152  }
153  pts_info.num /= common_factor;
154  }
155 
156  st = avformat_new_stream(s, NULL);
157  if (!st)
158  return AVERROR(ENOMEM);
159  avpriv_set_pts_info(st, 64, pts_info.den, pts_info.num);
162 
163  ff_subtitles_queue_finalize(s, &mpsub->q);
164 
165 end:
166  if (res < 0)
167  ff_subtitles_queue_clean(&mpsub->q);
168 
169  av_bprint_finalize(&buf, NULL);
170  return res;
171 }
172 
174 {
175  MPSubContext *mpsub = s->priv_data;
176  return ff_subtitles_queue_read_packet(&mpsub->q, pkt);
177 }
178 
179 static int mpsub_read_seek(AVFormatContext *s, int stream_index,
180  int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
181 {
182  MPSubContext *mpsub = s->priv_data;
183  return ff_subtitles_queue_seek(&mpsub->q, s, stream_index,
184  min_ts, ts, max_ts, flags);
185 }
186 
188 {
189  MPSubContext *mpsub = s->priv_data;
190  ff_subtitles_queue_clean(&mpsub->q);
191  return 0;
192 }
193 
195  .name = "mpsub",
196  .long_name = NULL_IF_CONFIG_SMALL("MPlayer subtitles"),
197  .priv_data_size = sizeof(MPSubContext),
201  .read_seek2 = mpsub_read_seek,
203  .extensions = "sub",
204 };
AVInputFormat ff_mpsub_demuxer
Definition: mpsubdec.c:194
#define NULL
Definition: coverity.c:32
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
static int mpsub_probe(const AVProbeData *p)
Definition: mpsubdec.c:36
int64_t pos
byte position in stream, -1 if unknown
Definition: avcodec.h:1500
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:4929
void ff_subtitles_read_chunk(AVIOContext *pb, AVBPrint *buf)
Same as ff_subtitles_read_text_chunk(), but read from an AVIOContext.
Definition: subtitles.c:400
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3968
#define TSBASE
Definition: mpsubdec.c:30
int num
Numerator.
Definition: rational.h:59
void ff_subtitles_queue_clean(FFDemuxSubtitlesQueue *q)
Remove and destroy all the subtitles packets.
Definition: subtitles.c:300
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:1358
int ff_subtitles_queue_read_packet(FFDemuxSubtitlesQueue *q, AVPacket *pkt)
Generic read_packet() callback for subtitles demuxers using this queue system.
Definition: subtitles.c:211
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:1498
static int mpsub_read_seek(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
Definition: mpsubdec.c:179
GLsizei GLboolean const GLfloat * value
Definition: opengl_enc.c:108
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4502
int64_t duration
Definition: movenc.c:63
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:145
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:557
const AVS_VideoInfo * vi
Definition: avisynth_c.h:887
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
#define AV_BPRINT_SIZE_UNLIMITED
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
void av_bprint_init(AVBPrint *buf, unsigned size_init, unsigned size_max)
Definition: bprint.c:69
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3964
Definition: graph2dot.c:48
int64_t av_gcd(int64_t a, int64_t b)
Compute the greatest common divisor of two integer operands.
Definition: mathematics.c:37
static int mpsub_read_header(AVFormatContext *s)
Definition: mpsubdec.c:89
int av_sscanf(const char *string, const char *format,...)
See libc sscanf manual for more information.
Definition: avsscanf.c:962
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:449
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:448
static int parse_line(const char *line, int64_t *value, int64_t *value2)
Definition: mpsubdec.c:56
#define s(width, name)
Definition: cbs_vp9.c:257
int n
Definition: avisynth_c.h:760
int ff_get_line(AVIOContext *s, char *buf, int maxlen)
Read a whole line of text from AVIOContext.
Definition: aviobuf.c:811
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:530
Stream structure.
Definition: avformat.h:881
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:248
AVIOContext * pb
I/O context.
Definition: avformat.h:1400
void * buf
Definition: avisynth_c.h:766
static int mpsub_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: mpsubdec.c:173
Rational number (pair of numerator and denominator).
Definition: rational.h:58
static int mpsub_read_close(AVFormatContext *s)
Definition: mpsubdec.c:187
#define AVPROBE_SCORE_EXTENSION
score for file extension
Definition: avformat.h:456
This structure contains the data a format has to probe a file.
Definition: avformat.h:446
static int64_t pts
#define flags(name, subs,...)
Definition: cbs_av1.c:561
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
static int read_probe(const AVProbeData *pd)
Definition: jvdec.c:55
Main libavformat public API header.
raw UTF-8 text
Definition: avcodec.h:662
AVPacket * subs
array of subtitles packets
Definition: subtitles.h:103
FFDemuxSubtitlesQueue q
Definition: mpsubdec.c:33
int den
Denominator.
Definition: rational.h:60
int len
void * priv_data
Format private data.
Definition: avformat.h:1386
void INT64 start
Definition: avisynth_c.h:766
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:654
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1028
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:361
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
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
This structure stores compressed data.
Definition: avcodec.h:1457
int nb_subs
number of subtitles packets
Definition: subtitles.h:104
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:1473