FFmpeg
pjsdec.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  * PJS (Phoenix Japanimation Society) subtitles format demuxer
24  *
25  * @see http://subs.com.ru/page.php?al=pjs
26  */
27 
28 #include "avformat.h"
29 #include "internal.h"
30 #include "subtitles.h"
31 
32 typedef struct {
34 } PJSContext;
35 
36 static int pjs_probe(const AVProbeData *p)
37 {
38  char c;
39  int64_t start, end;
40  const unsigned char *ptr = p->buf;
41 
42  if (sscanf(ptr, "%"SCNd64",%"SCNd64",%c", &start, &end, &c) == 3) {
43  size_t q1pos = strcspn(ptr, "\"");
44  size_t q2pos = q1pos + strcspn(ptr + q1pos + 1, "\"") + 1;
45  if (strcspn(ptr, "\r\n") > q2pos)
46  return AVPROBE_SCORE_MAX;
47  }
48  return 0;
49 }
50 
51 static int64_t read_ts(char **line, int *duration)
52 {
53  int64_t start, end;
54 
55  if (sscanf(*line, "%"SCNd64",%"SCNd64, &start, &end) == 2) {
56  *line += strcspn(*line, "\"");
57  *line += !!**line;
58  if (end < start || end - (uint64_t)start > INT_MAX)
59  return AV_NOPTS_VALUE;
60  *duration = end - start;
61  return start;
62  }
63  return AV_NOPTS_VALUE;
64 }
65 
67 {
68  PJSContext *pjs = s->priv_data;
70 
71  if (!st)
72  return AVERROR(ENOMEM);
73  avpriv_set_pts_info(st, 64, 1, 10);
76 
77  while (!avio_feof(s->pb)) {
78  char line[4096];
79  char *p = line;
80  const int64_t pos = avio_tell(s->pb);
81  int len = ff_get_line(s->pb, line, sizeof(line));
82  int64_t pts_start;
83  int duration;
84 
85  if (!len)
86  break;
87 
88  line[strcspn(line, "\r\n")] = 0;
89 
90  pts_start = read_ts(&p, &duration);
91  if (pts_start != AV_NOPTS_VALUE) {
92  AVPacket *sub;
93 
94  p[strcspn(p, "\"")] = 0;
95  sub = ff_subtitles_queue_insert(&pjs->q, p, strlen(p), 0);
96  if (!sub)
97  return AVERROR(ENOMEM);
98  sub->pos = pos;
99  sub->pts = pts_start;
100  sub->duration = duration;
101  }
102  }
103 
105  return 0;
106 }
107 
109  .name = "pjs",
110  .long_name = NULL_IF_CONFIG_SMALL("PJS (Phoenix Japanimation Society) subtitles"),
111  .priv_data_size = sizeof(PJSContext),
112  .flags_internal = FF_FMT_INIT_CLEANUP,
115  .extensions = "pjs",
117  .read_seek2 = ff_subtitles_read_seek,
119 };
AVMEDIA_TYPE_SUBTITLE
@ AVMEDIA_TYPE_SUBTITLE
Definition: avutil.h:204
ff_subtitles_read_close
int ff_subtitles_read_close(AVFormatContext *s)
Definition: subtitles.c:337
FF_FMT_INIT_CLEANUP
#define FF_FMT_INIT_CLEANUP
For an AVInputFormat with this flag set read_close() needs to be called by the caller upon read_heade...
Definition: internal.h:46
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
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:51
pjs_read_header
static int pjs_read_header(AVFormatContext *s)
Definition: pjsdec.c:66
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const struct AVCodec *c)
Add a new stream to a media file.
AVPacket::duration
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: packet.h:540
PJSContext::q
FFDemuxSubtitlesQueue q
Definition: pjsdec.c:33
AVPROBE_SCORE_MAX
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:464
avpriv_set_pts_info
void avpriv_set_pts_info(AVStream *st, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: avformat.c:843
read_close
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:143
avio_tell
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:513
read_ts
static int64_t read_ts(char **line, int *duration)
Definition: pjsdec.c:51
PJSContext
Definition: pjsdec.c:32
AVInputFormat
Definition: avformat.h:549
ff_subtitles_read_packet
int ff_subtitles_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: subtitles.c:323
duration
int64_t duration
Definition: movenc.c:64
read_packet
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_read_callback.c:41
s
#define s(width, name)
Definition: cbs_vp9.c:198
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:554
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:454
AVFormatContext
Format I/O context.
Definition: avformat.h:1363
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:864
read_header
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:550
NULL
#define NULL
Definition: coverity.c:32
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:452
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:109
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
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:106
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:204
FFDemuxSubtitlesQueue
Definition: subtitles.h:103
line
Definition: graph2dot.c:48
AVPacket::pts
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: packet.h:515
AV_CODEC_ID_PJS
@ AV_CODEC_ID_PJS
Definition: codec_id.h:573
ff_subtitles_read_seek
int ff_subtitles_read_seek(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
Definition: subtitles.c:329
ff_get_line
int ff_get_line(AVIOContext *s, char *buf, int maxlen)
Read a whole line of text from AVIOContext.
Definition: aviobuf.c:816
len
int len
Definition: vorbis_enc_data.h:426
AVStream
Stream structure.
Definition: avformat.h:841
pos
unsigned int pos
Definition: spdifenc.c:413
avformat.h
ff_pjs_demuxer
const AVInputFormat ff_pjs_demuxer
Definition: pjsdec.c:108
subtitles.h
pjs_probe
static int pjs_probe(const AVProbeData *p)
Definition: pjsdec.c:36
read_probe
static int read_probe(const AVProbeData *p)
Definition: cdg.c:29
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:55
AVPacket
This structure stores compressed data.
Definition: packet.h:499
AVPacket::pos
int64_t pos
byte position in stream, -1 if unknown
Definition: packet.h:542
line
The official guide to swscale for confused that consecutive non overlapping rectangles of slice_bottom special converter These generally are unscaled converters of common like for each output line the vertical scaler pulls lines from a ring buffer When the ring buffer does not contain the wanted line
Definition: swscale.txt:40
avio_feof
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:393