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1 /*
2  * MicroDVD subtitle demuxer
3  * Copyright (c) 2010 Aurelien Jacobs <aurel@gnuage.org>
4  * Copyright (c) 2012 Clément Bœsch <u pkh me>
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
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  */
23 #include "avformat.h"
24 #include "internal.h"
25 #include "subtitles.h"
26 #include "libavutil/intreadwrite.h"
27 #include "libavutil/opt.h"
29 #define MAX_LINESIZE 2048
32 typedef struct {
33  const AVClass *class;
39 static int microdvd_probe(const AVProbeData *p)
40 {
41  unsigned char c;
42  const uint8_t *ptr = p->buf;
43  int i;
45  if (AV_RB24(ptr) == 0xEFBBBF)
46  ptr += 3; /* skip UTF-8 BOM */
48  for (i=0; i<3; i++) {
49  if (sscanf(ptr, "{%*d}{}%c", &c) != 1 &&
50  sscanf(ptr, "{%*d}{%*d}%c", &c) != 1 &&
51  sscanf(ptr, "{DEFAULT}{}%c", &c) != 1)
52  return 0;
53  ptr += ff_subtitles_next_line(ptr);
54  }
56 }
58 static int64_t get_pts(const char *buf)
59 {
60  int frame;
61  char c;
63  if (sscanf(buf, "{%d}{%c", &frame, &c) == 2)
64  return frame;
65  return AV_NOPTS_VALUE;
66 }
68 static int64_t get_duration(const char *buf)
69 {
72  if (sscanf(buf, "{%d}{%d}", &frame_start, &frame_end) == 2)
73  return frame_end - (int64_t)frame_start;
74  return -1;
75 }
77 static const char *bom = "\xEF\xBB\xBF";
80 {
81  AVRational pts_info = (AVRational){ 2997, 125 }; /* default: 23.976 fps */
82  MicroDVDContext *microdvd = s->priv_data;
84  int i = 0, ret;
85  char line_buf[MAX_LINESIZE];
86  int has_real_fps = 0;
88  if (!st)
89  return AVERROR(ENOMEM);
91  while (!avio_feof(s->pb)) {
92  char *p;
93  AVPacket *sub;
94  int64_t pos = avio_tell(s->pb);
95  int len = ff_get_line(s->pb, line_buf, sizeof(line_buf));
96  char *line = line_buf;
97  int64_t pts;
99  if (!strncmp(line, bom, 3))
100  line += 3;
101  p = line;
103  if (!len)
104  break;
105  line[strcspn(line, "\r\n")] = 0;
106  if (!*p)
107  continue;
108  if (i++ < 3) {
109  int frame;
110  double fps;
111  char c;
113  if ((sscanf(line, "{%d}{}%6lf", &frame, &fps) == 2 ||
114  sscanf(line, "{%d}{%*d}%6lf", &frame, &fps) == 2)
115  && frame <= 1 && fps > 3 && fps < 100) {
116  pts_info = av_d2q(fps, 100000);
117  has_real_fps = 1;
118  continue;
119  }
120  if (!st->codecpar->extradata && sscanf(line, "{DEFAULT}{}%c", &c) == 1) {
121  int size = strlen(line + 11);
122  ret = ff_alloc_extradata(st->codecpar, size);
123  if (ret < 0)
124  goto fail;
125  memcpy(st->codecpar->extradata, line + 11, size);
126  continue;
127  }
128  }
129 #define SKIP_FRAME_ID \
130  p = strchr(p, '}'); \
131  if (!p) { \
132  av_log(s, AV_LOG_WARNING, "Invalid event \"%s\"" \
133  " at line %d\n", line, i); \
134  continue; \
135  } \
136  p++
139  if (!*p)
140  continue;
141  pts = get_pts(line);
142  if (pts == AV_NOPTS_VALUE)
143  continue;
144  sub = ff_subtitles_queue_insert(&microdvd->q, p, strlen(p), 0);
145  if (!sub) {
146  ret = AVERROR(ENOMEM);
147  goto fail;
148  }
149  sub->pos = pos;
150  sub->pts = pts;
151  sub->duration = get_duration(line);
152  }
153  ff_subtitles_queue_finalize(s, &microdvd->q);
154  if (has_real_fps) {
155  /* export the FPS info only if set in the file */
156  microdvd->frame_rate = pts_info;
157  } else if (microdvd->frame_rate.num) {
158  /* fallback on user specified frame rate */
159  pts_info = microdvd->frame_rate;
160  }
161  avpriv_set_pts_info(st, 64, pts_info.den, pts_info.num);
164  return 0;
165 fail:
166  ff_subtitles_queue_clean(&microdvd->q);
167  return ret;
168 }
171 {
172  MicroDVDContext *microdvd = s->priv_data;
173  return ff_subtitles_queue_read_packet(&microdvd->q, pkt);
174 }
176 static int microdvd_read_seek(AVFormatContext *s, int stream_index,
177  int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
178 {
179  MicroDVDContext *microdvd = s->priv_data;
180  return ff_subtitles_queue_seek(&microdvd->q, s, stream_index,
181  min_ts, ts, max_ts, flags);
182 }
185 {
186  MicroDVDContext *microdvd = s->priv_data;
187  ff_subtitles_queue_clean(&microdvd->q);
188  return 0;
189 }
192 #define OFFSET(x) offsetof(MicroDVDContext, x)
194 static const AVOption microdvd_options[] = {
195  { "subfps", "set the movie frame rate fallback", OFFSET(frame_rate), AV_OPT_TYPE_RATIONAL, {.dbl=0}, 0, INT_MAX, SD },
196  { NULL }
197 };
199 static const AVClass microdvd_class = {
200  .class_name = "microdvddec",
201  .item_name = av_default_item_name,
202  .option = microdvd_options,
203  .version = LIBAVUTIL_VERSION_INT,
204 };
207  .name = "microdvd",
208  .long_name = NULL_IF_CONFIG_SMALL("MicroDVD subtitle format"),
209  .priv_data_size = sizeof(MicroDVDContext),
213  .read_seek2 = microdvd_read_seek,
215  .priv_class = &microdvd_class,
216 };
#define NULL
Definition: coverity.c:32
static int microdvd_read_seek(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
Definition: microdvddec.c:176
Definition: opt.h:248
Definition: version.h:85
int64_t pos
byte position in stream, -1 if unknown
Definition: packet.h:383
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:4905
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
int num
Definition: rational.h:59
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:235
void ff_subtitles_queue_clean(FFDemuxSubtitlesQueue *q)
Remove and destroy all the subtitles packets.
Definition: subtitles.c:302
static AVPacket pkt
Format I/O context.
Definition: avformat.h:1243
static int microdvd_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: microdvddec.c:170
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:72
#define OFFSET(x)
Definition: microdvddec.c:192
int ff_subtitles_queue_read_packet(FFDemuxSubtitlesQueue *q, AVPacket *pkt)
Generic read_packet() callback for subtitles demuxers using this queue system.
Definition: subtitles.c:212
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: packet.h:381
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
#define SD
Definition: microdvddec.c:193
Definition: microdvddec.c:29
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4481
static int64_t get_pts(const char *buf)
Definition: microdvddec.c:58
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:145
ptrdiff_t size
Definition: opengl_enc.c:100
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:557
static const char * bom
Definition: microdvddec.c:77
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:115
unsigned int pos
Definition: spdifenc.c:410
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
Definition: graph2dot.c:48
#define fail()
Definition: checkasm.h:133
static int microdvd_read_header(AVFormatContext *s)
Definition: microdvddec.c:79
static void frame_end(MpegEncContext *s)
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:443
int ff_alloc_extradata(AVCodecParameters *par, int size)
Allocate extradata with additional AV_INPUT_BUFFER_PADDING_SIZE at end which is always set to 0...
Definition: utils.c:3291
AVInputFormat ff_microdvd_demuxer
Definition: microdvddec.c:206
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
#define s(width, name)
Definition: cbs_vp9.c:257
static const AVClass microdvd_class
Definition: microdvddec.c:199
int ff_get_line(AVIOContext *s, char *buf, int maxlen)
Read a whole line of text from AVIOContext.
Definition: aviobuf.c:793
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:527
Stream structure.
Definition: avformat.h:884
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:250
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_WB32 unsigned int_TMPL AV_RB24
Definition: bytestream.h:91
AVIOContext * pb
I/O context.
Definition: avformat.h:1285
static int frame_start(MpegEncContext *s)
FFDemuxSubtitlesQueue q
Definition: microdvddec.c:34
Describe the class of an AVClass context structure.
Definition: log.h:67
Rational number (pair of numerator and denominator).
Definition: rational.h:58
This structure contains the data a format has to probe a file.
Definition: avformat.h:441
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
AVRational av_d2q(double d, int max)
Convert a double precision floating point number to a rational.
Definition: rational.c:106
maximum score
Definition: avformat.h:453
static const AVOption microdvd_options[]
Definition: microdvddec.c:194
Main libavformat public API header.
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:33
int den
Definition: rational.h:60
static int microdvd_read_close(AVFormatContext *s)
Definition: microdvddec.c:184
int len
void * priv_data
Format private data.
Definition: avformat.h:1271
static int microdvd_probe(const AVProbeData *p)
Definition: microdvddec.c:39
uint8_t * extradata
Extra binary data needed for initializing the decoder, codec-dependent.
Definition: codec_par.h:74
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:654
static float sub(float src0, float src1)
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1049
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:368
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
static int64_t get_duration(const char *buf)
Definition: microdvddec.c:68
This structure stores compressed data.
Definition: packet.h:340
AVRational frame_rate
Definition: microdvddec.c:35
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:194
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: packet.h:356
int i
Definition: input.c:407
Undefined timestamp value.
Definition: avutil.h:248