FFmpeg
sccdec.c
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1 /*
2  * SCC subtitle demuxer
3  * Copyright (c) 2017 Paul B Mahol
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 "libavutil/bprint.h"
26 #include "libavutil/intreadwrite.h"
27 
28 typedef struct SCCContext {
30 } SCCContext;
31 
32 static int scc_probe(const AVProbeData *p)
33 {
34  char buf[18];
35  FFTextReader tr;
36 
37  ff_text_init_buf(&tr, p->buf, p->buf_size);
38 
39  while (ff_text_peek_r8(&tr) == '\r' || ff_text_peek_r8(&tr) == '\n')
40  ff_text_r8(&tr);
41 
42  ff_text_read(&tr, buf, sizeof(buf));
43 
44  if (!memcmp(buf, "Scenarist_SCC V1.0", 18))
45  return AVPROBE_SCORE_MAX;
46 
47  return 0;
48 }
49 
50 static int convert(uint8_t x)
51 {
52  if (x >= 'a')
53  x -= 87;
54  else if (x >= 'A')
55  x -= 55;
56  else
57  x -= '0';
58  return x;
59 }
60 
62 {
63  SCCContext *scc = s->priv_data;
65  char line[4096], line2[4096];
66  int64_t ts_start, ts_end;
67  int count = 0, ret = 0;
68  ptrdiff_t len2, len;
69  uint8_t out[4096];
70  FFTextReader tr;
71 
72  ff_text_init_avio(s, &tr, s->pb);
73 
74  if (!st)
75  return AVERROR(ENOMEM);
76  avpriv_set_pts_info(st, 64, 1, 1000);
79 
80  while (!ff_text_eof(&tr)) {
81  int64_t current_pos, next_pos;
82  char *saveptr = NULL, *lline;
83  int hh1, mm1, ss1, fs1, i;
84  int hh2, mm2, ss2, fs2;
85  AVPacket *sub;
86 
87  if (count == 0) {
88  current_pos = ff_text_pos(&tr);
89  while (!ff_text_eof(&tr)) {
90  len = ff_subtitles_read_line(&tr, line, sizeof(line));
91  if (len > 13)
92  break;
93  }
94  }
95 
96  if (!strncmp(line, "Scenarist_SCC V1.0", 18))
97  continue;
98  if (sscanf(line, "%d:%d:%d%*[:;]%d", &hh1, &mm1, &ss1, &fs1) != 4)
99  continue;
100 
101  ts_start = (hh1 * 3600LL + mm1 * 60LL + ss1) * 1000LL + fs1 * 33;
102 
103  next_pos = ff_text_pos(&tr);
104  while (!ff_text_eof(&tr)) {
105  len2 = ff_subtitles_read_line(&tr, line2, sizeof(line2));
106  if (len2 > 13)
107  break;
108  }
109  if (sscanf(line2, "%d:%d:%d%*[:;]%d", &hh2, &mm2, &ss2, &fs2) != 4)
110  continue;
111 
112  ts_end = (hh2 * 3600LL + mm2 * 60LL + ss2) * 1000LL + fs2 * 33;
113  count++;
114 
115 try_again:
116  lline = (char *)&line;
117  lline += 12;
118 
119  for (i = 0; i < 4095; i += 3) {
120  char *ptr = av_strtok(lline, " ", &saveptr);
121  char c1, c2, c3, c4;
122 
123  if (!ptr)
124  break;
125 
126  if (sscanf(ptr, "%c%c%c%c", &c1, &c2, &c3, &c4) != 4)
127  break;
128 
129  lline = NULL;
130  out[i+0] = 0xfc;
131  out[i+1] = convert(c2) | (convert(c1) << 4);
132  out[i+2] = convert(c4) | (convert(c3) << 4);
133  }
134  out[i] = 0;
135 
136  sub = ff_subtitles_queue_insert(&scc->q, out, i, 0);
137  if (!sub)
138  return AVERROR(ENOMEM);
139 
140  sub->pos = current_pos;
141  sub->pts = ts_start;
142  sub->duration = ts_end - ts_start;
143  memmove(line, line2, sizeof(line));
144  current_pos = next_pos;
145  line2[0] = 0;
146  }
147 
148  if (line[0]) {
149  ts_start = ts_end;
150  ts_end += 1200;
151  goto try_again;
152  }
153 
154  ff_subtitles_queue_finalize(s, &scc->q);
155 
156  return ret;
157 }
158 
160 {
161  SCCContext *scc = s->priv_data;
162  return ff_subtitles_queue_read_packet(&scc->q, pkt);
163 }
164 
165 static int scc_read_seek(AVFormatContext *s, int stream_index,
166  int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
167 {
168  SCCContext *scc = s->priv_data;
169  return ff_subtitles_queue_seek(&scc->q, s, stream_index,
170  min_ts, ts, max_ts, flags);
171 }
172 
174 {
175  SCCContext *scc = s->priv_data;
177  return 0;
178 }
179 
181  .name = "scc",
182  .long_name = NULL_IF_CONFIG_SMALL("Scenarist Closed Captions"),
183  .priv_data_size = sizeof(SCCContext),
187  .read_seek2 = scc_read_seek,
189  .extensions = "scc",
190 };
#define NULL
Definition: coverity.c:32
int64_t pos
byte position in stream, -1 if unknown
Definition: avcodec.h:1513
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:4928
static int scc_read_close(AVFormatContext *s)
Definition: sccdec.c:173
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3981
void ff_subtitles_queue_clean(FFDemuxSubtitlesQueue *q)
Remove and destroy all the subtitles packets.
Definition: subtitles.c:301
int ff_text_peek_r8(FFTextReader *r)
Like ff_text_r8(), but don&#39;t remove the byte from the buffer.
Definition: subtitles.c:97
static AVPacket pkt
Format I/O context.
Definition: avformat.h:1357
static int scc_read_header(AVFormatContext *s)
Definition: sccdec.c:61
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:211
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: avcodec.h:1511
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4501
static const uint64_t c1
Definition: murmur3.c:49
FFDemuxSubtitlesQueue q
Definition: sccdec.c:29
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:145
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
int ff_text_eof(FFTextReader *r)
Return non-zero if EOF was reached.
Definition: subtitles.c:92
ptrdiff_t ff_subtitles_read_line(FFTextReader *tr, char *buf, size_t size)
Read a line of text.
Definition: subtitles.c:410
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3977
Definition: graph2dot.c:48
GLsizei count
Definition: opengl_enc.c:108
void ff_text_init_avio(void *s, FFTextReader *r, AVIOContext *pb)
Initialize the FFTextReader from the given AVIOContext.
Definition: subtitles.c:27
static int scc_probe(const AVProbeData *p)
Definition: sccdec.c:32
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
int64_t ff_text_pos(FFTextReader *r)
Return the byte position of the next byte returned by ff_text_r8().
Definition: subtitles.c:60
AVInputFormat ff_scc_demuxer
Definition: sccdec.c:180
static int scc_read_seek(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
Definition: sccdec.c:165
#define s(width, name)
Definition: cbs_vp9.c:257
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 convert(uint8_t x)
Definition: sccdec.c:50
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:530
int ff_text_r8(FFTextReader *r)
Return the next byte.
Definition: subtitles.c:65
Stream structure.
Definition: avformat.h:880
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:249
AVIOContext * pb
I/O context.
Definition: avformat.h:1399
void * buf
Definition: avisynth_c.h:766
This structure contains the data a format has to probe a file.
Definition: avformat.h:446
#define flags(name, subs,...)
Definition: cbs_av1.c:561
static int read_probe(const AVProbeData *pd)
Definition: jvdec.c:55
char * av_strtok(char *s, const char *delim, char **saveptr)
Split the string into several tokens which can be accessed by successive calls to av_strtok()...
Definition: avstring.c:184
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:458
Main libavformat public API header.
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
static const uint64_t c2
Definition: murmur3.c:50
int len
void * priv_data
Format private data.
Definition: avformat.h:1385
FILE * out
Definition: movenc.c:54
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:1027
static int scc_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: sccdec.c:159
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:1470
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:1486