FFmpeg  4.4.5
mccdec.c
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1 /*
2  * MCC subtitle demuxer
3  * Copyright (c) 2020 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/avstring.h"
26 #include "libavutil/bprint.h"
27 #include "libavutil/intreadwrite.h"
28 
29 typedef struct MCCContext {
31 } MCCContext;
32 
33 static int mcc_probe(const AVProbeData *p)
34 {
35  char buf[28];
36  FFTextReader tr;
37 
38  ff_text_init_buf(&tr, p->buf, p->buf_size);
39 
40  while (ff_text_peek_r8(&tr) == '\r' || ff_text_peek_r8(&tr) == '\n')
41  ff_text_r8(&tr);
42 
43  ff_text_read(&tr, buf, sizeof(buf));
44 
45  if (!memcmp(buf, "File Format=MacCaption_MCC V", 28))
46  return AVPROBE_SCORE_MAX;
47 
48  return 0;
49 }
50 
51 static int convert(uint8_t x)
52 {
53  if (x >= 'a')
54  x -= 87;
55  else if (x >= 'A')
56  x -= 55;
57  else
58  x -= '0';
59  return x;
60 }
61 
62 typedef struct alias {
64  int len;
65  const char *value;
66 } alias;
67 
68 static const alias aliases[20] = {
69  { .key = 16, .len = 3, .value = "\xFA\x0\x0", },
70  { .key = 17, .len = 6, .value = "\xFA\x0\x0\xFA\x0\x0", },
71  { .key = 18, .len = 9, .value = "\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0", },
72  { .key = 19, .len = 12, .value = "\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0", },
73  { .key = 20, .len = 15, .value = "\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0", },
74  { .key = 21, .len = 18, .value = "\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0", },
75  { .key = 22, .len = 21, .value = "\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0", },
76  { .key = 23, .len = 24, .value = "\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0", },
77  { .key = 24, .len = 27, .value = "\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0\xFA\x0\x0", },
78  { .key = 25, .len = 3, .value = "\xFB\x80\x80", },
79  { .key = 26, .len = 3, .value = "\xFC\x80\x80", },
80  { .key = 27, .len = 3, .value = "\xFD\x80\x80", },
81  { .key = 28, .len = 2, .value = "\x96\x69", },
82  { .key = 29, .len = 2, .value = "\x61\x01", },
83  { .key = 30, .len = 3, .value = "\xFC\x80\x80", },
84  { .key = 31, .len = 3, .value = "\xFC\x80\x80", },
85  { .key = 32, .len = 4, .value = "\xE1\x00\x00\x00", },
86  { .key = 33, .len = 0, .value = NULL, },
87  { .key = 34, .len = 0, .value = NULL, },
88  { .key = 35, .len = 1, .value = "\x0", },
89 };
90 
92 {
93  MCCContext *mcc = s->priv_data;
95  AVRational rate;
96  int64_t ts, pos;
97  uint8_t out[4096];
98  char line[4096];
99  FFTextReader tr;
100  int ret = 0;
101 
102  ff_text_init_avio(s, &tr, s->pb);
103 
104  if (!st)
105  return AVERROR(ENOMEM);
108  avpriv_set_pts_info(st, 64, 1, 30);
109 
110  while (!ff_text_eof(&tr)) {
111  int hh, mm, ss, fs, i = 0, j = 0;
112  int start = 12, count = 0;
113  AVPacket *sub;
114  char *lline;
115 
116  ff_subtitles_read_line(&tr, line, sizeof(line));
117  if (!strncmp(line, "File Format=MacCaption_MCC V", 28))
118  continue;
119  if (!strncmp(line, "//", 2))
120  continue;
121  if (!strncmp(line, "Time Code Rate=", 15)) {
122  char *rate_str = line + 15;
123  char *df = NULL;
124  int num = -1, den = -1;
125 
126  if (rate_str[0]) {
127  num = strtol(rate_str, &df, 10);
128  den = 1;
129  if (df && !av_strncasecmp(df, "DF", 2)) {
130  av_reduce(&num, &den, num * 1000LL, 1001, INT_MAX);
131  }
132  }
133 
134  if (num > 0 && den > 0) {
135  rate = av_make_q(num, den);
136  avpriv_set_pts_info(st, 64, rate.den, rate.num);
137  }
138  continue;
139  }
140 
141  if (av_sscanf(line, "%d:%d:%d:%d", &hh, &mm, &ss, &fs) != 4)
142  continue;
143 
144  ts = av_sat_add64(av_rescale(hh * 3600LL + mm * 60LL + ss, rate.num, rate.den), fs);
145 
146  lline = (char *)&line;
147  lline += 12;
148  pos = ff_text_pos(&tr);
149 
150  while (lline[i]) {
151  uint8_t v = convert(lline[i]);
152 
153  if (v >= 16 && v <= 35) {
154  int idx = v - 16;
155  if (aliases[idx].len) {
156  if (j >= sizeof(out) - 1 - aliases[idx].len) {
157  j = 0;
158  break;
159  }
160  memcpy(out + j, aliases[idx].value, aliases[idx].len);
161  j += aliases[idx].len;
162  }
163  } else {
164  uint8_t vv;
165 
166  if (i + 13 >= sizeof(line) - 1)
167  break;
168  vv = convert(lline[i + 1]);
169  if (j >= sizeof(out) - 1) {
170  j = 0;
171  break;
172  }
173  out[j++] = vv | (v << 4);
174  i++;
175  }
176 
177  i++;
178  }
179  out[j] = 0;
180 
181  if (out[7] & 0x80)
182  start += 4;
183  count = (out[11] & 0x1f) * 3;
184  if (j < start + count + 1)
185  continue;
186 
187  if (!count)
188  continue;
189  sub = ff_subtitles_queue_insert(&mcc->q, out + start, count, 0);
190  if (!sub)
191  goto fail;
192 
193  sub->pos = pos;
194  sub->pts = ts;
195  sub->duration = 1;
196  }
197 
199 
200  return ret;
201 fail:
203  return AVERROR(ENOMEM);
204 }
205 
207 {
208  MCCContext *mcc = s->priv_data;
209  return ff_subtitles_queue_read_packet(&mcc->q, pkt);
210 }
211 
212 static int mcc_read_seek(AVFormatContext *s, int stream_index,
213  int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
214 {
215  MCCContext *mcc = s->priv_data;
216  return ff_subtitles_queue_seek(&mcc->q, s, stream_index,
217  min_ts, ts, max_ts, flags);
218 }
219 
221 {
222  MCCContext *mcc = s->priv_data;
224  return 0;
225 }
226 
228  .name = "mcc",
229  .long_name = NULL_IF_CONFIG_SMALL("MacCaption"),
230  .priv_data_size = sizeof(MCCContext),
234  .read_seek2 = mcc_read_seek,
236  .extensions = "mcc",
237 };
uint8_t
Main libavformat public API header.
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:453
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
#define flags(name, subs,...)
Definition: cbs_av1.c:572
#define ss(width, name, subs,...)
Definition: cbs_vp9.c:261
#define s(width, name)
Definition: cbs_vp9.c:257
#define fs(width, name, subs,...)
Definition: cbs_vp9.c:259
#define fail()
Definition: checkasm.h:133
#define av_sat_add64
Definition: common.h:164
#define NULL
Definition: coverity.c:32
long long int64_t
Definition: coverity.c:34
static float sub(float src0, float src1)
double value
Definition: eval.c:98
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:545
@ AV_CODEC_ID_EIA_608
Definition: codec_id.h:534
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4509
#define AVERROR(e)
Definition: error.h:43
int av_reduce(int *dst_num, int *dst_den, int64_t num, int64_t den, int64_t max)
Reduce a fraction.
Definition: rational.c:35
static AVRational av_make_q(int num, int den)
Create an AVRational.
Definition: rational.h:71
int64_t av_rescale(int64_t a, int64_t b, int64_t c)
Rescale a 64-bit integer with rounding to nearest.
Definition: mathematics.c:129
@ AVMEDIA_TYPE_SUBTITLE
Definition: avutil.h:204
int av_sscanf(const char *string, const char *format,...)
See libc sscanf manual for more information.
Definition: avsscanf.c:962
int av_strncasecmp(const char *a, const char *b, size_t n)
Locale-independent case-insensitive compare.
Definition: avstring.c:225
int i
Definition: input.c:407
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:4945
static int read_probe(const AVProbeData *pd)
Definition: jvdec.c:55
common internal API header
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:145
static int mcc_read_seek(AVFormatContext *s, int stream_index, int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
Definition: mccdec.c:212
static int mcc_read_header(AVFormatContext *s)
Definition: mccdec.c:91
static int convert(uint8_t x)
Definition: mccdec.c:51
static const alias aliases[20]
Definition: mccdec.c:68
AVInputFormat ff_mcc_demuxer
Definition: mccdec.c:227
static int mcc_read_close(AVFormatContext *s)
Definition: mccdec.c:220
static int mcc_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: mccdec.c:206
static int mcc_probe(const AVProbeData *p)
Definition: mccdec.c:33
unsigned int pos
Definition: spdifenc.c:412
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
Format I/O context.
Definition: avformat.h:1232
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:645
This structure stores compressed data.
Definition: packet.h:346
This structure contains the data a format has to probe a file.
Definition: avformat.h:441
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:444
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:443
Rational number (pair of numerator and denominator).
Definition: rational.h:58
int num
Numerator.
Definition: rational.h:59
int den
Denominator.
Definition: rational.h:60
Stream structure.
Definition: avformat.h:873
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1038
FFDemuxSubtitlesQueue q
Definition: mccdec.c:30
Definition: mccdec.c:62
uint8_t key
Definition: mccdec.c:63
const char * value
Definition: mccdec.c:65
int len
Definition: mccdec.c:64
Definition: graph2dot.c:48
ptrdiff_t ff_subtitles_read_line(FFTextReader *tr, char *buf, size_t size)
Read a line of text.
Definition: subtitles.c:416
int64_t ff_text_pos(FFTextReader *r)
Return the byte position of the next byte returned by ff_text_r8().
Definition: subtitles.c:60
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:255
void ff_text_read(FFTextReader *r, char *buf, size_t size)
Read the given number of bytes (in UTF-8).
Definition: subtitles.c:86
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
int ff_text_eof(FFTextReader *r)
Return non-zero if EOF was reached.
Definition: subtitles.c:92
void ff_text_init_avio(void *s, FFTextReader *r, AVIOContext *pb)
Initialize the FFTextReader from the given AVIOContext.
Definition: subtitles.c:27
int ff_text_r8(FFTextReader *r)
Return the next byte.
Definition: subtitles.c:65
int ff_subtitles_queue_read_packet(FFDemuxSubtitlesQueue *q, AVPacket *pkt)
Generic read_packet() callback for subtitles demuxers using this queue system.
Definition: subtitles.c:216
int ff_text_peek_r8(FFTextReader *r)
Like ff_text_r8(), but don't remove the byte from the buffer.
Definition: subtitles.c:97
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:198
void ff_subtitles_queue_clean(FFDemuxSubtitlesQueue *q)
Remove and destroy all the subtitles packets.
Definition: subtitles.c:307
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
FILE * out
Definition: movenc.c:54
AVPacket * pkt
Definition: movenc.c:59
#define df(A, B)
Definition: vf_xbr.c:90
int len