FFmpeg
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 {
63  uint8_t key;
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  return AVERROR(ENOMEM);
192 
193  sub->pos = pos;
194  sub->pts = ts;
195  sub->duration = 1;
196  }
197 
199 
200  return ret;
201 }
202 
204  .name = "mcc",
205  .long_name = NULL_IF_CONFIG_SMALL("MacCaption"),
206  .priv_data_size = sizeof(MCCContext),
207  .flags_internal = FF_FMT_INIT_CLEANUP,
210  .extensions = "mcc",
212  .read_seek2 = ff_subtitles_read_seek,
214 };
AV_CODEC_ID_EIA_608
@ AV_CODEC_ID_EIA_608
Definition: codec_id.h:532
AVMEDIA_TYPE_SUBTITLE
@ AVMEDIA_TYPE_SUBTITLE
Definition: avutil.h:204
ff_subtitles_read_close
int ff_subtitles_read_close(AVFormatContext *s)
Definition: subtitles.c:329
ff_text_r8
int ff_text_r8(FFTextReader *r)
Return the next byte.
Definition: subtitles.c:63
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:48
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
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:724
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
out
FILE * out
Definition: movenc.c:54
df
#define df(A, B)
Definition: vf_xbr.c:89
sub
static float sub(float src0, float src1)
Definition: dnn_backend_native_layer_mathbinary.c:31
convert
static int convert(uint8_t x)
Definition: mccdec.c:51
FFTextReader
Definition: subtitles.h:41
AVProbeData::buf_size
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:449
ff_subtitles_read_line
ptrdiff_t ff_subtitles_read_line(FFTextReader *tr, char *buf, size_t size)
Read a line of text.
Definition: subtitles.c:435
AVPROBE_SCORE_MAX
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:458
MCCContext
Definition: mccdec.c:29
alias::len
int len
Definition: mccdec.c:64
read_close
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:141
ss
#define ss(width, name, subs,...)
Definition: cbs_vp9.c:261
av_reduce
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
AVRational::num
int num
Numerator.
Definition: rational.h:59
MCCContext::q
FFDemuxSubtitlesQueue q
Definition: mccdec.c:30
AVInputFormat
Definition: avformat.h:638
ff_text_init_buf
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:52
ff_subtitles_read_packet
int ff_subtitles_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: subtitles.c:315
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:257
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:643
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:448
AVFormatContext
Format I/O context.
Definition: avformat.h:1109
internal.h
ff_text_read
void ff_text_read(FFTextReader *r, char *buf, size_t size)
Read the given number of bytes (in UTF-8).
Definition: subtitles.c:84
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1004
av_sscanf
int av_sscanf(const char *string, const char *format,...)
See libc sscanf manual for more information.
Definition: avsscanf.c:960
read_header
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:527
alias::key
uint8_t key
Definition: mccdec.c:63
NULL
#define NULL
Definition: coverity.c:32
read_probe
static int read_probe(const AVProbeData *pd)
Definition: jvdec.c:55
fs
#define fs(width, name, subs,...)
Definition: cbs_vp9.c:259
AVRational
Rational number (pair of numerator and denominator).
Definition: rational.h:58
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:446
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
ff_text_init_avio
void ff_text_init_avio(void *s, FFTextReader *r, AVIOContext *pb)
Initialize the FFTextReader from the given AVIOContext.
Definition: subtitles.c:26
av_strncasecmp
int av_strncasecmp(const char *a, const char *b, size_t n)
Locale-independent case-insensitive compare.
Definition: avstring.c:225
ff_mcc_demuxer
const AVInputFormat ff_mcc_demuxer
Definition: mccdec.c:203
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:117
av_make_q
static AVRational av_make_q(int num, int den)
Create an AVRational.
Definition: rational.h:71
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:196
aliases
static const alias aliases[20]
Definition: mccdec.c:68
FFDemuxSubtitlesQueue
Definition: subtitles.h:103
line
Definition: graph2dot.c:48
mcc_probe
static int mcc_probe(const AVProbeData *p)
Definition: mccdec.c:33
bprint.h
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:271
ff_text_pos
int64_t ff_text_pos(FFTextReader *r)
Return the byte position of the next byte returned by ff_text_r8().
Definition: subtitles.c:58
value
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf default value
Definition: writing_filters.txt:86
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:321
len
int len
Definition: vorbis_enc_data.h:426
av_rescale
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:128
ret
ret
Definition: filter_design.txt:187
read_packet
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
AVStream
Stream structure.
Definition: avformat.h:857
pos
unsigned int pos
Definition: spdifenc.c:412
avformat.h
ff_text_peek_r8
int ff_text_peek_r8(FFTextReader *r)
Like ff_text_r8(), but don't remove the byte from the buffer.
Definition: subtitles.c:95
av_sat_add64
#define av_sat_add64
Definition: common.h:138
subtitles.h
AVRational::den
int den
Denominator.
Definition: rational.h:60
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: utils.c:1146
ff_text_eof
int ff_text_eof(FFTextReader *r)
Return non-zero if EOF was reached.
Definition: subtitles.c:90
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
AVPacket
This structure stores compressed data.
Definition: packet.h:350
alias
Definition: mccdec.c:62
avstring.h
alias::value
const char * value
Definition: mccdec.c:65
mcc_read_header
static int mcc_read_header(AVFormatContext *s)
Definition: mccdec.c:91