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 {
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  num *= 1000;
131  den = 1001;
132  }
133  }
134 
135  if (num > 0 && den > 0) {
136  rate = av_make_q(num, den);
137  avpriv_set_pts_info(st, 64, rate.den, rate.num);
138  }
139  continue;
140  }
141 
142  if (av_sscanf(line, "%d:%d:%d:%d", &hh, &mm, &ss, &fs) != 4)
143  continue;
144 
145  ts = av_rescale(hh * 3600LL + mm * 60LL + ss, rate.num, rate.den) + fs;
146 
147  lline = (char *)&line;
148  lline += 12;
149  pos = ff_text_pos(&tr);
150 
151  while (lline[i]) {
152  uint8_t v = convert(lline[i]);
153 
154  if (v >= 16 && v <= 35) {
155  int idx = v - 16;
156  if (aliases[idx].len) {
157  if (j >= sizeof(out) - 1 - aliases[idx].len) {
158  j = 0;
159  break;
160  }
161  memcpy(out + j, aliases[idx].value, aliases[idx].len);
162  j += aliases[idx].len;
163  }
164  } else {
165  uint8_t vv;
166 
167  if (i + 13 >= sizeof(line) - 1)
168  break;
169  vv = convert(lline[i + 1]);
170  if (j >= sizeof(out) - 1) {
171  j = 0;
172  break;
173  }
174  out[j++] = vv | (v << 4);
175  i++;
176  }
177 
178  i++;
179  }
180  out[j] = 0;
181 
182  if (out[7] & 0x80)
183  start += 4;
184  count = (out[11] & 0x1f) * 3;
185  if (j < start + count + 1)
186  continue;
187 
188  if (!count)
189  continue;
190  sub = ff_subtitles_queue_insert(&mcc->q, out + start, count, 0);
191  if (!sub)
192  goto fail;
193 
194  sub->pos = pos;
195  sub->pts = ts;
196  sub->duration = 1;
197  }
198 
199  ff_subtitles_queue_finalize(s, &mcc->q);
200 
201  return ret;
202 fail:
204  return AVERROR(ENOMEM);
205 }
206 
208 {
209  MCCContext *mcc = s->priv_data;
210  return ff_subtitles_queue_read_packet(&mcc->q, pkt);
211 }
212 
213 static int mcc_read_seek(AVFormatContext *s, int stream_index,
214  int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
215 {
216  MCCContext *mcc = s->priv_data;
217  return ff_subtitles_queue_seek(&mcc->q, s, stream_index,
218  min_ts, ts, max_ts, flags);
219 }
220 
222 {
223  MCCContext *mcc = s->priv_data;
225  return 0;
226 }
227 
229  .name = "mcc",
230  .long_name = NULL_IF_CONFIG_SMALL("MacCaption"),
231  .priv_data_size = sizeof(MCCContext),
235  .read_seek2 = mcc_read_seek,
237  .extensions = "mcc",
238 };
#define NULL
Definition: coverity.c:32
static int mcc_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: mccdec.c:207
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:4868
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
int num
Numerator.
Definition: rational.h:59
void ff_subtitles_queue_clean(FFDemuxSubtitlesQueue *q)
Remove and destroy all the subtitles packets.
Definition: subtitles.c:302
int av_strncasecmp(const char *a, const char *b, size_t n)
Locale-independent case-insensitive compare.
Definition: avstring.c:225
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 int mcc_read_header(AVFormatContext *s)
Definition: mccdec.c:91
static AVPacket pkt
int len
Definition: mccdec.c:64
uint8_t key
Definition: mccdec.c:63
FFDemuxSubtitlesQueue q
Definition: mccdec.c:30
Format I/O context.
Definition: avformat.h:1355
uint8_t
#define fs(width, name, subs,...)
Definition: cbs_vp9.c:259
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
GLsizei GLboolean const GLfloat * value
Definition: opengl_enc.c:108
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4449
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:145
static const alias aliases[20]
Definition: mccdec.c:68
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:411
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:153
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
GLsizei count
Definition: opengl_enc.c:108
#define fail()
Definition: checkasm.h:123
int av_sscanf(const char *string, const char *format,...)
See libc sscanf manual for more information.
Definition: avsscanf.c:962
void ff_text_init_avio(void *s, FFTextReader *r, AVIOContext *pb)
Initialize the FFTextReader from the given AVIOContext.
Definition: subtitles.c:27
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
int64_t ff_text_pos(FFTextReader *r)
Return the byte position of the next byte returned by ff_text_r8().
Definition: subtitles.c:60
#define ss(width, name, subs,...)
Definition: cbs_vp9.c:261
static int mcc_read_close(AVFormatContext *s)
Definition: mccdec.c:221
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
static int mcc_probe(const AVProbeData *p)
Definition: mccdec.c:33
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:213
const char * value
Definition: mccdec.c:65
#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 read_header(FFV1Context *f)
Definition: ffv1dec.c:527
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:250
AVIOContext * pb
I/O context.
Definition: avformat.h:1397
static AVRational av_make_q(int num, int den)
Create an AVRational.
Definition: rational.h:71
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 int convert(uint8_t x)
Definition: mccdec.c:51
#define flags(name, subs,...)
Definition: cbs_av1.c:560
static int read_probe(const AVProbeData *pd)
Definition: jvdec.c:55
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:453
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
int den
Denominator.
Definition: rational.h:60
int len
AVInputFormat ff_mcc_demuxer
Definition: mccdec.c:228
void * priv_data
Format private data.
Definition: avformat.h:1383
Definition: mccdec.c:62
FILE * out
Definition: movenc.c:54
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:652
static float sub(float src0, float src1)
#define df(A, B)
Definition: vf_xbr.c:90
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1027
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: packet.h:340
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