FFmpeg  4.3
sccdec.c
Go to the documentation of this file.
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/avstring.h"
26 #include "libavutil/bprint.h"
27 #include "libavutil/intreadwrite.h"
28 
29 typedef struct SCCContext {
31 } SCCContext;
32 
33 static int scc_probe(const AVProbeData *p)
34 {
35  char buf[18];
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, "Scenarist_SCC V1.0", 18))
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 
63 {
64  SCCContext *scc = s->priv_data;
66  char line[4096], line2[4096];
67  int64_t ts_start, ts_end;
68  int count = 0, ret = 0;
69  ptrdiff_t len2, len;
70  uint8_t out[4096];
71  FFTextReader tr;
72 
73  ff_text_init_avio(s, &tr, s->pb);
74 
75  if (!st)
76  return AVERROR(ENOMEM);
77  avpriv_set_pts_info(st, 64, 1, 1000);
80 
81  while (!ff_text_eof(&tr)) {
82  int64_t current_pos, next_pos;
83  char *saveptr = NULL, *lline;
84  int hh1, mm1, ss1, fs1, i;
85  int hh2, mm2, ss2, fs2;
86  AVPacket *sub;
87 
88  if (count == 0) {
89  current_pos = ff_text_pos(&tr);
90  while (!ff_text_eof(&tr)) {
91  len = ff_subtitles_read_line(&tr, line, sizeof(line));
92  if (len > 13)
93  break;
94  }
95  }
96 
97  if (!strncmp(line, "Scenarist_SCC V1.0", 18))
98  continue;
99  if (av_sscanf(line, "%d:%d:%d%*[:;]%d", &hh1, &mm1, &ss1, &fs1) != 4)
100  continue;
101 
102  ts_start = (hh1 * 3600LL + mm1 * 60LL + ss1) * 1000LL + fs1 * 33;
103 
104  next_pos = ff_text_pos(&tr);
105  while (!ff_text_eof(&tr)) {
106  len2 = ff_subtitles_read_line(&tr, line2, sizeof(line2));
107  if (len2 > 13)
108  break;
109  }
110  if (av_sscanf(line2, "%d:%d:%d%*[:;]%d", &hh2, &mm2, &ss2, &fs2) != 4)
111  continue;
112 
113  ts_end = (hh2 * 3600LL + mm2 * 60LL + ss2) * 1000LL + fs2 * 33;
114  count++;
115 
116 try_again:
117  lline = (char *)&line;
118  lline += 12;
119 
120  for (i = 0; i < 4095; i += 3) {
121  char *ptr = av_strtok(lline, " ", &saveptr);
122  char c1, c2, c3, c4;
123 
124  if (!ptr)
125  break;
126 
127  if (av_sscanf(ptr, "%c%c%c%c", &c1, &c2, &c3, &c4) != 4)
128  break;
129 
130  lline = NULL;
131  out[i+0] = 0xfc;
132  out[i+1] = convert(c2) | (convert(c1) << 4);
133  out[i+2] = convert(c4) | (convert(c3) << 4);
134  }
135  out[i] = 0;
136 
137  sub = ff_subtitles_queue_insert(&scc->q, out, i, 0);
138  if (!sub)
139  goto fail;
140 
141  sub->pos = current_pos;
142  sub->pts = ts_start;
143  sub->duration = ts_end - ts_start;
144  memmove(line, line2, sizeof(line));
145  current_pos = next_pos;
146  line2[0] = 0;
147  }
148 
149  if (line[0]) {
150  ts_start = ts_end;
151  ts_end += 1200;
152  goto try_again;
153  }
154 
156 
157  return ret;
158 fail:
160  return AVERROR(ENOMEM);
161 }
162 
164 {
165  SCCContext *scc = s->priv_data;
166  return ff_subtitles_queue_read_packet(&scc->q, pkt);
167 }
168 
169 static int scc_read_seek(AVFormatContext *s, int stream_index,
170  int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
171 {
172  SCCContext *scc = s->priv_data;
173  return ff_subtitles_queue_seek(&scc->q, s, stream_index,
174  min_ts, ts, max_ts, flags);
175 }
176 
178 {
179  SCCContext *scc = s->priv_data;
181  return 0;
182 }
183 
185  .name = "scc",
186  .long_name = NULL_IF_CONFIG_SMALL("Scenarist Closed Captions"),
187  .priv_data_size = sizeof(SCCContext),
191  .read_seek2 = scc_read_seek,
193  .extensions = "scc",
194 };
AV_CODEC_ID_EIA_608
@ AV_CODEC_ID_EIA_608
Definition: codec_id.h:519
AVMEDIA_TYPE_SUBTITLE
@ AVMEDIA_TYPE_SUBTITLE
Definition: avutil.h:204
ff_text_r8
int ff_text_r8(FFTextReader *r)
Return the next byte.
Definition: subtitles.c:65
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:4519
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
AVPacket::duration
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: packet.h:373
FFTextReader
Definition: subtitles.h:40
AVProbeData::buf_size
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:444
c1
static const uint64_t c1
Definition: murmur3.c:49
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:411
AVPROBE_SCORE_MAX
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:453
fail
#define fail()
Definition: checkasm.h:123
x
FFmpeg Automated Testing Environment ************************************Introduction Using FATE from your FFmpeg source directory Submitting the results to the FFmpeg result aggregation server Uploading new samples to the fate suite FATE makefile targets and variables Makefile targets Makefile variables Examples Introduction **************FATE is an extended regression suite on the client side and a means for results aggregation and presentation on the server side The first part of this document explains how you can use FATE from your FFmpeg source directory to test your ffmpeg binary The second part describes how you can run FATE to submit the results to FFmpeg’s FATE server In any way you can have a look at the publicly viewable FATE results by visiting this as it can be seen if some test on some platform broke with their recent contribution This usually happens on the platforms the developers could not test on The second part of this document describes how you can run FATE to submit your results to FFmpeg’s FATE server If you want to submit your results be sure to check that your combination of OS and compiler is not already listed on the above mentioned website In the third part you can find a comprehensive listing of FATE makefile targets and variables Using FATE from your FFmpeg source directory **********************************************If you want to run FATE on your machine you need to have the samples in place You can get the samples via the build target fate rsync Use this command from the top level source this will cause FATE to fail NOTE To use a custom wrapper to run the pass ‘ target exec’ to ‘configure’ or set the TARGET_EXEC Make variable Submitting the results to the FFmpeg result aggregation server ****************************************************************To submit your results to the server you should run fate through the shell script ‘tests fate sh’ from the FFmpeg sources This script needs to be invoked with a configuration file as its first argument tests fate sh path to fate_config A configuration file template with comments describing the individual configuration variables can be found at ‘doc fate_config sh template’ Create a configuration that suits your based on the configuration template The ‘slot’ configuration variable can be any string that is not yet but it is suggested that you name it adhering to the following pattern ‘ARCH OS COMPILER COMPILER VERSION’ The configuration file itself will be sourced in a shell therefore all shell features may be used This enables you to setup the environment as you need it for your build For your first test runs the ‘fate_recv’ variable should be empty or commented out This will run everything as normal except that it will omit the submission of the results to the server The following files should be present in $workdir as specified in the configuration it may help to try out the ‘ssh’ command with one or more ‘ v’ options You should get detailed output concerning your SSH configuration and the authentication process The only thing left is to automate the execution of the fate sh script and the synchronisation of the samples directory Uploading new samples to the fate suite *****************************************If you need a sample uploaded send a mail to samples request This is for developers who have an account on the fate suite server If you upload new please make sure they are as small as space on each network bandwidth and so on benefit from smaller test cases Also keep in mind older checkouts use existing sample that means in practice generally do not remove or overwrite files as it likely would break older checkouts or releases Also all needed samples for a commit should be ideally before the push If you need an account for frequently uploading samples or you wish to help others by doing that send a mail to ffmpeg devel rsync vauL Duo x
Definition: fate.txt:150
read_close
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:145
SCCContext
Definition: sccdec.c:29
ff_subtitles_queue_seek
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
scc_probe
static int scc_probe(const AVProbeData *p)
Definition: sccdec.c:33
AVInputFormat
Definition: avformat.h:636
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:53
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:641
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:443
av_strtok
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
scc_read_header
static int scc_read_header(AVFormatContext *s)
Definition: sccdec.c:62
ff_subtitles_queue_read_packet
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
AVFormatContext
Format I/O context.
Definition: avformat.h:1335
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:86
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1012
av_sscanf
int av_sscanf(const char *string, const char *format,...)
See libc sscanf manual for more information.
Definition: avsscanf.c:962
read_header
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:527
NULL
#define NULL
Definition: coverity.c:32
read_probe
static int read_probe(const AVProbeData *pd)
Definition: jvdec.c:55
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:441
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:111
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:27
scc_read_close
static int scc_read_close(AVFormatContext *s)
Definition: sccdec.c:177
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:186
avpriv_set_pts_info
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:4938
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:194
FFDemuxSubtitlesQueue
Definition: subtitles.h:102
ff_subtitles_queue_clean
void ff_subtitles_queue_clean(FFDemuxSubtitlesQueue *q)
Remove and destroy all the subtitles packets.
Definition: subtitles.c:302
line
Definition: graph2dot.c:48
bprint.h
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
AVPacket::pts
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: packet.h:348
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:60
uint8_t
uint8_t
Definition: audio_convert.c:194
len
int len
Definition: vorbis_enc_data.h:452
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:865
scc_read_packet
static int scc_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: sccdec.c:163
avformat.h
SCCContext::q
FFDemuxSubtitlesQueue q
Definition: sccdec.c:30
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:97
c2
static const uint64_t c2
Definition: murmur3.c:50
subtitles.h
pkt
static AVPacket pkt
Definition: demuxing_decoding.c:54
ff_scc_demuxer
AVInputFormat ff_scc_demuxer
Definition: sccdec.c:184
ff_text_eof
int ff_text_eof(FFTextReader *r)
Return non-zero if EOF was reached.
Definition: subtitles.c:92
scc_read_seek
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:169
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:332
AVPacket::pos
int64_t pos
byte position in stream, -1 if unknown
Definition: packet.h:375
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:564
convert
static int convert(uint8_t x)
Definition: sccdec.c:51
avstring.h