FFmpeg
assenc.c
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1 /*
2  * SSA/ASS muxer
3  * Copyright (c) 2008 Michael Niedermayer
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 "libavutil/avstring.h"
23 #include "avformat.h"
24 #include "internal.h"
25 
26 #include "libavutil/opt.h"
27 
28 typedef struct DialogueLine {
29  int readorder;
30  char *line;
31  struct DialogueLine *prev, *next;
32 } DialogueLine;
33 
34 typedef struct ASSContext {
35  const AVClass *class;
40  int ssa_mode;
43  size_t trailer_size;
44 } ASSContext;
45 
47 {
48  ASSContext *ass = s->priv_data;
49  AVCodecParameters *par = s->streams[0]->codecpar;
50 
51  if (s->nb_streams != 1 || par->codec_id != AV_CODEC_ID_ASS) {
52  av_log(s, AV_LOG_ERROR, "Exactly one ASS/SSA stream is needed.\n");
53  return AVERROR(EINVAL);
54  }
55  avpriv_set_pts_info(s->streams[0], 64, 1, 100);
56  if (par->extradata_size > 0) {
57  size_t header_size = par->extradata_size;
58  uint8_t *trailer = strstr(par->extradata, "\n[Events]");
59 
60  if (trailer)
61  trailer = strstr(trailer, "Format:");
62  if (trailer)
63  trailer = strstr(trailer, "\n");
64 
65  if (trailer++) {
66  header_size = (trailer - par->extradata);
67  ass->trailer_size = par->extradata_size - header_size;
68  if (ass->trailer_size)
69  ass->trailer = trailer;
70  }
71 
72  avio_write(s->pb, par->extradata, header_size);
73  if (par->extradata[header_size - 1] != '\n')
74  avio_write(s->pb, "\r\n", 2);
75  ass->ssa_mode = !strstr(par->extradata, "\n[V4+ Styles]");
76  if (!strstr(par->extradata, "\n[Events]"))
77  avio_printf(s->pb, "[Events]\r\nFormat: %s, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text\r\n",
78  ass->ssa_mode ? "Marked" : "Layer");
79  }
80  avio_flush(s->pb);
81 
82  return 0;
83 }
84 
85 static void purge_dialogues(AVFormatContext *s, int force)
86 {
87  int n = 0;
88  ASSContext *ass = s->priv_data;
89  DialogueLine *dialogue = ass->dialogue_cache;
90 
91  while (dialogue && (dialogue->readorder == ass->expected_readorder || force)) {
92  DialogueLine *next = dialogue->next;
93  if (dialogue->readorder != ass->expected_readorder) {
94  av_log(s, AV_LOG_WARNING, "ReadOrder gap found between %d and %d\n",
95  ass->expected_readorder, dialogue->readorder);
96  ass->expected_readorder = dialogue->readorder;
97  }
98  avio_printf(s->pb, "Dialogue: %s\r\n", dialogue->line);
99  if (dialogue == ass->last_added_dialogue)
100  ass->last_added_dialogue = next;
101  av_freep(&dialogue->line);
102  av_free(dialogue);
103  if (next)
104  next->prev = NULL;
105  dialogue = ass->dialogue_cache = next;
106  ass->expected_readorder++;
107  n++;
108  }
109  ass->cache_size -= n;
110  if (n > 1)
111  av_log(s, AV_LOG_DEBUG, "wrote %d ASS lines, cached dialogues: %d, waiting for event id %d\n",
112  n, ass->cache_size, ass->expected_readorder);
113 }
114 
115 static void insert_dialogue(ASSContext *ass, DialogueLine *dialogue)
116 {
117  DialogueLine *cur, *next = NULL, *prev = NULL;
118 
119  /* from the last added to the end of the list */
120  if (ass->last_added_dialogue) {
121  for (cur = ass->last_added_dialogue; cur; cur = cur->next) {
122  if (cur->readorder > dialogue->readorder)
123  break;
124  prev = cur;
125  next = cur->next;
126  }
127  }
128 
129  /* from the beginning to the last one added */
130  if (!prev) {
131  next = ass->dialogue_cache;
132  for (cur = next; cur != ass->last_added_dialogue; cur = cur->next) {
133  if (cur->readorder > dialogue->readorder)
134  break;
135  prev = cur;
136  next = cur->next;
137  }
138  }
139 
140  if (prev) {
141  prev->next = dialogue;
142  dialogue->prev = prev;
143  } else {
144  dialogue->prev = ass->dialogue_cache;
145  ass->dialogue_cache = dialogue;
146  }
147  if (next) {
148  next->prev = dialogue;
149  dialogue->next = next;
150  }
151  ass->cache_size++;
152  ass->last_added_dialogue = dialogue;
153 }
154 
156 {
157  ASSContext *ass = s->priv_data;
158 
159  long int layer;
160  char *p = pkt->data;
161  int64_t start = pkt->pts;
162  int64_t end = start + pkt->duration;
163  int hh1, mm1, ss1, ms1;
164  int hh2, mm2, ss2, ms2;
165  DialogueLine *dialogue = av_mallocz(sizeof(*dialogue));
166 
167  if (!dialogue)
168  return AVERROR(ENOMEM);
169 
170  dialogue->readorder = strtol(p, &p, 10);
171  if (dialogue->readorder < ass->expected_readorder)
172  av_log(s, AV_LOG_WARNING, "Unexpected ReadOrder %d\n",
173  dialogue->readorder);
174  if (*p == ',')
175  p++;
176 
177  if (ass->ssa_mode && !strncmp(p, "Marked=", 7))
178  p += 7;
179 
180  layer = strtol(p, &p, 10);
181  if (*p == ',')
182  p++;
183  hh1 = (int)(start / 360000); mm1 = (int)(start / 6000) % 60;
184  hh2 = (int)(end / 360000); mm2 = (int)(end / 6000) % 60;
185  ss1 = (int)(start / 100) % 60; ms1 = (int)(start % 100);
186  ss2 = (int)(end / 100) % 60; ms2 = (int)(end % 100);
187  if (hh1 > 9) hh1 = 9, mm1 = 59, ss1 = 59, ms1 = 99;
188  if (hh2 > 9) hh2 = 9, mm2 = 59, ss2 = 59, ms2 = 99;
189 
190  dialogue->line = av_asprintf("%s%ld,%d:%02d:%02d.%02d,%d:%02d:%02d.%02d,%s",
191  ass->ssa_mode ? "Marked=" : "",
192  layer, hh1, mm1, ss1, ms1, hh2, mm2, ss2, ms2, p);
193  if (!dialogue->line) {
194  av_free(dialogue);
195  return AVERROR(ENOMEM);
196  }
197  insert_dialogue(ass, dialogue);
199 
200  return 0;
201 }
202 
204 {
205  ASSContext *ass = s->priv_data;
206 
207  purge_dialogues(s, 1);
208 
209  if (ass->trailer) {
210  avio_write(s->pb, ass->trailer, ass->trailer_size);
211  }
212 
213  return 0;
214 }
215 
216 #define OFFSET(x) offsetof(ASSContext, x)
217 #define E AV_OPT_FLAG_ENCODING_PARAM
218 static const AVOption options[] = {
219  { "ignore_readorder", "write events immediately, even if they're out-of-order", OFFSET(ignore_readorder), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, E },
220  { NULL },
221 };
222 
223 static const AVClass ass_class = {
224  .class_name = "ass muxer",
225  .item_name = av_default_item_name,
226  .option = options,
227  .version = LIBAVUTIL_VERSION_INT,
228 };
229 
231  .name = "ass",
232  .long_name = NULL_IF_CONFIG_SMALL("SSA (SubStation Alpha) subtitle"),
233  .mime_type = "text/x-ass",
234  .extensions = "ass,ssa",
235  .priv_data_size = sizeof(ASSContext),
236  .subtitle_codec = AV_CODEC_ID_ASS,
241  .priv_class = &ass_class,
242 };
static int write_header(AVFormatContext *s)
Definition: assenc.c:46
#define NULL
Definition: coverity.c:32
AVOption.
Definition: opt.h:246
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
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:4884
static int write_packet(AVFormatContext *s, AVPacket *pkt)
Definition: assenc.c:155
static const AVClass ass_class
Definition: assenc.c:223
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3957
int cache_size
Definition: assenc.c:39
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:191
struct DialogueLine * next
Definition: assenc.c:31
size_t trailer_size
Definition: assenc.c:43
void * av_mallocz(size_t size)
Allocate a memory block with alignment suitable for all memory accesses (including vectors if availab...
Definition: mem.c:236
static AVPacket pkt
AVOutputFormat ff_ass_muxer
Definition: assenc.c:230
#define AVFMT_TS_NONSTRICT
Format does not require strictly increasing timestamps, but they must still be monotonic.
Definition: avformat.h:477
This struct describes the properties of an encoded stream.
Definition: avcodec.h:3949
Format I/O context.
Definition: avformat.h:1358
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:72
uint8_t
AVOptions.
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: avcodec.h:1495
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1426
int expected_readorder
Definition: assenc.c:36
uint8_t * data
Definition: avcodec.h:1477
void avio_write(AVIOContext *s, const unsigned char *buf, int size)
Definition: aviobuf.c:218
#define av_log(a,...)
static int write_trailer(AVFormatContext *s)
Definition: assenc.c:203
static void insert_dialogue(ASSContext *ass, DialogueLine *dialogue)
Definition: assenc.c:115
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:197
static void purge_dialogues(AVFormatContext *s, int force)
Definition: assenc.c:85
int extradata_size
Size of the extradata content in bytes.
Definition: avcodec.h:3975
struct DialogueLine * prev
Definition: assenc.c:31
char * av_asprintf(const char *fmt,...)
Definition: avstring.c:113
unsigned int nb_streams
Number of elements in AVFormatContext.streams.
Definition: avformat.h:1414
#define OFFSET(x)
Definition: assenc.c:216
int void avio_flush(AVIOContext *s)
Force flushing of buffered data.
Definition: aviobuf.c:238
uint8_t * trailer
Definition: assenc.c:42
#define AVFMT_GLOBALHEADER
Format wants global header.
Definition: avformat.h:466
const char * name
Definition: avformat.h:505
#define s(width, name)
Definition: cbs_vp9.c:257
int n
Definition: avisynth_c.h:760
static const AVOption options[]
Definition: assenc.c:218
DialogueLine * dialogue_cache
Definition: assenc.c:37
#define AVFMT_NOTIMESTAMPS
Format does not need / have any timestamps.
Definition: avformat.h:467
#define E
Definition: assenc.c:217
AVIOContext * pb
I/O context.
Definition: avformat.h:1400
Describe the class of an AVClass context structure.
Definition: log.h:67
int readorder
Definition: assenc.c:29
#define flags(name, subs,...)
Definition: cbs_av1.c:561
Main libavformat public API header.
int
char * line
Definition: assenc.c:30
int ignore_readorder
Definition: assenc.c:41
DialogueLine * last_added_dialogue
Definition: assenc.c:38
#define av_free(p)
void * priv_data
Format private data.
Definition: avformat.h:1386
uint8_t * extradata
Extra binary data needed for initializing the decoder, codec-dependent.
Definition: avcodec.h:3971
#define av_freep(p)
void INT64 start
Definition: avisynth_c.h:766
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1028
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:1454
int ssa_mode
Definition: assenc.c:40
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:1470
int avio_printf(AVIOContext *s, const char *fmt,...) av_printf_format(2