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 "libavutil/mem.h"
24 #include "avformat.h"
25 #include "avio_internal.h"
26 #include "internal.h"
27 #include "mux.h"
28 
29 #include "libavutil/opt.h"
30 
31 typedef struct DialogueLine {
32  int readorder;
33  char *line;
34  struct DialogueLine *prev, *next;
35 } DialogueLine;
36 
37 typedef struct ASSContext {
38  const AVClass *class;
39  int expected_readorder;
40  DialogueLine *dialogue_cache;
41  DialogueLine *last_added_dialogue;
42  int cache_size;
43  int ssa_mode;
44  int ignore_readorder;
45  uint8_t *trailer;
46  size_t trailer_size;
47 } ASSContext;
48 
49 static int write_header(AVFormatContext *s)
50 {
51  ASSContext *ass = s->priv_data;
52  AVCodecParameters *par = s->streams[0]->codecpar;
53 
54  avpriv_set_pts_info(s->streams[0], 64, 1, 100);
55  if (par->extradata_size > 0) {
56  size_t header_size = par->extradata_size;
57  uint8_t *trailer = strstr(par->extradata, "\n[Events]");
58 
59  if (trailer)
60  trailer = strstr(trailer, "Format:");
61  if (trailer)
62  trailer = strstr(trailer, "\n");
63 
64  if (trailer) {
65  header_size = (++trailer - par->extradata);
66  ass->trailer_size = par->extradata_size - header_size;
67  if (ass->trailer_size)
68  ass->trailer = trailer;
69  }
70 
71  ffio_write_lines(s->pb, par->extradata, header_size, NULL);
72 
73  ass->ssa_mode = !strstr(par->extradata, "\n[V4+ Styles]");
74  if (!strstr(par->extradata, "\n[Events]"))
75  avio_printf(s->pb, "[Events]\nFormat: %s, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text\n",
76  ass->ssa_mode ? "Marked" : "Layer");
77  }
78 
79  return 0;
80 }
81 
82 static void purge_dialogues(AVFormatContext *s, int force)
83 {
84  int n = 0;
85  ASSContext *ass = s->priv_data;
86  DialogueLine *dialogue = ass->dialogue_cache;
87 
88  while (dialogue && (dialogue->readorder == ass->expected_readorder || force)) {
89  DialogueLine *next = dialogue->next;
90  if (dialogue->readorder != ass->expected_readorder) {
91  av_log(s, AV_LOG_WARNING, "ReadOrder gap found between %d and %d\n",
92  ass->expected_readorder, dialogue->readorder);
93  ass->expected_readorder = dialogue->readorder;
94  }
95  avio_print(s->pb, "Dialogue: ", dialogue->line, "\n");
96  if (dialogue == ass->last_added_dialogue)
97  ass->last_added_dialogue = next;
98  av_freep(&dialogue->line);
99  av_free(dialogue);
100  if (next)
101  next->prev = NULL;
102  dialogue = ass->dialogue_cache = next;
103  ass->expected_readorder++;
104  n++;
105  }
106  ass->cache_size -= n;
107  if (n > 1)
108  av_log(s, AV_LOG_DEBUG, "wrote %d ASS lines, cached dialogues: %d, waiting for event id %d\n",
109  n, ass->cache_size, ass->expected_readorder);
110 }
111 
112 static void insert_dialogue(ASSContext *ass, DialogueLine *dialogue)
113 {
114  DialogueLine *cur, *next = NULL, *prev = NULL;
115 
116  /* from the last added to the end of the list */
117  if (ass->last_added_dialogue) {
118  for (cur = ass->last_added_dialogue; cur; cur = cur->next) {
119  if (cur->readorder > dialogue->readorder)
120  break;
121  prev = cur;
122  next = cur->next;
123  }
124  }
125 
126  /* from the beginning to the last one added */
127  if (!prev) {
128  next = ass->dialogue_cache;
129  for (cur = next; cur != ass->last_added_dialogue; cur = cur->next) {
130  if (cur->readorder > dialogue->readorder)
131  break;
132  prev = cur;
133  next = cur->next;
134  }
135  }
136 
137  if (prev) {
138  prev->next = dialogue;
139  dialogue->prev = prev;
140  } else {
141  dialogue->prev = ass->dialogue_cache;
142  ass->dialogue_cache = dialogue;
143  }
144  if (next) {
145  next->prev = dialogue;
146  dialogue->next = next;
147  }
148  ass->cache_size++;
149  ass->last_added_dialogue = dialogue;
150 }
151 
152 static int write_packet(AVFormatContext *s, AVPacket *pkt)
153 {
154  ASSContext *ass = s->priv_data;
155 
156  long int layer;
157  int text_len;
158  char *p = pkt->data;
159  int64_t start = pkt->pts;
160  int64_t end = start + pkt->duration;
161  int hh1, mm1, ss1, ms1;
162  int hh2, mm2, ss2, ms2;
163  DialogueLine *dialogue = av_mallocz(sizeof(*dialogue));
164 
165  if (!dialogue)
166  return AVERROR(ENOMEM);
167 
168  dialogue->readorder = strtol(p, &p, 10);
169  if (dialogue->readorder < ass->expected_readorder)
170  av_log(s, AV_LOG_WARNING, "Unexpected ReadOrder %d\n",
171  dialogue->readorder);
172  if (*p == ',')
173  p++;
174 
175  if (ass->ssa_mode && !strncmp(p, "Marked=", 7))
176  p += 7;
177 
178  layer = strtol(p, &p, 10);
179  if (*p == ',')
180  p++;
181  hh1 = (int)(start / 360000); mm1 = (int)(start / 6000) % 60;
182  hh2 = (int)(end / 360000); mm2 = (int)(end / 6000) % 60;
183  ss1 = (int)(start / 100) % 60; ms1 = (int)(start % 100);
184  ss2 = (int)(end / 100) % 60; ms2 = (int)(end % 100);
185  if (hh1 > 9) hh1 = 9, mm1 = 59, ss1 = 59, ms1 = 99;
186  if (hh2 > 9) hh2 = 9, mm2 = 59, ss2 = 59, ms2 = 99;
187 
188  text_len = strlen(p);
189  while (text_len > 0 && p[text_len - 1] == '\r' || p[text_len - 1] == '\n')
190  text_len--;
191 
192  dialogue->line = av_asprintf("%s%ld,%d:%02d:%02d.%02d,%d:%02d:%02d.%02d,%.*s",
193  ass->ssa_mode ? "Marked=" : "",
194  layer, hh1, mm1, ss1, ms1, hh2, mm2, ss2, ms2, text_len, p);
195  if (!dialogue->line) {
196  av_free(dialogue);
197  return AVERROR(ENOMEM);
198  }
199  insert_dialogue(ass, dialogue);
200  purge_dialogues(s, ass->ignore_readorder);
201 
202  return 0;
203 }
204 
205 static int write_trailer(AVFormatContext *s)
206 {
207  ASSContext *ass = s->priv_data;
208 
209  purge_dialogues(s, 1);
210 
211  if (ass->trailer) {
212  ffio_write_lines(s->pb, ass->trailer, ass->trailer_size, NULL);
213  }
214 
215  return 0;
216 }
217 
218 #define OFFSET(x) offsetof(ASSContext, x)
219 #define E AV_OPT_FLAG_ENCODING_PARAM
220 static const AVOption options[] = {
221  { "ignore_readorder", "write events immediately, even if they're out-of-order", OFFSET(ignore_readorder), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, E },
222  { NULL },
223 };
224 
225 static const AVClass ass_class = {
226  .class_name = "ass muxer",
227  .item_name = av_default_item_name,
228  .option = options,
229  .version = LIBAVUTIL_VERSION_INT,
230 };
231 
232 const FFOutputFormat ff_ass_muxer = {
233  .p.name = "ass",
234  .p.long_name = NULL_IF_CONFIG_SMALL("SSA (SubStation Alpha) subtitle"),
235  .p.mime_type = "text/x-ass",
236  .p.extensions = "ass,ssa",
237  .p.audio_codec = AV_CODEC_ID_NONE,
238  .p.video_codec = AV_CODEC_ID_NONE,
239  .p.subtitle_codec = AV_CODEC_ID_ASS,
240  .p.flags = AVFMT_GLOBALHEADER | AVFMT_NOTIMESTAMPS | AVFMT_TS_NONSTRICT,
241  .flags_internal = FF_OFMT_FLAG_MAX_ONE_OF_EACH |
242  FF_OFMT_FLAG_ONLY_DEFAULT_CODECS,
243  .p.priv_class = &ass_class,
244  .priv_data_size = sizeof(ASSContext),
245  .write_header = write_header,
246  .write_packet = write_packet,
247  .write_trailer = write_trailer,
248 };
AV_LOG_WARNING
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:215
AVCodecParameters::extradata
uint8_t * extradata
Extra binary data needed for initializing the decoder, codec-dependent.
Definition: codec_par.h:69
AVOutputFormat::name
const char * name
Definition: avformat.h:510
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
opt.h
ASSContext::cache_size
int cache_size
Definition: assenc.c:42
AVCodecParameters
This struct describes the properties of an encoded stream.
Definition: codec_par.h:47
AVFMT_NOTIMESTAMPS
#define AVFMT_NOTIMESTAMPS
Format does not need / have any timestamps.
Definition: avformat.h:479
int64_t
long long int64_t
Definition: coverity.c:34
av_asprintf
char * av_asprintf(const char *fmt,...)
Definition: avstring.c:115
insert_dialogue
static void insert_dialogue(ASSContext *ass, DialogueLine *dialogue)
Definition: assenc.c:112
AVPacket::data
uint8_t * data
Definition: packet.h:539
AVOption
AVOption.
Definition: opt.h:429
AVPacket::duration
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: packet.h:557
DialogueLine::readorder
int readorder
Definition: assenc.c:32
FF_OFMT_FLAG_ONLY_DEFAULT_CODECS
#define FF_OFMT_FLAG_ONLY_DEFAULT_CODECS
If this flag is set, then the only permitted audio/video/subtitle codec ids are AVOutputFormat....
Definition: mux.h:59
ASSContext::trailer_size
size_t trailer_size
Definition: assenc.c:46
ASSContext::ignore_readorder
int ignore_readorder
Definition: assenc.c:44
FFOutputFormat::p
AVOutputFormat p
The public AVOutputFormat.
Definition: mux.h:65
AV_CODEC_ID_ASS
@ AV_CODEC_ID_ASS
Definition: codec_id.h:572
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: avformat.c:862
DialogueLine::line
char * line
Definition: assenc.c:33
ASSContext::trailer
uint8_t * trailer
Definition: assenc.c:45
purge_dialogues
static void purge_dialogues(AVFormatContext *s, int force)
Definition: assenc.c:82
pkt
AVPacket * pkt
Definition: movenc.c:60
s
#define s(width, name)
Definition: cbs_vp9.c:198
DialogueLine
Definition: assenc.c:31
write_header
static int write_header(AVFormatContext *s)
Definition: assenc.c:49
AV_LOG_DEBUG
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:230
AVFormatContext
Format I/O context.
Definition: avformat.h:1300
DialogueLine::prev
struct DialogueLine * prev
Definition: assenc.c:34
internal.h
LIBAVUTIL_VERSION_INT
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:75
NULL
#define NULL
Definition: coverity.c:32
ass_class
static const AVClass ass_class
Definition: assenc.c:225
avio_print
#define avio_print(s,...)
Write strings (const char *) to the context.
Definition: avio.h:537
ASSContext::ssa_mode
int ssa_mode
Definition: assenc.c:43
av_default_item_name
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:237
FFOutputFormat
Definition: mux.h:61
OFFSET
#define OFFSET(x)
Definition: assenc.c:218
ff_ass_muxer
const FFOutputFormat ff_ass_muxer
Definition: assenc.c:232
DialogueLine::next
struct DialogueLine * next
Definition: assenc.c:34
AVCodecParameters::extradata_size
int extradata_size
Size of the extradata content in bytes.
Definition: codec_par.h:73
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:94
ASSContext::expected_readorder
int expected_readorder
Definition: assenc.c:39
write_packet
static int write_packet(AVFormatContext *s, AVPacket *pkt)
Definition: assenc.c:152
AVFMT_GLOBALHEADER
#define AVFMT_GLOBALHEADER
Format wants global header.
Definition: avformat.h:478
AV_CODEC_ID_NONE
@ AV_CODEC_ID_NONE
Definition: codec_id.h:50
AVPacket::pts
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: packet.h:532
avio_internal.h
FF_OFMT_FLAG_MAX_ONE_OF_EACH
#define FF_OFMT_FLAG_MAX_ONE_OF_EACH
If this flag is set, it indicates that for each codec type whose corresponding default codec (i....
Definition: mux.h:50
av_mallocz
void * av_mallocz(size_t size)
Allocate a memory block with alignment suitable for all memory accesses (including vectors if availab...
Definition: mem.c:256
AVFMT_TS_NONSTRICT
#define AVFMT_TS_NONSTRICT
Format does not require strictly increasing timestamps, but they must still be monotonic.
Definition: avformat.h:491
AVClass::class_name
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:80
avformat.h
ffio_write_lines
void ffio_write_lines(AVIOContext *s, const unsigned char *buf, int size, const unsigned char *ending)
Write a sequence of text lines, converting line endings.
Definition: aviobuf.c:960
avio_printf
int avio_printf(AVIOContext *s, const char *fmt,...) av_printf_format(2
Writes a formatted string to the context.
E
#define E
Definition: assenc.c:219
ASSContext
Definition: assdec.c:31
mem.h
av_free
#define av_free(p)
Definition: tableprint_vlc.h:33
AVPacket
This structure stores compressed data.
Definition: packet.h:516
AV_OPT_TYPE_BOOL
@ AV_OPT_TYPE_BOOL
Underlying C type is int.
Definition: opt.h:327
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:34
ASSContext::last_added_dialogue
DialogueLine * last_added_dialogue
Definition: assenc.c:41
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
avstring.h
options
static const AVOption options[]
Definition: assenc.c:220
ASSContext::dialogue_cache
DialogueLine * dialogue_cache
Definition: assenc.c:40
write_trailer
static int write_trailer(AVFormatContext *s)
Definition: assenc.c:205
mux.h
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