FFmpeg
ass.c
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1 /*
2  * SSA/ASS common functions
3  * Copyright (c) 2010 Aurelien Jacobs <aurel@gnuage.org>
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 "avcodec.h"
23 #include "ass.h"
24 #include "libavutil/avassert.h"
25 #include "libavutil/avstring.h"
26 #include "libavutil/bprint.h"
27 #include "libavutil/common.h"
28 
30  const char *font, int font_size,
31  int color, int back_color,
32  int bold, int italic, int underline,
33  int border_style, int alignment)
34 {
36  "[Script Info]\r\n"
37  "; Script generated by FFmpeg/Lavc%s\r\n"
38  "ScriptType: v4.00+\r\n"
39  "PlayResX: %d\r\n"
40  "PlayResY: %d\r\n"
41  "\r\n"
42  "[V4+ Styles]\r\n"
43 
44  /* ASSv4 header */
45  "Format: Name, "
46  "Fontname, Fontsize, "
47  "PrimaryColour, SecondaryColour, OutlineColour, BackColour, "
48  "Bold, Italic, Underline, StrikeOut, "
49  "ScaleX, ScaleY, "
50  "Spacing, Angle, "
51  "BorderStyle, Outline, Shadow, "
52  "Alignment, MarginL, MarginR, MarginV, "
53  "Encoding\r\n"
54 
55  "Style: "
56  "Default," /* Name */
57  "%s,%d," /* Font{name,size} */
58  "&H%x,&H%x,&H%x,&H%x," /* {Primary,Secondary,Outline,Back}Colour */
59  "%d,%d,%d,0," /* Bold, Italic, Underline, StrikeOut */
60  "100,100," /* Scale{X,Y} */
61  "0,0," /* Spacing, Angle */
62  "%d,1,0," /* BorderStyle, Outline, Shadow */
63  "%d,10,10,10," /* Alignment, Margin[LRV] */
64  "0\r\n" /* Encoding */
65 
66  "\r\n"
67  "[Events]\r\n"
68  "Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text\r\n",
71  font, font_size, color, color, back_color, back_color,
72  -bold, -italic, -underline, border_style, alignment);
73 
74  if (!avctx->subtitle_header)
75  return AVERROR(ENOMEM);
76  avctx->subtitle_header_size = strlen(avctx->subtitle_header);
77  return 0;
78 }
79 
81 {
91 }
92 
93 char *ff_ass_get_dialog(int readorder, int layer, const char *style,
94  const char *speaker, const char *text)
95 {
96  return av_asprintf("%d,%d,%s,%s,0,0,0,,%s",
97  readorder, layer, style ? style : "Default",
98  speaker ? speaker : "", text);
99 }
100 
101 int ff_ass_add_rect(AVSubtitle *sub, const char *dialog,
102  int readorder, int layer, const char *style,
103  const char *speaker)
104 {
105  char *ass_str;
106  AVSubtitleRect **rects;
107 
108  rects = av_realloc_array(sub->rects, (sub->num_rects+1), sizeof(*sub->rects));
109  if (!rects)
110  return AVERROR(ENOMEM);
111  sub->rects = rects;
112  rects[sub->num_rects] = av_mallocz(sizeof(*rects[0]));
113  if (!rects[sub->num_rects])
114  return AVERROR(ENOMEM);
115  rects[sub->num_rects]->type = SUBTITLE_ASS;
116  ass_str = ff_ass_get_dialog(readorder, layer, style, speaker, dialog);
117  if (!ass_str)
118  return AVERROR(ENOMEM);
119  rects[sub->num_rects]->ass = ass_str;
120  sub->num_rects++;
121  return 0;
122 }
123 
125 {
126  FFASSDecoderContext *s = avctx->priv_data;
127  if (!(avctx->flags2 & AV_CODEC_FLAG2_RO_FLUSH_NOOP))
128  s->readorder = 0;
129 }
130 
131 void ff_ass_bprint_text_event(AVBPrint *buf, const char *p, int size,
132  const char *linebreaks, int keep_ass_markup)
133 {
134  const char *p_end = p + size;
135 
136  for (; p < p_end && *p; p++) {
137 
138  /* forced custom line breaks, not accounted as "normal" EOL */
139  if (linebreaks && strchr(linebreaks, *p)) {
140  av_bprintf(buf, "\\N");
141 
142  /* standard ASS escaping so random characters don't get mis-interpreted
143  * as ASS */
144  } else if (!keep_ass_markup && strchr("{}\\", *p)) {
145  av_bprintf(buf, "\\%c", *p);
146 
147  /* some packets might end abruptly (no \0 at the end, like for example
148  * in some cases of demuxing from a classic video container), some
149  * might be terminated with \n or \r\n which we have to remove (for
150  * consistency with those who haven't), and we also have to deal with
151  * evil cases such as \r at the end of the buffer (and no \0 terminated
152  * character) */
153  } else if (p[0] == '\n') {
154  /* some stuff left so we can insert a line break */
155  if (p < p_end - 1)
156  av_bprintf(buf, "\\N");
157  } else if (p[0] == '\r' && p < p_end - 1 && p[1] == '\n') {
158  /* \r followed by a \n, we can skip it. We don't insert the \N yet
159  * because we don't know if it is followed by more text */
160  continue;
161 
162  /* finally, a sane character */
163  } else {
164  av_bprint_chars(buf, *p, 1);
165  }
166  }
167 }
void av_bprintf(AVBPrint *buf, const char *fmt,...)
Definition: bprint.c:94
#define ASS_DEFAULT_BORDERSTYLE
Definition: ass.h:43
int ff_ass_subtitle_header(AVCodecContext *avctx, const char *font, int font_size, int color, int back_color, int bold, int italic, int underline, int border_style, int alignment)
Generate a suitable AVCodecContext.subtitle_header for SUBTITLE_ASS.
Definition: ass.c:29
unsigned num_rects
Definition: avcodec.h:3939
int ff_ass_add_rect(AVSubtitle *sub, const char *dialog, int readorder, int layer, const char *style, const char *speaker)
Add an ASS dialog to a subtitle.
Definition: ass.c:101
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
AVSubtitleRect ** rects
Definition: avcodec.h:3940
#define ASS_DEFAULT_ALIGNMENT
Definition: ass.h:42
int subtitle_header_size
Definition: avcodec.h:3053
int ff_ass_subtitle_header_default(AVCodecContext *avctx)
Generate a suitable AVCodecContext.subtitle_header for SUBTITLE_ASS with default style.
Definition: ass.c:80
ptrdiff_t size
Definition: opengl_enc.c:100
#define AV_CODEC_FLAG2_RO_FLUSH_NOOP
Do not reset ASS ReadOrder field on flush (subtitles decoding)
Definition: avcodec.h:965
void * av_realloc_array(void *ptr, size_t nmemb, size_t size)
Definition: mem.c:198
#define ASS_DEFAULT_PLAYRESY
Definition: ass.h:29
#define ASS_DEFAULT_BACK_COLOR
Definition: ass.h:38
#define ASS_DEFAULT_UNDERLINE
Definition: ass.h:41
char * ff_ass_get_dialog(int readorder, int layer, const char *style, const char *speaker, const char *text)
Craft an ASS dialog string.
Definition: ass.c:93
#define ASS_DEFAULT_FONT
Definition: ass.h:35
int flags
AV_CODEC_FLAG_*.
Definition: avcodec.h:1647
simple assert() macros that are a bit more flexible than ISO C assert().
#define ASS_DEFAULT_FONT_SIZE
Definition: ass.h:36
char * av_asprintf(const char *fmt,...)
Definition: avstring.c:113
#define AV_CODEC_FLAG_BITEXACT
Use only bitexact stuff (except (I)DCT).
Definition: avcodec.h:910
#define s(width, name)
Definition: cbs_vp9.c:257
Libavcodec external API header.
main external API structure.
Definition: avcodec.h:1567
void * buf
Definition: avisynth_c.h:766
#define AV_STRINGIFY(s)
Definition: macros.h:36
void ff_ass_decoder_flush(AVCodecContext *avctx)
Helper to flush a text subtitles decoder making use of the FFASSDecoderContext.
Definition: ass.c:124
#define LIBAVCODEC_VERSION
Definition: version.h:37
common internal and external API header
#define ASS_DEFAULT_COLOR
Definition: ass.h:37
void * priv_data
Definition: avcodec.h:1594
Formatted text, the ass field must be set by the decoder and is authoritative.
Definition: avcodec.h:3895
#define ASS_DEFAULT_ITALIC
Definition: ass.h:40
void ff_ass_bprint_text_event(AVBPrint *buf, const char *p, int size, const char *linebreaks, int keep_ass_markup)
Escape a text subtitle using ASS syntax into an AVBPrint buffer.
Definition: ass.c:131
#define ASS_DEFAULT_BOLD
Definition: ass.h:39
char * ass
0 terminated ASS/SSA compatible event line.
Definition: avcodec.h:3930
int flags2
AV_CODEC_FLAG2_*.
Definition: avcodec.h:1654
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
enum AVSubtitleType type
Definition: avcodec.h:3921
#define ASS_DEFAULT_PLAYRESX
Definition: ass.h:28
uint8_t * subtitle_header
Header containing style information for text subtitles.
Definition: avcodec.h:3052
void av_bprint_chars(AVBPrint *buf, char c, unsigned n)
Append char c n times to a print buffer.
Definition: bprint.c:140