FFmpeg
ass.c
Go to the documentation of this file.
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/avstring.h"
25 #include "libavutil/bprint.h"
26 #include "libavutil/common.h"
27 
29  int play_res_x, int play_res_y,
30  const char *font, int font_size,
31  int primary_color, int secondary_color,
32  int outline_color, int back_color,
33  int bold, int italic, int underline,
34  int border_style, int alignment)
35 {
37  "[Script Info]\r\n"
38  "; Script generated by FFmpeg/Lavc%s\r\n"
39  "ScriptType: v4.00+\r\n"
40  "PlayResX: %d\r\n"
41  "PlayResY: %d\r\n"
42  "ScaledBorderAndShadow: yes\r\n"
43  "\r\n"
44  "[V4+ Styles]\r\n"
45 
46  /* ASSv4 header */
47  "Format: Name, "
48  "Fontname, Fontsize, "
49  "PrimaryColour, SecondaryColour, OutlineColour, BackColour, "
50  "Bold, Italic, Underline, StrikeOut, "
51  "ScaleX, ScaleY, "
52  "Spacing, Angle, "
53  "BorderStyle, Outline, Shadow, "
54  "Alignment, MarginL, MarginR, MarginV, "
55  "Encoding\r\n"
56 
57  "Style: "
58  "Default," /* Name */
59  "%s,%d," /* Font{name,size} */
60  "&H%x,&H%x,&H%x,&H%x," /* {Primary,Secondary,Outline,Back}Colour */
61  "%d,%d,%d,0," /* Bold, Italic, Underline, StrikeOut */
62  "100,100," /* Scale{X,Y} */
63  "0,0," /* Spacing, Angle */
64  "%d,1,0," /* BorderStyle, Outline, Shadow */
65  "%d,10,10,10," /* Alignment, Margin[LRV] */
66  "0\r\n" /* Encoding */
67 
68  "\r\n"
69  "[Events]\r\n"
70  "Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text\r\n",
72  play_res_x, play_res_y, font, font_size,
73  primary_color, secondary_color, outline_color, back_color,
74  -bold, -italic, -underline, border_style, alignment);
75 
76  if (!avctx->subtitle_header)
77  return AVERROR(ENOMEM);
78  avctx->subtitle_header_size = strlen(avctx->subtitle_header);
79  return 0;
80 }
81 
83  const char *font, int font_size,
84  int color, int back_color,
85  int bold, int italic, int underline,
86  int border_style, int alignment)
87 {
88  return ff_ass_subtitle_header_full(avctx,
90  font, font_size, color, color,
91  back_color, back_color,
92  bold, italic, underline,
93  border_style, alignment);
94 }
95 
97 {
107 }
108 
109 char *ff_ass_get_dialog(int readorder, int layer, const char *style,
110  const char *speaker, const char *text)
111 {
112  return av_asprintf("%d,%d,%s,%s,0,0,0,,%s",
113  readorder, layer, style ? style : "Default",
114  speaker ? speaker : "", text);
115 }
116 
117 int ff_ass_add_rect2(AVSubtitle *sub, const char *dialog,
118  int readorder, int layer, const char *style,
119  const char *speaker, unsigned *nb_rect_allocated)
120 {
121  AVSubtitleRect **rects = sub->rects, *rect;
122  char *ass_str;
123  uint64_t new_nb = 0;
124 
125  if (sub->num_rects >= UINT_MAX)
126  return AVERROR(ENOMEM);
127 
128  if (nb_rect_allocated && *nb_rect_allocated <= sub->num_rects) {
129  if (sub->num_rects < UINT_MAX / 17 * 16) {
130  new_nb = sub->num_rects + sub->num_rects/16 + 1;
131  } else
132  new_nb = UINT_MAX;
133  } else if (!nb_rect_allocated)
134  new_nb = sub->num_rects + 1;
135 
136  if (new_nb) {
137  rects = av_realloc_array(rects, new_nb, sizeof(*sub->rects));
138  if (!rects)
139  return AVERROR(ENOMEM);
140  if (nb_rect_allocated)
141  *nb_rect_allocated = new_nb;
142  sub->rects = rects;
143  }
144 
145  rect = av_mallocz(sizeof(*rect));
146  if (!rect)
147  return AVERROR(ENOMEM);
148  rects[sub->num_rects++] = rect;
149  rect->type = SUBTITLE_ASS;
150  ass_str = ff_ass_get_dialog(readorder, layer, style, speaker, dialog);
151  if (!ass_str)
152  return AVERROR(ENOMEM);
153  rect->ass = ass_str;
154  return 0;
155 }
156 
157 int ff_ass_add_rect(AVSubtitle *sub, const char *dialog,
158  int readorder, int layer, const char *style,
159  const char *speaker)
160 {
161  return ff_ass_add_rect2(sub, dialog, readorder, layer, style, speaker, NULL);
162 }
163 
165 {
166  FFASSDecoderContext *s = avctx->priv_data;
167  if (!(avctx->flags2 & AV_CODEC_FLAG2_RO_FLUSH_NOOP))
168  s->readorder = 0;
169 }
170 
171 void ff_ass_bprint_text_event(AVBPrint *buf, const char *p, int size,
172  const char *linebreaks, int keep_ass_markup)
173 {
174  const char *p_end = p + size;
175 
176  for (; p < p_end && *p; p++) {
177 
178  /* forced custom line breaks, not accounted as "normal" EOL */
179  if (linebreaks && strchr(linebreaks, *p)) {
180  av_bprintf(buf, "\\N");
181 
182  /* standard ASS escaping so random characters don't get mis-interpreted
183  * as ASS */
184  } else if (!keep_ass_markup && strchr("{}\\", *p)) {
185  av_bprintf(buf, "\\%c", *p);
186 
187  /* some packets might end abruptly (no \0 at the end, like for example
188  * in some cases of demuxing from a classic video container), some
189  * might be terminated with \n or \r\n which we have to remove (for
190  * consistency with those who haven't), and we also have to deal with
191  * evil cases such as \r at the end of the buffer (and no \0 terminated
192  * character) */
193  } else if (p[0] == '\n') {
194  /* some stuff left so we can insert a line break */
195  if (p < p_end - 1)
196  av_bprintf(buf, "\\N");
197  } else if (p[0] == '\r' && p < p_end - 1 && p[1] == '\n') {
198  /* \r followed by a \n, we can skip it. We don't insert the \N yet
199  * because we don't know if it is followed by more text */
200  continue;
201 
202  /* finally, a sane character */
203  } else {
204  av_bprint_chars(buf, *p, 1);
205  }
206  }
207 }
LIBAVCODEC_VERSION
#define LIBAVCODEC_VERSION
Definition: version.h:38
ff_ass_subtitle_header
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:82
AVSubtitle
Definition: avcodec.h:2314
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
ff_ass_subtitle_header_default
int ff_ass_subtitle_header_default(AVCodecContext *avctx)
Generate a suitable AVCodecContext.subtitle_header for SUBTITLE_ASS with default style.
Definition: ass.c:96
color
Definition: vf_paletteuse.c:600
sub
static float sub(float src0, float src1)
Definition: dnn_backend_native_layer_mathbinary.c:31
rect
Definition: f_ebur128.c:76
AVSubtitleRect
Definition: avcodec.h:2286
av_asprintf
char * av_asprintf(const char *fmt,...)
Definition: avstring.c:116
ASS_DEFAULT_ALIGNMENT
#define ASS_DEFAULT_ALIGNMENT
Definition: ass.h:42
ff_ass_add_rect
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:157
AVCodecContext::subtitle_header
uint8_t * subtitle_header
Header containing style information for text subtitles.
Definition: avcodec.h:1714
ASS_DEFAULT_BORDERSTYLE
#define ASS_DEFAULT_BORDERSTYLE
Definition: ass.h:43
SUBTITLE_ASS
@ SUBTITLE_ASS
Formatted text, the ass field must be set by the decoder and is authoritative.
Definition: avcodec.h:2281
ff_ass_add_rect2
int ff_ass_add_rect2(AVSubtitle *sub, const char *dialog, int readorder, int layer, const char *style, const char *speaker, unsigned *nb_rect_allocated)
Add an ASS dialog to a subtitle.
Definition: ass.c:117
AVCodecContext::flags
int flags
AV_CODEC_FLAG_*.
Definition: avcodec.h:478
ass.h
ff_ass_get_dialog
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:109
ASS_DEFAULT_FONT
#define ASS_DEFAULT_FONT
Definition: ass.h:35
s
#define s(width, name)
Definition: cbs_vp9.c:256
av_realloc_array
void * av_realloc_array(void *ptr, size_t nmemb, size_t size)
Definition: mem.c:225
ff_ass_bprint_text_event
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:171
ff_ass_subtitle_header_full
int ff_ass_subtitle_header_full(AVCodecContext *avctx, int play_res_x, int play_res_y, const char *font, int font_size, int primary_color, int secondary_color, int outline_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:28
ASS_DEFAULT_BACK_COLOR
#define ASS_DEFAULT_BACK_COLOR
Definition: ass.h:38
NULL
#define NULL
Definition: coverity.c:32
AVCodecContext::subtitle_header_size
int subtitle_header_size
Definition: avcodec.h:1715
ASS_DEFAULT_PLAYRESY
#define ASS_DEFAULT_PLAYRESY
Definition: ass.h:29
AVCodecContext::flags2
int flags2
AV_CODEC_FLAG2_*.
Definition: avcodec.h:485
ASS_DEFAULT_BOLD
#define ASS_DEFAULT_BOLD
Definition: ass.h:39
size
int size
Definition: twinvq_data.h:10344
ASS_DEFAULT_PLAYRESX
#define ASS_DEFAULT_PLAYRESX
Definition: ass.h:28
ASS_DEFAULT_UNDERLINE
#define ASS_DEFAULT_UNDERLINE
Definition: ass.h:41
ff_ass_decoder_flush
void ff_ass_decoder_flush(AVCodecContext *avctx)
Helper to flush a text subtitles decoder making use of the FFASSDecoderContext.
Definition: ass.c:164
bprint.h
common.h
AV_STRINGIFY
#define AV_STRINGIFY(s)
Definition: macros.h:66
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:264
ASS_DEFAULT_ITALIC
#define ASS_DEFAULT_ITALIC
Definition: ass.h:40
ASS_DEFAULT_COLOR
#define ASS_DEFAULT_COLOR
Definition: ass.h:37
avcodec.h
av_bprintf
void av_bprintf(AVBPrint *buf, const char *fmt,...)
Definition: bprint.c:94
ASS_DEFAULT_FONT_SIZE
#define ASS_DEFAULT_FONT_SIZE
Definition: ass.h:36
AVCodecContext
main external API structure.
Definition: avcodec.h:398
AV_CODEC_FLAG_BITEXACT
#define AV_CODEC_FLAG_BITEXACT
Use only bitexact stuff (except (I)DCT).
Definition: avcodec.h:288
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:425
FFASSDecoderContext
Definition: ass.h:46
avstring.h
AV_CODEC_FLAG2_RO_FLUSH_NOOP
#define AV_CODEC_FLAG2_RO_FLUSH_NOOP
Do not reset ASS ReadOrder field on flush (subtitles decoding)
Definition: avcodec.h:343
av_bprint_chars
void av_bprint_chars(AVBPrint *buf, char c, unsigned n)
Append char c n times to a print buffer.
Definition: bprint.c:140